From patchwork Thu Nov 14 13:06:42 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Wieczorkiewicz, Pawel" X-Patchwork-Id: 11243693 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id E3A2F1393 for ; Thu, 14 Nov 2019 13:08:38 +0000 (UTC) Received: from lists.xenproject.org (lists.xenproject.org [192.237.175.120]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id B511F20709 for ; Thu, 14 Nov 2019 13:08:38 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=amazon.de header.i=@amazon.de header.b="TnNE05Fk" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org B511F20709 Authentication-Results: mail.kernel.org; dmarc=fail (p=quarantine dis=none) header.from=amazon.de Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=xen-devel-bounces@lists.xenproject.org Received: from localhost ([127.0.0.1] helo=lists.xenproject.org) by lists.xenproject.org with esmtp (Exim 4.89) (envelope-from ) id 1iVEqH-0007A7-Cq; Thu, 14 Nov 2019 13:07:21 +0000 Received: from all-amaz-eas1.inumbo.com ([34.197.232.57] helo=us1-amaz-eas2.inumbo.com) by lists.xenproject.org with esmtp (Exim 4.89) (envelope-from ) id 1iVEqG-00079w-D7 for xen-devel@lists.xenproject.org; Thu, 14 Nov 2019 13:07:20 +0000 X-Inumbo-ID: afa6b130-06df-11ea-a24b-12813bfff9fa Received: from smtp-fw-4101.amazon.com (unknown [72.21.198.25]) by us1-amaz-eas2.inumbo.com (Halon) with ESMTPS id afa6b130-06df-11ea-a24b-12813bfff9fa; Thu, 14 Nov 2019 13:07:18 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=amazon.de; i=@amazon.de; q=dns/txt; s=amazon201209; t=1573736838; x=1605272838; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version; bh=3tRw49h6hB5sPH1YXiG7Cn7dB4E8KdgRvfbKuNf8550=; b=TnNE05FkB6dd+20bXTA8zaC20BhGt2E5xuHJHkCXP1sJt6cwfBecSMWQ KtWrleIIGgBTnlVzXTCN9jEWS0hf5qEVXjlwXnKK/Tx8X9S7VZt0ZTwUT dZcuSVRX7fSGs3nHezmy6gZCY5WVf4ZRYrNv8pDuOiRs2kta5dbqVDE0J M=; IronPort-SDR: ZcWIzVEfRnGcrtbRmcNn8793+ym8DCVmCh137761cJohnT5cJdAb28f85ack+vff/nM7e1EnQc MtuqS+MoRwCA== X-IronPort-AV: E=Sophos;i="5.68,304,1569283200"; d="scan'208";a="3871996" Received: from iad6-co-svc-p1-lb1-vlan3.amazon.com (HELO email-inbound-relay-1e-a70de69e.us-east-1.amazon.com) ([10.124.125.6]) by smtp-border-fw-out-4101.iad4.amazon.com with ESMTP; 14 Nov 2019 13:07:18 +0000 Received: from EX13MTAUEA001.ant.amazon.com (iad55-ws-svc-p15-lb9-vlan3.iad.amazon.com [10.40.159.166]) by email-inbound-relay-1e-a70de69e.us-east-1.amazon.com (Postfix) with ESMTPS id E20F0A27ED; Thu, 14 Nov 2019 13:07:14 +0000 (UTC) Received: from EX13D05EUB002.ant.amazon.com (10.43.166.45) by EX13MTAUEA001.ant.amazon.com (10.43.61.82) with Microsoft SMTP Server (TLS) id 15.0.1367.3; Thu, 14 Nov 2019 13:07:13 +0000 Received: from EX13MTAUWA001.ant.amazon.com (10.43.160.58) by EX13D05EUB002.ant.amazon.com (10.43.166.45) with Microsoft SMTP Server (TLS) id 15.0.1367.3; Thu, 14 Nov 2019 13:07:12 +0000 Received: from dev-dsk-wipawel-1a-0c4e6d58.eu-west-1.amazon.com (10.4.134.33) by mail-relay.amazon.com (10.43.160.118) with Microsoft SMTP Server id 15.0.1367.3 via Frontend Transport; Thu, 14 Nov 2019 13:07:09 +0000 From: Pawel Wieczorkiewicz To: Date: Thu, 14 Nov 2019 13:06:42 +0000 Message-ID: <20191114130653.51185-2-wipawel@amazon.de> X-Mailer: git-send-email 2.16.5 In-Reply-To: <20191114130653.51185-1-wipawel@amazon.de> References: <20191114130653.51185-1-wipawel@amazon.de> MIME-Version: 1.0 Precedence: Bulk Subject: [Xen-devel] [PATCH v5 01/12] livepatch: Always check hypervisor build ID upon livepatch upload X-BeenThere: xen-devel@lists.xenproject.org X-Mailman-Version: 2.1.23 List-Id: Xen developer discussion List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Cc: Stefano Stabellini , Julien Grall , Wei Liu , Konrad Rzeszutek Wilk , George Dunlap , Andrew Cooper , Ross Lagerwall , Ian Jackson , mpohlack@amazon.com, Pawel Wieczorkiewicz , Jan Beulich Errors-To: xen-devel-bounces@lists.xenproject.org Sender: "Xen-devel" This change is part of a independant stacked livepatch modules feature. This feature allows to bypass dependencies between modules upon loading, but still verifies Xen build ID matching. In order to prevent (up)loading any livepatches built for different hypervisor version as indicated by the Xen Build ID, add checking for the payload's vs Xen's build id match. To achieve that embed into every livepatch another section with a dedicated hypervisor build id in it. After the payload is loaded and the .livepatch.xen_depends section becomes available, perform the check and reject the payload if there is no match. Signed-off-by: Pawel Wieczorkiewicz Reviewed-by: Andra-Irina Paraschiv Reviewed-by: Bjoern Doebel Reviewed-by: Eslam Elnikety Reviewed-by: Martin Pohlack Signed-off-by: Konrad Rzeszutek Wilk Reviewed-by: Ross Lagerwall --- Changed since v3: * renamed check_xen_build_id() to xen_build_id_dep() Changed since v1: * always print XENLOG_ERR message from check_xen_build_id() * fix typo in test/livepatch/Makefile --- .gitignore | 1 + docs/misc/livepatch.pandoc | 28 +++++++++++++++++++-------- xen/common/livepatch.c | 47 +++++++++++++++++++++++++++++++++++++++++++++ xen/include/xen/livepatch.h | 7 ++++--- xen/test/livepatch/Makefile | 31 +++++++++++++++++++++++++----- 5 files changed, 98 insertions(+), 16 deletions(-) diff --git a/.gitignore b/.gitignore index 3ada0c4f0b..223bedcd2b 100644 --- a/.gitignore +++ b/.gitignore @@ -312,6 +312,7 @@ xen/test/livepatch/xen_bye_world.livepatch xen/test/livepatch/xen_hello_world.livepatch xen/test/livepatch/xen_nop.livepatch xen/test/livepatch/xen_replace_world.livepatch +xen/test/livepatch/xen_no_xen_buildid.livepatch xen/tools/kconfig/.tmp_gtkcheck xen/tools/kconfig/.tmp_qtcheck xen/tools/symbols diff --git a/docs/misc/livepatch.pandoc b/docs/misc/livepatch.pandoc index 6d9f72f49b..fd1f5d0126 100644 --- a/docs/misc/livepatch.pandoc +++ b/docs/misc/livepatch.pandoc @@ -270,6 +270,8 @@ like what the Linux kernel module loader does. The payload contains at least three sections: * `.livepatch.funcs` - which is an array of livepatch_func structures. + * `.livepatch.xen_depends` - which is an ELF Note that describes what Xen + build-id the payload depends on. **MUST** have one. * `.livepatch.depends` - which is an ELF Note that describes what the payload depends on. **MUST** have one. * `.note.gnu.build-id` - the build-id of this payload. **MUST** have one. @@ -383,16 +385,16 @@ The type definition of the function are as follow: typedef void (*livepatch_loadcall_t)(void); typedef void (*livepatch_unloadcall_t)(void); -### .livepatch.depends and .note.gnu.build-id +### .livepatch.xen_depends, .livepatch.depends and .note.gnu.build-id To support dependencies checking and safe loading (to load the appropiate payload against the right hypervisor) there is a need to embbed an build-id dependency. -This is done by the payload containing an section `.livepatch.depends` -which follows the format of an ELF Note. The contents of this -(name, and description) are specific to the linker utilized to -build the hypevisor and payload. +This is done by the payload containing sections `.livepatch.xen_depends` +and `.livepatch.depends` which follow the format of an ELF Note. +The contents of these (name, and description) are specific to the linker +utilized to build the hypevisor and payload. If GNU linker is used then the name is `GNU` and the description is a NT_GNU_BUILD_ID type ID. The description can be an SHA1 @@ -400,6 +402,13 @@ checksum, MD5 checksum or any unique value. The size of these structures varies with the `--build-id` linker option. +There are two kinds of build-id dependencies: + + * Xen build-id dependency (.livepatch.xen_depends section) + * previous payload build-id dependency (.livepatch.depends section) + +See "Live patch interdependencies" for more information. + ## Hypercalls We will employ the sub operations of the system management hypercall (sysctl). @@ -894,13 +903,16 @@ but is more complex to implement. The second option which requires an build-id of the hypervisor is implemented in the Xen hypervisor. -Specifically each payload has two build-id ELF notes: +Specifically each payload has three build-id ELF notes: * The build-id of the payload itself (generated via --build-id). + * The build-id of the Xen hypervisor it depends on (extracted from the + hypervisor during build time). * The build-id of the payload it depends on (extracted from the the previous payload or hypervisor during build time). -This means that the very first payload depends on the hypervisor -build-id. +This means that every payload depends on the hypervisor build-id and on +the build-id of the previous payload in the stack. +The very first payload depends on the hypervisor build-id only. # Not Yet Done diff --git a/xen/common/livepatch.c b/xen/common/livepatch.c index 7caa30c202..163c9c79ea 100644 --- a/xen/common/livepatch.c +++ b/xen/common/livepatch.c @@ -74,6 +74,7 @@ struct payload { unsigned int nsyms; /* Nr of entries in .strtab and symbols. */ struct livepatch_build_id id; /* ELFNOTE_DESC(.note.gnu.build-id) of the payload. */ struct livepatch_build_id dep; /* ELFNOTE_DESC(.livepatch.depends). */ + struct livepatch_build_id xen_dep; /* ELFNOTE_DESC(.livepatch.xen_depends). */ livepatch_loadcall_t *const *load_funcs; /* The array of funcs to call after */ livepatch_unloadcall_t *const *unload_funcs;/* load and unload of the payload. */ unsigned int n_load_funcs; /* Nr of the funcs to load and execute. */ @@ -476,11 +477,34 @@ static bool section_ok(const struct livepatch_elf *elf, return true; } +static int xen_build_id_dep(const struct payload *payload) +{ + const void *id = NULL; + unsigned int len = 0; + int rc; + + ASSERT(payload->xen_dep.len); + ASSERT(payload->xen_dep.p); + + rc = xen_build_id(&id, &len); + if ( rc ) + return rc; + + if ( payload->xen_dep.len != len || memcmp(id, payload->xen_dep.p, len) ) { + printk(XENLOG_ERR LIVEPATCH "%s: check against hypervisor build-id failed\n", + payload->name); + return -EINVAL; + } + + return 0; +} + static int check_special_sections(const struct livepatch_elf *elf) { unsigned int i; static const char *const names[] = { ELF_LIVEPATCH_FUNC, ELF_LIVEPATCH_DEPENDS, + ELF_LIVEPATCH_XEN_DEPENDS, ELF_BUILD_ID_NOTE}; DECLARE_BITMAP(found, ARRAY_SIZE(names)) = { 0 }; @@ -632,6 +656,22 @@ static int prepare_payload(struct payload *payload, return -EINVAL; } + sec = livepatch_elf_sec_by_name(elf, ELF_LIVEPATCH_XEN_DEPENDS); + if ( sec ) + { + n = sec->load_addr; + + if ( sec->sec->sh_size <= sizeof(*n) ) + return -EINVAL; + + if ( xen_build_id_check(n, sec->sec->sh_size, + &payload->xen_dep.p, &payload->xen_dep.len) ) + return -EINVAL; + + if ( !payload->xen_dep.len || !payload->xen_dep.p ) + return -EINVAL; + } + /* Setup the virtual region with proper data. */ region = &payload->region; @@ -882,6 +922,10 @@ static int load_payload_data(struct payload *payload, void *raw, size_t len) if ( rc ) goto out; + rc = xen_build_id_dep(payload); + if ( rc ) + goto out; + rc = build_symbol_table(payload, &elf); if ( rc ) goto out; @@ -1655,6 +1699,9 @@ static void livepatch_printall(unsigned char key) if ( data->dep.len ) printk("depend-on=%*phN\n", data->dep.len, data->dep.p); + + if ( data->xen_dep.len ) + printk("depend-on-xen=%*phN\n", data->xen_dep.len, data->xen_dep.p); } spin_unlock(&payload_lock); diff --git a/xen/include/xen/livepatch.h b/xen/include/xen/livepatch.h index 1b1817ca0d..ed997aa4cc 100644 --- a/xen/include/xen/livepatch.h +++ b/xen/include/xen/livepatch.h @@ -29,9 +29,10 @@ struct xen_sysctl_livepatch_op; /* Convenience define for printk. */ #define LIVEPATCH "livepatch: " /* ELF payload special section names. */ -#define ELF_LIVEPATCH_FUNC ".livepatch.funcs" -#define ELF_LIVEPATCH_DEPENDS ".livepatch.depends" -#define ELF_BUILD_ID_NOTE ".note.gnu.build-id" +#define ELF_LIVEPATCH_FUNC ".livepatch.funcs" +#define ELF_LIVEPATCH_DEPENDS ".livepatch.depends" +#define ELF_LIVEPATCH_XEN_DEPENDS ".livepatch.xen_depends" +#define ELF_BUILD_ID_NOTE ".note.gnu.build-id" /* Arbitrary limit for payload size and .bss section size. */ #define LIVEPATCH_MAX_SIZE MB(2) diff --git a/xen/test/livepatch/Makefile b/xen/test/livepatch/Makefile index 6831383db1..938aee17ec 100644 --- a/xen/test/livepatch/Makefile +++ b/xen/test/livepatch/Makefile @@ -19,11 +19,13 @@ LIVEPATCH := xen_hello_world.livepatch LIVEPATCH_BYE := xen_bye_world.livepatch LIVEPATCH_REPLACE := xen_replace_world.livepatch LIVEPATCH_NOP := xen_nop.livepatch +LIVEPATCH_NO_XEN_BUILDID := xen_no_xen_buildid.livepatch LIVEPATCHES += $(LIVEPATCH) LIVEPATCHES += $(LIVEPATCH_BYE) LIVEPATCHES += $(LIVEPATCH_REPLACE) LIVEPATCHES += $(LIVEPATCH_NOP) +LIVEPATCHES += $(LIVEPATCH_NO_XEN_BUILDID) LIVEPATCH_DEBUG_DIR ?= $(DEBUG_DIR)/xen-livepatch @@ -59,7 +61,7 @@ config.h: xen_hello_world_func.o xen_hello_world.o: config.h .PHONY: $(LIVEPATCH) -$(LIVEPATCH): xen_hello_world_func.o xen_hello_world.o note.o +$(LIVEPATCH): xen_hello_world_func.o xen_hello_world.o note.o xen_note.o $(LD) $(LDFLAGS) $(build_id_linker) -r -o $(LIVEPATCH) $^ # @@ -78,6 +80,17 @@ note.o: --rename-section=.data=.livepatch.depends,alloc,load,readonly,data,contents -S $@.bin $@ rm -f $@.bin +# +# Append .livepatch.xen_depends section +# with Xen build-id derived from xen-syms. +# +.PHONY: xen_note.o +xen_note.o: + $(OBJCOPY) -O binary --only-section=.note.gnu.build-id $(BASEDIR)/xen-syms $@.bin + $(OBJCOPY) $(OBJCOPY_MAGIC) \ + --rename-section=.data=.livepatch.xen_depends,alloc,load,readonly,data,contents -S $@.bin $@ + rm -f $@.bin + # # Extract the build-id of the xen_hello_world.livepatch # (which xen_bye_world will depend on). @@ -92,20 +105,28 @@ hello_world_note.o: $(LIVEPATCH) xen_bye_world.o: config.h .PHONY: $(LIVEPATCH_BYE) -$(LIVEPATCH_BYE): xen_bye_world_func.o xen_bye_world.o hello_world_note.o +$(LIVEPATCH_BYE): xen_bye_world_func.o xen_bye_world.o hello_world_note.o xen_note.o $(LD) $(LDFLAGS) $(build_id_linker) -r -o $(LIVEPATCH_BYE) $^ xen_replace_world.o: config.h .PHONY: $(LIVEPATCH_REPLACE) -$(LIVEPATCH_REPLACE): xen_replace_world_func.o xen_replace_world.o note.o +$(LIVEPATCH_REPLACE): xen_replace_world_func.o xen_replace_world.o note.o xen_note.o $(LD) $(LDFLAGS) $(build_id_linker) -r -o $(LIVEPATCH_REPLACE) $^ xen_nop.o: config.h .PHONY: $(LIVEPATCH_NOP) -$(LIVEPATCH_NOP): xen_nop.o note.o +$(LIVEPATCH_NOP): xen_nop.o note.o xen_note.o $(LD) $(LDFLAGS) $(build_id_linker) -r -o $(LIVEPATCH_NOP) $^ +# This one always fails upon upload, because it deliberately +# does not have a .livepatch.xen_depends (xen_note.o) section. +xen_no_xen_buildid.o: config.h + +.PHONY: $(LIVEPATCH_NO_XEN_BUILDID) +$(LIVEPATCH_NO_XEN_BUILDID): xen_nop.o note.o + $(LD) $(LDFLAGS) $(build_id_linker) -r -o $(LIVEPATCH_NO_XEN_BUILDID) $^ + .PHONY: livepatch -livepatch: $(LIVEPATCH) $(LIVEPATCH_BYE) $(LIVEPATCH_REPLACE) $(LIVEPATCH_NOP) +livepatch: $(LIVEPATCH) $(LIVEPATCH_BYE) $(LIVEPATCH_REPLACE) $(LIVEPATCH_NOP) $(LIVEPATCH_NO_XEN_BUILDID) From patchwork Thu Nov 14 13:06:43 2019 Content-Type: text/plain; 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Thu, 14 Nov 2019 13:07:13 +0000 From: Pawel Wieczorkiewicz To: Date: Thu, 14 Nov 2019 13:06:43 +0000 Message-ID: <20191114130653.51185-3-wipawel@amazon.de> X-Mailer: git-send-email 2.16.5 In-Reply-To: <20191114130653.51185-1-wipawel@amazon.de> References: <20191114130653.51185-1-wipawel@amazon.de> MIME-Version: 1.0 Precedence: Bulk Subject: [Xen-devel] [PATCH v5 02/12] livepatch: Allow to override inter-modules buildid dependency X-BeenThere: xen-devel@lists.xenproject.org X-Mailman-Version: 2.1.23 List-Id: Xen developer discussion List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Cc: Stefano Stabellini , Julien Grall , Wei Liu , Konrad Rzeszutek Wilk , George Dunlap , Andrew Cooper , Ross Lagerwall , Ian Jackson , mpohlack@amazon.com, Pawel Wieczorkiewicz , Jan Beulich Errors-To: xen-devel-bounces@lists.xenproject.org Sender: "Xen-devel" By default Livepatch enforces the following buildid-based dependency chain between livepatch modules: 1) first module depends on given hypervisor buildid 2) every consecutive module depends on previous module's buildid This way proper livepatch stack order is maintained and enforced. While it is important for production livepatches it limits agility and blocks usage of testing or debug livepatches. These kinds of livepatch modules are typically expected to be loaded at any time irrespective of current state of the modules stack. To enable testing and debug livepatches allow user dynamically ignore the inter-modules dependency. In this case only hypervisor buildid match is verified and enforced. To allow userland pass additional paremeters for livepatch actions add support for action flags. Each of the apply, revert, unload and revert action gets additional 32-bit parameter 'flags' where extra flags can be applied in a mask form. Initially only one flag '--nodeps' is added for the apply action. This flag modifies the default buildid dependency check as described above. The global sysctl interface input flag parameter is defined with a single corresponding flag macro: LIVEPATCH_ACTION_APPLY_NODEPS (1 << 0) The userland xen-livepatch tool is modified to support the '--nodeps' flag for apply and load commands. A general mechanism for specifying more flags in the future for apply and other action is however added. Signed-off-by: Pawel Wieczorkiewicz Reviewed-by: Andra-Irina Paraschiv Reviewed-by: Eslam Elnikety Reviewed-by: Petre Eftime Reviewed-by: Leonard Foerster Reviewed-by: Martin Pohlack Reviewed-by: Norbert Manthey Signed-off-by: Konrad Rzeszutek Wilk Reviewed-by: Ross Lagerwall --- Changed since v4: * changed flags field type from uint64_t to uint32_t * added 'pad' field after the changed flags field Changed since v3: * simplified loop in xen-livepatch.c --- docs/misc/livepatch.pandoc | 8 +++ tools/libxc/include/xenctrl.h | 9 ++-- tools/libxc/xc_misc.c | 20 +++---- tools/misc/xen-livepatch.c | 121 +++++++++++++++++++++++++++++++++++------- xen/common/livepatch.c | 17 ++++-- xen/include/public/sysctl.h | 12 ++++- 6 files changed, 151 insertions(+), 36 deletions(-) diff --git a/docs/misc/livepatch.pandoc b/docs/misc/livepatch.pandoc index fd1f5d0126..cd859bb811 100644 --- a/docs/misc/livepatch.pandoc +++ b/docs/misc/livepatch.pandoc @@ -659,6 +659,10 @@ The caller provides: * `time` The upper bound of time (ns) the cmd should take. Zero means to use the hypervisor default. If within the time the operation does not succeed the operation would go in error state. + * `flags` provides additional parameters for an action: + * *LIVEPATCH_ACTION_APPLY_NODEPS* (1) Apply action ignores inter-module + buildid dependency. Checks only if module is built for given hypervisor by + comparing buildid. * `pad` - *MUST* be zero. The return value will be zero unless the provided fields are incorrect. @@ -676,6 +680,10 @@ The structure is as follow: /* hypervisor default. */ /* Or upper bound of time (ns) */ /* for operation to take. */ + uint32_t flags; /* IN: action flags. */ + /* Provide additional parameters */ + /* for an action. */ + uint32_t pad; /* IN: Always zero. */ }; diff --git a/tools/libxc/include/xenctrl.h b/tools/libxc/include/xenctrl.h index f4431687b3..b06738c471 100644 --- a/tools/libxc/include/xenctrl.h +++ b/tools/libxc/include/xenctrl.h @@ -2605,11 +2605,12 @@ int xc_livepatch_list(xc_interface *xch, unsigned int max, unsigned int start, * to complete them. The `timeout` offers an option to expire the * operation if it could not be completed within the specified time * (in ns). Value of 0 means let hypervisor decide the best timeout. + * The `flags` allows to pass extra parameters to the actions. */ -int xc_livepatch_apply(xc_interface *xch, char *name, uint32_t timeout); -int xc_livepatch_revert(xc_interface *xch, char *name, uint32_t timeout); -int xc_livepatch_unload(xc_interface *xch, char *name, uint32_t timeout); -int xc_livepatch_replace(xc_interface *xch, char *name, uint32_t timeout); +int xc_livepatch_apply(xc_interface *xch, char *name, uint32_t timeout, uint32_t flags); +int xc_livepatch_revert(xc_interface *xch, char *name, uint32_t timeout, uint32_t flags); +int xc_livepatch_unload(xc_interface *xch, char *name, uint32_t timeout, uint32_t flags); +int xc_livepatch_replace(xc_interface *xch, char *name, uint32_t timeout, uint32_t flags); /* * Ensure cache coherency after memory modifications. A call to this function diff --git a/tools/libxc/xc_misc.c b/tools/libxc/xc_misc.c index 8e60b6e9f0..2dc526bda7 100644 --- a/tools/libxc/xc_misc.c +++ b/tools/libxc/xc_misc.c @@ -854,7 +854,8 @@ int xc_livepatch_list(xc_interface *xch, unsigned int max, unsigned int start, static int _xc_livepatch_action(xc_interface *xch, char *name, unsigned int action, - uint32_t timeout) + uint32_t timeout, + uint32_t flags) { int rc; DECLARE_SYSCTL; @@ -880,6 +881,7 @@ static int _xc_livepatch_action(xc_interface *xch, sysctl.u.livepatch.pad = 0; sysctl.u.livepatch.u.action.cmd = action; sysctl.u.livepatch.u.action.timeout = timeout; + sysctl.u.livepatch.u.action.flags = flags; sysctl.u.livepatch.u.action.name = def_name; set_xen_guest_handle(sysctl.u.livepatch.u.action.name.name, name); @@ -891,24 +893,24 @@ static int _xc_livepatch_action(xc_interface *xch, return rc; } -int xc_livepatch_apply(xc_interface *xch, char *name, uint32_t timeout) +int xc_livepatch_apply(xc_interface *xch, char *name, uint32_t timeout, uint32_t flags) { - return _xc_livepatch_action(xch, name, LIVEPATCH_ACTION_APPLY, timeout); + return _xc_livepatch_action(xch, name, LIVEPATCH_ACTION_APPLY, timeout, flags); } -int xc_livepatch_revert(xc_interface *xch, char *name, uint32_t timeout) +int xc_livepatch_revert(xc_interface *xch, char *name, uint32_t timeout, uint32_t flags) { - return _xc_livepatch_action(xch, name, LIVEPATCH_ACTION_REVERT, timeout); + return _xc_livepatch_action(xch, name, LIVEPATCH_ACTION_REVERT, timeout, flags); } -int xc_livepatch_unload(xc_interface *xch, char *name, uint32_t timeout) +int xc_livepatch_unload(xc_interface *xch, char *name, uint32_t timeout, uint32_t flags) { - return _xc_livepatch_action(xch, name, LIVEPATCH_ACTION_UNLOAD, timeout); + return _xc_livepatch_action(xch, name, LIVEPATCH_ACTION_UNLOAD, timeout, flags); } -int xc_livepatch_replace(xc_interface *xch, char *name, uint32_t timeout) +int xc_livepatch_replace(xc_interface *xch, char *name, uint32_t timeout, uint32_t flags) { - return _xc_livepatch_action(xch, name, LIVEPATCH_ACTION_REPLACE, timeout); + return _xc_livepatch_action(xch, name, LIVEPATCH_ACTION_REPLACE, timeout, flags); } /* diff --git a/tools/misc/xen-livepatch.c b/tools/misc/xen-livepatch.c index 3233472157..b469b253ad 100644 --- a/tools/misc/xen-livepatch.c +++ b/tools/misc/xen-livepatch.c @@ -23,18 +23,23 @@ void show_help(void) { fprintf(stderr, "xen-livepatch: live patching tool\n" - "Usage: xen-livepatch [args]\n" + "Usage: xen-livepatch [args] [command-flags]\n" " An unique name of payload. Up to %d characters.\n" "Commands:\n" " help display this help\n" " upload upload file with name\n" " list list payloads uploaded.\n" - " apply apply patch.\n" + " apply [flags] apply patch.\n" + " Supported flags:\n" + " --nodeps Disable inter-module buildid dependency check.\n" + " Check only against hypervisor buildid.\n" " revert revert name patch.\n" " replace apply patch and revert all others.\n" " unload unload name patch.\n" - " load upload and apply .\n" - " name is the name\n", + " load [flags] upload and apply with name as the name\n" + " Supported flags:\n" + " --nodeps Disable inter-module buildid dependency check.\n" + " Check only against hypervisor buildid.\n", XEN_LIVEPATCH_NAME_SIZE); } @@ -225,12 +230,13 @@ static int upload_func(int argc, char *argv[]) return rc; } -/* These MUST match to the 'action_options[]' array slots. */ +/* These MUST match to the 'action_options[]' and 'flag_options[]' array slots. */ enum { ACTION_APPLY = 0, ACTION_REVERT = 1, ACTION_UNLOAD = 2, ACTION_REPLACE = 3, + ACTION_NUM }; struct { @@ -238,7 +244,7 @@ struct { int expected; /* The state to be in after the function. */ const char *name; const char *verb; - int (*function)(xc_interface *xch, char *name, uint32_t timeout); + int (*function)(xc_interface *xch, char *name, uint32_t timeout, uint32_t flags); } action_options[] = { { .allow = LIVEPATCH_STATE_CHECKED, .expected = LIVEPATCH_STATE_APPLIED, @@ -266,6 +272,66 @@ struct { }, }; +/* + * This structure defines supported flag options for actions. + * It defines entries for each action and supports up to 32 + * flags per action. + */ +struct { + const char *name; + const uint32_t flag; +} flag_options[ACTION_NUM][8 * sizeof(uint32_t)] = { + { /* ACTION_APPLY */ + { .name = "--nodeps", + .flag = LIVEPATCH_ACTION_APPLY_NODEPS, + }, + }, + { /* ACTION_REVERT */ + }, + { /* ACTION_UNLOAD */ + }, + { /* ACTION_REPLACE */ + } +}; + +/* + * Parse user provided action flags. + * This function expects to only receive an array of input parameters being flags. + * Expected action is specified via idx paramater (index of flag_options[]). + */ +static int get_flags(int argc, char *argv[], unsigned int idx, uint32_t *flags) +{ + int i, j; + + if ( !flags || idx >= ARRAY_SIZE(flag_options) ) + return -1; + + *flags = 0; + for ( i = 0; i < argc; i++ ) + { + for ( j = 0; j < ARRAY_SIZE(flag_options[idx]); j++ ) + { + if ( !flag_options[idx][j].name ) + goto error; + + if ( !strcmp(flag_options[idx][j].name, argv[i]) ) + { + *flags |= flag_options[idx][j].flag; + break; + } + } + + if ( j == ARRAY_SIZE(flag_options[idx]) ) + goto error; + } + + return 0; +error: + fprintf(stderr, "Unsupported flag: %s.\n", argv[i]); + errno = EINVAL; + return errno; +} + /* The hypervisor timeout for the live patching operation is 30 msec, * but it could take some time for the operation to start, so wait twice * that period. */ @@ -291,8 +357,9 @@ int action_func(int argc, char *argv[], unsigned int idx) char name[XEN_LIVEPATCH_NAME_SIZE]; int rc; xen_livepatch_status_t status; + uint32_t flags; - if ( argc != 1 ) + if ( argc < 1 ) { show_help(); return -1; @@ -301,7 +368,10 @@ int action_func(int argc, char *argv[], unsigned int idx) if ( idx >= ARRAY_SIZE(action_options) ) return -1; - if ( get_name(argc, argv, name) ) + if ( get_name(argc--, argv++, name) ) + return EINVAL; + + if ( get_flags(argc, argv, idx, &flags) ) return EINVAL; /* Check initial status. */ @@ -332,7 +402,7 @@ int action_func(int argc, char *argv[], unsigned int idx) if ( action_options[idx].allow & status.state ) { printf("%s %s... ", action_options[idx].verb, name); - rc = action_options[idx].function(xch, name, HYPERVISOR_TIMEOUT_NS); + rc = action_options[idx].function(xch, name, HYPERVISOR_TIMEOUT_NS, flags); if ( rc ) { int saved_errno = errno; @@ -394,17 +464,23 @@ int action_func(int argc, char *argv[], unsigned int idx) static int load_func(int argc, char *argv[]) { - int rc; - char *new_argv[2]; - char *path, *name, *lastdot; + int i, rc = ENOMEM; + char *upload_argv[2]; + char **apply_argv, *path, *name, *lastdot; - if ( argc != 1 ) + if ( argc < 1 ) { show_help(); return -1; } + + /* apply action has [flags] input requirement, which must be constructed */ + apply_argv = (char **) malloc(argc * sizeof(*apply_argv)); + if ( !apply_argv ) + return rc; + /* */ - new_argv[1] = argv[0]; + upload_argv[1] = argv[0]; /* Synthesize the */ path = strdup(argv[0]); @@ -413,16 +489,23 @@ static int load_func(int argc, char *argv[]) lastdot = strrchr(name, '.'); if ( lastdot != NULL ) *lastdot = '\0'; - new_argv[0] = name; + upload_argv[0] = name; + apply_argv[0] = name; - rc = upload_func(2 /* */, new_argv); + /* Fill in all user provided flags */ + for ( i = 1; i < argc; i++ ) + apply_argv[i] = argv[i]; + + rc = upload_func(2 /* */, upload_argv); if ( rc ) - return rc; + goto error; - rc = action_func(1 /* only */, new_argv, ACTION_APPLY); + rc = action_func(argc, apply_argv, ACTION_APPLY); if ( rc ) - action_func(1, new_argv, ACTION_UNLOAD); + action_func(1 /* only */, upload_argv, ACTION_UNLOAD); +error: + free(apply_argv); free(path); return rc; } diff --git a/xen/common/livepatch.c b/xen/common/livepatch.c index 163c9c79ea..4e96e2e9b2 100644 --- a/xen/common/livepatch.c +++ b/xen/common/livepatch.c @@ -1502,6 +1502,9 @@ static int livepatch_action(struct xen_sysctl_livepatch_action *action) char n[XEN_LIVEPATCH_NAME_SIZE]; int rc; + if ( action->pad ) + return -EINVAL; + rc = get_name(&action->name, n); if ( rc ) return rc; @@ -1575,9 +1578,17 @@ static int livepatch_action(struct xen_sysctl_livepatch_action *action) break; } - rc = build_id_dep(data, !!list_empty(&applied_list)); - if ( rc ) - break; + /* + * Check if action is issued with nodeps flags to ignore module + * stack dependencies. + */ + if ( !(action->flags & LIVEPATCH_ACTION_APPLY_NODEPS) ) + { + rc = build_id_dep(data, !!list_empty(&applied_list)); + if ( rc ) + break; + } + data->rc = -EAGAIN; rc = schedule_work(data, action->cmd, action->timeout); } diff --git a/xen/include/public/sysctl.h b/xen/include/public/sysctl.h index 19457a4e30..7a0884b70b 100644 --- a/xen/include/public/sysctl.h +++ b/xen/include/public/sysctl.h @@ -35,7 +35,7 @@ #include "domctl.h" #include "physdev.h" -#define XEN_SYSCTL_INTERFACE_VERSION 0x00000012 +#define XEN_SYSCTL_INTERFACE_VERSION 0x00000013 /* * Read console content from Xen buffer ring. @@ -970,6 +970,16 @@ struct xen_sysctl_livepatch_action { /* hypervisor default. */ /* Or upper bound of time (ns) */ /* for operation to take. */ + +/* + * Override default inter-module buildid dependency chain enforcement. + * Check only if module is built for given hypervisor by comparing buildid. + */ +#define LIVEPATCH_ACTION_APPLY_NODEPS (1 << 0) + uint32_t flags; /* IN: action flags. */ + /* Provide additional parameters */ + /* for an action. */ + uint32_t pad; /* IN: Always zero. */ }; struct xen_sysctl_livepatch_op { From patchwork Thu Nov 14 13:06:44 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Wieczorkiewicz, Pawel" X-Patchwork-Id: 11243695 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id AAA521393 for ; Thu, 14 Nov 2019 13:08:57 +0000 (UTC) Received: from lists.xenproject.org (lists.xenproject.org [192.237.175.120]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 86997206DC for ; Thu, 14 Nov 2019 13:08:57 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=amazon.de header.i=@amazon.de header.b="IoTWXfGS" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 86997206DC Authentication-Results: mail.kernel.org; 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Thu, 14 Nov 2019 13:07:22 +0000 Received: from EX13MTAUWA001.ant.amazon.com (10.43.160.58) by EX13D05EUC001.ant.amazon.com (10.43.164.118) with Microsoft SMTP Server (TLS) id 15.0.1367.3; Thu, 14 Nov 2019 13:07:21 +0000 Received: from dev-dsk-wipawel-1a-0c4e6d58.eu-west-1.amazon.com (10.4.134.33) by mail-relay.amazon.com (10.43.160.118) with Microsoft SMTP Server id 15.0.1367.3 via Frontend Transport; Thu, 14 Nov 2019 13:07:18 +0000 From: Pawel Wieczorkiewicz To: Date: Thu, 14 Nov 2019 13:06:44 +0000 Message-ID: <20191114130653.51185-4-wipawel@amazon.de> X-Mailer: git-send-email 2.16.5 In-Reply-To: <20191114130653.51185-1-wipawel@amazon.de> References: <20191114130653.51185-1-wipawel@amazon.de> MIME-Version: 1.0 Precedence: Bulk Subject: [Xen-devel] [PATCH v5 03/12] livepatch: Export payload structure via livepatch_payload.h X-BeenThere: xen-devel@lists.xenproject.org X-Mailman-Version: 2.1.23 List-Id: Xen developer discussion List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Cc: Pawel Wieczorkiewicz , Ross Lagerwall , mpohlack@amazon.com, Konrad Rzeszutek Wilk Errors-To: xen-devel-bounces@lists.xenproject.org Sender: "Xen-devel" The payload structure will be used by the new hooks implementation and therefore its definition has to be exported via the livepatch_payload header. The new hooks will make use of the payload structure fields and the hooks' pointers will also be defined in the payload structure, so the structure along with all field definitions needs to be available to the code being patched in. Signed-off-by: Pawel Wieczorkiewicz Reviewed-by: Andra-Irina Paraschiv Reviewed-by: Eslam Elnikety Reviewed-by: Leonard Foerster Reviewed-by: Martin Pohlack Reviewed-by: Ross Lagerwall Signed-off-by: Konrad Rzeszutek Wilk --- xen/common/livepatch.c | 37 ---------------------------------- xen/include/xen/livepatch_payload.h | 40 +++++++++++++++++++++++++++++++++++++ 2 files changed, 40 insertions(+), 37 deletions(-) diff --git a/xen/common/livepatch.c b/xen/common/livepatch.c index 4e96e2e9b2..04a19c1856 100644 --- a/xen/common/livepatch.c +++ b/xen/common/livepatch.c @@ -45,43 +45,6 @@ static LIST_HEAD(applied_list); static unsigned int payload_cnt; static unsigned int payload_version = 1; -/* To contain the ELF Note header. */ -struct livepatch_build_id { - const void *p; - unsigned int len; -}; - -struct payload { - uint32_t state; /* One of the LIVEPATCH_STATE_*. */ - int32_t rc; /* 0 or -XEN_EXX. */ - bool reverted; /* Whether it was reverted. */ - bool safe_to_reapply; /* Can apply safely after revert. */ - struct list_head list; /* Linked to 'payload_list'. */ - const void *text_addr; /* Virtual address of .text. */ - size_t text_size; /* .. and its size. */ - const void *rw_addr; /* Virtual address of .data. */ - size_t rw_size; /* .. and its size (if any). */ - const void *ro_addr; /* Virtual address of .rodata. */ - size_t ro_size; /* .. and its size (if any). */ - unsigned int pages; /* Total pages for [text,rw,ro]_addr */ - struct list_head applied_list; /* Linked to 'applied_list'. */ - struct livepatch_func *funcs; /* The array of functions to patch. */ - unsigned int nfuncs; /* Nr of functions to patch. */ - const struct livepatch_symbol *symtab; /* All symbols. */ - const char *strtab; /* Pointer to .strtab. */ - struct virtual_region region; /* symbol, bug.frame patching and - exception table (x86). */ - unsigned int nsyms; /* Nr of entries in .strtab and symbols. */ - struct livepatch_build_id id; /* ELFNOTE_DESC(.note.gnu.build-id) of the payload. */ - struct livepatch_build_id dep; /* ELFNOTE_DESC(.livepatch.depends). */ - struct livepatch_build_id xen_dep; /* ELFNOTE_DESC(.livepatch.xen_depends). */ - livepatch_loadcall_t *const *load_funcs; /* The array of funcs to call after */ - livepatch_unloadcall_t *const *unload_funcs;/* load and unload of the payload. */ - unsigned int n_load_funcs; /* Nr of the funcs to load and execute. */ - unsigned int n_unload_funcs; /* Nr of funcs to call durung unload. */ - char name[XEN_LIVEPATCH_NAME_SIZE]; /* Name of it. */ -}; - /* Defines an outstanding patching action. */ struct livepatch_work { diff --git a/xen/include/xen/livepatch_payload.h b/xen/include/xen/livepatch_payload.h index 4a1a96d054..99613af2db 100644 --- a/xen/include/xen/livepatch_payload.h +++ b/xen/include/xen/livepatch_payload.h @@ -4,6 +4,15 @@ #ifndef __XEN_LIVEPATCH_PAYLOAD_H__ #define __XEN_LIVEPATCH_PAYLOAD_H__ +#include + +/* To contain the ELF Note header. */ +struct livepatch_build_id { + const void *p; + unsigned int len; +}; + +typedef struct payload livepatch_payload_t; /* * The following definitions are to be used in patches. They are taken @@ -12,6 +21,37 @@ typedef void livepatch_loadcall_t(void); typedef void livepatch_unloadcall_t(void); +struct payload { + uint32_t state; /* One of the LIVEPATCH_STATE_*. */ + int32_t rc; /* 0 or -XEN_EXX. */ + bool reverted; /* Whether it was reverted. */ + bool safe_to_reapply; /* Can apply safely after revert. */ + struct list_head list; /* Linked to 'payload_list'. */ + const void *text_addr; /* Virtual address of .text. */ + size_t text_size; /* .. and its size. */ + const void *rw_addr; /* Virtual address of .data. */ + size_t rw_size; /* .. and its size (if any). */ + const void *ro_addr; /* Virtual address of .rodata. */ + size_t ro_size; /* .. and its size (if any). */ + unsigned int pages; /* Total pages for [text,rw,ro]_addr */ + struct list_head applied_list; /* Linked to 'applied_list'. */ + struct livepatch_func *funcs; /* The array of functions to patch. */ + unsigned int nfuncs; /* Nr of functions to patch. */ + const struct livepatch_symbol *symtab; /* All symbols. */ + const char *strtab; /* Pointer to .strtab. */ + struct virtual_region region; /* symbol, bug.frame patching and + exception table (x86). */ + unsigned int nsyms; /* Nr of entries in .strtab and symbols. */ + struct livepatch_build_id id; /* ELFNOTE_DESC(.note.gnu.build-id) of the payload. */ + struct livepatch_build_id dep; /* ELFNOTE_DESC(.livepatch.depends). */ + struct livepatch_build_id xen_dep; /* ELFNOTE_DESC(.livepatch.xen_depends). */ + livepatch_loadcall_t *const *load_funcs; /* The array of funcs to call after */ + livepatch_unloadcall_t *const *unload_funcs;/* load and unload of the payload. */ + unsigned int n_load_funcs; /* Nr of the funcs to load and execute. */ + unsigned int n_unload_funcs; /* Nr of funcs to call durung unload. */ + char name[XEN_LIVEPATCH_NAME_SIZE]; /* Name of it. */ +}; + /* * LIVEPATCH_LOAD_HOOK macro * From patchwork Thu Nov 14 13:06:45 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Wieczorkiewicz, Pawel" X-Patchwork-Id: 11243701 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 8995C1393 for ; 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14 Nov 2019 13:07:44 +0000 Received: from EX13MTAUEA001.ant.amazon.com (iad55-ws-svc-p15-lb9-vlan2.iad.amazon.com [10.40.159.162]) by email-inbound-relay-1d-5dd976cd.us-east-1.amazon.com (Postfix) with ESMTPS id 7D87EA2C0A; Thu, 14 Nov 2019 13:07:39 +0000 (UTC) Received: from EX13D03EUA003.ant.amazon.com (10.43.165.89) by EX13MTAUEA001.ant.amazon.com (10.43.61.243) with Microsoft SMTP Server (TLS) id 15.0.1367.3; Thu, 14 Nov 2019 13:07:26 +0000 Received: from EX13MTAUWA001.ant.amazon.com (10.43.160.58) by EX13D03EUA003.ant.amazon.com (10.43.165.89) with Microsoft SMTP Server (TLS) id 15.0.1367.3; Thu, 14 Nov 2019 13:07:24 +0000 Received: from dev-dsk-wipawel-1a-0c4e6d58.eu-west-1.amazon.com (10.4.134.33) by mail-relay.amazon.com (10.43.160.118) with Microsoft SMTP Server id 15.0.1367.3 via Frontend Transport; Thu, 14 Nov 2019 13:07:22 +0000 From: Pawel Wieczorkiewicz To: Date: Thu, 14 Nov 2019 13:06:45 +0000 Message-ID: <20191114130653.51185-5-wipawel@amazon.de> X-Mailer: git-send-email 2.16.5 In-Reply-To: <20191114130653.51185-1-wipawel@amazon.de> References: <20191114130653.51185-1-wipawel@amazon.de> MIME-Version: 1.0 Precedence: Bulk Subject: [Xen-devel] [PATCH v5 04/12] livepatch: Implement pre-|post- apply|revert hooks X-BeenThere: xen-devel@lists.xenproject.org X-Mailman-Version: 2.1.23 List-Id: Xen developer discussion List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Cc: Stefano Stabellini , Julien Grall , Wei Liu , Konrad Rzeszutek Wilk , George Dunlap , Andrew Cooper , Ross Lagerwall , Ian Jackson , mpohlack@amazon.com, Pawel Wieczorkiewicz , Jan Beulich Errors-To: xen-devel-bounces@lists.xenproject.org Sender: "Xen-devel" This is an implementation of 4 new livepatch module vetoing hooks, that can be optionally supplied along with modules. Hooks that currently exists in the livepatch mechanism aren't agile enough and have various limitations: * run only from within a quiescing zone * cannot conditionally prevent applying or reverting * do not have access to the module context To address these limitations the following has been implemented: 1) pre-apply hook runs before the apply action is scheduled for execution. Its main purpose is to prevent from applying a livepatch when certain expected conditions aren't met or when mutating actions implemented in the hook fail or cannot be executed. 2) post-apply hook runs after the apply action has been executed and quiescing zone exited. Its main purpose is to provide an ability to follow-up on actions performed by the pre- hook, when module application was successful or undo certain preparation steps of the pre- hook in case of a failure. The success/failure error code is provided to the post- hooks via the rc field of the payload structure. 3) pre-revert hook runs before the revert action is scheduled for execution. Its main purpose is to prevent from reverting a livepatch when certain expected conditions aren't met or when mutating actions implemented in the hook fail or cannot be executed. 4) post-revert hook runs after the revert action has been executed and quiescing zone exited. Its main purpose is to perform cleanup of all previously executed mutating actions in order to restore the original system state from before the current module application. The success/failure error code is provided to the post- hooks via the rc field of the payload structure. The replace action performs atomically the following actions: - revert all applied modules - apply a single replacement module. With the vetoing hooks in place various inter-hook dependencies may arise. Also, during the revert part of the operation certain vetoing hooks may detect failing conditions that previously were satisfied. That could in turn lead to situation when the revert part must be rolled back with all the pre- and post- hooks re-applied, which again can't be guaranteed to always succeed. The simplest response to this complication is to disallow the replace action completely on modules with vetoing hooks. Signed-off-by: Pawel Wieczorkiewicz Reviewed-by: Andra-Irina Paraschiv Reviewed-by: Petre Eftime Reviewed-by: Martin Pohlack Reviewed-by: Norbert Manthey Signed-off-by: Konrad Rzeszutek Wilk Reviewed-by: Ross Lagerwall --- Changed since v3: * s/hotpatch/livepatch/g * s/bool_t/bool/g Changed since v1: * added corresponding documentation * added tests --- .gitignore | 6 +- docs/misc/livepatch.pandoc | 90 +++++++++++++- xen/common/livepatch.c | 179 +++++++++++++++++++++++++--- xen/include/xen/livepatch_payload.h | 27 +++++ xen/test/livepatch/Makefile | 19 ++- xen/test/livepatch/xen_prepost_hooks.c | 122 +++++++++++++++++++ xen/test/livepatch/xen_prepost_hooks_fail.c | 75 ++++++++++++ 7 files changed, 492 insertions(+), 26 deletions(-) create mode 100644 xen/test/livepatch/xen_prepost_hooks.c create mode 100644 xen/test/livepatch/xen_prepost_hooks_fail.c diff --git a/.gitignore b/.gitignore index 223bedcd2b..ab765a5cdd 100644 --- a/.gitignore +++ b/.gitignore @@ -308,11 +308,7 @@ xen/include/xen/acm_policy.h xen/include/xen/compile.h xen/include/xen/lib/x86/cpuid-autogen.h xen/test/livepatch/config.h -xen/test/livepatch/xen_bye_world.livepatch -xen/test/livepatch/xen_hello_world.livepatch -xen/test/livepatch/xen_nop.livepatch -xen/test/livepatch/xen_replace_world.livepatch -xen/test/livepatch/xen_no_xen_buildid.livepatch +xen/test/livepatch/*.livepatch xen/tools/kconfig/.tmp_gtkcheck xen/tools/kconfig/.tmp_qtcheck xen/tools/symbols diff --git a/docs/misc/livepatch.pandoc b/docs/misc/livepatch.pandoc index cd859bb811..5e8e2ff6f6 100644 --- a/docs/misc/livepatch.pandoc +++ b/docs/misc/livepatch.pandoc @@ -23,6 +23,9 @@ The document is split in four sections: * payload - telemetries of the old code along with binary blob of the new function (if needed). * reloc - telemetries contained in the payload to construct proper trampoline. + * hook - an auxiliary function being called before, during or after payload + application or revert. + * quiescing zone - period when all CPUs are lock-step with each other. ## History @@ -270,6 +273,10 @@ like what the Linux kernel module loader does. The payload contains at least three sections: * `.livepatch.funcs` - which is an array of livepatch_func structures. + and/or any of: + * `.livepatch.hooks.{preapply,postapply,prerevert,postrevert}' + - which are a pointer to a hook function pointer. + * `.livepatch.xen_depends` - which is an ELF Note that describes what Xen build-id the payload depends on. **MUST** have one. * `.livepatch.depends` - which is an ELF Note that describes what the payload @@ -330,12 +337,24 @@ When reverting a patch, the hypervisor iterates over each `livepatch_func` and the core code copies the data from the undo buffer (private internal copy) to `old_addr`. -It optionally may contain the address of functions to be called right before -being applied and after being reverted: +It optionally may contain the address of hooks to be called right before +being applied and after being reverted (while all CPUs are still in quiescing +zone). These hooks do not have access to payload structure. * `.livepatch.hooks.load` - an array of function pointers. * `.livepatch.hooks.unload` - an array of function pointers. +It optionally may also contain the address of pre- and post- vetoing hooks to +be called before (pre) or after (post) apply and revert payload actions (while +all CPUs are already released from quiescing zone). These hooks do have +access to payload structure. The pre-apply hook can prevent from loading the +payload if encoded in it condition is not met. Accordingly, the pre-revert +hook can prevent from unloading the livepatch if encoded in it condition is not +met. + + * `.livepatch.hooks.{preapply,postapply}` + * `.livepatch.hooks.{prerevert,postrevert}` + - which are a pointer to a single hook function pointer. ### Example of .livepatch.funcs @@ -371,7 +390,9 @@ A simple example of what a payload file can be: Code must be compiled with `-fPIC`. -### .livepatch.hooks.load and .livepatch.hooks.unload +### Hooks + +#### .livepatch.hooks.load and .livepatch.hooks.unload This section contains an array of function pointers to be executed before payload is being applied (.livepatch.funcs) or after reverting @@ -385,6 +406,69 @@ The type definition of the function are as follow: typedef void (*livepatch_loadcall_t)(void); typedef void (*livepatch_unloadcall_t)(void); +#### .livepatch.hooks.preapply + +This section contains a pointer to a single function pointer to be executed +before apply action is scheduled (and thereby before CPUs are put into +quiescing zone). This is useful to prevent from applying a payload when +certain expected conditions aren't met or when mutating actions implemented +in the hook fail or cannot be executed. +This type of hooks do have access to payload structure. + +Each entry in this array is eight bytes. + +The type definition of the function are as follow: + + typedef int livepatch_precall_t(livepatch_payload_t *arg); + +#### .livepatch.hooks.postapply + +This section contains a pointer to a single function pointer to be executed +after apply action has finished and after all CPUs left the quiescing zone. +This is useful to provide an ability to follow up on actions performed by +the preapply hook. Especially, when module application was successful or to +be able to undo certain preparation steps of the preapply hook in case of a +failure. The success/failure error code is provided to the postapply hooks +via the `rc` field of the payload structure. +This type of hooks do have access to payload structure. + +Each entry in this array is eight bytes. + +The type definition of the function are as follow: + + typedef void livepatch_postcall_t(livepatch_payload_t *arg); + +#### .livepatch.hooks.prerevert + +This section contains a pointer to a single function pointer to be executed +before revert action is scheduled (and thereby before CPUs are put into +quiescing zone). This is useful to prevent from reverting a payload when +certain expected conditions aren't met or when mutating actions implemented +in the hook fail or cannot be executed. +This type of hooks do have access to payload structure. + +Each entry in this array is eight bytes. + +The type definition of the function are as follow: + + typedef int livepatch_precall_t(livepatch_payload_t *arg); + +#### .livepatch.hooks.postrevert + +This section contains a pointer to a single function pointer to be executed +after revert action has finished and after all CPUs left the quiescing zone. +This is useful to provide an ability to perform cleanup of all previously +executed mutating actions in order to restore the original system state from +before the current payload application. The success/failure error code is +provided to the postrevert hook via the `rc` field of the payload structure. +This type of hooks do have access to payload structure. + +Each entry in this array is eight bytes. + +The type definition of the function are as follow: + + typedef void livepatch_postcall_t(livepatch_payload_t *arg); + ### .livepatch.xen_depends, .livepatch.depends and .note.gnu.build-id To support dependencies checking and safe loading (to load the diff --git a/xen/common/livepatch.c b/xen/common/livepatch.c index 04a19c1856..d9934a7d70 100644 --- a/xen/common/livepatch.c +++ b/xen/common/livepatch.c @@ -28,6 +28,8 @@ #include #include +#define is_hook_enabled(hook) ({ (hook) && *(hook); }) + /* * Protects against payload_list operations and also allows only one * caller in schedule_work. @@ -501,6 +503,35 @@ static int check_special_sections(const struct livepatch_elf *elf) return 0; } +/* + * Lookup specified section and when exists assign its address to a specified hook. + * Perform section pointer and size validation: single hook sections must contain a + * single pointer only. + */ +#define LIVEPATCH_ASSIGN_SINGLE_HOOK(elf, hook, section_name) do { \ + const struct livepatch_elf_sec *__sec = livepatch_elf_sec_by_name(elf, section_name); \ + if ( !__sec ) \ + break; \ + if ( !section_ok(elf, __sec, sizeof(*hook)) || __sec->sec->sh_size != sizeof(*hook) ) \ + return -EINVAL; \ + hook = __sec->load_addr; \ +} while (0) + +/* + * Lookup specified section and when exists assign its address to a specified hook. + * Perform section pointer and size validation: multi hook sections must contain an + * array whose size must be a multiple of the array's items size. + */ +#define LIVEPATCH_ASSIGN_MULTI_HOOK(elf, hook, nhooks, section_name) do { \ + const struct livepatch_elf_sec *__sec = livepatch_elf_sec_by_name(elf, section_name); \ + if ( !__sec ) \ + break; \ + if ( !section_ok(elf, __sec, sizeof(*hook)) ) \ + return -EINVAL; \ + hook = __sec->load_addr; \ + nhooks = __sec->sec->sh_size / sizeof(*hook); \ +} while (0) + static int prepare_payload(struct payload *payload, struct livepatch_elf *elf) { @@ -552,25 +583,14 @@ static int prepare_payload(struct payload *payload, return rc; } - sec = livepatch_elf_sec_by_name(elf, ".livepatch.hooks.load"); - if ( sec ) - { - if ( !section_ok(elf, sec, sizeof(*payload->load_funcs)) ) - return -EINVAL; + LIVEPATCH_ASSIGN_MULTI_HOOK(elf, payload->load_funcs, payload->n_load_funcs, ".livepatch.hooks.load"); + LIVEPATCH_ASSIGN_MULTI_HOOK(elf, payload->unload_funcs, payload->n_unload_funcs, ".livepatch.hooks.unload"); - payload->load_funcs = sec->load_addr; - payload->n_load_funcs = sec->sec->sh_size / sizeof(*payload->load_funcs); - } - - sec = livepatch_elf_sec_by_name(elf, ".livepatch.hooks.unload"); - if ( sec ) - { - if ( !section_ok(elf, sec, sizeof(*payload->unload_funcs)) ) - return -EINVAL; + LIVEPATCH_ASSIGN_SINGLE_HOOK(elf, payload->hooks.apply.pre, ".livepatch.hooks.preapply"); + LIVEPATCH_ASSIGN_SINGLE_HOOK(elf, payload->hooks.apply.post, ".livepatch.hooks.postapply"); + LIVEPATCH_ASSIGN_SINGLE_HOOK(elf, payload->hooks.revert.pre, ".livepatch.hooks.prerevert"); + LIVEPATCH_ASSIGN_SINGLE_HOOK(elf, payload->hooks.revert.post, ".livepatch.hooks.postrevert"); - payload->unload_funcs = sec->load_addr; - payload->n_unload_funcs = sec->sec->sh_size / sizeof(*payload->unload_funcs); - } sec = livepatch_elf_sec_by_name(elf, ELF_BUILD_ID_NOTE); if ( sec ) { @@ -1217,6 +1237,39 @@ static bool_t is_work_scheduled(const struct payload *data) return livepatch_work.do_work && livepatch_work.data == data; } +/* + * Check if payload has any of the vetoing, non-atomic hooks assigned. + * A vetoing, non-atmic hook may perform an operation that changes the + * hypervisor state and may not be guaranteed to succeed. Result of + * such operation may be returned and may change the livepatch workflow. + * Such hooks may require additional cleanup actions performed by other + * hooks. Thus they are not suitable for replace action. + */ +static inline bool has_payload_any_vetoing_hooks(const struct payload *payload) +{ + return is_hook_enabled(payload->hooks.apply.pre) || + is_hook_enabled(payload->hooks.apply.post) || + is_hook_enabled(payload->hooks.revert.pre) || + is_hook_enabled(payload->hooks.revert.post); +} + +/* + * Checks if any of the already applied livepatches has any vetoing, + * non-atomic hooks assigned. + */ +static inline bool livepatch_applied_have_vetoing_hooks(void) +{ + struct payload *p; + + list_for_each_entry ( p, &applied_list, applied_list ) + { + if ( has_payload_any_vetoing_hooks(p) ) + return true; + } + + return false; +} + static int schedule_work(struct payload *data, uint32_t cmd, uint32_t timeout) { ASSERT(spin_is_locked(&payload_lock)); @@ -1317,6 +1370,7 @@ void check_for_livepatch_work(void) { struct payload *p; unsigned int cpus; + bool action_done = false; p = livepatch_work.data; if ( !get_cpu_maps() ) @@ -1369,6 +1423,7 @@ void check_for_livepatch_work(void) livepatch_do_action(); /* Serialize and flush out the CPU via CPUID instruction (on x86). */ arch_livepatch_post_action(); + action_done = true; local_irq_restore(flags); } @@ -1381,6 +1436,43 @@ void check_for_livepatch_work(void) /* put_cpu_maps has an barrier(). */ put_cpu_maps(); + if ( action_done ) + { + switch ( livepatch_work.cmd ) + { + case LIVEPATCH_ACTION_REVERT: + if ( is_hook_enabled(p->hooks.revert.post) ) + { + printk(XENLOG_INFO LIVEPATCH "%s: Calling post-revert hook function with rc=%d\n", + p->name, p->rc); + + (*p->hooks.revert.post)(p); + } + break; + + case LIVEPATCH_ACTION_APPLY: + if ( is_hook_enabled(p->hooks.apply.post) ) + { + printk(XENLOG_INFO LIVEPATCH "%s: Calling post-apply hook function with rc=%d\n", + p->name, p->rc); + + (*p->hooks.apply.post)(p); + } + break; + + case LIVEPATCH_ACTION_REPLACE: + if ( has_payload_any_vetoing_hooks(p) ) + { + /* It should be impossible to get here since livepatch_action() guards against that. */ + panic(LIVEPATCH "%s: REPLACE action is not supported on livepatches with vetoing hooks!\n", + p->name); + ASSERT_UNREACHABLE(); + } + default: + break; + } + } + printk(XENLOG_INFO LIVEPATCH "%s finished %s with rc=%d\n", p->name, names[livepatch_work.cmd], p->rc); } @@ -1519,6 +1611,21 @@ static int livepatch_action(struct xen_sysctl_livepatch_action *action) rc = -EBUSY; break; } + + if ( is_hook_enabled(data->hooks.revert.pre) ) + { + printk(XENLOG_INFO LIVEPATCH "%s: Calling pre-revert hook function\n", data->name); + + rc = (*data->hooks.revert.pre)(data); + if ( rc ) + { + printk(XENLOG_ERR LIVEPATCH "%s: pre-revert hook failed (rc=%d), aborting!\n", + data->name, rc); + data->rc = rc; + break; + } + } + data->rc = -EAGAIN; rc = schedule_work(data, action->cmd, action->timeout); } @@ -1552,6 +1659,20 @@ static int livepatch_action(struct xen_sysctl_livepatch_action *action) break; } + if ( is_hook_enabled(data->hooks.apply.pre) ) + { + printk(XENLOG_INFO LIVEPATCH "%s: Calling pre-apply hook function\n", data->name); + + rc = (*data->hooks.apply.pre)(data); + if ( rc ) + { + printk(XENLOG_ERR LIVEPATCH "%s: pre-apply hook failed (rc=%d), aborting!\n", + data->name, rc); + data->rc = rc; + break; + } + } + data->rc = -EAGAIN; rc = schedule_work(data, action->cmd, action->timeout); } @@ -1563,6 +1684,30 @@ static int livepatch_action(struct xen_sysctl_livepatch_action *action) rc = build_id_dep(data, 1 /* against hypervisor. */); if ( rc ) break; + + /* + * REPLACE action is not supported on livepatches with vetoing hooks. + * Vetoing hooks usually perform mutating actions on the system and + * typically exist in pairs (pre- hook doing an action and post- hook + * undoing the action). Coalescing all hooks from all applied modules + * cannot be performed without inspecting potential dependencies between + * the mutating hooks and hence cannot be performed automatically by + * the replace action. Also, the replace action cannot safely assume a + * successful revert of all the module with vetoing hooks. When one + * of the hooks fails due to not meeting certain conditions the whole + * replace operation must have been reverted with all previous pre- and + * post- hooks re-executed (which cannot be guaranteed to succeed). + * The simplest response to this complication is disallow replace + * action on modules with vetoing hooks. + */ + if ( has_payload_any_vetoing_hooks(data) || livepatch_applied_have_vetoing_hooks() ) + { + printk(XENLOG_ERR LIVEPATCH "%s: REPLACE action is not supported on livepatches with vetoing hooks!\n", + data->name); + rc = -EOPNOTSUPP; + break; + } + data->rc = -EAGAIN; rc = schedule_work(data, action->cmd, action->timeout); } diff --git a/xen/include/xen/livepatch_payload.h b/xen/include/xen/livepatch_payload.h index 99613af2db..cd20944cc4 100644 --- a/xen/include/xen/livepatch_payload.h +++ b/xen/include/xen/livepatch_payload.h @@ -21,6 +21,16 @@ typedef struct payload livepatch_payload_t; typedef void livepatch_loadcall_t(void); typedef void livepatch_unloadcall_t(void); +typedef int livepatch_precall_t(livepatch_payload_t *arg); +typedef void livepatch_postcall_t(livepatch_payload_t *arg); + +struct livepatch_hooks { + struct { + livepatch_precall_t *const *pre; + livepatch_postcall_t *const *post; + } apply, revert; +}; + struct payload { uint32_t state; /* One of the LIVEPATCH_STATE_*. */ int32_t rc; /* 0 or -XEN_EXX. */ @@ -47,6 +57,7 @@ struct payload { struct livepatch_build_id xen_dep; /* ELFNOTE_DESC(.livepatch.xen_depends). */ livepatch_loadcall_t *const *load_funcs; /* The array of funcs to call after */ livepatch_unloadcall_t *const *unload_funcs;/* load and unload of the payload. */ + struct livepatch_hooks hooks; /* Pre and post hooks for apply and revert */ unsigned int n_load_funcs; /* Nr of the funcs to load and execute. */ unsigned int n_unload_funcs; /* Nr of funcs to call durung unload. */ char name[XEN_LIVEPATCH_NAME_SIZE]; /* Name of it. */ @@ -76,6 +87,22 @@ struct payload { livepatch_unloadcall_t *__weak \ const livepatch_unload_data_##_fn __section(".livepatch.hooks.unload") = _fn; +#define LIVEPATCH_PREAPPLY_HOOK(_fn) \ + livepatch_precall_t *__attribute__((weak, used)) \ + const livepatch_preapply_data_##_fn __section(".livepatch.hooks.preapply") = _fn; + +#define LIVEPATCH_POSTAPPLY_HOOK(_fn) \ + livepatch_postcall_t *__attribute__((weak, used)) \ + const livepatch_postapply_data_##_fn __section(".livepatch.hooks.postapply") = _fn; + +#define LIVEPATCH_PREREVERT_HOOK(_fn) \ + livepatch_precall_t *__attribute__((weak, used)) \ + const livepatch_prerevert_data_##_fn __section(".livepatch.hooks.prerevert") = _fn; + +#define LIVEPATCH_POSTREVERT_HOOK(_fn) \ + livepatch_postcall_t *__attribute__((weak, used)) \ + const livepatch_postrevert_data_##_fn __section(".livepatch.hooks.postrevert") = _fn; + #endif /* __XEN_LIVEPATCH_PAYLOAD_H__ */ /* diff --git a/xen/test/livepatch/Makefile b/xen/test/livepatch/Makefile index 938aee17ec..a94bc48536 100644 --- a/xen/test/livepatch/Makefile +++ b/xen/test/livepatch/Makefile @@ -20,12 +20,16 @@ LIVEPATCH_BYE := xen_bye_world.livepatch LIVEPATCH_REPLACE := xen_replace_world.livepatch LIVEPATCH_NOP := xen_nop.livepatch LIVEPATCH_NO_XEN_BUILDID := xen_no_xen_buildid.livepatch +LIVEPATCH_PREPOST_HOOKS := xen_prepost_hooks.livepatch +LIVEPATCH_PREPOST_HOOKS_FAIL := xen_prepost_hooks_fail.livepatch LIVEPATCHES += $(LIVEPATCH) LIVEPATCHES += $(LIVEPATCH_BYE) LIVEPATCHES += $(LIVEPATCH_REPLACE) LIVEPATCHES += $(LIVEPATCH_NOP) LIVEPATCHES += $(LIVEPATCH_NO_XEN_BUILDID) +LIVEPATCHES += $(LIVEPATCH_PREPOST_HOOKS) +LIVEPATCHES += $(LIVEPATCH_PREPOST_HOOKS_FAIL) LIVEPATCH_DEBUG_DIR ?= $(DEBUG_DIR)/xen-livepatch @@ -128,5 +132,18 @@ xen_no_xen_buildid.o: config.h $(LIVEPATCH_NO_XEN_BUILDID): xen_nop.o note.o $(LD) $(LDFLAGS) $(build_id_linker) -r -o $(LIVEPATCH_NO_XEN_BUILDID) $^ +xen_prepost_hooks.o: config.h + +.PHONY: $(LIVEPATCH_PREPOST_HOOKS) +$(LIVEPATCH_PREPOST_HOOKS): xen_prepost_hooks.o xen_hello_world_func.o note.o xen_note.o + $(LD) $(LDFLAGS) $(build_id_linker) -r -o $(LIVEPATCH_PREPOST_HOOKS) $^ + +xen_prepost_hooks_fail.o: config.h + +.PHONY: $(LIVEPATCH_PREPOST_HOOKS_FAIL) +$(LIVEPATCH_PREPOST_HOOKS_FAIL): xen_prepost_hooks_fail.o xen_hello_world_func.o note.o xen_note.o + $(LD) $(LDFLAGS) $(build_id_linker) -r -o $(LIVEPATCH_PREPOST_HOOKS_FAIL) $^ + .PHONY: livepatch -livepatch: $(LIVEPATCH) $(LIVEPATCH_BYE) $(LIVEPATCH_REPLACE) $(LIVEPATCH_NOP) $(LIVEPATCH_NO_XEN_BUILDID) +livepatch: $(LIVEPATCH) $(LIVEPATCH_BYE) $(LIVEPATCH_REPLACE) $(LIVEPATCH_NOP) $(LIVEPATCH_NO_XEN_BUILDID) \ + $(LIVEPATCH_PREPOST_HOOKS) $(LIVEPATCH_PREPOST_HOOKS_FAIL) diff --git a/xen/test/livepatch/xen_prepost_hooks.c b/xen/test/livepatch/xen_prepost_hooks.c new file mode 100644 index 0000000000..889377d6eb --- /dev/null +++ b/xen/test/livepatch/xen_prepost_hooks.c @@ -0,0 +1,122 @@ +/* + * Copyright (c) 2019 Amazon.com, Inc. or its affiliates. All rights reserved. + * + */ + +#include "config.h" +#include +#include +#include +#include +#include + +#include + +static const char hello_world_patch_this_fnc[] = "xen_extra_version"; +extern const char *xen_hello_world(void); + +static unsigned int pre_apply_cnt; +static unsigned int post_apply_cnt; +static unsigned int pre_revert_cnt; +static unsigned int post_revert_cnt; + +static unsigned int pre_revert_retry = 1; + +static int pre_apply_hook(livepatch_payload_t *payload) +{ + int i; + + printk(KERN_DEBUG "%s: Hook starting.\n", __func__); + + for (i = 0; i < payload->nfuncs; i++) + { + struct livepatch_func *func = &payload->funcs[i]; + + pre_apply_cnt++; + printk(KERN_DEBUG "%s: applying: %s\n", __func__, func->name); + } + + printk(KERN_DEBUG "%s: Hook done.\n", __func__); + + return 0; +} + +static void post_apply_hook(livepatch_payload_t *payload) +{ + int i; + + printk(KERN_DEBUG "%s: Hook starting.\n", __func__); + + for (i = 0; i < payload->nfuncs; i++) + { + struct livepatch_func *func = &payload->funcs[i]; + + post_apply_cnt++; + printk(KERN_DEBUG "%s: applied: %s\n", __func__, func->name); + } + + printk(KERN_DEBUG "%s: Hook done.\n", __func__); +} + +static int pre_revert_hook(livepatch_payload_t *payload) +{ + int i; + + printk(KERN_DEBUG "%s: Hook starting.\n", __func__); + + for (i = 0; i < payload->nfuncs; i++) + { + struct livepatch_func *func = &payload->funcs[i]; + + pre_revert_cnt++; + printk(KERN_DEBUG "%s: reverting: %s\n", __func__, func->name); + } + + printk(KERN_DEBUG "%s: Hook done.\n", __func__); + + /* First revert attempt always fails. Second attempt succeeds. */ + return -(pre_revert_retry--); +} + +static void post_revert_hook(livepatch_payload_t *payload) +{ + int i; + + printk(KERN_DEBUG "%s: Hook starting.\n", __func__); + + for (i = 0; i < payload->nfuncs; i++) + { + struct livepatch_func *func = &payload->funcs[i]; + + post_revert_cnt++; + printk(KERN_DEBUG "%s: reverted: %s\n", __func__, func->name); + } + + BUG_ON(pre_apply_cnt != 1 || post_apply_cnt != 1); + BUG_ON(pre_revert_cnt != 2 || post_revert_cnt != 1); + printk(KERN_DEBUG "%s: Hook done.\n", __func__); +} + +LIVEPATCH_PREAPPLY_HOOK(pre_apply_hook); +LIVEPATCH_POSTAPPLY_HOOK(post_apply_hook); +LIVEPATCH_PREREVERT_HOOK(pre_revert_hook); +LIVEPATCH_POSTREVERT_HOOK(post_revert_hook); + +struct livepatch_func __section(".livepatch.funcs") livepatch_xen_hello_world = { + .version = LIVEPATCH_PAYLOAD_VERSION, + .name = hello_world_patch_this_fnc, + .new_addr = xen_hello_world, + .old_addr = xen_extra_version, + .new_size = NEW_CODE_SZ, + .old_size = OLD_CODE_SZ, +}; + +/* + * Local variables: + * mode: C + * c-file-style: "BSD" + * c-basic-offset: 4 + * tab-width: 4 + * indent-tabs-mode: nil + * End: + */ diff --git a/xen/test/livepatch/xen_prepost_hooks_fail.c b/xen/test/livepatch/xen_prepost_hooks_fail.c new file mode 100644 index 0000000000..c6feb5d32d --- /dev/null +++ b/xen/test/livepatch/xen_prepost_hooks_fail.c @@ -0,0 +1,75 @@ +/* + * Copyright (c) 2019 Amazon.com, Inc. or its affiliates. All rights reserved. + * + */ + +#include "config.h" +#include +#include +#include +#include +#include + +#include + +static const char hello_world_patch_this_fnc[] = "xen_extra_version"; +extern const char *xen_hello_world(void); + +/* This hook always fail and should prevent from loading the livepatch. */ +static int pre_apply_hook(livepatch_payload_t *payload) +{ + int i; + + printk(KERN_DEBUG "%s: Hook starting.\n", __func__); + + for (i = 0; i < payload->nfuncs; i++) + { + struct livepatch_func *func = &payload->funcs[i]; + + printk(KERN_DEBUG "%s: pre applying: %s\n", __func__, func->name); + } + + printk(KERN_DEBUG "%s: Hook done.\n", __func__); + + return -EINVAL; +} + +static int unreachable_pre_hook(livepatch_payload_t *payload) +{ + printk(KERN_DEBUG "%s: Hook starting.\n", __func__); + BUG(); + printk(KERN_DEBUG "%s: Hook done.\n", __func__); + + return -EINVAL; +} + +static void unreachable_post_hook(livepatch_payload_t *payload) +{ + printk(KERN_DEBUG "%s: Hook starting.\n", __func__); + BUG(); + printk(KERN_DEBUG "%s: Hook done.\n", __func__); +} + +LIVEPATCH_PREAPPLY_HOOK(pre_apply_hook); +LIVEPATCH_POSTAPPLY_HOOK(unreachable_post_hook); +LIVEPATCH_PREREVERT_HOOK(unreachable_pre_hook); +LIVEPATCH_POSTREVERT_HOOK(unreachable_post_hook); + +struct livepatch_func __section(".livepatch.funcs") livepatch_xen_hello_world = { + .version = LIVEPATCH_PAYLOAD_VERSION, + .name = hello_world_patch_this_fnc, + .new_addr = xen_hello_world, + .old_addr = xen_extra_version, + .new_size = NEW_CODE_SZ, + .old_size = OLD_CODE_SZ, +}; + +/* + * Local variables: + * mode: C + * c-file-style: "BSD" + * c-basic-offset: 4 + * tab-width: 4 + * indent-tabs-mode: nil + * End: + */ From patchwork Thu Nov 14 13:06:46 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Wieczorkiewicz, Pawel" X-Patchwork-Id: 11243705 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 80A8914BC for ; 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14 Nov 2019 13:07:45 +0000 Received: from EX13MTAUEA001.ant.amazon.com (iad55-ws-svc-p15-lb9-vlan3.iad.amazon.com [10.40.159.166]) by email-inbound-relay-1d-474bcd9f.us-east-1.amazon.com (Postfix) with ESMTPS id 2B209A26C9; Thu, 14 Nov 2019 13:07:41 +0000 (UTC) Received: from EX13D05EUB003.ant.amazon.com (10.43.166.253) by EX13MTAUEA001.ant.amazon.com (10.43.61.82) with Microsoft SMTP Server (TLS) id 15.0.1367.3; Thu, 14 Nov 2019 13:07:30 +0000 Received: from EX13MTAUWA001.ant.amazon.com (10.43.160.58) by EX13D05EUB003.ant.amazon.com (10.43.166.253) with Microsoft SMTP Server (TLS) id 15.0.1367.3; Thu, 14 Nov 2019 13:07:29 +0000 Received: from dev-dsk-wipawel-1a-0c4e6d58.eu-west-1.amazon.com (10.4.134.33) by mail-relay.amazon.com (10.43.160.118) with Microsoft SMTP Server id 15.0.1367.3 via Frontend Transport; Thu, 14 Nov 2019 13:07:25 +0000 From: Pawel Wieczorkiewicz To: Date: Thu, 14 Nov 2019 13:06:46 +0000 Message-ID: <20191114130653.51185-6-wipawel@amazon.de> X-Mailer: git-send-email 2.16.5 In-Reply-To: <20191114130653.51185-1-wipawel@amazon.de> References: <20191114130653.51185-1-wipawel@amazon.de> MIME-Version: 1.0 Precedence: Bulk Subject: [Xen-devel] [PATCH v5 05/12] livepatch: Add support for apply|revert action replacement hooks X-BeenThere: xen-devel@lists.xenproject.org X-Mailman-Version: 2.1.23 List-Id: Xen developer discussion List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Cc: Stefano Stabellini , Julien Grall , Wei Liu , Konrad Rzeszutek Wilk , George Dunlap , Andrew Cooper , Ross Lagerwall , Ian Jackson , mpohlack@amazon.com, Pawel Wieczorkiewicz , Jan Beulich Errors-To: xen-devel-bounces@lists.xenproject.org Sender: "Xen-devel" By default, in the quiescing zone, a livepatch payload is applied with apply_payload() and reverted with revert_payload() functions. Both of the functions receive the payload struct pointer as a parameter. The functions are also a place where standard 'load' and 'unload' module hooks are executed. To increase livepatching system's agility and provide more flexible long-term livepatch solution, allow to overwrite the default apply and revert action functions with hook-like supplied alternatives. The alternative functions are optional and the default functions are used by default. Since the alternative functions have direct access to the livepatch payload structure, they can better control context of the 'load' and 'unload' hooks execution as well as exact instructions replacement workflows. They can be also easily extended to support extra features in the future. To simplify the alternative function generation move code responsible for payload and livepatch region registration outside of the function. That way it is guaranteed that the registration step occurs even for newly supplied functions. Signed-off-by: Pawel Wieczorkiewicz Reviewed-by: Petre Eftime Reviewed-by: Martin Pohlack Reviewed-by: Norbert Manthey Reviewed-by: Andra-Irina Paraschiv Reviewed-by: Bjoern Doebel Signed-off-by: Konrad Rzeszutek Wilk Reviewed-by: Ross Lagerwall --- Changed since v3: * s/hotpatch/livepatch/g * remove extra newline Changed since v1: * added corresponding documentation * added tests --- docs/misc/livepatch.pandoc | 23 ++++++++ xen/common/livepatch.c | 65 ++++++++++++++++++---- xen/include/xen/livepatch_payload.h | 10 ++++ xen/test/livepatch/Makefile | 10 +++- xen/test/livepatch/xen_action_hooks.c | 100 ++++++++++++++++++++++++++++++++++ 5 files changed, 197 insertions(+), 11 deletions(-) create mode 100644 xen/test/livepatch/xen_action_hooks.c diff --git a/docs/misc/livepatch.pandoc b/docs/misc/livepatch.pandoc index 5e8e2ff6f6..3c635add92 100644 --- a/docs/misc/livepatch.pandoc +++ b/docs/misc/livepatch.pandoc @@ -275,6 +275,7 @@ The payload contains at least three sections: * `.livepatch.funcs` - which is an array of livepatch_func structures. and/or any of: * `.livepatch.hooks.{preapply,postapply,prerevert,postrevert}' + * `.livepatch.hooks.{apply,revert}` - which are a pointer to a hook function pointer. * `.livepatch.xen_depends` - which is an ELF Note that describes what Xen @@ -356,6 +357,14 @@ met. * `.livepatch.hooks.{prerevert,postrevert}` - which are a pointer to a single hook function pointer. +Finally, it optionally may also contain the address of apply or revert action +hooks to be called instead of the default apply and revert payload actions +(while all CPUs are kept in quiescing zone). These hooks do have access to +payload structure. + + * `.livepatch.hooks.{apply,revert}` + - which are a pointer to a single hook function pointer. + ### Example of .livepatch.funcs A simple example of what a payload file can be: @@ -469,6 +478,20 @@ The type definition of the function are as follow: typedef void livepatch_postcall_t(livepatch_payload_t *arg); +#### .livepatch.hooks.apply and .livepatch.hooks.revert + +This section contains a pointer to a single function pointer to be executed +instead of a default apply (or revert) action function. This is useful to +replace or augment default behavior of the apply (or revert) action that +requires all CPUs to be in the quiescing zone. +This type of hooks do have access to payload structure. + +Each entry in this array is eight bytes. + +The type definition of the function are as follow: + + typedef int livepatch_actioncall_t(livepatch_payload_t *arg); + ### .livepatch.xen_depends, .livepatch.depends and .note.gnu.build-id To support dependencies checking and safe loading (to load the diff --git a/xen/common/livepatch.c b/xen/common/livepatch.c index d9934a7d70..c8d911a167 100644 --- a/xen/common/livepatch.c +++ b/xen/common/livepatch.c @@ -587,8 +587,11 @@ static int prepare_payload(struct payload *payload, LIVEPATCH_ASSIGN_MULTI_HOOK(elf, payload->unload_funcs, payload->n_unload_funcs, ".livepatch.hooks.unload"); LIVEPATCH_ASSIGN_SINGLE_HOOK(elf, payload->hooks.apply.pre, ".livepatch.hooks.preapply"); + LIVEPATCH_ASSIGN_SINGLE_HOOK(elf, payload->hooks.apply.action, ".livepatch.hooks.apply"); LIVEPATCH_ASSIGN_SINGLE_HOOK(elf, payload->hooks.apply.post, ".livepatch.hooks.postapply"); + LIVEPATCH_ASSIGN_SINGLE_HOOK(elf, payload->hooks.revert.pre, ".livepatch.hooks.prerevert"); + LIVEPATCH_ASSIGN_SINGLE_HOOK(elf, payload->hooks.revert.action, ".livepatch.hooks.revert"); LIVEPATCH_ASSIGN_SINGLE_HOOK(elf, payload->hooks.revert.post, ".livepatch.hooks.postrevert"); sec = livepatch_elf_sec_by_name(elf, ELF_BUILD_ID_NOTE); @@ -1114,6 +1117,11 @@ static int apply_payload(struct payload *data) arch_livepatch_revive(); + return 0; +} + +static inline void apply_payload_tail(struct payload *data) +{ /* * We need RCU variant (which has barriers) in case we crash here. * The applied_list is iterated by the trap code. @@ -1121,7 +1129,7 @@ static int apply_payload(struct payload *data) list_add_tail_rcu(&data->applied_list, &applied_list); register_virtual_region(&data->region); - return 0; + data->state = LIVEPATCH_STATE_APPLIED; } static int revert_payload(struct payload *data) @@ -1154,6 +1162,11 @@ static int revert_payload(struct payload *data) ASSERT(!local_irq_is_enabled()); arch_livepatch_revive(); + return 0; +} + +static inline void revert_payload_tail(struct payload *data) +{ /* * We need RCU variant (which has barriers) in case we crash here. @@ -1163,7 +1176,7 @@ static int revert_payload(struct payload *data) unregister_virtual_region(&data->region); data->reverted = true; - return 0; + data->state = LIVEPATCH_STATE_CHECKED; } /* @@ -1183,15 +1196,31 @@ static void livepatch_do_action(void) switch ( livepatch_work.cmd ) { case LIVEPATCH_ACTION_APPLY: - rc = apply_payload(data); + if ( is_hook_enabled(data->hooks.apply.action) ) + { + printk(XENLOG_INFO LIVEPATCH "%s: Calling apply action hook function\n", data->name); + + rc = (*data->hooks.apply.action)(data); + } + else + rc = apply_payload(data); + if ( rc == 0 ) - data->state = LIVEPATCH_STATE_APPLIED; + apply_payload_tail(data); break; case LIVEPATCH_ACTION_REVERT: - rc = revert_payload(data); + if ( is_hook_enabled(data->hooks.revert.action) ) + { + printk(XENLOG_INFO LIVEPATCH "%s: Calling revert action hook function\n", data->name); + + rc = (*data->hooks.revert.action)(data); + } + else + rc = revert_payload(data); + if ( rc == 0 ) - data->state = LIVEPATCH_STATE_CHECKED; + revert_payload_tail(data); break; case LIVEPATCH_ACTION_REPLACE: @@ -1202,9 +1231,17 @@ static void livepatch_do_action(void) */ list_for_each_entry_safe_reverse ( other, tmp, &applied_list, applied_list ) { - other->rc = revert_payload(other); + if ( is_hook_enabled(other->hooks.revert.action) ) + { + printk(XENLOG_INFO LIVEPATCH "%s: Calling revert action hook function\n", other->name); + + other->rc = (*other->hooks.revert.action)(other); + } + else + other->rc = revert_payload(other); + if ( other->rc == 0 ) - other->state = LIVEPATCH_STATE_CHECKED; + revert_payload_tail(other); else { rc = -EINVAL; @@ -1214,9 +1251,17 @@ static void livepatch_do_action(void) if ( rc == 0 ) { - rc = apply_payload(data); + if ( is_hook_enabled(data->hooks.apply.action) ) + { + printk(XENLOG_INFO LIVEPATCH "%s: Calling apply action hook function\n", data->name); + + rc = (*data->hooks.apply.action)(data); + } + else + rc = apply_payload(data); + if ( rc == 0 ) - data->state = LIVEPATCH_STATE_APPLIED; + apply_payload_tail(data); } break; diff --git a/xen/include/xen/livepatch_payload.h b/xen/include/xen/livepatch_payload.h index cd20944cc4..ff16af0dd6 100644 --- a/xen/include/xen/livepatch_payload.h +++ b/xen/include/xen/livepatch_payload.h @@ -22,11 +22,13 @@ typedef void livepatch_loadcall_t(void); typedef void livepatch_unloadcall_t(void); typedef int livepatch_precall_t(livepatch_payload_t *arg); +typedef int livepatch_actioncall_t(livepatch_payload_t *arg); typedef void livepatch_postcall_t(livepatch_payload_t *arg); struct livepatch_hooks { struct { livepatch_precall_t *const *pre; + livepatch_actioncall_t *const *action; livepatch_postcall_t *const *post; } apply, revert; }; @@ -91,6 +93,10 @@ struct payload { livepatch_precall_t *__attribute__((weak, used)) \ const livepatch_preapply_data_##_fn __section(".livepatch.hooks.preapply") = _fn; +#define LIVEPATCH_APPLY_HOOK(_fn) \ + livepatch_actioncall_t *__attribute__((weak, used)) \ + const livepatch_apply_data_##_fn __section(".livepatch.hooks.apply") = _fn; + #define LIVEPATCH_POSTAPPLY_HOOK(_fn) \ livepatch_postcall_t *__attribute__((weak, used)) \ const livepatch_postapply_data_##_fn __section(".livepatch.hooks.postapply") = _fn; @@ -99,6 +105,10 @@ struct payload { livepatch_precall_t *__attribute__((weak, used)) \ const livepatch_prerevert_data_##_fn __section(".livepatch.hooks.prerevert") = _fn; +#define LIVEPATCH_REVERT_HOOK(_fn) \ + livepatch_actioncall_t *__attribute__((weak, used)) \ + const livepatch_revert_data_##_fn __section(".livepatch.hooks.revert") = _fn; + #define LIVEPATCH_POSTREVERT_HOOK(_fn) \ livepatch_postcall_t *__attribute__((weak, used)) \ const livepatch_postrevert_data_##_fn __section(".livepatch.hooks.postrevert") = _fn; diff --git a/xen/test/livepatch/Makefile b/xen/test/livepatch/Makefile index a94bc48536..116e52e774 100644 --- a/xen/test/livepatch/Makefile +++ b/xen/test/livepatch/Makefile @@ -22,6 +22,7 @@ LIVEPATCH_NOP := xen_nop.livepatch LIVEPATCH_NO_XEN_BUILDID := xen_no_xen_buildid.livepatch LIVEPATCH_PREPOST_HOOKS := xen_prepost_hooks.livepatch LIVEPATCH_PREPOST_HOOKS_FAIL := xen_prepost_hooks_fail.livepatch +LIVEPATCH_ACTION_HOOKS := xen_action_hooks.livepatch LIVEPATCHES += $(LIVEPATCH) LIVEPATCHES += $(LIVEPATCH_BYE) @@ -30,6 +31,7 @@ LIVEPATCHES += $(LIVEPATCH_NOP) LIVEPATCHES += $(LIVEPATCH_NO_XEN_BUILDID) LIVEPATCHES += $(LIVEPATCH_PREPOST_HOOKS) LIVEPATCHES += $(LIVEPATCH_PREPOST_HOOKS_FAIL) +LIVEPATCHES += $(LIVEPATCH_ACTION_HOOKS) LIVEPATCH_DEBUG_DIR ?= $(DEBUG_DIR)/xen-livepatch @@ -144,6 +146,12 @@ xen_prepost_hooks_fail.o: config.h $(LIVEPATCH_PREPOST_HOOKS_FAIL): xen_prepost_hooks_fail.o xen_hello_world_func.o note.o xen_note.o $(LD) $(LDFLAGS) $(build_id_linker) -r -o $(LIVEPATCH_PREPOST_HOOKS_FAIL) $^ +xen_actions_hooks.o: config.h + +.PHONY: $(LIVEPATCH_ACTION_HOOKS) +$(LIVEPATCH_ACTION_HOOKS): xen_action_hooks.o xen_hello_world_func.o note.o xen_note.o + $(LD) $(LDFLAGS) $(build_id_linker) -r -o $(LIVEPATCH_ACTION_HOOKS) $^ + .PHONY: livepatch livepatch: $(LIVEPATCH) $(LIVEPATCH_BYE) $(LIVEPATCH_REPLACE) $(LIVEPATCH_NOP) $(LIVEPATCH_NO_XEN_BUILDID) \ - $(LIVEPATCH_PREPOST_HOOKS) $(LIVEPATCH_PREPOST_HOOKS_FAIL) + $(LIVEPATCH_PREPOST_HOOKS) $(LIVEPATCH_PREPOST_HOOKS_FAIL) $(LIVEPATCH_ACTION_HOOKS) diff --git a/xen/test/livepatch/xen_action_hooks.c b/xen/test/livepatch/xen_action_hooks.c new file mode 100644 index 0000000000..a947afc41f --- /dev/null +++ b/xen/test/livepatch/xen_action_hooks.c @@ -0,0 +1,100 @@ +/* + * Copyright (c) 2019 Amazon.com, Inc. or its affiliates. All rights reserved. + * + */ + +#include "config.h" +#include +#include +#include +#include +#include + +#include + +static const char hello_world_patch_this_fnc[] = "xen_extra_version"; +extern const char *xen_hello_world(void); + +static unsigned int apply_cnt; +static unsigned int revert_cnt; + +static int apply_hook(livepatch_payload_t *payload) +{ + int i; + + printk(KERN_DEBUG "%s: Hook starting.\n", __func__); + + for (i = 0; i < payload->nfuncs; i++) + { + struct livepatch_func *func = &payload->funcs[i]; + + apply_cnt++; + + printk(KERN_DEBUG "%s: applying: %s\n", __func__, func->name); + } + + printk(KERN_DEBUG "%s: Hook done.\n", __func__); + + return 0; +} + +static int revert_hook(livepatch_payload_t *payload) +{ + int i; + + printk(KERN_DEBUG "%s: Hook starting.\n", __func__); + + for (i = 0; i < payload->nfuncs; i++) + { + struct livepatch_func *func = &payload->funcs[i]; + + revert_cnt++; + + printk(KERN_DEBUG "%s: reverting: %s\n", __func__, func->name); + } + + printk(KERN_DEBUG "%s: Hook done.\n", __func__); + + return 0; +} + +static void post_revert_hook(livepatch_payload_t *payload) +{ + int i; + + printk(KERN_DEBUG "%s: Hook starting.\n", __func__); + + for (i = 0; i < payload->nfuncs; i++) + { + struct livepatch_func *func = &payload->funcs[i]; + + printk(KERN_DEBUG "%s: reverted: %s\n", __func__, func->name); + } + + BUG_ON(apply_cnt != 1 || revert_cnt != 1); + printk(KERN_DEBUG "%s: Hook done.\n", __func__); +} + +LIVEPATCH_APPLY_HOOK(apply_hook); +LIVEPATCH_REVERT_HOOK(revert_hook); + +LIVEPATCH_POSTREVERT_HOOK(post_revert_hook); + +struct livepatch_func __section(".livepatch.funcs") livepatch_xen_hello_world = { + .version = LIVEPATCH_PAYLOAD_VERSION, + .name = hello_world_patch_this_fnc, + .new_addr = xen_hello_world, + .old_addr = xen_extra_version, + .new_size = NEW_CODE_SZ, + .old_size = OLD_CODE_SZ, +}; + +/* + * Local variables: + * mode: C + * c-file-style: "BSD" + * c-basic-offset: 4 + * tab-width: 4 + * indent-tabs-mode: nil + * End: + */ From patchwork Thu Nov 14 13:06:47 2019 Content-Type: text/plain; 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Thu, 14 Nov 2019 13:07:30 +0000 From: Pawel Wieczorkiewicz To: Date: Thu, 14 Nov 2019 13:06:47 +0000 Message-ID: <20191114130653.51185-7-wipawel@amazon.de> X-Mailer: git-send-email 2.16.5 In-Reply-To: <20191114130653.51185-1-wipawel@amazon.de> References: <20191114130653.51185-1-wipawel@amazon.de> MIME-Version: 1.0 Precedence: Bulk Subject: [Xen-devel] [PATCH v5 06/12] livepatch: Do not enforce ELF_LIVEPATCH_FUNC section presence X-BeenThere: xen-devel@lists.xenproject.org X-Mailman-Version: 2.1.23 List-Id: Xen developer discussion List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Cc: Pawel Wieczorkiewicz , Ross Lagerwall , mpohlack@amazon.com, Konrad Rzeszutek Wilk Errors-To: xen-devel-bounces@lists.xenproject.org Sender: "Xen-devel" With default implementation the ELF_LIVEPATCH_FUNC section containing all functions to be replaced or added must be part of the livepatch payload, otherwise the payload is rejected (with -EINVAL). However, with the extended hooks implementation, a livepatch may be constructed of only hooks to perform certain actions without any code to be added or replaced. Therefore, do not always expect the functions section and allow it to be missing, provided there is at least one section containing hooks present. The functions section, when present in a payload, must be a single, non-empty section. Check also all extended hooks sections if they are a single, non-empty sections each. At least one of the functions or hooks section must be present in a valid payload. Signed-off-by: Pawel Wieczorkiewicz Reviewed-by: Andra-Irina Paraschiv Reviewed-by: Bjoern Doebel Reviewed-by: Martin Pohlack Signed-off-by: Konrad Rzeszutek Wilk Reviewed-by: Ross Lagerwall --- Changed since v3: * fix indent Changed since v1: * always print XENLOG_ERR messages * remove ASSERT from build_symbol_table() * added corresponding documentation * added tests --- xen/common/livepatch.c | 147 +++++++++++++++++++-------- xen/include/xen/livepatch.h | 8 ++ xen/test/livepatch/Makefile | 9 +- xen/test/livepatch/xen_action_hooks_nofunc.c | 86 ++++++++++++++++ 4 files changed, 206 insertions(+), 44 deletions(-) create mode 100644 xen/test/livepatch/xen_action_hooks_nofunc.c diff --git a/xen/common/livepatch.c b/xen/common/livepatch.c index c8d911a167..db066f5732 100644 --- a/xen/common/livepatch.c +++ b/xen/common/livepatch.c @@ -467,8 +467,7 @@ static int xen_build_id_dep(const struct payload *payload) static int check_special_sections(const struct livepatch_elf *elf) { unsigned int i; - static const char *const names[] = { ELF_LIVEPATCH_FUNC, - ELF_LIVEPATCH_DEPENDS, + static const char *const names[] = { ELF_LIVEPATCH_DEPENDS, ELF_LIVEPATCH_XEN_DEPENDS, ELF_BUILD_ID_NOTE}; DECLARE_BITMAP(found, ARRAY_SIZE(names)) = { 0 }; @@ -503,6 +502,64 @@ static int check_special_sections(const struct livepatch_elf *elf) return 0; } +static int check_patching_sections(const struct livepatch_elf *elf) +{ + unsigned int i; + static const char *const names[] = { ELF_LIVEPATCH_FUNC, + ELF_LIVEPATCH_LOAD_HOOKS, + ELF_LIVEPATCH_UNLOAD_HOOKS, + ELF_LIVEPATCH_PREAPPLY_HOOK, + ELF_LIVEPATCH_APPLY_HOOK, + ELF_LIVEPATCH_POSTAPPLY_HOOK, + ELF_LIVEPATCH_PREREVERT_HOOK, + ELF_LIVEPATCH_REVERT_HOOK, + ELF_LIVEPATCH_POSTREVERT_HOOK}; + DECLARE_BITMAP(found, ARRAY_SIZE(names)) = { 0 }; + + /* + * The patching sections are optional, but at least one + * must be present. Otherwise, there is nothing to do. + * All the existing sections must not be empty and must + * be present at most once. + */ + for ( i = 0; i < ARRAY_SIZE(names); i++ ) + { + const struct livepatch_elf_sec *sec; + + sec = livepatch_elf_sec_by_name(elf, names[i]); + if ( !sec ) + { + dprintk(XENLOG_DEBUG, LIVEPATCH "%s: %s is missing\n", + elf->name, names[i]); + continue; /* This section is optional */ + } + + if ( !sec->sec->sh_size ) + { + printk(XENLOG_ERR LIVEPATCH "%s: %s is empty\n", + elf->name, names[i]); + return -EINVAL; + } + + if ( test_and_set_bit(i, found) ) + { + printk(XENLOG_ERR LIVEPATCH "%s: %s was seen more than once\n", + elf->name, names[i]); + return -EINVAL; + } + } + + /* Checking if at least one section is present. */ + if ( bitmap_empty(found, ARRAY_SIZE(names)) ) + { + printk(XENLOG_ERR LIVEPATCH "%s: Nothing to patch. Aborting...\n", + elf->name); + return -EINVAL; + } + + return 0; +} + /* * Lookup specified section and when exists assign its address to a specified hook. * Perform section pointer and size validation: single hook sections must contain a @@ -542,57 +599,59 @@ static int prepare_payload(struct payload *payload, const Elf_Note *n; sec = livepatch_elf_sec_by_name(elf, ELF_LIVEPATCH_FUNC); - ASSERT(sec); - if ( !section_ok(elf, sec, sizeof(*payload->funcs)) ) - return -EINVAL; - - payload->funcs = sec->load_addr; - payload->nfuncs = sec->sec->sh_size / sizeof(*payload->funcs); - - for ( i = 0; i < payload->nfuncs; i++ ) + if ( sec ) { - int rc; + if ( !section_ok(elf, sec, sizeof(*payload->funcs)) ) + return -EINVAL; - f = &(payload->funcs[i]); + payload->funcs = sec->load_addr; + payload->nfuncs = sec->sec->sh_size / sizeof(*payload->funcs); - if ( f->version != LIVEPATCH_PAYLOAD_VERSION ) + for ( i = 0; i < payload->nfuncs; i++ ) { - printk(XENLOG_ERR LIVEPATCH "%s: Wrong version (%u). Expected %d\n", - elf->name, f->version, LIVEPATCH_PAYLOAD_VERSION); - return -EOPNOTSUPP; - } + int rc; - /* 'old_addr', 'new_addr', 'new_size' can all be zero. */ - if ( !f->old_size ) - { - printk(XENLOG_ERR LIVEPATCH "%s: Address or size fields are zero\n", - elf->name); - return -EINVAL; - } + f = &(payload->funcs[i]); - rc = arch_livepatch_verify_func(f); - if ( rc ) - return rc; + if ( f->version != LIVEPATCH_PAYLOAD_VERSION ) + { + printk(XENLOG_ERR LIVEPATCH "%s: Wrong version (%u). Expected %d\n", + elf->name, f->version, LIVEPATCH_PAYLOAD_VERSION); + return -EOPNOTSUPP; + } - rc = resolve_old_address(f, elf); - if ( rc ) - return rc; + /* 'old_addr', 'new_addr', 'new_size' can all be zero. */ + if ( !f->old_size ) + { + printk(XENLOG_ERR LIVEPATCH "%s: Address or size fields are zero\n", + elf->name); + return -EINVAL; + } - rc = livepatch_verify_distance(f); - if ( rc ) - return rc; + rc = arch_livepatch_verify_func(f); + if ( rc ) + return rc; + + rc = resolve_old_address(f, elf); + if ( rc ) + return rc; + + rc = livepatch_verify_distance(f); + if ( rc ) + return rc; + } } - LIVEPATCH_ASSIGN_MULTI_HOOK(elf, payload->load_funcs, payload->n_load_funcs, ".livepatch.hooks.load"); - LIVEPATCH_ASSIGN_MULTI_HOOK(elf, payload->unload_funcs, payload->n_unload_funcs, ".livepatch.hooks.unload"); + LIVEPATCH_ASSIGN_MULTI_HOOK(elf, payload->load_funcs, payload->n_load_funcs, ELF_LIVEPATCH_LOAD_HOOKS); + LIVEPATCH_ASSIGN_MULTI_HOOK(elf, payload->unload_funcs, payload->n_unload_funcs, ELF_LIVEPATCH_UNLOAD_HOOKS); - LIVEPATCH_ASSIGN_SINGLE_HOOK(elf, payload->hooks.apply.pre, ".livepatch.hooks.preapply"); - LIVEPATCH_ASSIGN_SINGLE_HOOK(elf, payload->hooks.apply.action, ".livepatch.hooks.apply"); - LIVEPATCH_ASSIGN_SINGLE_HOOK(elf, payload->hooks.apply.post, ".livepatch.hooks.postapply"); + LIVEPATCH_ASSIGN_SINGLE_HOOK(elf, payload->hooks.apply.pre, ELF_LIVEPATCH_PREAPPLY_HOOK); + LIVEPATCH_ASSIGN_SINGLE_HOOK(elf, payload->hooks.apply.action, ELF_LIVEPATCH_APPLY_HOOK); + LIVEPATCH_ASSIGN_SINGLE_HOOK(elf, payload->hooks.apply.post, ELF_LIVEPATCH_POSTAPPLY_HOOK); - LIVEPATCH_ASSIGN_SINGLE_HOOK(elf, payload->hooks.revert.pre, ".livepatch.hooks.prerevert"); - LIVEPATCH_ASSIGN_SINGLE_HOOK(elf, payload->hooks.revert.action, ".livepatch.hooks.revert"); - LIVEPATCH_ASSIGN_SINGLE_HOOK(elf, payload->hooks.revert.post, ".livepatch.hooks.postrevert"); + LIVEPATCH_ASSIGN_SINGLE_HOOK(elf, payload->hooks.revert.pre, ELF_LIVEPATCH_PREREVERT_HOOK); + LIVEPATCH_ASSIGN_SINGLE_HOOK(elf, payload->hooks.revert.action, ELF_LIVEPATCH_REVERT_HOOK); + LIVEPATCH_ASSIGN_SINGLE_HOOK(elf, payload->hooks.revert.post, ELF_LIVEPATCH_POSTREVERT_HOOK); sec = livepatch_elf_sec_by_name(elf, ELF_BUILD_ID_NOTE); if ( sec ) @@ -786,8 +845,6 @@ static int build_symbol_table(struct payload *payload, struct livepatch_symbol *symtab; char *strtab; - ASSERT(payload->nfuncs); - /* Recall that section @0 is always NULL. */ for ( i = 1; i < elf->nsym; i++ ) { @@ -904,6 +961,10 @@ static int load_payload_data(struct payload *payload, void *raw, size_t len) if ( rc ) goto out; + rc = check_patching_sections(&elf); + if ( rc ) + goto out; + rc = prepare_payload(payload, &elf); if ( rc ) goto out; diff --git a/xen/include/xen/livepatch.h b/xen/include/xen/livepatch.h index ed997aa4cc..2aec532ee2 100644 --- a/xen/include/xen/livepatch.h +++ b/xen/include/xen/livepatch.h @@ -33,6 +33,14 @@ struct xen_sysctl_livepatch_op; #define ELF_LIVEPATCH_DEPENDS ".livepatch.depends" #define ELF_LIVEPATCH_XEN_DEPENDS ".livepatch.xen_depends" #define ELF_BUILD_ID_NOTE ".note.gnu.build-id" +#define ELF_LIVEPATCH_LOAD_HOOKS ".livepatch.hooks.load" +#define ELF_LIVEPATCH_UNLOAD_HOOKS ".livepatch.hooks.unload" +#define ELF_LIVEPATCH_PREAPPLY_HOOK ".livepatch.hooks.preapply" +#define ELF_LIVEPATCH_APPLY_HOOK ".livepatch.hooks.apply" +#define ELF_LIVEPATCH_POSTAPPLY_HOOK ".livepatch.hooks.postapply" +#define ELF_LIVEPATCH_PREREVERT_HOOK ".livepatch.hooks.prerevert" +#define ELF_LIVEPATCH_REVERT_HOOK ".livepatch.hooks.revert" +#define ELF_LIVEPATCH_POSTREVERT_HOOK ".livepatch.hooks.postrevert" /* Arbitrary limit for payload size and .bss section size. */ #define LIVEPATCH_MAX_SIZE MB(2) diff --git a/xen/test/livepatch/Makefile b/xen/test/livepatch/Makefile index 116e52e774..bbc6bdaf64 100644 --- a/xen/test/livepatch/Makefile +++ b/xen/test/livepatch/Makefile @@ -23,6 +23,7 @@ LIVEPATCH_NO_XEN_BUILDID := xen_no_xen_buildid.livepatch LIVEPATCH_PREPOST_HOOKS := xen_prepost_hooks.livepatch LIVEPATCH_PREPOST_HOOKS_FAIL := xen_prepost_hooks_fail.livepatch LIVEPATCH_ACTION_HOOKS := xen_action_hooks.livepatch +LIVEPATCH_ACTION_HOOKS_NOFUNC := xen_action_hooks_nofunc.livepatch LIVEPATCHES += $(LIVEPATCH) LIVEPATCHES += $(LIVEPATCH_BYE) @@ -32,6 +33,7 @@ LIVEPATCHES += $(LIVEPATCH_NO_XEN_BUILDID) LIVEPATCHES += $(LIVEPATCH_PREPOST_HOOKS) LIVEPATCHES += $(LIVEPATCH_PREPOST_HOOKS_FAIL) LIVEPATCHES += $(LIVEPATCH_ACTION_HOOKS) +LIVEPATCHES += $(LIVEPATCH_ACTION_HOOKS_NOFUNC) LIVEPATCH_DEBUG_DIR ?= $(DEBUG_DIR)/xen-livepatch @@ -152,6 +154,11 @@ xen_actions_hooks.o: config.h $(LIVEPATCH_ACTION_HOOKS): xen_action_hooks.o xen_hello_world_func.o note.o xen_note.o $(LD) $(LDFLAGS) $(build_id_linker) -r -o $(LIVEPATCH_ACTION_HOOKS) $^ +.PHONY: $(LIVEPATCH_ACTION_HOOKS_NOFUNC) +$(LIVEPATCH_ACTION_HOOKS_NOFUNC): xen_action_hooks_nofunc.o note.o xen_note.o + $(LD) $(LDFLAGS) $(build_id_linker) -r -o $(LIVEPATCH_ACTION_HOOKS_NOFUNC) $^ + .PHONY: livepatch livepatch: $(LIVEPATCH) $(LIVEPATCH_BYE) $(LIVEPATCH_REPLACE) $(LIVEPATCH_NOP) $(LIVEPATCH_NO_XEN_BUILDID) \ - $(LIVEPATCH_PREPOST_HOOKS) $(LIVEPATCH_PREPOST_HOOKS_FAIL) $(LIVEPATCH_ACTION_HOOKS) + $(LIVEPATCH_PREPOST_HOOKS) $(LIVEPATCH_PREPOST_HOOKS_FAIL) $(LIVEPATCH_ACTION_HOOKS) \ + $(LIVEPATCH_ACTION_HOOKS_NOFUNC) diff --git a/xen/test/livepatch/xen_action_hooks_nofunc.c b/xen/test/livepatch/xen_action_hooks_nofunc.c new file mode 100644 index 0000000000..2b4e90436f --- /dev/null +++ b/xen/test/livepatch/xen_action_hooks_nofunc.c @@ -0,0 +1,86 @@ +/* + * Copyright (c) 2019 Amazon.com, Inc. or its affiliates. All rights reserved. + * + */ + +#include "config.h" +#include +#include +#include +#include +#include + +#include + +static unsigned int apply_cnt; +static unsigned int revert_cnt; + +static int apply_hook(livepatch_payload_t *payload) +{ + int i; + + printk(KERN_DEBUG "%s: Hook starting.\n", __func__); + + for (i = 0; i < payload->nfuncs; i++) + { + struct livepatch_func *func = &payload->funcs[i]; + + apply_cnt++; + printk(KERN_DEBUG "%s: applying: %s\n", __func__, func->name); + } + + printk(KERN_DEBUG "%s: Hook done.\n", __func__); + + return 0; +} + +static int revert_hook(livepatch_payload_t *payload) +{ + int i; + + printk(KERN_DEBUG "%s: Hook starting.\n", __func__); + + for (i = 0; i < payload->nfuncs; i++) + { + struct livepatch_func *func = &payload->funcs[i]; + + revert_cnt++; + printk(KERN_DEBUG "%s: reverting: %s\n", __func__, func->name); + } + + printk(KERN_DEBUG "%s: Hook done.\n", __func__); + + return 0; +} + +static void post_revert_hook(livepatch_payload_t *payload) +{ + int i; + + printk(KERN_DEBUG "%s: Hook starting.\n", __func__); + + for (i = 0; i < payload->nfuncs; i++) + { + struct livepatch_func *func = &payload->funcs[i]; + + printk(KERN_DEBUG "%s: reverted: %s\n", __func__, func->name); + } + + BUG_ON(apply_cnt > 0 || revert_cnt > 0); + printk(KERN_DEBUG "%s: Hook done.\n", __func__); +} + +LIVEPATCH_APPLY_HOOK(apply_hook); +LIVEPATCH_REVERT_HOOK(revert_hook); + +LIVEPATCH_POSTREVERT_HOOK(post_revert_hook); + +/* + * Local variables: + * mode: C + * c-file-style: "BSD" + * c-basic-offset: 4 + * tab-width: 4 + * indent-tabs-mode: nil + * End: + */ From patchwork Thu Nov 14 13:06:48 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Wieczorkiewicz, Pawel" X-Patchwork-Id: 11243713 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id E0F881393 for ; Thu, 14 Nov 2019 13:09:43 +0000 (UTC) Received: from lists.xenproject.org (lists.xenproject.org [192.237.175.120]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id B125B206DC for ; 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Thu, 14 Nov 2019 13:07:53 +0000 (UTC) Received: from EX13D05EUB003.ant.amazon.com (10.43.166.253) by EX13MTAUEA001.ant.amazon.com (10.43.61.82) with Microsoft SMTP Server (TLS) id 15.0.1367.3; Thu, 14 Nov 2019 13:07:38 +0000 Received: from EX13MTAUWA001.ant.amazon.com (10.43.160.58) by EX13D05EUB003.ant.amazon.com (10.43.166.253) with Microsoft SMTP Server (TLS) id 15.0.1367.3; Thu, 14 Nov 2019 13:07:37 +0000 Received: from dev-dsk-wipawel-1a-0c4e6d58.eu-west-1.amazon.com (10.4.134.33) by mail-relay.amazon.com (10.43.160.118) with Microsoft SMTP Server id 15.0.1367.3 via Frontend Transport; Thu, 14 Nov 2019 13:07:34 +0000 From: Pawel Wieczorkiewicz To: Date: Thu, 14 Nov 2019 13:06:48 +0000 Message-ID: <20191114130653.51185-8-wipawel@amazon.de> X-Mailer: git-send-email 2.16.5 In-Reply-To: <20191114130653.51185-1-wipawel@amazon.de> References: <20191114130653.51185-1-wipawel@amazon.de> MIME-Version: 1.0 Precedence: Bulk Subject: [Xen-devel] [PATCH v5 07/12] livepatch: Add per-function applied/reverted state tracking marker X-BeenThere: xen-devel@lists.xenproject.org X-Mailman-Version: 2.1.23 List-Id: Xen developer discussion List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Cc: Stefano Stabellini , Julien Grall , Wei Liu , Konrad Rzeszutek Wilk , George Dunlap , Andrew Cooper , Ross Lagerwall , Ian Jackson , mpohlack@amazon.com, Pawel Wieczorkiewicz , Jan Beulich Errors-To: xen-devel-bounces@lists.xenproject.org Sender: "Xen-devel" Livepatch only tracks an entire payload applied/reverted state. But, with an option to supply the apply_payload() and/or revert_payload() functions as optional hooks, it becomes possible to intermix the execution of the original apply_payload()/revert_payload() functions with their dynamically supplied counterparts. It is important then to track the current state of every function being patched and prevent situations of unintentional double-apply or unapplied revert. To support that, it is necessary to extend public interface of the livepatch. The struct livepatch_func gets additional field holding the applied/reverted state marker. To reflect the livepatch payload ABI change, bump the version flag LIVEPATCH_PAYLOAD_VERSION up to 2. [And also update the top of the design document] Signed-off-by: Pawel Wieczorkiewicz Reviewed-by: Andra-Irina Paraschiv Reviewed-by: Bjoern Doebel Reviewed-by: Martin Pohlack Signed-off-by: Konrad Rzeszutek Wilk Acked-by: Julien Grall Reviewed-by: Ross Lagerwall --- Changed since v3: * Use common_livepatch_{apply,revert} instead of modifying arch_livepatch_{apply,revert}. * s/bool_t/bool/g Changed since v2: * Documentation fixes Changed since v1: * support the feature for all arch (add handling for Arm) * add common is_func_applied() and is_func_reverted() to be used by all arch * remove explicit enum values from enum livepatch_func_state * added corresponding documentation * added tests --- docs/misc/livepatch.pandoc | 17 ++- xen/common/livepatch.c | 39 ++++++- xen/include/public/sysctl.h | 9 +- xen/include/xen/livepatch.h | 28 +++++ xen/test/livepatch/Makefile | 27 ++++- xen/test/livepatch/xen_action_hooks.c | 2 + xen/test/livepatch/xen_action_hooks_marker.c | 112 +++++++++++++++++++ xen/test/livepatch/xen_action_hooks_noapply.c | 136 +++++++++++++++++++++++ xen/test/livepatch/xen_action_hooks_norevert.c | 143 +++++++++++++++++++++++++ 9 files changed, 507 insertions(+), 6 deletions(-) create mode 100644 xen/test/livepatch/xen_action_hooks_marker.c create mode 100644 xen/test/livepatch/xen_action_hooks_noapply.c create mode 100644 xen/test/livepatch/xen_action_hooks_norevert.c diff --git a/docs/misc/livepatch.pandoc b/docs/misc/livepatch.pandoc index 3c635add92..02348dd49e 100644 --- a/docs/misc/livepatch.pandoc +++ b/docs/misc/livepatch.pandoc @@ -1,4 +1,4 @@ -# Xen Live Patching Design v1 +# Xen Live Patching Design v2 ## Rationale @@ -297,10 +297,14 @@ which describe the functions to be patched: uint32_t old_size; uint8_t version; uint8_t opaque[31]; + /* Added to livepatch payload version 2: */ + uint8_t applied; + uint8_t _pad[7]; }; The size of the structure is 64 bytes on 64-bit hypervisors. It will be 52 on 32-bit hypervisors. +The version 2 of the payload adds additional 8 bytes to the structure size. * `name` is the symbol name of the old function. Only used if `old_addr` is zero, otherwise will be used during dynamic linking (when hypervisor loads @@ -324,9 +328,15 @@ The size of the structure is 64 bytes on 64-bit hypervisors. It will be * If the value of `new_addr` is zero then `new_size` determines how many instruction bytes to NOP (up to opaque size modulo smallest platform instruction - 1 byte x86 and 4 bytes on ARM). - * `version` is to be one. + * `version` indicates version of the generated payload. * `opaque` **MUST** be zero. +The version 2 of the payload adds the following fields to the structure: + + * `applied` tracks function's applied/reverted state. It has a boolean type + either LIVEPATCH_FUNC_NOT_APPLIED or LIVEPATCH_FUNC_APPLIED. + * `_pad[7]` adds padding to align to 8 bytes. + The size of the `livepatch_func` array is determined from the ELF section size. @@ -378,6 +388,9 @@ A simple example of what a payload file can be: uint32_t old_size; uint8_t version; uint8_t pad[31]; + /* Added to livepatch payload version 2: */ + uint8_t applied; + uint8_t _pad[7]; }; /* Our replacement function for xen_extra_version. */ diff --git a/xen/common/livepatch.c b/xen/common/livepatch.c index db066f5732..62827f96a8 100644 --- a/xen/common/livepatch.c +++ b/xen/common/livepatch.c @@ -1174,7 +1174,7 @@ static int apply_payload(struct payload *data) ASSERT(!local_irq_is_enabled()); for ( i = 0; i < data->nfuncs; i++ ) - arch_livepatch_apply(&data->funcs[i]); + common_livepatch_apply(&data->funcs[i]); arch_livepatch_revive(); @@ -1208,7 +1208,7 @@ static int revert_payload(struct payload *data) } for ( i = 0; i < data->nfuncs; i++ ) - arch_livepatch_revert(&data->funcs[i]); + common_livepatch_revert(&data->funcs[i]); /* * Since we are running with IRQs disabled and the hooks may call common @@ -1240,6 +1240,29 @@ static inline void revert_payload_tail(struct payload *data) data->state = LIVEPATCH_STATE_CHECKED; } +/* + * Check if an action has applied the same state to all payload's functions consistently. + */ +static inline bool was_action_consistent(const struct payload *data, livepatch_func_state_t expected_state) +{ + int i; + + for ( i = 0; i < data->nfuncs; i++ ) + { + struct livepatch_func *f = &(data->funcs[i]); + + if ( f->applied != expected_state ) + { + printk(XENLOG_ERR LIVEPATCH "%s: Payload has a function: '%s' with inconsistent applied state.\n", + data->name, f->name ?: "noname"); + + return false; + } + } + + return true; +} + /* * This function is executed having all other CPUs with no deep stack (we may * have cpu_idle on it) and IRQs disabled. @@ -1266,6 +1289,9 @@ static void livepatch_do_action(void) else rc = apply_payload(data); + if ( !was_action_consistent(data, rc ? LIVEPATCH_FUNC_NOT_APPLIED : LIVEPATCH_FUNC_APPLIED) ) + panic("livepatch: partially applied payload '%s'!\n", data->name); + if ( rc == 0 ) apply_payload_tail(data); break; @@ -1280,6 +1306,9 @@ static void livepatch_do_action(void) else rc = revert_payload(data); + if ( !was_action_consistent(data, rc ? LIVEPATCH_FUNC_APPLIED : LIVEPATCH_FUNC_NOT_APPLIED) ) + panic("livepatch: partially reverted payload '%s'!\n", data->name); + if ( rc == 0 ) revert_payload_tail(data); break; @@ -1301,6 +1330,9 @@ static void livepatch_do_action(void) else other->rc = revert_payload(other); + if ( !was_action_consistent(other, rc ? LIVEPATCH_FUNC_APPLIED : LIVEPATCH_FUNC_NOT_APPLIED) ) + panic("livepatch: partially reverted payload '%s'!\n", other->name); + if ( other->rc == 0 ) revert_payload_tail(other); else @@ -1321,6 +1353,9 @@ static void livepatch_do_action(void) else rc = apply_payload(data); + if ( !was_action_consistent(data, rc ? LIVEPATCH_FUNC_NOT_APPLIED : LIVEPATCH_FUNC_APPLIED) ) + panic("livepatch: partially applied payload '%s'!\n", data->name); + if ( rc == 0 ) apply_payload_tail(data); } diff --git a/xen/include/public/sysctl.h b/xen/include/public/sysctl.h index 7a0884b70b..4f52ad581f 100644 --- a/xen/include/public/sysctl.h +++ b/xen/include/public/sysctl.h @@ -832,7 +832,7 @@ struct xen_sysctl_cpu_featureset { * If zero exit with success. */ -#define LIVEPATCH_PAYLOAD_VERSION 1 +#define LIVEPATCH_PAYLOAD_VERSION 2 /* * .livepatch.funcs structure layout defined in the `Payload format` * section in the Live Patch design document. @@ -840,6 +840,11 @@ struct xen_sysctl_cpu_featureset { * We guard this with __XEN__ as toolstacks SHOULD not use it. */ #ifdef __XEN__ +typedef enum livepatch_func_state { + LIVEPATCH_FUNC_NOT_APPLIED, + LIVEPATCH_FUNC_APPLIED +} livepatch_func_state_t; + struct livepatch_func { const char *name; /* Name of function to be patched. */ void *new_addr; @@ -848,6 +853,8 @@ struct livepatch_func { uint32_t old_size; uint8_t version; /* MUST be LIVEPATCH_PAYLOAD_VERSION. */ uint8_t opaque[31]; + uint8_t applied; + uint8_t _pad[7]; }; typedef struct livepatch_func livepatch_func_t; #endif diff --git a/xen/include/xen/livepatch.h b/xen/include/xen/livepatch.h index 2aec532ee2..64d1fc2cae 100644 --- a/xen/include/xen/livepatch.h +++ b/xen/include/xen/livepatch.h @@ -122,6 +122,34 @@ void arch_livepatch_post_action(void); void arch_livepatch_mask(void); void arch_livepatch_unmask(void); + +static inline void common_livepatch_apply(struct livepatch_func *func) +{ + /* If the action has been already executed on this function, do nothing. */ + if ( func->applied == LIVEPATCH_FUNC_APPLIED ) + { + printk(XENLOG_WARNING LIVEPATCH "%s: %s has been already applied before\n", + __func__, func->name); + return; + } + + arch_livepatch_apply(func); + func->applied = LIVEPATCH_FUNC_APPLIED; +} + +static inline void common_livepatch_revert(struct livepatch_func *func) +{ + /* If the apply action hasn't been executed on this function, do nothing. */ + if ( !func->old_addr || func->applied == LIVEPATCH_FUNC_NOT_APPLIED ) + { + printk(XENLOG_WARNING LIVEPATCH "%s: %s has not been applied before\n", + __func__, func->name); + return; + } + + arch_livepatch_revert(func); + func->applied = LIVEPATCH_FUNC_NOT_APPLIED; +} #else /* diff --git a/xen/test/livepatch/Makefile b/xen/test/livepatch/Makefile index bbc6bdaf64..23113d3418 100644 --- a/xen/test/livepatch/Makefile +++ b/xen/test/livepatch/Makefile @@ -24,6 +24,9 @@ LIVEPATCH_PREPOST_HOOKS := xen_prepost_hooks.livepatch LIVEPATCH_PREPOST_HOOKS_FAIL := xen_prepost_hooks_fail.livepatch LIVEPATCH_ACTION_HOOKS := xen_action_hooks.livepatch LIVEPATCH_ACTION_HOOKS_NOFUNC := xen_action_hooks_nofunc.livepatch +LIVEPATCH_ACTION_HOOKS_MARKER:= xen_action_hooks_marker.livepatch +LIVEPATCH_ACTION_HOOKS_NOAPPLY:= xen_action_hooks_noapply.livepatch +LIVEPATCH_ACTION_HOOKS_NOREVERT:= xen_action_hooks_norevert.livepatch LIVEPATCHES += $(LIVEPATCH) LIVEPATCHES += $(LIVEPATCH_BYE) @@ -34,6 +37,9 @@ LIVEPATCHES += $(LIVEPATCH_PREPOST_HOOKS) LIVEPATCHES += $(LIVEPATCH_PREPOST_HOOKS_FAIL) LIVEPATCHES += $(LIVEPATCH_ACTION_HOOKS) LIVEPATCHES += $(LIVEPATCH_ACTION_HOOKS_NOFUNC) +LIVEPATCHES += $(LIVEPATCH_ACTION_HOOKS_MARKER) +LIVEPATCHES += $(LIVEPATCH_ACTION_HOOKS_NOAPPLY) +LIVEPATCHES += $(LIVEPATCH_ACTION_HOOKS_NOREVERT) LIVEPATCH_DEBUG_DIR ?= $(DEBUG_DIR)/xen-livepatch @@ -158,7 +164,26 @@ $(LIVEPATCH_ACTION_HOOKS): xen_action_hooks.o xen_hello_world_func.o note.o xen_ $(LIVEPATCH_ACTION_HOOKS_NOFUNC): xen_action_hooks_nofunc.o note.o xen_note.o $(LD) $(LDFLAGS) $(build_id_linker) -r -o $(LIVEPATCH_ACTION_HOOKS_NOFUNC) $^ +xen_actions_hooks_marker.o: config.h + +.PHONY: $(LIVEPATCH_ACTION_HOOKS_MARKER) +$(LIVEPATCH_ACTION_HOOKS_MARKER): xen_action_hooks_marker.o xen_hello_world_func.o note.o xen_note.o + $(LD) $(LDFLAGS) $(build_id_linker) -r -o $(LIVEPATCH_ACTION_HOOKS_MARKER) $^ + +xen_actions_hooks_noapply.o: config.h + +.PHONY: $(LIVEPATCH_ACTION_HOOKS_NOAPPLY) +$(LIVEPATCH_ACTION_HOOKS_NOAPPLY): xen_action_hooks_marker.o xen_hello_world_func.o note.o xen_note.o + $(LD) $(LDFLAGS) $(build_id_linker) -r -o $(LIVEPATCH_ACTION_HOOKS_NOAPPLY) $^ + +xen_actions_hooks_norevert.o: config.h + +.PHONY: $(LIVEPATCH_ACTION_HOOKS_NOREVERT) +$(LIVEPATCH_ACTION_HOOKS_NOREVERT): xen_action_hooks_marker.o xen_hello_world_func.o note.o xen_note.o + $(LD) $(LDFLAGS) $(build_id_linker) -r -o $(LIVEPATCH_ACTION_HOOKS_NOREVERT) $^ + .PHONY: livepatch livepatch: $(LIVEPATCH) $(LIVEPATCH_BYE) $(LIVEPATCH_REPLACE) $(LIVEPATCH_NOP) $(LIVEPATCH_NO_XEN_BUILDID) \ $(LIVEPATCH_PREPOST_HOOKS) $(LIVEPATCH_PREPOST_HOOKS_FAIL) $(LIVEPATCH_ACTION_HOOKS) \ - $(LIVEPATCH_ACTION_HOOKS_NOFUNC) + $(LIVEPATCH_ACTION_HOOKS_NOFUNC) $(LIVEPATCH_ACTION_HOOKS_MARKER) $(LIVEPATCH_ACTION_HOOKS_NOAPPLY) \ + $(LIVEPATCH_ACTION_HOOKS_NOREVERT) diff --git a/xen/test/livepatch/xen_action_hooks.c b/xen/test/livepatch/xen_action_hooks.c index a947afc41f..39b5313027 100644 --- a/xen/test/livepatch/xen_action_hooks.c +++ b/xen/test/livepatch/xen_action_hooks.c @@ -28,6 +28,7 @@ static int apply_hook(livepatch_payload_t *payload) { struct livepatch_func *func = &payload->funcs[i]; + func->applied = LIVEPATCH_FUNC_APPLIED; apply_cnt++; printk(KERN_DEBUG "%s: applying: %s\n", __func__, func->name); @@ -48,6 +49,7 @@ static int revert_hook(livepatch_payload_t *payload) { struct livepatch_func *func = &payload->funcs[i]; + func->applied = LIVEPATCH_FUNC_NOT_APPLIED; revert_cnt++; printk(KERN_DEBUG "%s: reverting: %s\n", __func__, func->name); diff --git a/xen/test/livepatch/xen_action_hooks_marker.c b/xen/test/livepatch/xen_action_hooks_marker.c new file mode 100644 index 0000000000..4f807a577f --- /dev/null +++ b/xen/test/livepatch/xen_action_hooks_marker.c @@ -0,0 +1,112 @@ +/* + * Copyright (c) 2019 Amazon.com, Inc. or its affiliates. All rights reserved. + * + */ + +#include "config.h" +#include +#include +#include +#include +#include + +#include + +static const char hello_world_patch_this_fnc[] = "xen_extra_version"; +extern const char *xen_hello_world(void); + +static int pre_apply_hook(livepatch_payload_t *payload) +{ + int i; + + printk(KERN_DEBUG "%s: Hook starting.\n", __func__); + + for (i = 0; i < payload->nfuncs; i++) + { + struct livepatch_func *func = &payload->funcs[i]; + + BUG_ON(func->applied == LIVEPATCH_FUNC_APPLIED); + printk(KERN_DEBUG "%s: pre applied: %s\n", __func__, func->name); + } + + printk(KERN_DEBUG "%s: Hook done.\n", __func__); + + return 0; +} + +static void post_apply_hook(livepatch_payload_t *payload) +{ + int i; + + printk(KERN_DEBUG "%s: Hook starting.\n", __func__); + + for (i = 0; i < payload->nfuncs; i++) + { + struct livepatch_func *func = &payload->funcs[i]; + + BUG_ON(func->applied != LIVEPATCH_FUNC_APPLIED); + printk(KERN_DEBUG "%s: post applied: %s\n", __func__, func->name); + } + + printk(KERN_DEBUG "%s: Hook done.\n", __func__); +} + +static int pre_revert_hook(livepatch_payload_t *payload) +{ + int i; + + printk(KERN_DEBUG "%s: Hook starting.\n", __func__); + + for (i = 0; i < payload->nfuncs; i++) + { + struct livepatch_func *func = &payload->funcs[i]; + + BUG_ON(func->applied != LIVEPATCH_FUNC_APPLIED); + printk(KERN_DEBUG "%s: pre reverted: %s\n", __func__, func->name); + } + + printk(KERN_DEBUG "%s: Hook done.\n", __func__); + + return 0; +} + +static void post_revert_hook(livepatch_payload_t *payload) +{ + int i; + + printk(KERN_DEBUG "%s: Hook starting.\n", __func__); + + for (i = 0; i < payload->nfuncs; i++) + { + struct livepatch_func *func = &payload->funcs[i]; + + BUG_ON(func->applied == LIVEPATCH_FUNC_APPLIED); + printk(KERN_DEBUG "%s: post reverted: %s\n", __func__, func->name); + } + + printk(KERN_DEBUG "%s: Hook done.\n", __func__); +} + +LIVEPATCH_PREAPPLY_HOOK(pre_apply_hook); +LIVEPATCH_POSTAPPLY_HOOK(post_apply_hook); +LIVEPATCH_PREREVERT_HOOK(pre_revert_hook); +LIVEPATCH_POSTREVERT_HOOK(post_revert_hook); + +struct livepatch_func __section(".livepatch.funcs") livepatch_xen_hello_world = { + .version = LIVEPATCH_PAYLOAD_VERSION, + .name = hello_world_patch_this_fnc, + .new_addr = xen_hello_world, + .old_addr = xen_extra_version, + .new_size = NEW_CODE_SZ, + .old_size = OLD_CODE_SZ, +}; + +/* + * Local variables: + * mode: C + * c-file-style: "BSD" + * c-basic-offset: 4 + * tab-width: 4 + * indent-tabs-mode: nil + * End: + */ diff --git a/xen/test/livepatch/xen_action_hooks_noapply.c b/xen/test/livepatch/xen_action_hooks_noapply.c new file mode 100644 index 0000000000..4c55c156a6 --- /dev/null +++ b/xen/test/livepatch/xen_action_hooks_noapply.c @@ -0,0 +1,136 @@ +/* + * Copyright (c) 2019 Amazon.com, Inc. or its affiliates. All rights reserved. + * + */ + +#include "config.h" +#include +#include +#include +#include +#include + +#include + +static const char hello_world_patch_this_fnc[] = "xen_extra_version"; +extern const char *xen_hello_world(void); + +static unsigned int apply_cnt; + +static int pre_apply_hook(livepatch_payload_t *payload) +{ + int i; + + printk(KERN_DEBUG "%s: Hook starting.\n", __func__); + + for (i = 0; i < payload->nfuncs; i++) + { + struct livepatch_func *func = &payload->funcs[i]; + + BUG_ON(func->applied == LIVEPATCH_FUNC_APPLIED); + printk(KERN_DEBUG "%s: pre applied: %s\n", __func__, func->name); + } + + printk(KERN_DEBUG "%s: Hook done.\n", __func__); + + return 0; +} + +static int apply_hook(livepatch_payload_t *payload) +{ + int i; + + printk(KERN_DEBUG "%s: Hook starting.\n", __func__); + + for (i = 0; i < payload->nfuncs; i++) + { + struct livepatch_func *func = &payload->funcs[i]; + + apply_cnt++; + printk(KERN_DEBUG "%s: applying: %s\n", __func__, func->name); + } + + printk(KERN_DEBUG "%s: Hook done.\n", __func__); + + return -EINVAL; /* Mark action as inconsistent */ +} + +static void post_apply_hook(livepatch_payload_t *payload) +{ + int i; + + printk(KERN_DEBUG "%s: Hook starting.\n", __func__); + + for (i = 0; i < payload->nfuncs; i++) + { + struct livepatch_func *func = &payload->funcs[i]; + + BUG_ON(apply_cnt != 1); + BUG_ON(func->applied == LIVEPATCH_FUNC_APPLIED); + printk(KERN_DEBUG "%s: post applied: %s\n", __func__, func->name); + } + + printk(KERN_DEBUG "%s: Hook done.\n", __func__); +} + +static int pre_revert_hook(livepatch_payload_t *payload) +{ + int i; + + printk(KERN_DEBUG "%s: Hook starting.\n", __func__); + + for (i = 0; i < payload->nfuncs; i++) + { + struct livepatch_func *func = &payload->funcs[i]; + + BUG_ON(func->applied == LIVEPATCH_FUNC_APPLIED); + printk(KERN_DEBUG "%s: pre reverted: %s\n", __func__, func->name); + } + + printk(KERN_DEBUG "%s: Hook done.\n", __func__); + + return 0; +} + +static void post_revert_hook(livepatch_payload_t *payload) +{ + int i; + + printk(KERN_DEBUG "%s: Hook starting.\n", __func__); + + for (i = 0; i < payload->nfuncs; i++) + { + struct livepatch_func *func = &payload->funcs[i]; + + BUG_ON(func->applied == LIVEPATCH_FUNC_APPLIED); + printk(KERN_DEBUG "%s: post reverted: %s\n", __func__, func->name); + } + + printk(KERN_DEBUG "%s: Hook done.\n", __func__); +} + +LIVEPATCH_APPLY_HOOK(apply_hook); + +LIVEPATCH_PREAPPLY_HOOK(pre_apply_hook); +LIVEPATCH_POSTAPPLY_HOOK(post_apply_hook); +LIVEPATCH_PREREVERT_HOOK(pre_revert_hook); +LIVEPATCH_POSTREVERT_HOOK(post_revert_hook); + +struct livepatch_func __section(".livepatch.funcs") livepatch_xen_hello_world = { + .version = LIVEPATCH_PAYLOAD_VERSION, + .name = hello_world_patch_this_fnc, + .new_addr = xen_hello_world, + .old_addr = xen_extra_version, + .new_size = NEW_CODE_SZ, + .old_size = OLD_CODE_SZ, +}; + +/* + * Local variables: + * mode: C + * c-file-style: "BSD" + * c-basic-offset: 4 + * tab-width: 4 + * indent-tabs-mode: nil + * End: + */ diff --git a/xen/test/livepatch/xen_action_hooks_norevert.c b/xen/test/livepatch/xen_action_hooks_norevert.c new file mode 100644 index 0000000000..ef77e72071 --- /dev/null +++ b/xen/test/livepatch/xen_action_hooks_norevert.c @@ -0,0 +1,143 @@ +/* + * Copyright (c) 2019 Amazon.com, Inc. or its affiliates. All rights reserved. + * + */ + +#include "config.h" +#include +#include +#include +#include +#include + +#include + +static const char hello_world_patch_this_fnc[] = "xen_extra_version"; +extern const char *xen_hello_world(void); + +static unsigned int revert_cnt; + +static int pre_apply_hook(livepatch_payload_t *payload) +{ + int i; + + printk(KERN_DEBUG "%s: Hook starting.\n", __func__); + + for (i = 0; i < payload->nfuncs; i++) + { + struct livepatch_func *func = &payload->funcs[i]; + + BUG_ON(func->applied == LIVEPATCH_FUNC_APPLIED); + printk(KERN_DEBUG "%s: pre applied: %s\n", __func__, func->name); + } + + printk(KERN_DEBUG "%s: Hook done.\n", __func__); + + return 0; +} + +static void post_apply_hook(livepatch_payload_t *payload) +{ + int i; + + printk(KERN_DEBUG "%s: Hook starting.\n", __func__); + + for (i = 0; i < payload->nfuncs; i++) + { + struct livepatch_func *func = &payload->funcs[i]; + + BUG_ON(func->applied != LIVEPATCH_FUNC_APPLIED); + printk(KERN_DEBUG "%s: post applied: %s\n", __func__, func->name); + } + + printk(KERN_DEBUG "%s: Hook done.\n", __func__); +} + +static int pre_revert_hook(livepatch_payload_t *payload) +{ + int i; + + printk(KERN_DEBUG "%s: Hook starting.\n", __func__); + + for (i = 0; i < payload->nfuncs; i++) + { + struct livepatch_func *func = &payload->funcs[i]; + + BUG_ON(func->applied != LIVEPATCH_FUNC_APPLIED); + printk(KERN_DEBUG "%s: pre reverted: %s\n", __func__, func->name); + } + + printk(KERN_DEBUG "%s: Hook done.\n", __func__); + + return 0; +} + +static int revert_hook(livepatch_payload_t *payload) +{ + int i; + + printk(KERN_DEBUG "%s: Hook starting.\n", __func__); + + for (i = 0; i < payload->nfuncs; i++) + { + struct livepatch_func *func = &payload->funcs[i]; + + revert_cnt++; + printk(KERN_DEBUG "%s: reverting: %s\n", __func__, func->name); + } + + printk(KERN_DEBUG "%s: Hook done.\n", __func__); + + return -EINVAL; /* Mark action as inconsistent */ +} + +static void post_revert_hook(livepatch_payload_t *payload) +{ + int i; + + printk(KERN_DEBUG "%s: Hook starting.\n", __func__); + + for (i = 0; i < payload->nfuncs; i++) + { + struct livepatch_func *func = &payload->funcs[i]; + + BUG_ON(revert_cnt != 1); + BUG_ON(func->applied != LIVEPATCH_FUNC_APPLIED); + + /* Outside of quiesce zone: MAY TRIGGER HOST CRASH/UNDEFINED BEHAVIOR */ + arch_livepatch_quiesce(); + common_livepatch_revert(payload); + arch_livepatch_revive(); + BUG_ON(func->applied == LIVEPATCH_FUNC_APPLIED); + + printk(KERN_DEBUG "%s: post reverted: %s\n", __func__, func->name); + } + + printk(KERN_DEBUG "%s: Hook done.\n", __func__); +} + +LIVEPATCH_APPLY_HOOK(revert_hook); + +LIVEPATCH_PREAPPLY_HOOK(pre_apply_hook); +LIVEPATCH_POSTAPPLY_HOOK(post_apply_hook); +LIVEPATCH_PREREVERT_HOOK(pre_revert_hook); +LIVEPATCH_POSTREVERT_HOOK(post_revert_hook); + +struct livepatch_func __section(".livepatch.funcs") livepatch_xen_hello_world = { + .version = LIVEPATCH_PAYLOAD_VERSION, + .name = hello_world_patch_this_fnc, + .new_addr = xen_hello_world, + .old_addr = xen_extra_version, + .new_size = NEW_CODE_SZ, + .old_size = OLD_CODE_SZ, +}; + +/* + * Local variables: + * mode: C + * c-file-style: "BSD" + * c-basic-offset: 4 + * tab-width: 4 + * indent-tabs-mode: nil + * End: + */ From patchwork Thu Nov 14 13:06:49 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Wieczorkiewicz, Pawel" X-Patchwork-Id: 11243707 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 77EC21393 for ; Thu, 14 Nov 2019 13:09:26 +0000 (UTC) Received: from lists.xenproject.org (lists.xenproject.org [192.237.175.120]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 482B8206DC for ; Thu, 14 Nov 2019 13:09:26 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=amazon.de header.i=@amazon.de header.b="NUMdcTNa" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 482B8206DC Authentication-Results: mail.kernel.org; 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bh=Kw9Nu5dkh1bSCTyVUqlIlRRTTctXap1tuTFD/yvMTPA=; b=NUMdcTNaNl6n2s+Ykb4wnlvFTphHSC7WirqvxJZIMzLVeiqB0HkD/gSI Dui/RPYZr6pwPGuGpbNi/2w3HB4NPHi1fFQdGBN/sXNBb2BYz+tpI/la0 NNysydMRDJVkZ6/D7NDYHxq/XXtrLbr8aWqahd8BVJxBqQ/1tgqOOyogY M=; IronPort-SDR: G7JkyWH9vLrAwNsi+VLiNL3VR9tM5/PQvNlAP1lrIRuJcyp+qCvs1Yhl1CbY6uMiffHPTT+fBP HT3X1gZBme6Q== X-IronPort-AV: E=Sophos;i="5.68,304,1569283200"; d="scan'208";a="7613168" Received: from sea32-co-svc-lb4-vlan3.sea.corp.amazon.com (HELO email-inbound-relay-1e-a70de69e.us-east-1.amazon.com) ([10.47.23.38]) by smtp-border-fw-out-33001.sea14.amazon.com with ESMTP; 14 Nov 2019 13:08:03 +0000 Received: from EX13MTAUEA001.ant.amazon.com (iad55-ws-svc-p15-lb9-vlan3.iad.amazon.com [10.40.159.166]) by email-inbound-relay-1e-a70de69e.us-east-1.amazon.com (Postfix) with ESMTPS id BFE3DA24E0; Thu, 14 Nov 2019 13:07:59 +0000 (UTC) Received: from EX13D05EUC004.ant.amazon.com (10.43.164.38) by EX13MTAUEA001.ant.amazon.com (10.43.61.82) with Microsoft SMTP Server (TLS) id 15.0.1367.3; Thu, 14 Nov 2019 13:07:43 +0000 Received: from EX13MTAUWA001.ant.amazon.com (10.43.160.58) by EX13D05EUC004.ant.amazon.com (10.43.164.38) with Microsoft SMTP Server (TLS) id 15.0.1367.3; Thu, 14 Nov 2019 13:07:42 +0000 Received: from dev-dsk-wipawel-1a-0c4e6d58.eu-west-1.amazon.com (10.4.134.33) by mail-relay.amazon.com (10.43.160.118) with Microsoft SMTP Server id 15.0.1367.3 via Frontend Transport; Thu, 14 Nov 2019 13:07:38 +0000 From: Pawel Wieczorkiewicz To: Date: Thu, 14 Nov 2019 13:06:49 +0000 Message-ID: <20191114130653.51185-9-wipawel@amazon.de> X-Mailer: git-send-email 2.16.5 In-Reply-To: <20191114130653.51185-1-wipawel@amazon.de> References: <20191114130653.51185-1-wipawel@amazon.de> MIME-Version: 1.0 Precedence: Bulk Subject: [Xen-devel] [PATCH v5 08/12] livepatch: Add support for inline asm livepatching expectations X-BeenThere: xen-devel@lists.xenproject.org X-Mailman-Version: 2.1.23 List-Id: Xen developer discussion List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Cc: Stefano Stabellini , Julien Grall , Wei Liu , Konrad Rzeszutek Wilk , George Dunlap , Andrew Cooper , Ross Lagerwall , Ian Jackson , mpohlack@amazon.com, Pawel Wieczorkiewicz , Jan Beulich Errors-To: xen-devel-bounces@lists.xenproject.org Sender: "Xen-devel" This is the initial implementation of the expectations enhancement to improve inline asm livepatching. Expectations are designed as optional feature, since the main use of them is planned for inline asm livepatching. The flag enabled allows to control the expectation state. Each expectation has data and len fields that describe the data that is expected to be found at a given patching (old_addr) location. The len must not exceed the data array size. The data array size follows the size of the opaque array, since the opaque array holds the original data and therefore must match what is specified in the expectation (if enabled). The payload structure is modified as each expectation structure is part of the livepatch_func structure and hence extends the payload. Each expectation is checked prior to the apply action (i.e. as late as possible to check against the most current state of the code). For the replace action a new payload's expectations are checked AFTER all applied payloads are successfully reverted, but BEFORE new payload is applied. That breaks the replace action's atomicity and in case of an expectation check failure would leave a system with all payloads reverted. That is obviously insecure. Use it with caution and act upon replace errors! Signed-off-by: Pawel Wieczorkiewicz Reviewed-by: Andra-Irina Paraschiv Reviewed-by: Martin Pohlack Reviewed-by: Norbert Manthey Signed-off-by: Konrad Rzeszutek Wilk Reviewed-by: Ross Lagerwall --- Changed since v3: * Fix for test's automatic expectation generation Changed since v2: * Add rsv in the field. Update the size of the structure. (Konrad) * Fix expectation test to work also on Arm Changed since v1: * added corresponding documentation * added tests --- .gitignore | 1 + docs/misc/livepatch.pandoc | 35 +++++++++++++- xen/common/livepatch.c | 74 ++++++++++++++++++++++++++++++ xen/include/public/sysctl.h | 16 ++++++- xen/test/livepatch/Makefile | 27 ++++++++++- xen/test/livepatch/xen_expectations.c | 41 +++++++++++++++++ xen/test/livepatch/xen_expectations_fail.c | 42 +++++++++++++++++ 7 files changed, 231 insertions(+), 5 deletions(-) create mode 100644 xen/test/livepatch/xen_expectations.c create mode 100644 xen/test/livepatch/xen_expectations_fail.c diff --git a/.gitignore b/.gitignore index ab765a5cdd..017856c93e 100644 --- a/.gitignore +++ b/.gitignore @@ -308,6 +308,7 @@ xen/include/xen/acm_policy.h xen/include/xen/compile.h xen/include/xen/lib/x86/cpuid-autogen.h xen/test/livepatch/config.h +xen/test/livepatch/expect_config.h xen/test/livepatch/*.livepatch xen/tools/kconfig/.tmp_gtkcheck xen/tools/kconfig/.tmp_qtcheck diff --git a/docs/misc/livepatch.pandoc b/docs/misc/livepatch.pandoc index 02348dd49e..4f9238d235 100644 --- a/docs/misc/livepatch.pandoc +++ b/docs/misc/livepatch.pandoc @@ -300,10 +300,11 @@ which describe the functions to be patched: /* Added to livepatch payload version 2: */ uint8_t applied; uint8_t _pad[7]; + livepatch_expectation_t expect; }; -The size of the structure is 64 bytes on 64-bit hypervisors. It will be -52 on 32-bit hypervisors. +The size of the structure is 104 bytes on 64-bit hypervisors. It will be +92 on 32-bit hypervisors. The version 2 of the payload adds additional 8 bytes to the structure size. * `name` is the symbol name of the old function. Only used if `old_addr` is @@ -336,6 +337,28 @@ The version 2 of the payload adds the following fields to the structure: * `applied` tracks function's applied/reverted state. It has a boolean type either LIVEPATCH_FUNC_NOT_APPLIED or LIVEPATCH_FUNC_APPLIED. * `_pad[7]` adds padding to align to 8 bytes. + * `expect` is an optional structure containing expected to-be-replaced data + (mostly for inline asm patching). The `expect` structure format is: + + struct livepatch_expectation { + uint8_t enabled : 1; + uint8_t len : 5; + uint8_t rsv: 2; + uint8_t data[LIVEPATCH_OPAQUE_SIZE]; /* Same size as opaque[] buffer of + struct livepatch_func. This is the + max number of bytes to be patched */ + }; + typedef struct livepatch_expectation livepatch_expectation_t; + + * `enabled` allows to enable the expectation check for given function. + Default state is disabled. + * `len` specifies the number of valid bytes in `data` array. 5 bits is + enough to specify values up to 32 (of bytes), which is above the array + size. + * `rsv` reserved bitfields. **MUST** be zero. + * `data` contains expected bytes of content to be replaced. Same size as + `opaque` buffer of `struct livepatch_func` (max number of bytes to be + patched). The size of the `livepatch_func` array is determined from the ELF section size. @@ -391,6 +414,7 @@ A simple example of what a payload file can be: /* Added to livepatch payload version 2: */ uint8_t applied; uint8_t _pad[7]; + livepatch_expectation_t expect; }; /* Our replacement function for xen_extra_version. */ @@ -408,6 +432,13 @@ A simple example of what a payload file can be: .old_addr = (void *)0xffff82d08013963c, /* Extracted from xen-syms. */ .new_size = 13, /* To be be computed by scripts. */ .old_size = 13, /* -----------""--------------- */ + /* Added to livepatch payload version 2: */ + .expect = { /* All fields to be filled manually */ + .enabled = 1, + .len = 5, + .rsv = 0, + .data = { 0x48, 0x8d, 0x05, 0x33, 0x1C } + }, } __attribute__((__section__(".livepatch.funcs"))); Code must be compiled with `-fPIC`. diff --git a/xen/common/livepatch.c b/xen/common/livepatch.c index 62827f96a8..1c3c446220 100644 --- a/xen/common/livepatch.c +++ b/xen/common/livepatch.c @@ -560,6 +560,61 @@ static int check_patching_sections(const struct livepatch_elf *elf) return 0; } +static inline int livepatch_verify_expectation_fn(const struct livepatch_func *func) +{ + const livepatch_expectation_t *exp = &func->expect; + + /* Ignore disabled expectations. */ + if ( !exp->enabled ) + return 0; + + /* There is nothing to expect */ + if ( !func->old_addr ) + return -EFAULT; + + if ( exp->len > sizeof(exp->data)) + return -EOVERFLOW; + + if ( exp->rsv ) + return -EINVAL; + + /* Incorrect expectation */ + if ( func->old_size < exp->len ) + return -ERANGE; + + if ( memcmp(func->old_addr, exp->data, exp->len) ) + { + printk(XENLOG_ERR LIVEPATCH "%s: expectation failed: expected:%*phN, actual:%*phN\n", + func->name, exp->len, exp->data, exp->len, func->old_addr); + return -EINVAL; + } + + return 0; +} + +static inline int livepatch_check_expectations(const struct payload *payload) +{ + int i, rc; + + printk(XENLOG_INFO LIVEPATCH "%s: Verifying enabled expectations for all functions\n", + payload->name); + + for ( i = 0; i < payload->nfuncs; i++ ) + { + const struct livepatch_func *func = &(payload->funcs[i]); + + rc = livepatch_verify_expectation_fn(func); + if ( rc ) + { + printk(XENLOG_ERR LIVEPATCH "%s: expectations of %s failed (rc=%d), aborting!\n", + payload->name, func->name ?: "unknown", rc); + return rc; + } + } + + return 0; +} + /* * Lookup specified section and when exists assign its address to a specified hook. * Perform section pointer and size validation: single hook sections must contain a @@ -1344,6 +1399,20 @@ static void livepatch_do_action(void) if ( rc == 0 ) { + /* + * Make sure all expectation requirements are met. + * Beware all the payloads are reverted at this point. + * If expectations are not met the system is left in a + * completely UNPATCHED state! + */ + rc = livepatch_check_expectations(data); + if ( rc ) + { + printk(XENLOG_ERR LIVEPATCH "%s: SYSTEM MIGHT BE INSECURE: " + "Replace action has been aborted after reverting ALL payloads!\n", data->name); + break; + } + if ( is_hook_enabled(data->hooks.apply.action) ) { printk(XENLOG_INFO LIVEPATCH "%s: Calling apply action hook function\n", data->name); @@ -1800,6 +1869,11 @@ static int livepatch_action(struct xen_sysctl_livepatch_action *action) break; } + /* Make sure all expectation requirements are met. */ + rc = livepatch_check_expectations(data); + if ( rc ) + break; + if ( is_hook_enabled(data->hooks.apply.pre) ) { printk(XENLOG_INFO LIVEPATCH "%s: Calling pre-apply hook function\n", data->name); diff --git a/xen/include/public/sysctl.h b/xen/include/public/sysctl.h index 4f52ad581f..ec6f16f0e6 100644 --- a/xen/include/public/sysctl.h +++ b/xen/include/public/sysctl.h @@ -840,6 +840,19 @@ struct xen_sysctl_cpu_featureset { * We guard this with __XEN__ as toolstacks SHOULD not use it. */ #ifdef __XEN__ +#define LIVEPATCH_OPAQUE_SIZE 31 + +struct livepatch_expectation { + uint8_t enabled : 1; + uint8_t len : 5; /* Length of data up to LIVEPATCH_OPAQUE_SIZE + (5 bits is enough for now) */ + uint8_t rsv : 2; /* Reserved. Zero value */ + uint8_t data[LIVEPATCH_OPAQUE_SIZE]; /* Same size as opaque[] buffer of + struct livepatch_func. This is the + max number of bytes to be patched */ +}; +typedef struct livepatch_expectation livepatch_expectation_t; + typedef enum livepatch_func_state { LIVEPATCH_FUNC_NOT_APPLIED, LIVEPATCH_FUNC_APPLIED @@ -852,9 +865,10 @@ struct livepatch_func { uint32_t new_size; uint32_t old_size; uint8_t version; /* MUST be LIVEPATCH_PAYLOAD_VERSION. */ - uint8_t opaque[31]; + uint8_t opaque[LIVEPATCH_OPAQUE_SIZE]; uint8_t applied; uint8_t _pad[7]; + livepatch_expectation_t expect; }; typedef struct livepatch_func livepatch_func_t; #endif diff --git a/xen/test/livepatch/Makefile b/xen/test/livepatch/Makefile index 23113d3418..cebd3eb49c 100644 --- a/xen/test/livepatch/Makefile +++ b/xen/test/livepatch/Makefile @@ -27,6 +27,8 @@ LIVEPATCH_ACTION_HOOKS_NOFUNC := xen_action_hooks_nofunc.livepatch LIVEPATCH_ACTION_HOOKS_MARKER:= xen_action_hooks_marker.livepatch LIVEPATCH_ACTION_HOOKS_NOAPPLY:= xen_action_hooks_noapply.livepatch LIVEPATCH_ACTION_HOOKS_NOREVERT:= xen_action_hooks_norevert.livepatch +LIVEPATCH_EXPECTATIONS:= xen_expectations.livepatch +LIVEPATCH_EXPECTATIONS_FAIL:= xen_expectations_fail.livepatch LIVEPATCHES += $(LIVEPATCH) LIVEPATCHES += $(LIVEPATCH_BYE) @@ -40,6 +42,8 @@ LIVEPATCHES += $(LIVEPATCH_ACTION_HOOKS_NOFUNC) LIVEPATCHES += $(LIVEPATCH_ACTION_HOOKS_MARKER) LIVEPATCHES += $(LIVEPATCH_ACTION_HOOKS_NOAPPLY) LIVEPATCHES += $(LIVEPATCH_ACTION_HOOKS_NOREVERT) +LIVEPATCHES += $(LIVEPATCH_EXPECTATIONS) +LIVEPATCHES += $(LIVEPATCH_EXPECTATIONS_FAIL) LIVEPATCH_DEBUG_DIR ?= $(DEBUG_DIR)/xen-livepatch @@ -54,7 +58,7 @@ uninstall: .PHONY: clean clean:: - rm -f *.o .*.o.d *.livepatch config.h + rm -f *.o .*.o.d *.livepatch config.h expect_config.h # # To compute these values we need the binary files: xen-syms @@ -182,8 +186,27 @@ xen_actions_hooks_norevert.o: config.h $(LIVEPATCH_ACTION_HOOKS_NOREVERT): xen_action_hooks_marker.o xen_hello_world_func.o note.o xen_note.o $(LD) $(LDFLAGS) $(build_id_linker) -r -o $(LIVEPATCH_ACTION_HOOKS_NOREVERT) $^ +EXPECT_BYTES_COUNT := 8 +CODE_GET_EXPECT=$(shell $(OBJDUMP) -d --insn-width=1 $(1) | sed -n -e '/<'$(2)'>:$$/,/^$$/ p' | tail -n +2 | head -n $(EXPECT_BYTES_COUNT) | awk '{$$0=$$2; printf "%s", substr($$0,length-1)}' | sed 's/.\{2\}/0x&,/g' | sed 's/^/{/;s/,$$/}/g') +.PHONY: expect_config.h +expect_config.h: EXPECT_BYTES=$(call CODE_GET_EXPECT,$(BASEDIR)/xen-syms,xen_extra_version) +expect_config.h: xen_expectations.o + (set -e; \ + echo "#define EXPECT_BYTES $(EXPECT_BYTES)"; \ + echo "#define EXPECT_BYTES_COUNT $(EXPECT_BYTES_COUNT)") > $@ + +xen_expectations.o: expect_config.h + +.PHONY: $(LIVEPATCH_EXPECTATIONS) +$(LIVEPATCH_EXPECTATIONS): xen_expectations.o xen_hello_world_func.o note.o xen_note.o + $(LD) $(LDFLAGS) $(build_id_linker) -r -o $(LIVEPATCH_EXPECTATIONS) $^ + +.PHONY: $(LIVEPATCH_EXPECTATIONS_FAIL) +$(LIVEPATCH_EXPECTATIONS_FAIL): xen_expectations_fail.o xen_hello_world_func.o note.o xen_note.o + $(LD) $(LDFLAGS) $(build_id_linker) -r -o $(LIVEPATCH_EXPECTATIONS_FAIL) $^ + .PHONY: livepatch livepatch: $(LIVEPATCH) $(LIVEPATCH_BYE) $(LIVEPATCH_REPLACE) $(LIVEPATCH_NOP) $(LIVEPATCH_NO_XEN_BUILDID) \ $(LIVEPATCH_PREPOST_HOOKS) $(LIVEPATCH_PREPOST_HOOKS_FAIL) $(LIVEPATCH_ACTION_HOOKS) \ $(LIVEPATCH_ACTION_HOOKS_NOFUNC) $(LIVEPATCH_ACTION_HOOKS_MARKER) $(LIVEPATCH_ACTION_HOOKS_NOAPPLY) \ - $(LIVEPATCH_ACTION_HOOKS_NOREVERT) + $(LIVEPATCH_ACTION_HOOKS_NOREVERT) $(LIVEPATCH_EXPECTATIONS) $(LIVEPATCH_EXPECTATIONS_FAIL) diff --git a/xen/test/livepatch/xen_expectations.c b/xen/test/livepatch/xen_expectations.c new file mode 100644 index 0000000000..c8175a458b --- /dev/null +++ b/xen/test/livepatch/xen_expectations.c @@ -0,0 +1,41 @@ +/* + * Copyright (c) 2019 Amazon.com, Inc. or its affiliates. All rights reserved. + * + */ + +#include "expect_config.h" +#include +#include +#include +#include +#include + +#include + +static const char livepatch_exceptions_str[] = "xen_extra_version"; +extern const char *xen_hello_world(void); + +struct livepatch_func __section(".livepatch.funcs") livepatch_exceptions = { + .version = LIVEPATCH_PAYLOAD_VERSION, + .name = livepatch_exceptions_str, + .new_addr = xen_hello_world, + .old_addr = xen_extra_version, + .new_size = EXPECT_BYTES_COUNT, + .old_size = EXPECT_BYTES_COUNT, + .expect = { + .enabled = 1, + .len = EXPECT_BYTES_COUNT, + .data = EXPECT_BYTES + }, + +}; + +/* + * Local variables: + * mode: C + * c-file-style: "BSD" + * c-basic-offset: 4 + * tab-width: 4 + * indent-tabs-mode: nil + * End: + */ diff --git a/xen/test/livepatch/xen_expectations_fail.c b/xen/test/livepatch/xen_expectations_fail.c new file mode 100644 index 0000000000..36a110286f --- /dev/null +++ b/xen/test/livepatch/xen_expectations_fail.c @@ -0,0 +1,42 @@ +/* + * Copyright (c) 2019 Amazon.com, Inc. or its affiliates. All rights reserved. + * + */ + +#include +#include +#include +#include +#include + +#include + +static const char livepatch_exceptions_str[] = "xen_extra_version"; +extern const char *xen_hello_world(void); + +#define EXPECT_BYTES_COUNT 6 + +struct livepatch_func __section(".livepatch.funcs") livepatch_exceptions = { + .version = LIVEPATCH_PAYLOAD_VERSION, + .name = livepatch_exceptions_str, + .new_addr = xen_hello_world, + .old_addr = xen_extra_version, + .new_size = EXPECT_BYTES_COUNT, + .old_size = EXPECT_BYTES_COUNT, + .expect = { + .enabled = 1, + .len = EXPECT_BYTES_COUNT, + .data = { 0xDE, 0xAD, 0xC0, 0xDE, 0xBA, 0xBE } + }, + +}; + +/* + * Local variables: + * mode: C + * c-file-style: "BSD" + * c-basic-offset: 4 + * tab-width: 4 + * indent-tabs-mode: nil + * End: + */ From patchwork Thu Nov 14 13:06:50 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Wieczorkiewicz, Pawel" X-Patchwork-Id: 11243703 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 5ABF114BC for ; 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14 Nov 2019 13:08:02 +0000 Received: from EX13MTAUEA001.ant.amazon.com (iad55-ws-svc-p15-lb9-vlan3.iad.amazon.com [10.40.159.166]) by email-inbound-relay-1a-807d4a99.us-east-1.amazon.com (Postfix) with ESMTPS id 3DDFDA21DC; Thu, 14 Nov 2019 13:08:01 +0000 (UTC) Received: from EX13D05EUB001.ant.amazon.com (10.43.166.87) by EX13MTAUEA001.ant.amazon.com (10.43.61.243) with Microsoft SMTP Server (TLS) id 15.0.1367.3; Thu, 14 Nov 2019 13:07:47 +0000 Received: from EX13MTAUWA001.ant.amazon.com (10.43.160.58) by EX13D05EUB001.ant.amazon.com (10.43.166.87) with Microsoft SMTP Server (TLS) id 15.0.1367.3; Thu, 14 Nov 2019 13:07:46 +0000 Received: from dev-dsk-wipawel-1a-0c4e6d58.eu-west-1.amazon.com (10.4.134.33) by mail-relay.amazon.com (10.43.160.118) with Microsoft SMTP Server id 15.0.1367.3 via Frontend Transport; Thu, 14 Nov 2019 13:07:43 +0000 From: Pawel Wieczorkiewicz To: Date: Thu, 14 Nov 2019 13:06:50 +0000 Message-ID: <20191114130653.51185-10-wipawel@amazon.de> X-Mailer: git-send-email 2.16.5 In-Reply-To: <20191114130653.51185-1-wipawel@amazon.de> References: <20191114130653.51185-1-wipawel@amazon.de> MIME-Version: 1.0 Precedence: Bulk Subject: [Xen-devel] [PATCH v5 09/12] livepatch: Add support for modules .modinfo section metadata X-BeenThere: xen-devel@lists.xenproject.org X-Mailman-Version: 2.1.23 List-Id: Xen developer discussion List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Cc: Pawel Wieczorkiewicz , Ross Lagerwall , mpohlack@amazon.com, Konrad Rzeszutek Wilk Errors-To: xen-devel-bounces@lists.xenproject.org Sender: "Xen-devel" Having detailed livepatch metadata helps to properly identify module's origin and version. It also allows to keep track of the history of livepatch loads in the system (at least within dmesg buffer size limits). The livepatch metadata are embedded in a form of .modinfo section. Each such section contains data of the following format: key=value\0key=value\0...key=value\0 The .modinfo section may be generated and appended to the resulting livepatch ELF file optionally as an extra step of a higher level livepatch build system. The metadata section pointer and the section length is stored in the livepatch payload structure and is used to display the content upon livepatch apply operation. Signed-off-by: Pawel Wieczorkiewicz Reviewed-by: Andra-Irina Paraschiv Reviewed-by: Bjoern Doebel Reviewed-by: Leonard Foerster Reviewed-by: Martin Pohlack Reviewed-by: Norbert Manthey Signed-off-by: Konrad Rzeszutek Wilk Reviewed-by: Ross Lagerwall --- Changed since v2: * Added .modinfo tests (Konrad) --- xen/common/livepatch.c | 34 ++++++++++++++++++++++++++++++++++ xen/include/xen/livepatch_payload.h | 6 ++++++ xen/test/livepatch/Makefile | 10 +++++++++- 3 files changed, 49 insertions(+), 1 deletion(-) diff --git a/xen/common/livepatch.c b/xen/common/livepatch.c index 1c3c446220..48abf678c0 100644 --- a/xen/common/livepatch.c +++ b/xen/common/livepatch.c @@ -853,6 +853,23 @@ static int prepare_payload(struct payload *payload, #endif } + sec = livepatch_elf_sec_by_name(elf, ".modinfo"); + if ( sec ) + { + if ( !section_ok(elf, sec, sizeof(*payload->metadata.data)) ) + return -EINVAL; + + payload->metadata.data = sec->load_addr; + payload->metadata.len = sec->sec->sh_size; + + /* The metadata is required to consists of null terminated strings. */ + if ( payload->metadata.data[payload->metadata.len - 1] != '\0' ) + { + printk(XENLOG_ERR LIVEPATCH "%s: Incorrect metadata format detected\n", payload->name); + return -EINVAL; + } + } + return 0; } @@ -1201,6 +1218,19 @@ static int livepatch_list(struct xen_sysctl_livepatch_list *list) * for XEN_SYSCTL_LIVEPATCH_ACTION operation (see livepatch_action). */ +static inline void livepatch_display_metadata(const struct livepatch_metadata *metadata) +{ + const char *str; + + if ( metadata && metadata->data && metadata->len > 0 ) + { + printk(XENLOG_INFO LIVEPATCH "module metadata:\n"); + for ( str = metadata->data; str < (metadata->data + metadata->len); str += (strlen(str) + 1) ) + printk(XENLOG_INFO LIVEPATCH " %s\n", str); + } + +} + static int apply_payload(struct payload *data) { unsigned int i; @@ -1233,6 +1263,8 @@ static int apply_payload(struct payload *data) arch_livepatch_revive(); + livepatch_display_metadata(&data->metadata); + return 0; } @@ -2011,6 +2043,8 @@ static void livepatch_printall(unsigned char key) data->name, state2str(data->state), data->state, data->text_addr, data->rw_addr, data->ro_addr, data->pages); + livepatch_display_metadata(&data->metadata); + for ( i = 0; i < data->nfuncs; i++ ) { struct livepatch_func *f = &(data->funcs[i]); diff --git a/xen/include/xen/livepatch_payload.h b/xen/include/xen/livepatch_payload.h index ff16af0dd6..9f5f064205 100644 --- a/xen/include/xen/livepatch_payload.h +++ b/xen/include/xen/livepatch_payload.h @@ -33,6 +33,11 @@ struct livepatch_hooks { } apply, revert; }; +struct livepatch_metadata { + const char *data; /* Ptr to .modinfo section with ASCII data. */ + uint32_t len; /* Length of the metadata section. */ +}; + struct payload { uint32_t state; /* One of the LIVEPATCH_STATE_*. */ int32_t rc; /* 0 or -XEN_EXX. */ @@ -63,6 +68,7 @@ struct payload { unsigned int n_load_funcs; /* Nr of the funcs to load and execute. */ unsigned int n_unload_funcs; /* Nr of funcs to call durung unload. */ char name[XEN_LIVEPATCH_NAME_SIZE]; /* Name of it. */ + struct livepatch_metadata metadata; /* Module meta data record */ }; /* diff --git a/xen/test/livepatch/Makefile b/xen/test/livepatch/Makefile index cebd3eb49c..ebb343c314 100644 --- a/xen/test/livepatch/Makefile +++ b/xen/test/livepatch/Makefile @@ -79,9 +79,17 @@ config.h: xen_hello_world_func.o xen_hello_world.o: config.h .PHONY: $(LIVEPATCH) -$(LIVEPATCH): xen_hello_world_func.o xen_hello_world.o note.o xen_note.o +$(LIVEPATCH): xen_hello_world_func.o xen_hello_world.o note.o xen_note.o modinfo.o $(LD) $(LDFLAGS) $(build_id_linker) -r -o $(LIVEPATCH) $^ +.PHONY: modinfo.o +modinfo.o: + (set -e; \ + printf "LIVEPATCH_RULEZ\0") > $@.bin + $(OBJCOPY) $(OBJCOPY_MAGIC) \ + --rename-section=.data=.modinfo,alloc,load,readonly,data,contents -S $@.bin $@ + #rm -f $@.bin + # # This target is only accessible if CONFIG_LIVEPATCH is defined, which # depends on $(build_id_linker) being available. Hence we do not From patchwork Thu Nov 14 13:06:51 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Wieczorkiewicz, Pawel" X-Patchwork-Id: 11243709 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 8401414BC for ; Thu, 14 Nov 2019 13:09:33 +0000 (UTC) Received: from lists.xenproject.org (lists.xenproject.org [192.237.175.120]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 54198206DC for ; Thu, 14 Nov 2019 13:09:33 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=amazon.de header.i=@amazon.de header.b="QJuf6FJp" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 54198206DC Authentication-Results: mail.kernel.org; dmarc=fail (p=quarantine dis=none) header.from=amazon.de Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=xen-devel-bounces@lists.xenproject.org Received: from localhost ([127.0.0.1] helo=lists.xenproject.org) by lists.xenproject.org with esmtp (Exim 4.89) (envelope-from ) id 1iVEr8-0007X5-Hi; Thu, 14 Nov 2019 13:08:14 +0000 Received: from all-amaz-eas1.inumbo.com ([34.197.232.57] helo=us1-amaz-eas2.inumbo.com) by lists.xenproject.org with esmtp (Exim 4.89) (envelope-from ) id 1iVEr7-0007WI-GC for xen-devel@lists.xenproject.org; Thu, 14 Nov 2019 13:08:13 +0000 X-Inumbo-ID: ce190c58-06df-11ea-a24b-12813bfff9fa Received: from smtp-fw-6002.amazon.com (unknown [52.95.49.90]) by us1-amaz-eas2.inumbo.com (Halon) with ESMTPS id ce190c58-06df-11ea-a24b-12813bfff9fa; Thu, 14 Nov 2019 13:08:09 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=amazon.de; i=@amazon.de; q=dns/txt; s=amazon201209; t=1573736889; x=1605272889; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version; bh=ueZYEcaxRSg/bCV70lganUCWGPqkkn8EFV3G4VYyUgA=; b=QJuf6FJpOQePtebG9Hi5GNUjFT9O+RK/qMkiLC95IOjaugjq0lKQA8aV nqDcWmLNsFIsnbwqIn8IDzlBR3ISUUGUwPSWlzQ8jfeHG+asZPyOdNBrs l3Tm3J8OO/tVhSQ6WekS791zLC3ElcjKSg4CQ/n/Oicnub0WbfaldPwE4 U=; IronPort-SDR: y3bUe/tjuo6nJTDbxDrhFgW1fivDaX9phTQIp508096/oPnGUfxHuWHwkbRJn4UbxTUrtr+Vzw cuksZuRhw3bw== Received: from iad6-co-svc-p1-lb1-vlan3.amazon.com (HELO email-inbound-relay-1d-5dd976cd.us-east-1.amazon.com) ([10.124.125.6]) by smtp-border-fw-out-6002.iad6.amazon.com with ESMTP; 14 Nov 2019 13:08:09 +0000 Received: from EX13MTAUEA001.ant.amazon.com (iad55-ws-svc-p15-lb9-vlan2.iad.amazon.com [10.40.159.162]) by email-inbound-relay-1d-5dd976cd.us-east-1.amazon.com (Postfix) with ESMTPS id 344AEA2C0E; Thu, 14 Nov 2019 13:08:05 +0000 (UTC) Received: from EX13D03EUA001.ant.amazon.com (10.43.165.33) by EX13MTAUEA001.ant.amazon.com (10.43.61.243) with Microsoft SMTP Server (TLS) id 15.0.1367.3; Thu, 14 Nov 2019 13:07:51 +0000 Received: from EX13MTAUWA001.ant.amazon.com (10.43.160.58) by EX13D03EUA001.ant.amazon.com (10.43.165.33) with Microsoft SMTP Server (TLS) id 15.0.1367.3; Thu, 14 Nov 2019 13:07:50 +0000 Received: from dev-dsk-wipawel-1a-0c4e6d58.eu-west-1.amazon.com (10.4.134.33) by mail-relay.amazon.com (10.43.160.118) with Microsoft SMTP Server id 15.0.1367.3 via Frontend Transport; Thu, 14 Nov 2019 13:07:46 +0000 From: Pawel Wieczorkiewicz To: Date: Thu, 14 Nov 2019 13:06:51 +0000 Message-ID: <20191114130653.51185-11-wipawel@amazon.de> X-Mailer: git-send-email 2.16.5 In-Reply-To: <20191114130653.51185-1-wipawel@amazon.de> References: <20191114130653.51185-1-wipawel@amazon.de> MIME-Version: 1.0 Precedence: Bulk Subject: [Xen-devel] [PATCH v5 10/12] livepatch: Handle arbitrary size names with the list operation X-BeenThere: xen-devel@lists.xenproject.org X-Mailman-Version: 2.1.23 List-Id: Xen developer discussion List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Cc: Stefano Stabellini , Julien Grall , Wei Liu , Konrad Rzeszutek Wilk , George Dunlap , Andrew Cooper , Ross Lagerwall , Ian Jackson , mpohlack@amazon.com, Pawel Wieczorkiewicz , Jan Beulich Errors-To: xen-devel-bounces@lists.xenproject.org Sender: "Xen-devel" The payloads' name strings can be of arbitrary size (typically small with an upper bound of XEN_LIVEPATCH_NAME_SIZE). Current implementation of the list operation interface allows to copy names in the XEN_LIVEPATCH_NAME_SIZE chunks regardless of its actual size and enforces space allocation requirements on userland tools. To unify and simplify the interface, handle the name strings of arbitrary size by copying them in adhering chunks to the userland. In order to let the userland allocate enough space for the incoming data add an auxiliary interface xc_livepatch_list_get_sizes() that provides the current number of payload entries and the total size of all name strings. This is achieved by extending the sysctl list interface with an extra fields: name_total_size. The xc_livepatch_list_get_sizes() issues the livepatch sysctl list operation with the nr field set to 0. In this mode the operation returns the number of payload entries and calculates the total sizes for all payloads' names. When the sysctl operation is issued with a non-zero nr field (for instance with a value obtained earlier with the prior call to the xc_livepatch_list_get_sizes()) the new field name_total_size provides the total size of actually copied data. Extend the libxc to handle the name back-to-back data transfers. The xen-livepatch tool is modified to start the list operation with a call to the xc_livepatch_list_get_sizes() to obtain the actual number of payloads as well as the necessary space for names. The tool now always requests the actual number of entries and leaves the preemption handling to the libxc routine. The libxc still returns 'done' and 'left' parameters with the same semantic allowing the tool to detect anomalies and react to them. At the moment it is expected that the tool receives the exact number of entries as requested. The xen-livepatch tool has been also modified to handle the name back-to-back transfers correctly. Signed-off-by: Pawel Wieczorkiewicz Reviewed-by: Andra-Irina Paraschiv Reviewed-by: Bjoern Doebel Reviewed-by: Martin Pohlack Signed-off-by: Konrad Rzeszutek Wilk Reviewed-by: Ross Lagerwall --- Changed since v4: * remove 'pad' field from list sysctl Changed since v3: * use uint32_t instead of uint64_t and off_t for name_total_size and related variables Changed since v1: * added corresponding documentation --- docs/misc/livepatch.pandoc | 26 +++++----- tools/libxc/include/xenctrl.h | 49 +++++++++++++------ tools/libxc/xc_misc.c | 100 ++++++++++++++++++++++++++++--------- tools/misc/xen-livepatch.c | 111 ++++++++++++++++++++++-------------------- xen/common/livepatch.c | 34 +++++++++---- xen/include/public/sysctl.h | 16 +++--- 6 files changed, 218 insertions(+), 118 deletions(-) diff --git a/docs/misc/livepatch.pandoc b/docs/misc/livepatch.pandoc index 4f9238d235..43d0896aa8 100644 --- a/docs/misc/livepatch.pandoc +++ b/docs/misc/livepatch.pandoc @@ -717,17 +717,19 @@ The caller provides: * `idx` Index iterator. The index into the hypervisor's payload count. It is recommended that on first invocation zero be used so that `nr` (which the hypervisor will update with the remaining payload count) be provided. - Also the hypervisor will provide `version` with the most current value. + Also the hypervisor will provide `version` with the most current value and + calculated total size for all payloads' names. * `nr` The max number of entries to populate. Can be zero which will result in the hypercall being a probing one and return the number of payloads (and update the `version`). - * `pad` - *MUST* be zero. * `status` Virtual address of where to write `struct xen_livepatch_status` structures. Caller *MUST* allocate up to `nr` of them. - * `name` - Virtual address of where to write the unique name of the payload. - Caller *MUST* allocate up to `nr` of them. Each *MUST* be of - **XEN_LIVEPATCH_NAME_SIZE** size. Note that **XEN_LIVEPATCH_NAME_SIZE** includes - the NUL terminator. + * `name` - Virtual address of where to write the unique name of the payloads. + Caller *MUST* allocate enough space to be able to store all received data + (i.e. total allocated space *MUST* match the `name_total_size` value + provided by the hypervisor). Individual payload name cannot be longer than + **XEN_LIVEPATCH_NAME_SIZE** bytes. Note that **XEN_LIVEPATCH_NAME_SIZE** + includes the NUL terminator. * `len` - Virtual address of where to write the length of each unique name of the payload. Caller *MUST* allocate up to `nr` of them. Each *MUST* be of sizeof(uint32_t) (4 bytes). @@ -736,7 +738,8 @@ If the hypercall returns an positive number, it is the number (upto `nr` provided to the hypercall) of the payloads returned, along with `nr` updated with the number of remaining payloads, `version` updated (it may be the same across hypercalls - if it varies the data is stale and further calls could -fail). The `status`, `name`, and `len` are updated at their designed index +fail) and the `name_total_size` containing total size of transferred data for +the array. The `status`, `name`, and `len` are updated at their designed index value (`idx`) with the returned value of data. If the hypercall returns -XEN_E2BIG the `nr` is too big and should be @@ -774,12 +777,13 @@ The structure is as follow: should be filled out. Can be zero to get amount of payloads and version. OUT: How many payloads left. */ - uint32_t pad; /* IN: Must be zero. */ + uint32_t name_total_size; /* OUT: Total size of all transfer names */ XEN_GUEST_HANDLE_64(xen_livepatch_status_t) status; /* OUT. Must have enough space allocate for nr of them. */ - XEN_GUEST_HANDLE_64(char) id; /* OUT: Array of names. Each member - MUST XEN_LIVEPATCH_NAME_SIZE in size. - Must have nr of them. */ + XEN_GUEST_HANDLE_64(char) name; /* OUT: Array of names. Each member + may have an arbitrary length up to + XEN_LIVEPATCH_NAME_SIZE bytes. Must have + nr of them. */ XEN_GUEST_HANDLE_64(uint32) len; /* OUT: Array of lengths of name's. Must have nr of them. */ }; diff --git a/tools/libxc/include/xenctrl.h b/tools/libxc/include/xenctrl.h index b06738c471..f490a6debc 100644 --- a/tools/libxc/include/xenctrl.h +++ b/tools/libxc/include/xenctrl.h @@ -2558,7 +2558,25 @@ int xc_livepatch_get(xc_interface *xch, xen_livepatch_status_t *status); /* - * The heart of this function is to get an array of xen_livepatch_status_t. + * Get a number of available payloads and get actual total size of + * the payloads' name array. + * + * This functions is typically executed first before the xc_livepatch_list() + * to obtain the sizes and correctly allocate all necessary data resources. + * + * The return value is zero if the hypercall completed successfully. + * + * If there was an error performing the sysctl operation, the return value + * will contain the hypercall error code value. + */ +int xc_livepatch_list_get_sizes(xc_interface *xch, unsigned int *nr, + uint32_t *name_total_size); + +/* + * The heart of this function is to get an array of the following objects: + * - xen_livepatch_status_t: states and return codes of payloads + * - name: names of payloads + * - len: lengths of corresponding payloads' names * * However it is complex because it has to deal with the hypervisor * returning some of the requested data or data being stale @@ -2569,21 +2587,20 @@ int xc_livepatch_get(xc_interface *xch, * 'left' are also updated with the number of entries filled out * and respectively the number of entries left to get from hypervisor. * - * It is expected that the caller of this function will take the - * 'left' and use the value for 'start'. This way we have an - * cursor in the array. Note that the 'info','name', and 'len' will - * be updated at the subsequent calls. + * It is expected that the caller of this function will first issue the + * xc_livepatch_list_get_sizes() in order to obtain total sizes of names + * as well as the current number of payload entries. + * The total sizes are required and supplied via the 'name_total_size' + * parameter. * - * The 'max' is to be provided by the caller with the maximum - * number of entries that 'info', 'name', and 'len' arrays can - * be filled up with. - * - * Each entry in the 'name' array is expected to be of XEN_LIVEPATCH_NAME_SIZE - * length. + * The 'max' is to be provided by the caller with the maximum number of + * entries that 'info', 'name', 'len' arrays can be filled up with. * * Each entry in the 'info' array is expected to be of xen_livepatch_status_t * structure size. * + * Each entry in the 'name' array may have an arbitrary size. + * * Each entry in the 'len' array is expected to be of uint32_t size. * * The return value is zero if the hypercall completed successfully. @@ -2595,10 +2612,12 @@ int xc_livepatch_get(xc_interface *xch, * will contain the number of entries that had been succesfully * retrieved (if any). */ -int xc_livepatch_list(xc_interface *xch, unsigned int max, unsigned int start, - xen_livepatch_status_t *info, char *name, - uint32_t *len, unsigned int *done, - unsigned int *left); +int xc_livepatch_list(xc_interface *xch, const unsigned int max, + const unsigned int start, + struct xen_livepatch_status *info, + char *name, uint32_t *len, + const uint32_t name_total_size, + unsigned int *done, unsigned int *left); /* * The operations are asynchronous and the hypervisor may take a while diff --git a/tools/libxc/xc_misc.c b/tools/libxc/xc_misc.c index 2dc526bda7..4f26cdb623 100644 --- a/tools/libxc/xc_misc.c +++ b/tools/libxc/xc_misc.c @@ -662,7 +662,48 @@ int xc_livepatch_get(xc_interface *xch, } /* - * The heart of this function is to get an array of xen_livepatch_status_t. + * Get a number of available payloads and get actual total size of + * the payloads' name array. + * + * This functions is typically executed first before the xc_livepatch_list() + * to obtain the sizes and correctly allocate all necessary data resources. + * + * The return value is zero if the hypercall completed successfully. + * + * If there was an error performing the sysctl operation, the return value + * will contain the hypercall error code value. + */ +int xc_livepatch_list_get_sizes(xc_interface *xch, unsigned int *nr, + uint32_t *name_total_size) +{ + DECLARE_SYSCTL; + int rc; + + if ( !nr || !name_total_size ) + { + errno = EINVAL; + return -1; + } + + memset(&sysctl, 0, sizeof(sysctl)); + sysctl.cmd = XEN_SYSCTL_livepatch_op; + sysctl.u.livepatch.cmd = XEN_SYSCTL_LIVEPATCH_LIST; + + rc = do_sysctl(xch, &sysctl); + if ( rc ) + return rc; + + *nr = sysctl.u.livepatch.u.list.nr; + *name_total_size = sysctl.u.livepatch.u.list.name_total_size; + + return 0; +} + +/* + * The heart of this function is to get an array of the following objects: + * - xen_livepatch_status_t: states and return codes of payloads + * - name: names of payloads + * - len: lengths of corresponding payloads' names * * However it is complex because it has to deal with the hypervisor * returning some of the requested data or data being stale @@ -673,21 +714,20 @@ int xc_livepatch_get(xc_interface *xch, * 'left' are also updated with the number of entries filled out * and respectively the number of entries left to get from hypervisor. * - * It is expected that the caller of this function will take the - * 'left' and use the value for 'start'. This way we have an - * cursor in the array. Note that the 'info','name', and 'len' will - * be updated at the subsequent calls. + * It is expected that the caller of this function will first issue the + * xc_livepatch_list_get_sizes() in order to obtain total sizes of names + * as well as the current number of payload entries. + * The total sizes are required and supplied via the 'name_total_size' + * parameter. * - * The 'max' is to be provided by the caller with the maximum - * number of entries that 'info', 'name', and 'len' arrays can - * be filled up with. - * - * Each entry in the 'name' array is expected to be of XEN_LIVEPATCH_NAME_SIZE - * length. + * The 'max' is to be provided by the caller with the maximum number of + * entries that 'info', 'name', 'len' arrays can be filled up with. * * Each entry in the 'info' array is expected to be of xen_livepatch_status_t * structure size. * + * Each entry in the 'name' array may have an arbitrary size. + * * Each entry in the 'len' array is expected to be of uint32_t size. * * The return value is zero if the hypercall completed successfully. @@ -699,11 +739,12 @@ int xc_livepatch_get(xc_interface *xch, * will contain the number of entries that had been succesfully * retrieved (if any). */ -int xc_livepatch_list(xc_interface *xch, unsigned int max, unsigned int start, +int xc_livepatch_list(xc_interface *xch, const unsigned int max, + const unsigned int start, struct xen_livepatch_status *info, char *name, uint32_t *len, - unsigned int *done, - unsigned int *left) + const uint32_t name_total_size, + unsigned int *done, unsigned int *left) { int rc; DECLARE_SYSCTL; @@ -714,27 +755,33 @@ int xc_livepatch_list(xc_interface *xch, unsigned int max, unsigned int start, uint32_t max_batch_sz, nr; uint32_t version = 0, retries = 0; uint32_t adjust = 0; - ssize_t sz; + uint32_t name_off = 0; + uint32_t name_sz; - if ( !max || !info || !name || !len ) + if ( !max || !info || !name || !len || !done || !left ) { errno = EINVAL; return -1; } + if ( name_total_size == 0 ) + { + errno = ENOENT; + return -1; + } + + memset(&sysctl, 0, sizeof(sysctl)); sysctl.cmd = XEN_SYSCTL_livepatch_op; sysctl.u.livepatch.cmd = XEN_SYSCTL_LIVEPATCH_LIST; - sysctl.u.livepatch.pad = 0; - sysctl.u.livepatch.u.list.version = 0; sysctl.u.livepatch.u.list.idx = start; - sysctl.u.livepatch.u.list.pad = 0; max_batch_sz = max; - /* Convience value. */ - sz = sizeof(*name) * XEN_LIVEPATCH_NAME_SIZE; + name_sz = name_total_size; *done = 0; *left = 0; do { + uint32_t _name_sz; + /* * The first time we go in this loop our 'max' may be bigger * than what the hypervisor is comfortable with - hence the first @@ -754,11 +801,11 @@ int xc_livepatch_list(xc_interface *xch, unsigned int max, unsigned int start, sysctl.u.livepatch.u.list.nr = nr; /* Fix the size (may vary between hypercalls). */ HYPERCALL_BOUNCE_SET_SIZE(info, nr * sizeof(*info)); - HYPERCALL_BOUNCE_SET_SIZE(name, nr * nr); + HYPERCALL_BOUNCE_SET_SIZE(name, name_sz); HYPERCALL_BOUNCE_SET_SIZE(len, nr * sizeof(*len)); /* Move the pointer to proper offset into 'info'. */ (HYPERCALL_BUFFER(info))->ubuf = info + *done; - (HYPERCALL_BUFFER(name))->ubuf = name + (sz * *done); + (HYPERCALL_BUFFER(name))->ubuf = name + name_off; (HYPERCALL_BUFFER(len))->ubuf = len + *done; /* Allocate memory. */ rc = xc_hypercall_bounce_pre(xch, info); @@ -827,14 +874,19 @@ int xc_livepatch_list(xc_interface *xch, unsigned int max, unsigned int start, break; } *left = sysctl.u.livepatch.u.list.nr; /* Total remaining count. */ + _name_sz = sysctl.u.livepatch.u.list.name_total_size; /* Total received name size. */ /* Copy only up 'rc' of data' - we could add 'min(rc,nr) if desired. */ HYPERCALL_BOUNCE_SET_SIZE(info, (rc * sizeof(*info))); - HYPERCALL_BOUNCE_SET_SIZE(name, (rc * sz)); + HYPERCALL_BOUNCE_SET_SIZE(name, _name_sz); HYPERCALL_BOUNCE_SET_SIZE(len, (rc * sizeof(*len))); /* Bounce the data and free the bounce buffer. */ xc_hypercall_bounce_post(xch, info); xc_hypercall_bounce_post(xch, name); xc_hypercall_bounce_post(xch, len); + + name_sz -= _name_sz; + name_off += _name_sz; + /* And update how many elements of info we have copied into. */ *done += rc; /* Update idx. */ diff --git a/tools/misc/xen-livepatch.c b/tools/misc/xen-livepatch.c index b469b253ad..c93c50040c 100644 --- a/tools/misc/xen-livepatch.c +++ b/tools/misc/xen-livepatch.c @@ -64,14 +64,13 @@ static const char *state2str(unsigned int state) return names[state]; } -/* This value was choosen adhoc. It could be 42 too. */ -#define MAX_LEN 11 static int list_func(int argc, char *argv[]) { - unsigned int idx, done, left, i; + unsigned int nr, done, left, i; xen_livepatch_status_t *info = NULL; char *name = NULL; uint32_t *len = NULL; + uint32_t name_total_size, name_off; int rc = ENOMEM; if ( argc ) @@ -79,65 +78,73 @@ static int list_func(int argc, char *argv[]) show_help(); return -1; } - idx = left = 0; - info = malloc(sizeof(*info) * MAX_LEN); - if ( !info ) - return rc; - name = malloc(sizeof(*name) * XEN_LIVEPATCH_NAME_SIZE * MAX_LEN); - if ( !name ) + done = left = 0; + + rc = xc_livepatch_list_get_sizes(xch, &nr, &name_total_size); + if ( rc ) { - free(info); + rc = errno; + fprintf(stderr, "Failed to get list sizes.\n" + "Error %d: %s\n", + rc, strerror(rc)); return rc; } - len = malloc(sizeof(*len) * MAX_LEN); - if ( !len ) { - free(name); - free(info); + + if ( nr == 0 ) + { + fprintf(stdout, "Nothing to list\n"); + return 0; + } + + info = malloc(nr * sizeof(*info)); + if ( !info ) return rc; + + name = malloc(name_total_size * sizeof(*name)); + if ( !name ) + goto error_name; + + len = malloc(nr * sizeof(*len)); + if ( !len ) + goto error_len; + + memset(info, 'A', nr * sizeof(*info)); + memset(name, 'B', name_total_size * sizeof(*name)); + memset(len, 'C', nr * sizeof(*len)); + name_off = 0; + + rc = xc_livepatch_list(xch, nr, 0, info, name, len, name_total_size, &done, &left); + if ( rc || done != nr || left > 0) + { + rc = errno; + fprintf(stderr, "Failed to list %d/%d.\n" + "Error %d: %s\n", + left, nr, rc, strerror(rc)); + goto error; } - do { - done = 0; - /* The memset is done to catch errors. */ - memset(info, 'A', sizeof(*info) * MAX_LEN); - memset(name, 'B', sizeof(*name) * MAX_LEN * XEN_LIVEPATCH_NAME_SIZE); - memset(len, 'C', sizeof(*len) * MAX_LEN); - rc = xc_livepatch_list(xch, MAX_LEN, idx, info, name, len, &done, &left); - if ( rc ) - { - rc = errno; - fprintf(stderr, "Failed to list %d/%d.\n" - "Error %d: %s\n", - idx, left, rc, strerror(rc)); - break; - } - if ( !idx ) - fprintf(stdout," ID | status\n" - "----------------------------------------+------------\n"); + fprintf(stdout," ID | status\n" + "----------------------------------------+------------\n"); - for ( i = 0; i < done; i++ ) - { - unsigned int j; - uint32_t sz; - char *str; - - sz = len[i]; - str = name + (i * XEN_LIVEPATCH_NAME_SIZE); - for ( j = sz; j < XEN_LIVEPATCH_NAME_SIZE; j++ ) - str[j] = '\0'; - - printf("%-40s| %s", str, state2str(info[i].state)); - if ( info[i].rc ) - printf(" (%d, %s)\n", -info[i].rc, strerror(-info[i].rc)); - else - puts(""); - } - idx += done; - } while ( left ); + for ( i = 0; i < done; i++ ) + { + char *name_str = name + name_off; + + printf("%-40.*s| %s", len[i], name_str, state2str(info[i].state)); + if ( info[i].rc ) + printf(" (%d, %s)\n", -info[i].rc, strerror(-info[i].rc)); + else + puts(""); + + name_off += len[i]; + } +error: + free(len); +error_len: free(name); +error_name: free(info); - free(len); return rc; } #undef MAX_LEN diff --git a/xen/common/livepatch.c b/xen/common/livepatch.c index 48abf678c0..76f5b72740 100644 --- a/xen/common/livepatch.c +++ b/xen/common/livepatch.c @@ -1159,12 +1159,8 @@ static int livepatch_list(struct xen_sysctl_livepatch_list *list) if ( list->nr > 1024 ) return -E2BIG; - if ( list->pad ) - return -EINVAL; - if ( list->nr && (!guest_handle_okay(list->status, list->nr) || - !guest_handle_okay(list->name, XEN_LIVEPATCH_NAME_SIZE * list->nr) || !guest_handle_okay(list->len, list->nr)) ) return -EINVAL; @@ -1175,23 +1171,35 @@ static int livepatch_list(struct xen_sysctl_livepatch_list *list) return -EINVAL; } + list->name_total_size = 0; if ( list->nr ) { + uint64_t name_offset = 0; + list_for_each_entry( data, &payload_list, list ) { - uint32_t len; + uint32_t name_len; if ( list->idx > i++ ) continue; status.state = data->state; status.rc = data->rc; - len = strlen(data->name) + 1; + + name_len = strlen(data->name) + 1; + list->name_total_size += name_len; + + if ( !guest_handle_subrange_okay(list->name, name_offset, + name_offset + name_len - 1) ) + { + rc = -EINVAL; + break; + } /* N.B. 'idx' != 'i'. */ - if ( __copy_to_guest_offset(list->name, idx * XEN_LIVEPATCH_NAME_SIZE, - data->name, len) || - __copy_to_guest_offset(list->len, idx, &len, 1) || + if ( __copy_to_guest_offset(list->name, name_offset, + data->name, name_len) || + __copy_to_guest_offset(list->len, idx, &name_len, 1) || __copy_to_guest_offset(list->status, idx, &status, 1) ) { rc = -EFAULT; @@ -1199,11 +1207,19 @@ static int livepatch_list(struct xen_sysctl_livepatch_list *list) } idx++; + name_offset += name_len; if ( (idx >= list->nr) || hypercall_preempt_check() ) break; } } + else + { + list_for_each_entry( data, &payload_list, list ) + { + list->name_total_size += strlen(data->name) + 1; + } + } list->nr = payload_cnt - i; /* Remaining amount. */ list->version = payload_version; spin_unlock(&payload_lock); diff --git a/xen/include/public/sysctl.h b/xen/include/public/sysctl.h index ec6f16f0e6..4bfd1475bf 100644 --- a/xen/include/public/sysctl.h +++ b/xen/include/public/sysctl.h @@ -939,10 +939,11 @@ struct xen_sysctl_livepatch_get { * * If the hypercall returns an positive number, it is the number (up to `nr`) * of the payloads returned, along with `nr` updated with the number of remaining - * payloads, `version` updated (it may be the same across hypercalls. If it - * varies the data is stale and further calls could fail). The `status`, - * `name`, and `len`' are updated at their designed index value (`idx`) with - * the returned value of data. + * payloads, `version` updated (it may be the same across hypercalls. If it varies + * the data is stale and further calls could fail) and the name_total_size + * containing total size of transferred data for the array. + * The `status`, `name`, `len` are updated at their designed index value (`idx`) + * with the returned value of data. * * If the hypercall returns E2BIG the `nr` is too big and should be * lowered. The upper limit of `nr` is left to the implemention. @@ -964,12 +965,13 @@ struct xen_sysctl_livepatch_list { should fill out. Can be zero to get amount of payloads and version. OUT: How many payloads left. */ - uint32_t pad; /* IN: Must be zero. */ + uint32_t name_total_size; /* OUT: Total size of all transfer names */ XEN_GUEST_HANDLE_64(xen_livepatch_status_t) status; /* OUT. Must have enough space allocate for nr of them. */ XEN_GUEST_HANDLE_64(char) name; /* OUT: Array of names. Each member - MUST XEN_LIVEPATCH_NAME_SIZE in size. - Must have nr of them. */ + may have an arbitrary length up to + XEN_LIVEPATCH_NAME_SIZE bytes. Must have + nr of them. */ XEN_GUEST_HANDLE_64(uint32) len; /* OUT: Array of lengths of name's. Must have nr of them. */ }; From patchwork Thu Nov 14 13:06:52 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Wieczorkiewicz, Pawel" X-Patchwork-Id: 11243715 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 4782A14ED for ; Thu, 14 Nov 2019 13:09:44 +0000 (UTC) Received: from lists.xenproject.org (lists.xenproject.org [192.237.175.120]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 0CD7E206DC for ; Thu, 14 Nov 2019 13:09:44 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=amazon.de header.i=@amazon.de header.b="FFsFTCSC" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 0CD7E206DC Authentication-Results: mail.kernel.org; dmarc=fail (p=quarantine dis=none) header.from=amazon.de Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=xen-devel-bounces@lists.xenproject.org Received: from localhost ([127.0.0.1] helo=lists.xenproject.org) by lists.xenproject.org with esmtp (Exim 4.89) (envelope-from ) id 1iVErE-0007cH-DH; Thu, 14 Nov 2019 13:08:20 +0000 Received: from all-amaz-eas1.inumbo.com ([34.197.232.57] helo=us1-amaz-eas2.inumbo.com) by lists.xenproject.org with esmtp (Exim 4.89) (envelope-from ) id 1iVErC-0007aa-Gu for xen-devel@lists.xenproject.org; Thu, 14 Nov 2019 13:08:18 +0000 X-Inumbo-ID: cfa2b6fa-06df-11ea-a24c-12813bfff9fa Received: from smtp-fw-6002.amazon.com (unknown [52.95.49.90]) by us1-amaz-eas2.inumbo.com (Halon) with ESMTPS id cfa2b6fa-06df-11ea-a24c-12813bfff9fa; Thu, 14 Nov 2019 13:08:11 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=amazon.de; i=@amazon.de; q=dns/txt; s=amazon201209; t=1573736892; x=1605272892; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version; bh=hM1NDkB9pTlCGJAiPycnc9NOLLKj7kwlO17KP0MSueM=; b=FFsFTCSC/fVKboL8LrkFCH13pUhtesr6zbZWBDwuKwjcGu7CN4uDKVx3 g21zKz2xMdvl3m5yPwZRR3k7+WehDvciYtiHIheVh6ExZQICwPaqpwD2d GlxuOULjtxXUgVbGKz7wjDRY7s8evubLCm3bV4xNSBkaO3h1oxQuPU8Ol g=; IronPort-SDR: tPsGtShfLgDZtNNLZs1P7MwqYlv6Qqh6ZVT2L5AOxqgEkf+s/VoVcwlcSyz1uATQoGR96u/+G9 Z+Ni3cpOsZ5A== Received: from iad6-co-svc-p1-lb1-vlan3.amazon.com (HELO email-inbound-relay-1d-5dd976cd.us-east-1.amazon.com) ([10.124.125.6]) by smtp-border-fw-out-6002.iad6.amazon.com with ESMTP; 14 Nov 2019 13:08:12 +0000 Received: from EX13MTAUEA001.ant.amazon.com (iad55-ws-svc-p15-lb9-vlan2.iad.amazon.com [10.40.159.162]) by email-inbound-relay-1d-5dd976cd.us-east-1.amazon.com (Postfix) with ESMTPS id BF74DA2C0F; Thu, 14 Nov 2019 13:08:08 +0000 (UTC) Received: from EX13D03EUA002.ant.amazon.com (10.43.165.166) by EX13MTAUEA001.ant.amazon.com (10.43.61.82) with Microsoft SMTP Server (TLS) id 15.0.1367.3; Thu, 14 Nov 2019 13:07:56 +0000 Received: from EX13MTAUWA001.ant.amazon.com (10.43.160.58) by EX13D03EUA002.ant.amazon.com (10.43.165.166) with Microsoft SMTP Server (TLS) id 15.0.1367.3; Thu, 14 Nov 2019 13:07:55 +0000 Received: from dev-dsk-wipawel-1a-0c4e6d58.eu-west-1.amazon.com (10.4.134.33) by mail-relay.amazon.com (10.43.160.118) with Microsoft SMTP Server id 15.0.1367.3 via Frontend Transport; Thu, 14 Nov 2019 13:07:51 +0000 From: Pawel Wieczorkiewicz To: Date: Thu, 14 Nov 2019 13:06:52 +0000 Message-ID: <20191114130653.51185-12-wipawel@amazon.de> X-Mailer: git-send-email 2.16.5 In-Reply-To: <20191114130653.51185-1-wipawel@amazon.de> References: <20191114130653.51185-1-wipawel@amazon.de> MIME-Version: 1.0 Precedence: Bulk Subject: [Xen-devel] [PATCH v5 11/12] livepatch: Add metadata runtime retrieval mechanism X-BeenThere: xen-devel@lists.xenproject.org X-Mailman-Version: 2.1.23 List-Id: Xen developer discussion List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Cc: Stefano Stabellini , Julien Grall , Wei Liu , Konrad Rzeszutek Wilk , George Dunlap , Andrew Cooper , Ross Lagerwall , Ian Jackson , mpohlack@amazon.com, Pawel Wieczorkiewicz , Jan Beulich Errors-To: xen-devel-bounces@lists.xenproject.org Sender: "Xen-devel" Extend the livepatch list operation to fetch also payloads' metadata. This is achieved by extending the sysctl list interface with 2 extra guest handles: * metadata - an array of arbitrary size strings * metadata_len - an array of metadata strings' lengths (uin32_t each) Payloads' metadata is a string of arbitrary size and does not have an upper bound limit. It may also vary in size between payloads. In order to let the userland allocate enough space for the incoming data add a metadata total size field to the list sysctl operation and fill it with total size of all payloads' metadata. Extend the libxc to handle the metadata back-to-back data transfers as well as metadata length array data transfers. The xen-livepatch userland tool is extended to always display the metadata for each received module. The metadata is received with the following format: key=value\0key=value\0...key=value\0. The format is modified to the following one: key=value;key=value;...key=value. The new format allows to easily parse the metadata for a given module by a machine. Signed-off-by: Pawel Wieczorkiewicz Reviewed-by: Andra-Irina Paraschiv Reviewed-by: Martin Pohlack Reviewed-by: Norbert Manthey Signed-off-by: Konrad Rzeszutek Wilk Reviewed-by: Ross Lagerwall --- Changed since v4: * add 'pad' field to list sysctl Changed since v3: * use uint32_t instead of uint64_t and off_t for metadata_total_size and related variables Changed since v1: * added corresponding documentation * make metadata optional (do not display it when given payload does not have it) --- docs/misc/livepatch.pandoc | 33 +++++++++++++++++----- tools/libxc/include/xenctrl.h | 22 +++++++++++---- tools/libxc/xc_misc.c | 64 +++++++++++++++++++++++++++++++++++-------- tools/misc/xen-livepatch.c | 41 +++++++++++++++++++++------ xen/common/livepatch.c | 25 +++++++++++++---- xen/include/public/sysctl.h | 20 ++++++++++---- 6 files changed, 162 insertions(+), 43 deletions(-) diff --git a/docs/misc/livepatch.pandoc b/docs/misc/livepatch.pandoc index 43d0896aa8..2f3f95ed37 100644 --- a/docs/misc/livepatch.pandoc +++ b/docs/misc/livepatch.pandoc @@ -707,8 +707,8 @@ The structure is as follow: ### XEN_SYSCTL_LIVEPATCH_LIST (2) -Retrieve an array of abbreviated status and names of payloads that are loaded in the -hypervisor. +Retrieve an array of abbreviated status, names and metadata of payloads that are +loaded in the hypervisor. The caller provides: @@ -717,11 +717,13 @@ The caller provides: * `idx` Index iterator. The index into the hypervisor's payload count. It is recommended that on first invocation zero be used so that `nr` (which the hypervisor will update with the remaining payload count) be provided. - Also the hypervisor will provide `version` with the most current value and - calculated total size for all payloads' names. + Also the hypervisor will provide `version` with the most current value, + calculated total size of all payloads' names and calculated total size of + all payload's metadata. * `nr` The max number of entries to populate. Can be zero which will result in the hypercall being a probing one and return the number of payloads (and update the `version`). + * `pad` - *MUST* be zero. * `status` Virtual address of where to write `struct xen_livepatch_status` structures. Caller *MUST* allocate up to `nr` of them. * `name` - Virtual address of where to write the unique name of the payloads. @@ -733,14 +735,23 @@ The caller provides: * `len` - Virtual address of where to write the length of each unique name of the payload. Caller *MUST* allocate up to `nr` of them. Each *MUST* be of sizeof(uint32_t) (4 bytes). + * `metadata` - Virtual address of where to write the metadata of the payloads. + Caller *MUST* allocate enough space to be able to store all received data + (i.e. total allocated space *MUST* match the `metadata_total_size` value + provided by the hypervisor). Individual payload metadata string can be of + arbitrary length. The metadata string format is: key=value\0...key=value\0. + * `metadata_len` - Virtual address of where to write the length of each metadata + string of the payload. Caller *MUST* allocate up to `nr` of them. Each *MUST* + be of sizeof(uint32_t) (4 bytes). If the hypercall returns an positive number, it is the number (upto `nr` provided to the hypercall) of the payloads returned, along with `nr` updated with the number of remaining payloads, `version` updated (it may be the same across hypercalls - if it varies the data is stale and further calls could -fail) and the `name_total_size` containing total size of transferred data for -the array. The `status`, `name`, and `len` are updated at their designed index -value (`idx`) with the returned value of data. +fail), `name_total_size` and `metadata_total_size` containing total sizes of +transferred data for both the arrays. +The `status`, `name`, `len`, `metadata` and `metadata_len` are updated at their +designed index value (`idx`) with the returned value of data. If the hypercall returns -XEN_E2BIG the `nr` is too big and should be lowered. @@ -777,7 +788,9 @@ The structure is as follow: should be filled out. Can be zero to get amount of payloads and version. OUT: How many payloads left. */ + uint32_t pad; /* IN: Must be zero. */ uint32_t name_total_size; /* OUT: Total size of all transfer names */ + uint32_t metadata_total_size; /* OUT: Total size of all transfer metadata */ XEN_GUEST_HANDLE_64(xen_livepatch_status_t) status; /* OUT. Must have enough space allocate for nr of them. */ XEN_GUEST_HANDLE_64(char) name; /* OUT: Array of names. Each member @@ -786,6 +799,12 @@ The structure is as follow: nr of them. */ XEN_GUEST_HANDLE_64(uint32) len; /* OUT: Array of lengths of name's. Must have nr of them. */ + XEN_GUEST_HANDLE_64(char) metadata; /* OUT: Array of metadata strings. Each + member may have an arbitrary length. + Must have nr of them. */ + XEN_GUEST_HANDLE_64(uint32) metadata_len; /* OUT: Array of lengths of metadata's. + Must have nr of them. */ + }; ### XEN_SYSCTL_LIVEPATCH_ACTION (3) diff --git a/tools/libxc/include/xenctrl.h b/tools/libxc/include/xenctrl.h index f490a6debc..e549702fdd 100644 --- a/tools/libxc/include/xenctrl.h +++ b/tools/libxc/include/xenctrl.h @@ -2559,7 +2559,7 @@ int xc_livepatch_get(xc_interface *xch, /* * Get a number of available payloads and get actual total size of - * the payloads' name array. + * the payloads' name and metadata arrays. * * This functions is typically executed first before the xc_livepatch_list() * to obtain the sizes and correctly allocate all necessary data resources. @@ -2570,13 +2570,16 @@ int xc_livepatch_get(xc_interface *xch, * will contain the hypercall error code value. */ int xc_livepatch_list_get_sizes(xc_interface *xch, unsigned int *nr, - uint32_t *name_total_size); + uint32_t *name_total_size, + uint32_t *metadata_total_size); /* * The heart of this function is to get an array of the following objects: * - xen_livepatch_status_t: states and return codes of payloads * - name: names of payloads * - len: lengths of corresponding payloads' names + * - metadata: payloads' metadata + * - metadata_len: lengths of corresponding payloads' metadata * * However it is complex because it has to deal with the hypervisor * returning some of the requested data or data being stale @@ -2589,12 +2592,13 @@ int xc_livepatch_list_get_sizes(xc_interface *xch, unsigned int *nr, * * It is expected that the caller of this function will first issue the * xc_livepatch_list_get_sizes() in order to obtain total sizes of names - * as well as the current number of payload entries. - * The total sizes are required and supplied via the 'name_total_size' - * parameter. + * and all metadata as well as the current number of payload entries. + * The total sizes are required and supplied via the 'name_total_size' and + * 'metadata_total_size' parameters. * * The 'max' is to be provided by the caller with the maximum number of - * entries that 'info', 'name', 'len' arrays can be filled up with. + * entries that 'info', 'name', 'len', 'metadata' and 'metadata_len' arrays + * can be filled up with. * * Each entry in the 'info' array is expected to be of xen_livepatch_status_t * structure size. @@ -2603,6 +2607,10 @@ int xc_livepatch_list_get_sizes(xc_interface *xch, unsigned int *nr, * * Each entry in the 'len' array is expected to be of uint32_t size. * + * Each entry in the 'metadata' array may have an arbitrary size. + * + * Each entry in the 'metadata_len' array is expected to be of uint32_t size. + * * The return value is zero if the hypercall completed successfully. * Note that the return value is _not_ the amount of entries filled * out - that is saved in 'done'. @@ -2617,6 +2625,8 @@ int xc_livepatch_list(xc_interface *xch, const unsigned int max, struct xen_livepatch_status *info, char *name, uint32_t *len, const uint32_t name_total_size, + char *metadata, uint32_t *metadata_len, + const uint32_t metadata_total_size, unsigned int *done, unsigned int *left); /* diff --git a/tools/libxc/xc_misc.c b/tools/libxc/xc_misc.c index 4f26cdb623..7747ea83aa 100644 --- a/tools/libxc/xc_misc.c +++ b/tools/libxc/xc_misc.c @@ -663,7 +663,7 @@ int xc_livepatch_get(xc_interface *xch, /* * Get a number of available payloads and get actual total size of - * the payloads' name array. + * the payloads' name and metadata arrays. * * This functions is typically executed first before the xc_livepatch_list() * to obtain the sizes and correctly allocate all necessary data resources. @@ -674,12 +674,13 @@ int xc_livepatch_get(xc_interface *xch, * will contain the hypercall error code value. */ int xc_livepatch_list_get_sizes(xc_interface *xch, unsigned int *nr, - uint32_t *name_total_size) + uint32_t *name_total_size, + uint32_t *metadata_total_size) { DECLARE_SYSCTL; int rc; - if ( !nr || !name_total_size ) + if ( !nr || !name_total_size || !metadata_total_size ) { errno = EINVAL; return -1; @@ -695,6 +696,7 @@ int xc_livepatch_list_get_sizes(xc_interface *xch, unsigned int *nr, *nr = sysctl.u.livepatch.u.list.nr; *name_total_size = sysctl.u.livepatch.u.list.name_total_size; + *metadata_total_size = sysctl.u.livepatch.u.list.metadata_total_size; return 0; } @@ -704,6 +706,8 @@ int xc_livepatch_list_get_sizes(xc_interface *xch, unsigned int *nr, * - xen_livepatch_status_t: states and return codes of payloads * - name: names of payloads * - len: lengths of corresponding payloads' names + * - metadata: payloads' metadata + * - metadata_len: lengths of corresponding payloads' metadata * * However it is complex because it has to deal with the hypervisor * returning some of the requested data or data being stale @@ -716,12 +720,13 @@ int xc_livepatch_list_get_sizes(xc_interface *xch, unsigned int *nr, * * It is expected that the caller of this function will first issue the * xc_livepatch_list_get_sizes() in order to obtain total sizes of names - * as well as the current number of payload entries. - * The total sizes are required and supplied via the 'name_total_size' - * parameter. + * and all metadata as well as the current number of payload entries. + * The total sizes are required and supplied via the 'name_total_size' and + * 'metadata_total_size' parameters. * * The 'max' is to be provided by the caller with the maximum number of - * entries that 'info', 'name', 'len' arrays can be filled up with. + * entries that 'info', 'name', 'len', 'metadata' and 'metadata_len' arrays + * can be filled up with. * * Each entry in the 'info' array is expected to be of xen_livepatch_status_t * structure size. @@ -730,6 +735,10 @@ int xc_livepatch_list_get_sizes(xc_interface *xch, unsigned int *nr, * * Each entry in the 'len' array is expected to be of uint32_t size. * + * Each entry in the 'metadata' array may have an arbitrary size. + * + * Each entry in the 'metadata_len' array is expected to be of uint32_t size. + * * The return value is zero if the hypercall completed successfully. * Note that the return value is _not_ the amount of entries filled * out - that is saved in 'done'. @@ -744,6 +753,8 @@ int xc_livepatch_list(xc_interface *xch, const unsigned int max, struct xen_livepatch_status *info, char *name, uint32_t *len, const uint32_t name_total_size, + char *metadata, uint32_t *metadata_len, + const uint32_t metadata_total_size, unsigned int *done, unsigned int *left) { int rc; @@ -752,13 +763,16 @@ int xc_livepatch_list(xc_interface *xch, const unsigned int max, DECLARE_HYPERCALL_BOUNCE(info, 0, XC_HYPERCALL_BUFFER_BOUNCE_OUT); DECLARE_HYPERCALL_BOUNCE(name, 0, XC_HYPERCALL_BUFFER_BOUNCE_OUT); DECLARE_HYPERCALL_BOUNCE(len, 0, XC_HYPERCALL_BUFFER_BOUNCE_OUT); + DECLARE_HYPERCALL_BOUNCE(metadata, 0, XC_HYPERCALL_BUFFER_BOUNCE_OUT); + DECLARE_HYPERCALL_BOUNCE(metadata_len, 0, XC_HYPERCALL_BUFFER_BOUNCE_OUT); uint32_t max_batch_sz, nr; uint32_t version = 0, retries = 0; uint32_t adjust = 0; - uint32_t name_off = 0; - uint32_t name_sz; + uint32_t name_off = 0, metadata_off = 0; + uint32_t name_sz, metadata_sz; - if ( !max || !info || !name || !len || !done || !left ) + if ( !max || !info || !name || !len || + !metadata || !metadata_len || !done || !left ) { errno = EINVAL; return -1; @@ -777,10 +791,11 @@ int xc_livepatch_list(xc_interface *xch, const unsigned int max, max_batch_sz = max; name_sz = name_total_size; + metadata_sz = metadata_total_size; *done = 0; *left = 0; do { - uint32_t _name_sz; + uint32_t _name_sz, _metadata_sz; /* * The first time we go in this loop our 'max' may be bigger @@ -803,10 +818,14 @@ int xc_livepatch_list(xc_interface *xch, const unsigned int max, HYPERCALL_BOUNCE_SET_SIZE(info, nr * sizeof(*info)); HYPERCALL_BOUNCE_SET_SIZE(name, name_sz); HYPERCALL_BOUNCE_SET_SIZE(len, nr * sizeof(*len)); + HYPERCALL_BOUNCE_SET_SIZE(metadata, metadata_sz); + HYPERCALL_BOUNCE_SET_SIZE(metadata_len, nr * sizeof(*metadata_len)); /* Move the pointer to proper offset into 'info'. */ (HYPERCALL_BUFFER(info))->ubuf = info + *done; (HYPERCALL_BUFFER(name))->ubuf = name + name_off; (HYPERCALL_BUFFER(len))->ubuf = len + *done; + (HYPERCALL_BUFFER(metadata))->ubuf = metadata + metadata_off; + (HYPERCALL_BUFFER(metadata_len))->ubuf = metadata_len + *done; /* Allocate memory. */ rc = xc_hypercall_bounce_pre(xch, info); if ( rc ) @@ -820,9 +839,19 @@ int xc_livepatch_list(xc_interface *xch, const unsigned int max, if ( rc ) break; + rc = xc_hypercall_bounce_pre(xch, metadata); + if ( rc ) + break; + + rc = xc_hypercall_bounce_pre(xch, metadata_len); + if ( rc ) + break; + set_xen_guest_handle(sysctl.u.livepatch.u.list.status, info); set_xen_guest_handle(sysctl.u.livepatch.u.list.name, name); set_xen_guest_handle(sysctl.u.livepatch.u.list.len, len); + set_xen_guest_handle(sysctl.u.livepatch.u.list.metadata, metadata); + set_xen_guest_handle(sysctl.u.livepatch.u.list.metadata_len, metadata_len); rc = do_sysctl(xch, &sysctl); /* @@ -839,6 +868,8 @@ int xc_livepatch_list(xc_interface *xch, const unsigned int max, xc_hypercall_bounce_post(xch, info); xc_hypercall_bounce_post(xch, name); xc_hypercall_bounce_post(xch, len); + xc_hypercall_bounce_post(xch, metadata); + xc_hypercall_bounce_post(xch, metadata_len); continue; } else if ( rc < 0 ) /* For all other errors we bail out. */ @@ -863,6 +894,8 @@ int xc_livepatch_list(xc_interface *xch, const unsigned int max, xc_hypercall_bounce_post(xch, info); xc_hypercall_bounce_post(xch, name); xc_hypercall_bounce_post(xch, len); + xc_hypercall_bounce_post(xch, metadata); + xc_hypercall_bounce_post(xch, metadata_len); continue; } @@ -875,17 +908,24 @@ int xc_livepatch_list(xc_interface *xch, const unsigned int max, } *left = sysctl.u.livepatch.u.list.nr; /* Total remaining count. */ _name_sz = sysctl.u.livepatch.u.list.name_total_size; /* Total received name size. */ + _metadata_sz = sysctl.u.livepatch.u.list.metadata_total_size; /* Total received metadata size. */ /* Copy only up 'rc' of data' - we could add 'min(rc,nr) if desired. */ HYPERCALL_BOUNCE_SET_SIZE(info, (rc * sizeof(*info))); HYPERCALL_BOUNCE_SET_SIZE(name, _name_sz); HYPERCALL_BOUNCE_SET_SIZE(len, (rc * sizeof(*len))); + HYPERCALL_BOUNCE_SET_SIZE(metadata, _metadata_sz); + HYPERCALL_BOUNCE_SET_SIZE(metadata_len, (rc * sizeof(*metadata_len))); /* Bounce the data and free the bounce buffer. */ xc_hypercall_bounce_post(xch, info); xc_hypercall_bounce_post(xch, name); xc_hypercall_bounce_post(xch, len); + xc_hypercall_bounce_post(xch, metadata); + xc_hypercall_bounce_post(xch, metadata_len); name_sz -= _name_sz; name_off += _name_sz; + metadata_sz -= _metadata_sz; + metadata_off += _metadata_sz; /* And update how many elements of info we have copied into. */ *done += rc; @@ -898,6 +938,8 @@ int xc_livepatch_list(xc_interface *xch, const unsigned int max, xc_hypercall_bounce_post(xch, len); xc_hypercall_bounce_post(xch, name); xc_hypercall_bounce_post(xch, info); + xc_hypercall_bounce_post(xch, metadata); + xc_hypercall_bounce_post(xch, metadata_len); } return rc > 0 ? 0 : rc; diff --git a/tools/misc/xen-livepatch.c b/tools/misc/xen-livepatch.c index c93c50040c..16a4a47ab7 100644 --- a/tools/misc/xen-livepatch.c +++ b/tools/misc/xen-livepatch.c @@ -69,8 +69,10 @@ static int list_func(int argc, char *argv[]) unsigned int nr, done, left, i; xen_livepatch_status_t *info = NULL; char *name = NULL; + char *metadata = NULL; uint32_t *len = NULL; - uint32_t name_total_size, name_off; + uint32_t *metadata_len = NULL; + uint32_t name_total_size, metadata_total_size, name_off, metadata_off; int rc = ENOMEM; if ( argc ) @@ -80,7 +82,7 @@ static int list_func(int argc, char *argv[]) } done = left = 0; - rc = xc_livepatch_list_get_sizes(xch, &nr, &name_total_size); + rc = xc_livepatch_list_get_sizes(xch, &nr, &name_total_size, &metadata_total_size); if ( rc ) { rc = errno; @@ -108,12 +110,23 @@ static int list_func(int argc, char *argv[]) if ( !len ) goto error_len; + metadata = malloc(metadata_total_size * sizeof(*metadata) + 1); + if ( !metadata ) + goto error_metadata; + + metadata_len = malloc(nr * sizeof(*metadata_len)); + if ( !metadata_len ) + goto error_metadata_len; + memset(info, 'A', nr * sizeof(*info)); memset(name, 'B', name_total_size * sizeof(*name)); memset(len, 'C', nr * sizeof(*len)); - name_off = 0; + memset(metadata, 'D', metadata_total_size * sizeof(*metadata) + 1); + memset(metadata_len, 'E', nr * sizeof(*metadata_len)); + name_off = metadata_off = 0; - rc = xc_livepatch_list(xch, nr, 0, info, name, len, name_total_size, &done, &left); + rc = xc_livepatch_list(xch, nr, 0, info, name, len, name_total_size, + metadata, metadata_len, metadata_total_size, &done, &left); if ( rc || done != nr || left > 0) { rc = errno; @@ -123,23 +136,35 @@ static int list_func(int argc, char *argv[]) goto error; } - fprintf(stdout," ID | status\n" - "----------------------------------------+------------\n"); + fprintf(stdout," ID | status | metadata\n" + "----------------------------------------+------------+---------------\n"); for ( i = 0; i < done; i++ ) { + unsigned int j; char *name_str = name + name_off; + char *metadata_str = metadata + metadata_off; printf("%-40.*s| %s", len[i], name_str, state2str(info[i].state)); if ( info[i].rc ) - printf(" (%d, %s)\n", -info[i].rc, strerror(-info[i].rc)); + printf(" (%d, %s) | ", -info[i].rc, strerror(-info[i].rc)); else - puts(""); + printf(" | "); + + /* Replace all '\0' with semi-colons. */ + for ( j = 0; metadata_len[i] && j < metadata_len[i] - 1; j++ ) + metadata_str[j] = (metadata_str[j] ?: ';'); + printf("%.*s\n", metadata_len[i], metadata_str); name_off += len[i]; + metadata_off += metadata_len[i]; } error: + free(metadata_len); +error_metadata_len: + free(metadata); +error_metadata: free(len); error_len: free(name); diff --git a/xen/common/livepatch.c b/xen/common/livepatch.c index 76f5b72740..e21533bf2c 100644 --- a/xen/common/livepatch.c +++ b/xen/common/livepatch.c @@ -1159,9 +1159,13 @@ static int livepatch_list(struct xen_sysctl_livepatch_list *list) if ( list->nr > 1024 ) return -E2BIG; + if ( list->pad ) + return -EINVAL; + if ( list->nr && (!guest_handle_okay(list->status, list->nr) || - !guest_handle_okay(list->len, list->nr)) ) + !guest_handle_okay(list->len, list->nr) || + !guest_handle_okay(list->metadata_len, list->nr)) ) return -EINVAL; spin_lock(&payload_lock); @@ -1172,13 +1176,14 @@ static int livepatch_list(struct xen_sysctl_livepatch_list *list) } list->name_total_size = 0; + list->metadata_total_size = 0; if ( list->nr ) { - uint64_t name_offset = 0; + uint64_t name_offset = 0, metadata_offset = 0; list_for_each_entry( data, &payload_list, list ) { - uint32_t name_len; + uint32_t name_len, metadata_len; if ( list->idx > i++ ) continue; @@ -1189,8 +1194,13 @@ static int livepatch_list(struct xen_sysctl_livepatch_list *list) name_len = strlen(data->name) + 1; list->name_total_size += name_len; + metadata_len = data->metadata.len; + list->metadata_total_size += metadata_len; + if ( !guest_handle_subrange_okay(list->name, name_offset, - name_offset + name_len - 1) ) + name_offset + name_len - 1) || + !guest_handle_subrange_okay(list->metadata, metadata_offset, + metadata_offset + metadata_len - 1) ) { rc = -EINVAL; break; @@ -1200,7 +1210,10 @@ static int livepatch_list(struct xen_sysctl_livepatch_list *list) if ( __copy_to_guest_offset(list->name, name_offset, data->name, name_len) || __copy_to_guest_offset(list->len, idx, &name_len, 1) || - __copy_to_guest_offset(list->status, idx, &status, 1) ) + __copy_to_guest_offset(list->status, idx, &status, 1) || + __copy_to_guest_offset(list->metadata, metadata_offset, + data->metadata.data, metadata_len) || + __copy_to_guest_offset(list->metadata_len, idx, &metadata_len, 1) ) { rc = -EFAULT; break; @@ -1208,6 +1221,7 @@ static int livepatch_list(struct xen_sysctl_livepatch_list *list) idx++; name_offset += name_len; + metadata_offset += metadata_len; if ( (idx >= list->nr) || hypercall_preempt_check() ) break; @@ -1218,6 +1232,7 @@ static int livepatch_list(struct xen_sysctl_livepatch_list *list) list_for_each_entry( data, &payload_list, list ) { list->name_total_size += strlen(data->name) + 1; + list->metadata_total_size += data->metadata.len; } } list->nr = payload_cnt - i; /* Remaining amount. */ diff --git a/xen/include/public/sysctl.h b/xen/include/public/sysctl.h index 4bfd1475bf..7e43bfe1bd 100644 --- a/xen/include/public/sysctl.h +++ b/xen/include/public/sysctl.h @@ -934,16 +934,17 @@ struct xen_sysctl_livepatch_get { }; /* - * Retrieve an array of abbreviated status and names of payloads that are - * loaded in the hypervisor. + * Retrieve an array of abbreviated status, names and metadata of payloads that + * are loaded in the hypervisor. * * If the hypercall returns an positive number, it is the number (up to `nr`) * of the payloads returned, along with `nr` updated with the number of remaining * payloads, `version` updated (it may be the same across hypercalls. If it varies - * the data is stale and further calls could fail) and the name_total_size - * containing total size of transferred data for the array. - * The `status`, `name`, `len` are updated at their designed index value (`idx`) - * with the returned value of data. + * the data is stale and further calls could fail), `name_total_size` and + * `metadata_total_size` containing total sizes of transferred data for both the + * arrays. + * The `status`, `name`, `len`, `metadata` and `metadata_len` are updated at their + * designed index value (`idx`) with the returned value of data. * * If the hypercall returns E2BIG the `nr` is too big and should be * lowered. The upper limit of `nr` is left to the implemention. @@ -965,7 +966,9 @@ struct xen_sysctl_livepatch_list { should fill out. Can be zero to get amount of payloads and version. OUT: How many payloads left. */ + uint32_t pad; /* IN: Must be zero. */ uint32_t name_total_size; /* OUT: Total size of all transfer names */ + uint32_t metadata_total_size; /* OUT: Total size of all transfer metadata */ XEN_GUEST_HANDLE_64(xen_livepatch_status_t) status; /* OUT. Must have enough space allocate for nr of them. */ XEN_GUEST_HANDLE_64(char) name; /* OUT: Array of names. Each member @@ -974,6 +977,11 @@ struct xen_sysctl_livepatch_list { nr of them. */ XEN_GUEST_HANDLE_64(uint32) len; /* OUT: Array of lengths of name's. Must have nr of them. */ + XEN_GUEST_HANDLE_64(char) metadata; /* OUT: Array of metadata strings. Each + member may have an arbitrary length. + Must have nr of them. */ + XEN_GUEST_HANDLE_64(uint32) metadata_len; /* OUT: Array of lengths of metadata's. + Must have nr of them. */ }; /* From patchwork Thu Nov 14 13:06:53 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: "Wieczorkiewicz, Pawel" X-Patchwork-Id: 11243711 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 3F53014BC for ; Thu, 14 Nov 2019 13:09:41 +0000 (UTC) Received: from lists.xenproject.org (lists.xenproject.org [192.237.175.120]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 1051D206DC for ; Thu, 14 Nov 2019 13:09:41 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=amazon.de header.i=@amazon.de header.b="r1xzZGNR" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 1051D206DC Authentication-Results: mail.kernel.org; dmarc=fail (p=quarantine dis=none) header.from=amazon.de Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=xen-devel-bounces@lists.xenproject.org Received: from localhost ([127.0.0.1] helo=lists.xenproject.org) by lists.xenproject.org with esmtp (Exim 4.89) (envelope-from ) id 1iVErI-0007gV-W7; Thu, 14 Nov 2019 13:08:25 +0000 Received: from all-amaz-eas1.inumbo.com ([34.197.232.57] helo=us1-amaz-eas2.inumbo.com) by lists.xenproject.org with esmtp (Exim 4.89) (envelope-from ) id 1iVErH-0007fL-GO for xen-devel@lists.xenproject.org; Thu, 14 Nov 2019 13:08:23 +0000 X-Inumbo-ID: cfa7aa49-06df-11ea-a24c-12813bfff9fa Received: from smtp-fw-9102.amazon.com (unknown [207.171.184.29]) by us1-amaz-eas2.inumbo.com (Halon) with ESMTPS id cfa7aa49-06df-11ea-a24c-12813bfff9fa; Thu, 14 Nov 2019 13:08:12 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=amazon.de; i=@amazon.de; q=dns/txt; s=amazon201209; t=1573736893; x=1605272893; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=S5wJZkZNgEvgR4OD1RjH57qgoUjEHOe2x5Y16wwBsd0=; b=r1xzZGNRc/Vqf1qoXuKDYif1NXeGFZLlNNhXn0BcCeqIe6G2AFsJ9Q2I gpEhwxkYgd7RGgBxH6GonslVBbANLFQGOpMNKu2bSCzmiKmqTzYH6u+pM S0KTgZ7WkMgnXRfsXIh/3fDVBmQBcC+AJXoltpS3BkjS6JJ+R9qG0r3iM c=; IronPort-SDR: uM2wHZxNmBYXZiwOQtvGwh4BHsMoxOHe1FDmWY5x0SntbisQry6x5rCT/+Tqkk1ldQlcqixqVu qcnuTNUZrsFA== X-IronPort-AV: E=Sophos;i="5.68,304,1569283200"; d="scan'208";a="7280397" Received: from sea32-co-svc-lb4-vlan3.sea.corp.amazon.com (HELO email-inbound-relay-1a-807d4a99.us-east-1.amazon.com) ([10.47.23.38]) by smtp-border-fw-out-9102.sea19.amazon.com with ESMTP; 14 Nov 2019 13:08:11 +0000 Received: from EX13MTAUEA001.ant.amazon.com (iad55-ws-svc-p15-lb9-vlan3.iad.amazon.com [10.40.159.166]) by email-inbound-relay-1a-807d4a99.us-east-1.amazon.com (Postfix) with ESMTPS id 4A110A2B28; Thu, 14 Nov 2019 13:08:09 +0000 (UTC) Received: from EX13D03EUA002.ant.amazon.com (10.43.165.166) by EX13MTAUEA001.ant.amazon.com (10.43.61.82) with Microsoft SMTP Server (TLS) id 15.0.1367.3; Thu, 14 Nov 2019 13:07:59 +0000 Received: from EX13MTAUWA001.ant.amazon.com (10.43.160.58) by EX13D03EUA002.ant.amazon.com (10.43.165.166) with Microsoft SMTP Server (TLS) id 15.0.1367.3; Thu, 14 Nov 2019 13:07:58 +0000 Received: from dev-dsk-wipawel-1a-0c4e6d58.eu-west-1.amazon.com (10.4.134.33) by mail-relay.amazon.com (10.43.160.118) with Microsoft SMTP Server id 15.0.1367.3 via Frontend Transport; Thu, 14 Nov 2019 13:07:56 +0000 From: Pawel Wieczorkiewicz To: Date: Thu, 14 Nov 2019 13:06:53 +0000 Message-ID: <20191114130653.51185-13-wipawel@amazon.de> X-Mailer: git-send-email 2.16.5 In-Reply-To: <20191114130653.51185-1-wipawel@amazon.de> References: <20191114130653.51185-1-wipawel@amazon.de> MIME-Version: 1.0 Precedence: Bulk Subject: [Xen-devel] [PATCH v5 12/12] livepatch: Add python bindings for livepatch operations X-BeenThere: xen-devel@lists.xenproject.org X-Mailman-Version: 2.1.23 List-Id: Xen developer discussion List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Cc: Pawel Wieczorkiewicz , Ian Jackson , mpohlack@amazon.com, Wei Liu , =?utf-8?q?Marek_Marczykowski-G=C3=B3recki?= Errors-To: xen-devel-bounces@lists.xenproject.org Sender: "Xen-devel" Extend the XC python bindings library to support also all common livepatch operations and actions. Add the python bindings for the following operations: - status (pyxc_livepatch_status): Requires a payload name as an input. Returns a status dict containing a state string and a return code integer. - action (pyxc_livepatch_action): Requires a payload name and an action id as an input. Timeout and flags are optional parameters. Returns None or throws an exception. - upload (pyxc_livepatch_upload): Requires a payload name and a module's filename as an input. Returns None or throws an exception. - list (pyxc_livepatch_list): Takes no parameters. Returns a list of dicts containing each payload's: * name as a string * state as a string * return code as an integer * list of metadata key=value strings Each functions throws an exception error based on the errno value received from its corresponding libxc function call. Signed-off-by: Pawel Wieczorkiewicz Reviewed-by: Martin Mazein Reviewed-by: Andra-Irina Paraschiv Reviewed-by: Leonard Foerster Reviewed-by: Norbert Manthey Acked-by: Marek Marczykowski-Górecki Reviewed-by: Ross Lagerwall --- Changed since v4: * changed flags field type from uint64_t to uint32_t * fixed leaking fd in pyxc_livepatch_upload() Changed since v3: * return None instead of integer 0 from pyxc_livepatch_action() and pyxc_livepatch_upload() * use fstat() instead of stat() * simplify error condition handling code for pyxc_livepatch_upload and also save and restore errno value * check done and left values to handle errors in pyxc_livepatch_list() * use PyList_SET_ITEM() to avoid the need for PyDECREF Changed since v1: * changed PyList_Append() with PyList_SetItem() as requested by Marek --- tools/python/xen/lowlevel/xc/xc.c | 268 ++++++++++++++++++++++++++++++++++++++ 1 file changed, 268 insertions(+) diff --git a/tools/python/xen/lowlevel/xc/xc.c b/tools/python/xen/lowlevel/xc/xc.c index 44d3606141..9a1d3b6b92 100644 --- a/tools/python/xen/lowlevel/xc/xc.c +++ b/tools/python/xen/lowlevel/xc/xc.c @@ -1979,6 +1979,225 @@ static PyObject *pyflask_access(PyObject *self, PyObject *args, return Py_BuildValue("i",ret); } +static PyObject *pyxc_livepatch_status(XcObject *self, + PyObject *args, + PyObject *kwds) +{ + xen_livepatch_status_t status; + PyObject *info_dict = NULL; + char *name; + int rc; + + static char *kwd_list[] = { "name", NULL }; + + if ( !PyArg_ParseTupleAndKeywords(args, kwds, "s", kwd_list, &name) ) + goto error; + + rc = xc_livepatch_get(self->xc_handle, name, &status); + if ( rc ) + goto error; + + info_dict = Py_BuildValue( + "{s:i,s:i}", + "state", status.state, + "rc", status.rc); + +error: + return info_dict ?: pyxc_error_to_exception(self->xc_handle); +} + +static PyObject *pyxc_livepatch_action(XcObject *self, + PyObject *args, + PyObject *kwds) +{ + int (*action_func)(xc_interface *xch, char *name, uint32_t timeout, uint32_t flags); + char *name; + unsigned int action; + uint32_t timeout; + uint32_t flags; + int rc = -1; + + static char *kwd_list[] = { "name", "action", "timeout", "flags", NULL }; + + if ( !PyArg_ParseTupleAndKeywords(args, kwds, "sI|Ik", kwd_list, + &name, &action, &timeout, &flags) ) + goto error; + + switch (action) + { + case LIVEPATCH_ACTION_UNLOAD: + action_func = xc_livepatch_unload; + break; + case LIVEPATCH_ACTION_REVERT: + action_func = xc_livepatch_revert; + break; + case LIVEPATCH_ACTION_APPLY: + action_func = xc_livepatch_apply; + break; + case LIVEPATCH_ACTION_REPLACE: + action_func = xc_livepatch_replace; + break; + default: + goto error; + } + + rc = action_func(self->xc_handle, name, timeout, flags); + +error: + return rc ? pyxc_error_to_exception(self->xc_handle) : Py_None; +} + +static PyObject *pyxc_livepatch_upload(XcObject *self, + PyObject *args, + PyObject *kwds) +{ + unsigned char *fbuf = MAP_FAILED; + char *name, *filename; + struct stat buf; + int fd = 0, rc = -1, saved_errno; + ssize_t len; + + static char *kwd_list[] = { "name", "filename", NULL }; + + if ( !PyArg_ParseTupleAndKeywords(args, kwds, "ss", kwd_list, + &name, &filename)) + goto error; + + fd = open(filename, O_RDONLY); + if ( fd < 0 ) + goto error; + + if ( fstat(fd, &buf) != 0 ) + goto error_fd; + + len = buf.st_size; + fbuf = mmap(0, len, PROT_READ, MAP_PRIVATE, fd, 0); + if ( fbuf == MAP_FAILED ) + goto error_fd; + + rc = xc_livepatch_upload(self->xc_handle, name, fbuf, len); + + saved_errno = errno; + munmap(fbuf, len); + errno = saved_errno; + +error_fd: + close(fd); +error: + return rc ? pyxc_error_to_exception(self->xc_handle) : Py_None; +} + +static PyObject *pyxc_livepatch_list(XcObject *self) +{ + PyObject *list = Py_None; + unsigned int nr, done, left, i; + xen_livepatch_status_t *info = NULL; + char *name = NULL; + char *metadata = NULL; + uint32_t *len = NULL; + uint32_t *metadata_len = NULL; + uint32_t name_total_size, metadata_total_size; + uint32_t name_off, metadata_off; + int rc; + + done = left = 0; + rc = xc_livepatch_list_get_sizes(self->xc_handle, &nr, + &name_total_size, &metadata_total_size); + if ( rc ) + goto error; + + if ( nr == 0 ) + return PyList_New(0); + + rc = ENOMEM; + info = malloc(nr * sizeof(*info)); + if ( !info ) + goto error; + + name = malloc(name_total_size * sizeof(*name)); + if ( !name ) + goto error; + + len = malloc(nr * sizeof(*len)); + if ( !len ) + goto error; + + metadata = malloc(metadata_total_size * sizeof(*metadata)); + if ( !metadata ) + goto error; + + metadata_len = malloc(nr * sizeof(*metadata_len)); + if ( !metadata_len ) + goto error; + + rc = xc_livepatch_list(self->xc_handle, nr, 0, info, + name, len, name_total_size, + metadata, metadata_len, metadata_total_size, + &done, &left); + if ( rc ) + goto error; + + if ( done != nr || left > 0 ) + { + rc = EFAULT; + goto error; + } + + list = PyList_New(done); + name_off = metadata_off = 0; + for ( i = 0; i < done; i++ ) + { + PyObject *info_dict, *metadata_list; + char *name_str, *metadata_str; + + name_str = name + name_off; + metadata_str = metadata + metadata_off; + + metadata_list = PyList_New(0); + for ( char *s = metadata_str; s < metadata_str + metadata_len[i]; s += strlen(s) + 1 ) + { + PyObject *field = Py_BuildValue("s", s); + if ( field == NULL ) + { + Py_DECREF(list); + Py_DECREF(metadata_list); + rc = EFAULT; + goto error; + } + + PyList_Append(metadata_list, field); + Py_DECREF(field); + } + + info_dict = Py_BuildValue( + "{s:s,s:i,s:i,s:N}", + "name", name_str, + "state", info[i].state, + "rc", info[i].rc, + "metadata", metadata_list); + + if ( info_dict == NULL ) + { + Py_DECREF(list); + Py_DECREF(metadata_list); + rc = EFAULT; + goto error; + } + PyList_SET_ITEM(list, i, info_dict); + + name_off += len[i]; + metadata_off += metadata_len[i]; + } + +error: + free(info); + free(name); + free(len); + free(metadata); + free(metadata_len); + return rc ? pyxc_error_to_exception(self->xc_handle) : list; +} + static PyMethodDef pyxc_methods[] = { { "domain_create", (PyCFunction)pyxc_domain_create, @@ -2542,6 +2761,44 @@ static PyMethodDef pyxc_methods[] = { "Returns: [int]: 0 on all permission granted; -1 if any permissions are \ denied\n" }, + { "livepatch_status", + (PyCFunction)pyxc_livepatch_status, + METH_KEYWORDS, "\n" + "Gets current state and return code for a specified module.\n" + " name [str]: Module name to be used\n" + "Returns: [dict] on success; throwing an exception on error\n" + " state [int]: Module current state: CHECKED or APPLIED\n" + " rc [int]: Return code of last module's operation\n" }, + + { "livepatch_upload", + (PyCFunction)pyxc_livepatch_upload, + METH_KEYWORDS, "\n" + "Uploads a module with specified name from filename.\n" + " name [str]: Module name to be used\n" + " filename [str]: Filename of a module to be uploaded\n" + "Returns: None on success; throwing an exception on error\n" }, + + { "livepatch_action", + (PyCFunction)pyxc_livepatch_action, + METH_KEYWORDS, "\n" + "Performs an action (unload, revert, apply or replace) on a specified \ + module.\n" + " name [str]: Module name to be used\n" + " action [uint]: Action enum id\n" + " timeout [uint]: Action scheduled execution timeout\n" + " flags [ulong]: Flags specifying action's extra parameters\n" + "Returns: None on success; throwing an exception on error\n" }, + + { "livepatch_list", + (PyCFunction)pyxc_livepatch_list, + METH_NOARGS, "\n" + "List all uploaded livepatch modules with their current state and metadata.\n" + "Returns: [list of dicts] on success; throwing an exception on error\n" + " name [str]: Module name\n" + " state [int]: Module current state: CHECKED or APPLIED\n" + " rc [int]: Return code of last module's operation\n" + " metadata [list]: List of module's metadata 'key=value' strings\n" }, + { NULL, NULL, 0, NULL } }; @@ -2653,6 +2910,17 @@ PyMODINIT_FUNC initxc(void) PyModule_AddIntConstant(m, "XEN_SCHEDULER_CREDIT", XEN_SCHEDULER_CREDIT); PyModule_AddIntConstant(m, "XEN_SCHEDULER_CREDIT2", XEN_SCHEDULER_CREDIT2); + /* Expose livepatch constants to Python */ + PyModule_AddIntConstant(m, "LIVEPATCH_ACTION_UNLOAD", LIVEPATCH_ACTION_UNLOAD); + PyModule_AddIntConstant(m, "LIVEPATCH_ACTION_REVERT", LIVEPATCH_ACTION_REVERT); + PyModule_AddIntConstant(m, "LIVEPATCH_ACTION_APPLY", LIVEPATCH_ACTION_APPLY); + PyModule_AddIntConstant(m, "LIVEPATCH_ACTION_REPLACE", LIVEPATCH_ACTION_REPLACE); + + PyModule_AddIntConstant(m, "LIVEPATCH_ACTION_APPLY_NODEPS", LIVEPATCH_ACTION_APPLY_NODEPS); + + PyModule_AddIntConstant(m, "LIVEPATCH_STATE_APPLIED", LIVEPATCH_STATE_APPLIED); + PyModule_AddIntConstant(m, "LIVEPATCH_STATE_CHECKED", LIVEPATCH_STATE_CHECKED); + #if PY_MAJOR_VERSION >= 3 return m; #endif