From patchwork Thu Jan 24 16:32:54 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: James Morse X-Patchwork-Id: 10779491 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 1A14E13B5 for ; Thu, 24 Jan 2019 16:33:38 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 0686931AEC for ; Thu, 24 Jan 2019 16:33:38 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 03C7431B2C; Thu, 24 Jan 2019 16:33:38 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-5.2 required=2.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,MAILING_LIST_MULTI,RCVD_IN_DNSWL_MED autolearn=ham version=3.3.1 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id BA7F331B23 for ; Thu, 24 Jan 2019 16:33:36 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender: Content-Transfer-Encoding:Content-Type:Cc:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To: Message-Id:Date:Subject:To:From:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=Kr+UqQ/7kfPWMdzfNUtHey0xOjCbXO0KuHwEpzOCnPM=; b=AM6pQeilz54ohW TULiHalyOLorQ89EUvbe48j3FUZ8teGReLGN1VhQ5uu5lQdIHV6hJ4hSDKqa/vaCt8oyki60yjVwC Hd0aOhyPiwgRsn1khcynSL1p1xMr9nZjsP7krLatF3qrpaXQURRgc5DJdham+BL9FEzc0xo2vnmso 3EijSZmFM52/4Bn7S0esH42gbRBb1MT2pectPjpuTtBWoQ2sp2tSnWo6QrnZPls0Otojxis9bRum/ /IDzzBCBB2IhOWPTJOnRiQMWryVLdbCM20Tkgbm1j6iJ1j1EzirpKMcUK323Es5M9v0logDrPf2zE HqDolWK3P7anEwHiXwiQ==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.90_1 #2 (Red Hat Linux)) id 1gmhwb-0006DD-Ns; Thu, 24 Jan 2019 16:33:33 +0000 Received: from foss.arm.com ([217.140.101.70]) by bombadil.infradead.org with esmtp (Exim 4.90_1 #2 (Red Hat Linux)) id 1gmhwS-00065u-Sk for linux-arm-kernel@lists.infradead.org; Thu, 24 Jan 2019 16:33:27 +0000 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.72.51.249]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 7DB4EA78; Thu, 24 Jan 2019 08:33:24 -0800 (PST) Received: from eglon.cambridge.arm.com (eglon.cambridge.arm.com [10.1.196.105]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 014163F237; Thu, 24 Jan 2019 08:33:22 -0800 (PST) From: James Morse To: linux-arm-kernel@lists.infradead.org Subject: [PATCH v2 1/4] KVM: arm64: Forbid kprobing of the VHE world-switch code Date: Thu, 24 Jan 2019 16:32:54 +0000 Message-Id: <20190124163257.233929-2-james.morse@arm.com> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190124163257.233929-1-james.morse@arm.com> References: <20190124163257.233929-1-james.morse@arm.com> MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20190124_083325_363731_35E1D567 X-CRM114-Status: GOOD ( 13.90 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Marc Zyngier , Catalin Marinas , Will Deacon , Christoffer Dall , james.morse@arm.com, Masami Hiramatsu , kvmarm@lists.cs.columbia.edu Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org X-Virus-Scanned: ClamAV using ClamSMTP On systems with VHE the kernel and KVM's world-switch code run at the same exception level. Code that is only used on a VHE system does not need to be annotated as __hyp_text as it can reside anywhere in the kernel text. __hyp_text was also used to prevent kprobes from patching breakpoint instructions into this region, as this code runs at a different exception level. While this is no longer true with VHE, KVM still switches VBAR_EL1, meaning a kprobe's breakpoint executed in the world-switch code will cause a hyp-panic. echo "p:weasel sysreg_save_guest_state_vhe" > /sys/kernel/debug/tracing/kprobe_events echo 1 > /sys/kernel/debug/tracing/events/kprobes/weasel/enable lkvm run -k /boot/Image --console serial -p "console=ttyS0 earlycon=uart,mmio,0x3f8" # lkvm run -k /boot/Image -m 384 -c 3 --name guest-1474 Info: Placing fdt at 0x8fe00000 - 0x8fffffff Info: virtio-mmio.devices=0x200@0x10000:36 Info: virtio-mmio.devices=0x200@0x10200:37 Info: virtio-mmio.devices=0x200@0x10400:38 [ 614.178186] Kernel panic - not syncing: HYP panic: [ 614.178186] PS:404003c9 PC:ffff0000100d70e0 ESR:f2000004 [ 614.178186] FAR:0000000080080000 HPFAR:0000000000800800 PAR:1d00007edbadc0de [ 614.178186] VCPU:00000000f8de32f1 [ 614.178383] CPU: 2 PID: 1482 Comm: kvm-vcpu-0 Not tainted 5.0.0-rc2 #10799 [ 614.178446] Call trace: [ 614.178480] dump_backtrace+0x0/0x148 [ 614.178567] show_stack+0x24/0x30 [ 614.178658] dump_stack+0x90/0xb4 [ 614.178710] panic+0x13c/0x2d8 [ 614.178793] hyp_panic+0xac/0xd8 [ 614.178880] kvm_vcpu_run_vhe+0x9c/0xe0 [ 614.178958] kvm_arch_vcpu_ioctl_run+0x454/0x798 [ 614.179038] kvm_vcpu_ioctl+0x360/0x898 [ 614.179087] do_vfs_ioctl+0xc4/0x858 [ 614.179174] ksys_ioctl+0x84/0xb8 [ 614.179261] __arm64_sys_ioctl+0x28/0x38 [ 614.179348] el0_svc_common+0x94/0x108 [ 614.179401] el0_svc_handler+0x38/0x78 [ 614.179487] el0_svc+0x8/0xc [ 614.179558] SMP: stopping secondary CPUs [ 614.179661] Kernel Offset: disabled [ 614.179695] CPU features: 0x003,2a80aa38 [ 614.179758] Memory Limit: none [ 614.179858] ---[ end Kernel panic - not syncing: HYP panic: [ 614.179858] PS:404003c9 PC:ffff0000100d70e0 ESR:f2000004 [ 614.179858] FAR:0000000080080000 HPFAR:0000000000800800 PAR:1d00007edbadc0de [ 614.179858] VCPU:00000000f8de32f1 ]--- Annotate the VHE world-switch functions that aren't marked __hyp_text using NOKPROBE_SYMBOL(). Signed-off-by: James Morse Fixes: 3f5c90b890ac ("KVM: arm64: Introduce VHE-specific kvm_vcpu_run") Acked-by: Masami Hiramatsu --- This has been an issue since the VHE/non-VHE world-switch paths were split. Changes since v1: * Switched to NOKPROBE_SYMBOL() as this doesn't move code between sections. --- arch/arm64/kvm/hyp/switch.c | 5 +++++ arch/arm64/kvm/hyp/sysreg-sr.c | 5 +++++ 2 files changed, 10 insertions(+) diff --git a/arch/arm64/kvm/hyp/switch.c b/arch/arm64/kvm/hyp/switch.c index b0b1478094b4..421ebf6f7086 100644 --- a/arch/arm64/kvm/hyp/switch.c +++ b/arch/arm64/kvm/hyp/switch.c @@ -23,6 +23,7 @@ #include #include +#include #include #include #include @@ -107,6 +108,7 @@ static void activate_traps_vhe(struct kvm_vcpu *vcpu) write_sysreg(kvm_get_hyp_vector(), vbar_el1); } +NOKPROBE_SYMBOL(activate_traps_vhe); static void __hyp_text __activate_traps_nvhe(struct kvm_vcpu *vcpu) { @@ -154,6 +156,7 @@ static void deactivate_traps_vhe(void) write_sysreg(CPACR_EL1_DEFAULT, cpacr_el1); write_sysreg(vectors, vbar_el1); } +NOKPROBE_SYMBOL(deactivate_traps_vhe); static void __hyp_text __deactivate_traps_nvhe(void) { @@ -513,6 +516,7 @@ int kvm_vcpu_run_vhe(struct kvm_vcpu *vcpu) return exit_code; } +NOKPROBE_SYMBOL(kvm_vcpu_run_vhe); /* Switch to the guest for legacy non-VHE systems */ int __hyp_text __kvm_vcpu_run_nvhe(struct kvm_vcpu *vcpu) @@ -620,6 +624,7 @@ static void __hyp_call_panic_vhe(u64 spsr, u64 elr, u64 par, read_sysreg_el2(esr), read_sysreg_el2(far), read_sysreg(hpfar_el2), par, vcpu); } +NOKPROBE_SYMBOL(__hyp_call_panic_vhe); void __hyp_text __noreturn hyp_panic(struct kvm_cpu_context *host_ctxt) { diff --git a/arch/arm64/kvm/hyp/sysreg-sr.c b/arch/arm64/kvm/hyp/sysreg-sr.c index 68d6f7c3b237..b426e2cf973c 100644 --- a/arch/arm64/kvm/hyp/sysreg-sr.c +++ b/arch/arm64/kvm/hyp/sysreg-sr.c @@ -18,6 +18,7 @@ #include #include +#include #include #include #include @@ -98,12 +99,14 @@ void sysreg_save_host_state_vhe(struct kvm_cpu_context *ctxt) { __sysreg_save_common_state(ctxt); } +NOKPROBE_SYMBOL(sysreg_save_host_state_vhe); void sysreg_save_guest_state_vhe(struct kvm_cpu_context *ctxt) { __sysreg_save_common_state(ctxt); __sysreg_save_el2_return_state(ctxt); } +NOKPROBE_SYMBOL(sysreg_save_guest_state_vhe); static void __hyp_text __sysreg_restore_common_state(struct kvm_cpu_context *ctxt) { @@ -188,12 +191,14 @@ void sysreg_restore_host_state_vhe(struct kvm_cpu_context *ctxt) { __sysreg_restore_common_state(ctxt); } +NOKPROBE_SYMBOL(sysreg_restore_host_state_vhe); void sysreg_restore_guest_state_vhe(struct kvm_cpu_context *ctxt) { __sysreg_restore_common_state(ctxt); __sysreg_restore_el2_return_state(ctxt); } +NOKPROBE_SYMBOL(sysreg_restore_guest_state_vhe); void __hyp_text __sysreg32_save_state(struct kvm_vcpu *vcpu) { From patchwork Thu Jan 24 16:32:55 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: James Morse X-Patchwork-Id: 10779493 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id CC19A746 for ; Thu, 24 Jan 2019 16:33:53 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id B6485315FD for ; Thu, 24 Jan 2019 16:33:53 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id B3C68315EF; Thu, 24 Jan 2019 16:33:53 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-5.2 required=2.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,MAILING_LIST_MULTI,RCVD_IN_DNSWL_MED autolearn=ham version=3.3.1 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id 05BAB315FD for ; Thu, 24 Jan 2019 16:33:53 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender: Content-Transfer-Encoding:Content-Type:Cc:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To: Message-Id:Date:Subject:To:From:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=qf2qTS4Wnv7NQA1/ByIEX71Ageqoq7SMYH0PPJU1sMs=; b=nVzMdjygL9uG50 7pVc7PeWhvAitQa7vYByfChheM38hEZkCgDJ9uPqGrmuk76JIskYG7vwKdF/8Iyo+fzlWmMq9hvDA RBI0QxPzHcQtnRbsuUE+F4Yemp2tZzeEkjQ077JWTDaIcdI1jwLRVf43VrULZc/9zjUcSDmMwm/0G Ai2jWA8vjEt+flUrKHe8toq/OlVCkm50eKToDiOoegLjm93KKlpWjogBCelml1IbZaXu0jnzTar+c 9So8THmX06wehxosxrwur5/Uxrz3zn3Lb6Y7M+WwK5m0t/Cnwp35pF8cvk/AwtT+ECeJOmI5l1qke 6GCPPtpcg9WSZjohLwBQ==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.90_1 #2 (Red Hat Linux)) id 1gmhwq-0006PM-3y; Thu, 24 Jan 2019 16:33:48 +0000 Received: from usa-sjc-mx-foss1.foss.arm.com ([217.140.101.70] helo=foss.arm.com) by bombadil.infradead.org with esmtp (Exim 4.90_1 #2 (Red Hat Linux)) id 1gmhwV-00068j-E3 for linux-arm-kernel@lists.infradead.org; Thu, 24 Jan 2019 16:33:31 +0000 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.72.51.249]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id DE6B11596; Thu, 24 Jan 2019 08:33:26 -0800 (PST) Received: from eglon.cambridge.arm.com (eglon.cambridge.arm.com [10.1.196.105]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 62D0E3F237; Thu, 24 Jan 2019 08:33:25 -0800 (PST) From: James Morse To: linux-arm-kernel@lists.infradead.org Subject: [PATCH v2 2/4] arm64: kprobe: Always blacklist the KVM world-switch code Date: Thu, 24 Jan 2019 16:32:55 +0000 Message-Id: <20190124163257.233929-3-james.morse@arm.com> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190124163257.233929-1-james.morse@arm.com> References: <20190124163257.233929-1-james.morse@arm.com> MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20190124_083327_755321_71EBBBFF X-CRM114-Status: GOOD ( 15.79 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Marc Zyngier , Catalin Marinas , Will Deacon , Christoffer Dall , james.morse@arm.com, Masami Hiramatsu , kvmarm@lists.cs.columbia.edu Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org X-Virus-Scanned: ClamAV using ClamSMTP On systems with VHE the kernel and KVM's world-switch code run at the same exception level. Code that is only used on a VHE system does not need to be annotated as __hyp_text as it can reside anywhere in the kernel text. __hyp_text was also used to prevent kprobes from patching breakpoint instructions into this region, as this code runs at a different exception level. While this is no longer true with VHE, KVM still switches VBAR_EL1, meaning a kprobe's breakpoint executed in the world-switch code will cause a hyp-panic. Move the __hyp_text check in the kprobes blacklist so it applies on VHE systems too, to cover the common code and guest enter/exit assembly. Fixes: 888b3c8720e0 ("arm64: Treat all entry code as non-kprobe-able") Signed-off-by: James Morse Acked-by: Masami Hiramatsu Reviewed-by: Christoffer Dall --- arch/arm64/kernel/probes/kprobes.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/arch/arm64/kernel/probes/kprobes.c b/arch/arm64/kernel/probes/kprobes.c index 2a5b338b2542..f17afb99890c 100644 --- a/arch/arm64/kernel/probes/kprobes.c +++ b/arch/arm64/kernel/probes/kprobes.c @@ -478,13 +478,13 @@ bool arch_within_kprobe_blacklist(unsigned long addr) addr < (unsigned long)__entry_text_end) || (addr >= (unsigned long)__idmap_text_start && addr < (unsigned long)__idmap_text_end) || + (addr >= (unsigned long)__hyp_text_start && + addr < (unsigned long)__hyp_text_end) || !!search_exception_tables(addr)) return true; if (!is_kernel_in_hyp_mode()) { - if ((addr >= (unsigned long)__hyp_text_start && - addr < (unsigned long)__hyp_text_end) || - (addr >= (unsigned long)__hyp_idmap_text_start && + if ((addr >= (unsigned long)__hyp_idmap_text_start && addr < (unsigned long)__hyp_idmap_text_end)) return true; } From patchwork Thu Jan 24 16:32:56 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: James Morse X-Patchwork-Id: 10779503 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 2595813B5 for ; Thu, 24 Jan 2019 16:34:11 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 13F2D30AD8 for ; Thu, 24 Jan 2019 16:34:11 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 079C931A4D; Thu, 24 Jan 2019 16:34:11 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-5.2 required=2.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,MAILING_LIST_MULTI,RCVD_IN_DNSWL_MED autolearn=ham version=3.3.1 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id B048C308A3 for ; Thu, 24 Jan 2019 16:34:10 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender: Content-Transfer-Encoding:Content-Type:Cc:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To: Message-Id:Date:Subject:To:From:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=KsMaGk5JadMJ544b42+L5LIuU0WchXx9ffOe3dUH9cw=; b=BRDQwSEoeLjWay M7BUKyEJBL+lGElOBgvL7J8EsJOV1jw3AwsQu5ZpW3QREjOY2Qjw2mXmzaN9xi1VORngpMRzNMs9F o8fbbK5pnt1vkh6bHB2MbEhqAvh6RJNBZYu8AVRwpzjZxGbpp7So2V1eiTnAenFfjYUHbz7waY9OP sw9DrrkcBRK/z/ih6tTK2dDYeQ7HmdJBn58OqYSDnyTXTm0gawIoIjM9tMXSgvBjNNeEBXaUhezkC NNDq87v2XjZqN17d0BfTObXilUZP70wwGkWnWa9g0CCFLD/mn7Tex5ygxtvmtq24pkm/Lj7hyhqLJ FS/ATPEQAPZcJoxdqqZQ==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.90_1 #2 (Red Hat Linux)) id 1gmhx6-0006fR-W0; Thu, 24 Jan 2019 16:34:04 +0000 Received: from usa-sjc-mx-foss1.foss.arm.com ([217.140.101.70] helo=foss.arm.com) by bombadil.infradead.org with esmtp (Exim 4.90_1 #2 (Red Hat Linux)) id 1gmhwX-0006Af-HX for linux-arm-kernel@lists.infradead.org; Thu, 24 Jan 2019 16:33:31 +0000 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.72.51.249]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 5234BA78; Thu, 24 Jan 2019 08:33:29 -0800 (PST) Received: from eglon.cambridge.arm.com (eglon.cambridge.arm.com [10.1.196.105]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id CC5EB3F237; Thu, 24 Jan 2019 08:33:27 -0800 (PST) From: James Morse To: linux-arm-kernel@lists.infradead.org Subject: [PATCH v2 3/4] arm64: hyp-stub: Forbid kprobing of the hyp-stub Date: Thu, 24 Jan 2019 16:32:56 +0000 Message-Id: <20190124163257.233929-4-james.morse@arm.com> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190124163257.233929-1-james.morse@arm.com> References: <20190124163257.233929-1-james.morse@arm.com> MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20190124_083329_730630_B1A76E09 X-CRM114-Status: GOOD ( 14.07 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Marc Zyngier , Catalin Marinas , Will Deacon , Christoffer Dall , james.morse@arm.com, Masami Hiramatsu , kvmarm@lists.cs.columbia.edu Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org X-Virus-Scanned: ClamAV using ClamSMTP The hyp-stub is loaded by the kernel's early startup code at EL2 during boot, before KVM takes ownership later. The hyp-stub's text is part of the regular kernel text, meaning it can be kprobed. A breakpoint in the hyp-stub causes the CPU to spin in el2_sync_invalid. Add it to the __hyp_text. Signed-off-by: James Morse Cc: stable@vger.kernel.org --- This has been a problem since kprobes was merged, it should probably have been covered in 888b3c8720e0. I'm not sure __hyp_text is the right place. Its not idmaped, and as it contains a set of vectors, adding it to the host/hyp idmap sections could grow them beyond a page... but it does run with the MMU off, so does need to be cleaned to PoC when anything wacky, like hibernate happens. With this patch, hibernate should clean the __hyp_text to PoC too. --- arch/arm64/kernel/hyp-stub.S | 2 ++ 1 file changed, 2 insertions(+) diff --git a/arch/arm64/kernel/hyp-stub.S b/arch/arm64/kernel/hyp-stub.S index e1261fbaa374..17f325ba831e 100644 --- a/arch/arm64/kernel/hyp-stub.S +++ b/arch/arm64/kernel/hyp-stub.S @@ -28,6 +28,8 @@ #include .text + .pushsection .hyp.text, "ax" + .align 11 ENTRY(__hyp_stub_vectors) From patchwork Thu Jan 24 16:32:57 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: James Morse X-Patchwork-Id: 10779505 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 8C27113BF for ; Thu, 24 Jan 2019 16:34:59 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 7941C31B68 for ; Thu, 24 Jan 2019 16:34:59 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 6DC1A31B8B; Thu, 24 Jan 2019 16:34:59 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-5.2 required=2.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,MAILING_LIST_MULTI,RCVD_IN_DNSWL_MED autolearn=ham version=3.3.1 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id 19A0D31B81 for ; Thu, 24 Jan 2019 16:34:58 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender: Content-Transfer-Encoding:Content-Type:Cc:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To: Message-Id:Date:Subject:To:From:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=SZd9pKEqVq4eFbFSvX93VvKErmVV9SCLQItMFuozK1U=; b=ULtMhUPN9fD8BU tIByMh63Fsn58FjYRaJRMB82YbJDE24fi3vPjQcAv8cLCmlgX6TmSLwbPS47DgDMOZOjUuTaNJMjT YOLBS/US/nAS3HUmBAjM0uu7KPoWv76G13mE7EUsHJqoHqNLmFpwEKHIn1Eo4qgrdRrsKiGpKNW4a l3WckQNHIyhCOr0J7g+bjop0sE04Ozzix1WaOI8T0amg/SHCZOWwQWNZaqKv2k9vaNzyt441WY3/M 9MvOiis7RYftFECrGwDAzVTH6qtBWUkLY7B3OypftvbyOY8h8n+FyK/NLpJfYk4i/l+Ms70eCkFs1 /bS/rqszB96zHriCCwAA==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.90_1 #2 (Red Hat Linux)) id 1gmhxw-0007B5-Fa; Thu, 24 Jan 2019 16:34:56 +0000 Received: from foss.arm.com ([217.140.101.70]) by bombadil.infradead.org with esmtp (Exim 4.90_1 #2 (Red Hat Linux)) id 1gmhwa-0006Cg-1W for linux-arm-kernel@lists.infradead.org; Thu, 24 Jan 2019 16:33:33 +0000 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.72.51.249]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id C3820A78; Thu, 24 Jan 2019 08:33:31 -0800 (PST) Received: from eglon.cambridge.arm.com (eglon.cambridge.arm.com [10.1.196.105]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 499BF3F237; Thu, 24 Jan 2019 08:33:30 -0800 (PST) From: James Morse To: linux-arm-kernel@lists.infradead.org Subject: [PATCH v2 4/4] arm64: hibernate: Clean the __hyp_text to PoC after resume Date: Thu, 24 Jan 2019 16:32:57 +0000 Message-Id: <20190124163257.233929-5-james.morse@arm.com> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190124163257.233929-1-james.morse@arm.com> References: <20190124163257.233929-1-james.morse@arm.com> MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20190124_083332_261533_171FF69F X-CRM114-Status: GOOD ( 12.55 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Marc Zyngier , Catalin Marinas , Will Deacon , Christoffer Dall , james.morse@arm.com, Masami Hiramatsu , kvmarm@lists.cs.columbia.edu Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org X-Virus-Scanned: ClamAV using ClamSMTP During resume hibernate restores all physical memory. Any memory that is accessed with the MMU disabled needs to be cleaned to the PoC. KVMs __hyp_text was previously ommitted as it runs with the MMU enabled, but now that the hyp-stub is located in this section, we must clean __hyp_text too. This ensures secondary CPUs that come online after hibernate has finished resuming, and load KVM via the freshly written hyp-stub see the correct instructions. Signed-off-by: James Morse Cc: stable@vger.kernel.org --- arch/arm64/kernel/hibernate.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/arch/arm64/kernel/hibernate.c b/arch/arm64/kernel/hibernate.c index 29cdc99688f3..9859e1178e6b 100644 --- a/arch/arm64/kernel/hibernate.c +++ b/arch/arm64/kernel/hibernate.c @@ -299,8 +299,10 @@ int swsusp_arch_suspend(void) dcache_clean_range(__idmap_text_start, __idmap_text_end); /* Clean kvm setup code to PoC? */ - if (el2_reset_needed()) + if (el2_reset_needed()) { dcache_clean_range(__hyp_idmap_text_start, __hyp_idmap_text_end); + dcache_clean_range(__hyp_text_start, __hyp_text_end); + } /* make the crash dump kernel image protected again */ crash_post_resume();