From patchwork Fri Mar 17 14:52:36 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Roberto Sassu X-Patchwork-Id: 13179142 X-Patchwork-Delegate: kuba@kernel.org Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 6A61EC76195 for ; Fri, 17 Mar 2023 14:54:13 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231309AbjCQOyM (ORCPT ); Fri, 17 Mar 2023 10:54:12 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:34698 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229772AbjCQOyK (ORCPT ); Fri, 17 Mar 2023 10:54:10 -0400 Received: from frasgout11.his.huawei.com (frasgout11.his.huawei.com [14.137.139.23]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 7C611559C1; Fri, 17 Mar 2023 07:54:05 -0700 (PDT) Received: from mail02.huawei.com (unknown [172.18.147.228]) by frasgout11.his.huawei.com (SkyGuard) with ESMTP id 4PdRkB58cyz9xqwW; Fri, 17 Mar 2023 22:45:06 +0800 (CST) Received: from huaweicloud.com (unknown [10.204.63.22]) by APP2 (Coremail) with SMTP id GxC2BwBnOWDafhRkaQemAQ--.41316S3; Fri, 17 Mar 2023 15:53:41 +0100 (CET) From: Roberto Sassu To: corbet@lwn.net, ast@kernel.org, daniel@iogearbox.net, andrii@kernel.org, martin.lau@linux.dev, song@kernel.org, yhs@fb.com, john.fastabend@gmail.com, kpsingh@kernel.org, sdf@google.com, haoluo@google.com, jolsa@kernel.org, davem@davemloft.net, edumazet@google.com, kuba@kernel.org, pabeni@redhat.com, dsahern@kernel.org, shuah@kernel.org, brauner@kernel.org Cc: linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, bpf@vger.kernel.org, netdev@vger.kernel.org, linux-kselftest@vger.kernel.org, ebiederm@xmission.com, mcgrof@kernel.org, Roberto Sassu Subject: [PATCH 1/5] usermode_driver: Introduce umd_send_recv() from bpfilter Date: Fri, 17 Mar 2023 15:52:36 +0100 Message-Id: <20230317145240.363908-2-roberto.sassu@huaweicloud.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20230317145240.363908-1-roberto.sassu@huaweicloud.com> References: <20230317145240.363908-1-roberto.sassu@huaweicloud.com> MIME-Version: 1.0 X-CM-TRANSID: GxC2BwBnOWDafhRkaQemAQ--.41316S3 X-Coremail-Antispam: 1UD129KBjvJXoW3XF4ftFW7Xw4fGw48Kw1fXrb_yoW7WFy3pF WFkw13Cr4rtFy7ZFs3tan3AFyYg395G3W5KwnxWr9avan8Jr4qg3y5KFyYv34rGry5Cw1Y qrs0kFyUW3WDXrJanT9S1TB71UUUUU7qnTZGkaVYY2UrUUUUjbIjqfuFe4nvWSU5nxnvy2 9KBjDU0xBIdaVrnRJUUUPab4IE77IF4wAFF20E14v26rWj6s0DM7CY07I20VC2zVCF04k2 6cxKx2IYs7xG6rWj6s0DM7CIcVAFz4kK6r1j6r18M28IrcIa0xkI8VA2jI8067AKxVWUGw A2048vs2IY020Ec7CjxVAFwI0_Xr0E3s1l8cAvFVAK0II2c7xJM28CjxkF64kEwVA0rcxS w2x7M28EF7xvwVC0I7IYx2IY67AKxVWUJVWUCwA2z4x0Y4vE2Ix0cI8IcVCY1x0267AKxV WxJVW8Jr1l84ACjcxK6I8E87Iv67AKxVW8JVWxJwA2z4x0Y4vEx4A2jsIEc7CjxVAFwI0_ Gr1j6F4UJwAS0I0E0xvYzxvE52x082IY62kv0487Mc02F40EFcxC0VAKzVAqx4xG6I80ew Av7VC0I7IYx2IY67AKxVWUJVWUGwAv7VC2z280aVAFwI0_Jr0_Gr1lOx8S6xCaFVCjc4AY 6r1j6r4UM4x0Y48IcxkI7VAKI48JM4IIrI8v6xkF7I0E8cxan2IY04v7MxkF7I0En4kS14 v26r4a6rW5MxAIw28IcxkI7VAKI48JMxC20s026xCaFVCjc4AY6r1j6r4UMI8I3I0E5I8C rVAFwI0_Jr0_Jr4lx2IqxVCjr7xvwVAFwI0_JrI_JrWlx4CE17CEb7AF67AKxVW8ZVWrXw CIc40Y0x0EwIxGrwCI42IY6xIIjxv20xvE14v26r1j6r1xMIIF0xvE2Ix0cI8IcVCY1x02 67AKxVWxJVW8Jr1lIxAIcVCF04k26cxKx2IYs7xG6r1j6r1xMIIF0xvEx4A2jsIE14v26r 1j6r4UMIIF0xvEx4A2jsIEc7CjxVAFwI0_Gr1j6F4UJbIYCTnIWIevJa73UjIFyTuYvjxU Iw0eDUUUU X-CM-SenderInfo: purev21wro2thvvxqx5xdzvxpfor3voofrz/1tbiAgATBF1jj4asxgACsK X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org X-Patchwork-Delegate: kuba@kernel.org From: Roberto Sassu Move bpfilter_send_req() to usermode_driver.c and rename it to umd_send_recv(). Make the latter independent from the message format by passing to it the pointers to the request and reply message buffers and the respective lengths, and by merely doing read/write operations. >From umd_send_recv(), remove the call to __stop_umh() and returning reply.status, which is message format-specific. Let the callers of umd_send_recv(), such as bpfilter_process_sockopt(), call shutdown_umh() and evaluate the reply. Consequently, remove __stop_umh(), since in bpfilter_process_sockopt() the CONFIG_INET condition is always true. In addition to the original bpfilter_send_req() implementation, support partial reads and writes, so that callers are not limited by the length of the message to send or receive. Currently, the pipe supports receiving 64 KB at once. Signed-off-by: Roberto Sassu --- include/linux/usermode_driver.h | 2 ++ kernel/usermode_driver.c | 47 ++++++++++++++++++++++++++++++- net/bpfilter/bpfilter_kern.c | 50 +++++++++------------------------ 3 files changed, 62 insertions(+), 37 deletions(-) diff --git a/include/linux/usermode_driver.h b/include/linux/usermode_driver.h index ad970416260..37b8d08cc3d 100644 --- a/include/linux/usermode_driver.h +++ b/include/linux/usermode_driver.h @@ -15,5 +15,7 @@ int umd_load_blob(struct umd_info *info, const void *data, size_t len); int umd_unload_blob(struct umd_info *info); int fork_usermode_driver(struct umd_info *info); void umd_cleanup_helper(struct umd_info *info); +int umd_send_recv(struct umd_info *info, void *in, size_t in_len, void *out, + size_t out_len); #endif /* __LINUX_USERMODE_DRIVER_H__ */ diff --git a/kernel/usermode_driver.c b/kernel/usermode_driver.c index 8303f4c7ca7..cdbfaad99d7 100644 --- a/kernel/usermode_driver.c +++ b/kernel/usermode_driver.c @@ -188,4 +188,49 @@ int fork_usermode_driver(struct umd_info *info) } EXPORT_SYMBOL_GPL(fork_usermode_driver); - +/** + * umd_send_recv - send/receive a message through the pipe + * @info: user mode driver info + * @in: request message + * @in_len: size of @in + * @out: reply message + * @out_len: size of @out + * + * Send a message to the user space process through the created pipe and read + * the reply. Partial reads and writes are supported. + * + * Return: Zero on success, -EFAULT otherwise. + */ +int umd_send_recv(struct umd_info *info, void *in, size_t in_len, void *out, + size_t out_len) +{ + loff_t pos, offset; + ssize_t n; + + if (!info->tgid) + return -EFAULT; + pos = 0; + offset = 0; + while (in_len) { + n = kernel_write(info->pipe_to_umh, in + offset, in_len, &pos); + if (n <= 0) { + pr_err("write fail %zd\n", n); + return -EFAULT; + } + in_len -= n; + offset += n; + } + pos = 0; + offset = 0; + while (out_len) { + n = kernel_read(info->pipe_from_umh, out + offset, out_len, &pos); + if (n <= 0) { + pr_err("read fail %zd\n", n); + return -EFAULT; + } + out_len -= n; + offset += n; + } + return 0; +} +EXPORT_SYMBOL_GPL(umd_send_recv); diff --git a/net/bpfilter/bpfilter_kern.c b/net/bpfilter/bpfilter_kern.c index 422ec6e7ccf..17d4df5f8fe 100644 --- a/net/bpfilter/bpfilter_kern.c +++ b/net/bpfilter/bpfilter_kern.c @@ -25,40 +25,6 @@ static void shutdown_umh(void) } } -static void __stop_umh(void) -{ - if (IS_ENABLED(CONFIG_INET)) - shutdown_umh(); -} - -static int bpfilter_send_req(struct mbox_request *req) -{ - struct mbox_reply reply; - loff_t pos = 0; - ssize_t n; - - if (!bpfilter_ops.info.tgid) - return -EFAULT; - pos = 0; - n = kernel_write(bpfilter_ops.info.pipe_to_umh, req, sizeof(*req), - &pos); - if (n != sizeof(*req)) { - pr_err("write fail %zd\n", n); - goto stop; - } - pos = 0; - n = kernel_read(bpfilter_ops.info.pipe_from_umh, &reply, sizeof(reply), - &pos); - if (n != sizeof(reply)) { - pr_err("read fail %zd\n", n); - goto stop; - } - return reply.status; -stop: - __stop_umh(); - return -EFAULT; -} - static int bpfilter_process_sockopt(struct sock *sk, int optname, sockptr_t optval, unsigned int optlen, bool is_set) @@ -70,16 +36,27 @@ static int bpfilter_process_sockopt(struct sock *sk, int optname, .addr = (uintptr_t)optval.user, .len = optlen, }; + struct mbox_reply reply; + int err; + if (sockptr_is_kernel(optval)) { pr_err("kernel access not supported\n"); return -EFAULT; } - return bpfilter_send_req(&req); + err = umd_send_recv(&bpfilter_ops.info, &req, sizeof(req), &reply, + sizeof(reply)); + if (err) { + shutdown_umh(); + return err; + } + + return reply.status; } static int start_umh(void) { struct mbox_request req = { .pid = current->pid }; + struct mbox_reply reply; int err; /* fork usermode process */ @@ -89,7 +66,8 @@ static int start_umh(void) pr_info("Loaded bpfilter_umh pid %d\n", pid_nr(bpfilter_ops.info.tgid)); /* health check that usermode process started correctly */ - if (bpfilter_send_req(&req) != 0) { + if (umd_send_recv(&bpfilter_ops.info, &req, sizeof(req), &reply, + sizeof(reply)) != 0 || reply.status != 0) { shutdown_umh(); return -EFAULT; } From patchwork Fri Mar 17 14:52:37 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Roberto Sassu X-Patchwork-Id: 13179209 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 81846C76195 for ; Fri, 17 Mar 2023 15:33:21 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231237AbjCQPdT (ORCPT ); Fri, 17 Mar 2023 11:33:19 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:39562 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229767AbjCQPdR (ORCPT ); Fri, 17 Mar 2023 11:33:17 -0400 X-Greylist: delayed 1190 seconds by postgrey-1.37 at lindbergh.monkeyblade.net; Fri, 17 Mar 2023 08:32:44 PDT Received: from frasgout13.his.huawei.com (frasgout13.his.huawei.com [14.137.139.46]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 4D09CAD00A; Fri, 17 Mar 2023 08:32:43 -0700 (PDT) Received: from mail02.huawei.com (unknown [172.18.147.227]) by frasgout13.his.huawei.com (SkyGuard) with ESMTP id 4PdRkT0yYYz9xFGZ; Fri, 17 Mar 2023 22:45:21 +0800 (CST) Received: from huaweicloud.com (unknown [10.204.63.22]) by APP2 (Coremail) with SMTP id GxC2BwBnOWDafhRkaQemAQ--.41316S4; Fri, 17 Mar 2023 15:53:53 +0100 (CET) From: Roberto Sassu To: corbet@lwn.net, ast@kernel.org, daniel@iogearbox.net, andrii@kernel.org, martin.lau@linux.dev, song@kernel.org, yhs@fb.com, john.fastabend@gmail.com, kpsingh@kernel.org, sdf@google.com, haoluo@google.com, jolsa@kernel.org, davem@davemloft.net, edumazet@google.com, kuba@kernel.org, pabeni@redhat.com, dsahern@kernel.org, shuah@kernel.org, brauner@kernel.org Cc: linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, bpf@vger.kernel.org, netdev@vger.kernel.org, linux-kselftest@vger.kernel.org, ebiederm@xmission.com, mcgrof@kernel.org, Roberto Sassu Subject: [PATCH 2/5] usermode_driver_mgmt: Introduce management of user mode drivers Date: Fri, 17 Mar 2023 15:52:37 +0100 Message-Id: <20230317145240.363908-3-roberto.sassu@huaweicloud.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20230317145240.363908-1-roberto.sassu@huaweicloud.com> References: <20230317145240.363908-1-roberto.sassu@huaweicloud.com> MIME-Version: 1.0 X-CM-TRANSID: GxC2BwBnOWDafhRkaQemAQ--.41316S4 X-Coremail-Antispam: 1UD129KBjvJXoWxKFy5KF4rWr18AFW7ur4rZrb_yoWfJFyUpF WUJry5uws5J34UZ3Z3G3yUuayfZw4kZF1YgFZ3Ww4Svwn2qr1jqr17t3W5uryxKr95GF12 yrZ09Fn8Crs8WrJanT9S1TB71UUUUU7qnTZGkaVYY2UrUUUUjbIjqfuFe4nvWSU5nxnvy2 9KBjDU0xBIdaVrnRJUUUPab4IE77IF4wAFF20E14v26rWj6s0DM7CY07I20VC2zVCF04k2 6cxKx2IYs7xG6rWj6s0DM7CIcVAFz4kK6r1j6r18M28IrcIa0xkI8VA2jI8067AKxVWUXw A2048vs2IY020Ec7CjxVAFwI0_Xr0E3s1l8cAvFVAK0II2c7xJM28CjxkF64kEwVA0rcxS w2x7M28EF7xvwVC0I7IYx2IY67AKxVWUJVWUCwA2z4x0Y4vE2Ix0cI8IcVCY1x0267AKxV WxJVW8Jr1l84ACjcxK6I8E87Iv67AKxVW8JVWxJwA2z4x0Y4vEx4A2jsIEc7CjxVAFwI0_ Gr1j6F4UJwAS0I0E0xvYzxvE52x082IY62kv0487Mc02F40EFcxC0VAKzVAqx4xG6I80ew Av7VC0I7IYx2IY67AKxVWUJVWUGwAv7VC2z280aVAFwI0_Jr0_Gr1lOx8S6xCaFVCjc4AY 6r1j6r4UM4x0Y48IcxkI7VAKI48JM4IIrI8v6xkF7I0E8cxan2IY04v7MxkF7I0En4kS14 v26r4a6rW5MxAIw28IcxkI7VAKI48JMxC20s026xCaFVCjc4AY6r1j6r4UMI8I3I0E5I8C rVAFwI0_Jr0_Jr4lx2IqxVCjr7xvwVAFwI0_JrI_JrWlx4CE17CEb7AF67AKxVW8ZVWrXw CIc40Y0x0EwIxGrwCI42IY6xIIjxv20xvE14v26r1j6r1xMIIF0xvE2Ix0cI8IcVCY1x02 67AKxVWxJVW8Jr1lIxAIcVCF04k26cxKx2IYs7xG6r1j6r1xMIIF0xvEx4A2jsIE14v26r 1j6r4UMIIF0xvEx4A2jsIEc7CjxVAFwI0_Gr1j6F4UJbIYCTnIWIevJa73UjIFyTuYvjxU IID7DUUUU X-CM-SenderInfo: purev21wro2thvvxqx5xdzvxpfor3voofrz/1tbiAgATBF1jj4asxgADsL X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org From: Roberto Sassu Reuse the bpfilter code, with some adjustments to make the code more generic, and usable for other user mode drivers. :: struct umd_mgmt <=== struct bpfilter_umh_ops :: Replace the start method with post_start, to allow for some customization of the start procedure. All start procedures have in common the call to fork_usermode_driver(). Remove the sockopt method, as it is use case-specific. Instead, use one of the following two alternatives: generate the message from the manager of the driver (e.g. sockopt), by exporting the message format definition; or, define a new structure embedding the umd_mgmt and the custom method, which can be registered from the kernel module through the post_start method. Add kmod and kmod_loaded. Kmod is name of the kernel module that umd_mgmt_send_recv() (from bpfilter_mbox_request()) attempts to load if kmod_loaded is false (the driver is not yet started). Kmod_loaded is added to replace the sockopt method test, and ensure that the driver is ready for use. :: start_umh() <=== start_umh() :: Remove the connection test, and call the post_start method in umd_mgmt, if set, which could point to that test. :: shutdown_umh() <=== shutdown_umh() :: Same code. :: umd_mgmt_send_recv() <=== bpfilter_mbox_request() :: Replace the bpfilter_mbox_request() parameters with the parameters of umd_send_recv(), except for the first which is a umd_mgmt structure instead of umd_info. Also, call umd_send_recv() instead of the sockopt method, and shutdown the driver if there is an error. :: umd_mgmt_load() <=== load_umh() :: Same code except for the registration of the start and sockopt methods, replaced with setting kmod_loaded to true (not depending on CONFIG_INET), as mentioned in the explanation of umd_mgmt. :: umd_mgmt_unload() <=== fini_umh() :: Same code except for the deregistration of the start and sockopt methods, replaced with setting kmod_loaded to false (not depending on CONFIG_INET). Signed-off-by: Roberto Sassu --- MAINTAINERS | 7 ++ include/linux/usermode_driver_mgmt.h | 35 +++++++ kernel/Makefile | 2 +- kernel/usermode_driver_mgmt.c | 137 +++++++++++++++++++++++++++ 4 files changed, 180 insertions(+), 1 deletion(-) create mode 100644 include/linux/usermode_driver_mgmt.h create mode 100644 kernel/usermode_driver_mgmt.c diff --git a/MAINTAINERS b/MAINTAINERS index a3b14ec3383..7b27435fd20 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -11245,6 +11245,13 @@ S: Maintained F: include/linux/umh.h F: kernel/umh.c +KERNEL USERMODE DRIVER MANAGEMENT +M: Roberto Sassu +L: linux-kernel@vger.kernel.org +S: Maintained +F: include/linux/usermode_driver_mgmt.h +F: kernel/usermode_driver_mgmt.c + KERNEL VIRTUAL MACHINE (KVM) M: Paolo Bonzini L: kvm@vger.kernel.org diff --git a/include/linux/usermode_driver_mgmt.h b/include/linux/usermode_driver_mgmt.h new file mode 100644 index 00000000000..3f9fc783a09 --- /dev/null +++ b/include/linux/usermode_driver_mgmt.h @@ -0,0 +1,35 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* + * Copyright (C) 2023 Huawei Technologies Duesseldorf GmbH + * + * User mode driver management API. + */ +#ifndef __LINUX_USERMODE_DRIVER_MGMT_H__ +#define __LINUX_USERMODE_DRIVER_MGMT_H__ + +#include + +/** + * struct umd_mgmt - user mode driver management structure + * @info: user mode driver information + * @lock: lock to serialize requests to the UMD Handler + * @post_start: function with additional operations after UMD Handler is started + * @kmod: kernel module acting as UMD Loader, to start the UMD Handler + * @kmod_loaded: whether @kmod is loaded or not + * + * Information necessary to manage the UMD during its lifecycle. + */ +struct umd_mgmt { + struct umd_info info; + struct mutex lock; + int (*post_start)(struct umd_mgmt *mgmt); + const char *kmod; + bool kmod_loaded; +}; + +int umd_mgmt_send_recv(struct umd_mgmt *mgmt, void *in, size_t in_len, + void *out, size_t out_len); +int umd_mgmt_load(struct umd_mgmt *mgmt, char *start, char *end); +void umd_mgmt_unload(struct umd_mgmt *mgmt); + +#endif /* __LINUX_USERMODE_DRIVER_MGMT_H__ */ diff --git a/kernel/Makefile b/kernel/Makefile index 10ef068f598..ee47f7c2023 100644 --- a/kernel/Makefile +++ b/kernel/Makefile @@ -12,7 +12,7 @@ obj-y = fork.o exec_domain.o panic.o \ notifier.o ksysfs.o cred.o reboot.o \ async.o range.o smpboot.o ucount.o regset.o -obj-$(CONFIG_USERMODE_DRIVER) += usermode_driver.o +obj-$(CONFIG_USERMODE_DRIVER) += usermode_driver.o usermode_driver_mgmt.o obj-$(CONFIG_MODULES) += kmod.o obj-$(CONFIG_MULTIUSER) += groups.o diff --git a/kernel/usermode_driver_mgmt.c b/kernel/usermode_driver_mgmt.c new file mode 100644 index 00000000000..4fb06b37f62 --- /dev/null +++ b/kernel/usermode_driver_mgmt.c @@ -0,0 +1,137 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright (C) 2023 Huawei Technologies Duesseldorf GmbH + * + * User mode driver management library. + */ +#include +#include +#include + +static void shutdown_umh(struct umd_mgmt *mgmt) +{ + struct umd_info *info = &mgmt->info; + struct pid *tgid = info->tgid; + + if (tgid) { + kill_pid(tgid, SIGKILL, 1); + wait_event(tgid->wait_pidfd, thread_group_exited(tgid)); + umd_cleanup_helper(info); + } +} + +static int start_umh(struct umd_mgmt *mgmt) +{ + int err; + + /* fork usermode process */ + err = fork_usermode_driver(&mgmt->info); + if (err) + return err; + pr_info("Loaded %s pid %d\n", mgmt->info.driver_name, + pid_nr(mgmt->info.tgid)); + + if (mgmt->post_start) { + err = mgmt->post_start(mgmt); + if (err) + shutdown_umh(mgmt); + } + + return err; +} + +/** + * umd_mgmt_send_recv - Communicate with the UMD Handler and start it. + * @mgmt: user mode driver management structure + * @in: request message + * @in_len: size of @in + * @out: reply message + * @out_len: size of @out + * + * Send a message to the UMD Handler through the created pipe and read the + * reply. If the UMD Handler is not available, invoke the UMD Loader to + * instantiate it. If the UMD Handler exited, restart it. + * + * Return: Zero on success, a negative value otherwise. + */ +int umd_mgmt_send_recv(struct umd_mgmt *mgmt, void *in, size_t in_len, + void *out, size_t out_len) +{ + int err; + + mutex_lock(&mgmt->lock); + if (!mgmt->kmod_loaded) { + mutex_unlock(&mgmt->lock); + request_module(mgmt->kmod); + mutex_lock(&mgmt->lock); + + if (!mgmt->kmod_loaded) { + err = -ENOPROTOOPT; + goto out; + } + } + if (mgmt->info.tgid && + thread_group_exited(mgmt->info.tgid)) + umd_cleanup_helper(&mgmt->info); + + if (!mgmt->info.tgid) { + err = start_umh(mgmt); + if (err) + goto out; + } + err = umd_send_recv(&mgmt->info, in, in_len, out, out_len); + if (err) + shutdown_umh(mgmt); +out: + mutex_unlock(&mgmt->lock); + return err; +} +EXPORT_SYMBOL_GPL(umd_mgmt_send_recv); + +/** + * umd_mgmt_load - Load and start the UMD Handler. + * @mgmt: user mode driver management structure + * @start: start address of the binary blob of the UMD Handler + * @end: end address of the binary blob of the UMD Handler + * + * Copy the UMD Handler binary from the specified location to a private tmpfs + * filesystem. Then, start the UMD Handler. + * + * Return: Zero on success, a negative value otherwise. + */ +int umd_mgmt_load(struct umd_mgmt *mgmt, char *start, char *end) +{ + int err; + + err = umd_load_blob(&mgmt->info, start, end - start); + if (err) + return err; + + mutex_lock(&mgmt->lock); + err = start_umh(mgmt); + if (!err) + mgmt->kmod_loaded = true; + mutex_unlock(&mgmt->lock); + if (err) + umd_unload_blob(&mgmt->info); + return err; +} +EXPORT_SYMBOL_GPL(umd_mgmt_load); + +/** + * umd_mgmt_unload - Terminate and unload the UMD Handler. + * @mgmt: user mode driver management structure + * + * Terminate the UMD Handler, and cleanup the private tmpfs filesystem with the + * UMD Handler binary. + */ +void umd_mgmt_unload(struct umd_mgmt *mgmt) +{ + mutex_lock(&mgmt->lock); + shutdown_umh(mgmt); + mgmt->kmod_loaded = false; + mutex_unlock(&mgmt->lock); + + umd_unload_blob(&mgmt->info); +} +EXPORT_SYMBOL_GPL(umd_mgmt_unload); From patchwork Fri Mar 17 14:52:38 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Roberto Sassu X-Patchwork-Id: 13179143 X-Patchwork-Delegate: bpf@iogearbox.net Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 8EA85C76195 for ; Fri, 17 Mar 2023 14:54:43 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231303AbjCQOym (ORCPT ); Fri, 17 Mar 2023 10:54:42 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:35870 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230102AbjCQOyl (ORCPT ); Fri, 17 Mar 2023 10:54:41 -0400 Received: from frasgout11.his.huawei.com (frasgout11.his.huawei.com [14.137.139.23]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id C8F6EB6919; Fri, 17 Mar 2023 07:54:29 -0700 (PDT) Received: from mail02.huawei.com (unknown [172.18.147.227]) by frasgout11.his.huawei.com (SkyGuard) with ESMTP id 4PdRkf73zhz9xqpl; Fri, 17 Mar 2023 22:45:30 +0800 (CST) Received: from huaweicloud.com (unknown [10.204.63.22]) by APP2 (Coremail) with SMTP id GxC2BwBnOWDafhRkaQemAQ--.41316S5; Fri, 17 Mar 2023 15:54:05 +0100 (CET) From: Roberto Sassu To: corbet@lwn.net, ast@kernel.org, daniel@iogearbox.net, andrii@kernel.org, martin.lau@linux.dev, song@kernel.org, yhs@fb.com, john.fastabend@gmail.com, kpsingh@kernel.org, sdf@google.com, haoluo@google.com, jolsa@kernel.org, davem@davemloft.net, edumazet@google.com, kuba@kernel.org, pabeni@redhat.com, dsahern@kernel.org, shuah@kernel.org, brauner@kernel.org Cc: linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, bpf@vger.kernel.org, netdev@vger.kernel.org, linux-kselftest@vger.kernel.org, ebiederm@xmission.com, mcgrof@kernel.org, Roberto Sassu Subject: [PATCH 3/5] bpfilter: Port to user mode driver management API Date: Fri, 17 Mar 2023 15:52:38 +0100 Message-Id: <20230317145240.363908-4-roberto.sassu@huaweicloud.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20230317145240.363908-1-roberto.sassu@huaweicloud.com> References: <20230317145240.363908-1-roberto.sassu@huaweicloud.com> MIME-Version: 1.0 X-CM-TRANSID: GxC2BwBnOWDafhRkaQemAQ--.41316S5 X-Coremail-Antispam: 1UD129KBjvJXoWxuw4UXF43JF48Kw43Aw1xGrg_yoWfXrWkpF WYkw4UJr45XFyUXF1DGFy5Ar15Kr45Ww1UuryrG3sYyrsxWr1vg3yakrWFv345GrW7C34j qa98t3W5XasxXr7anT9S1TB71UUUUU7qnTZGkaVYY2UrUUUUjbIjqfuFe4nvWSU5nxnvy2 9KBjDU0xBIdaVrnRJUUUPqb4IE77IF4wAFF20E14v26rWj6s0DM7CY07I20VC2zVCF04k2 6cxKx2IYs7xG6rWj6s0DM7CIcVAFz4kK6r1j6r18M28IrcIa0xkI8VA2jI8067AKxVWUWw A2048vs2IY020Ec7CjxVAFwI0_Xr0E3s1l8cAvFVAK0II2c7xJM28CjxkF64kEwVA0rcxS w2x7M28EF7xvwVC0I7IYx2IY67AKxVWUJVWUCwA2z4x0Y4vE2Ix0cI8IcVCY1x0267AKxV W8Jr0_Cr1UM28EF7xvwVC2z280aVAFwI0_Gr0_Cr1l84ACjcxK6I8E87Iv6xkF7I0E14v2 6r4UJVWxJr1le2I262IYc4CY6c8Ij28IcVAaY2xG8wAqx4xG64xvF2IEw4CE5I8CrVC2j2 WlYx0E2Ix0cI8IcVAFwI0_Jr0_Jr4lYx0Ex4A2jsIE14v26r1j6r4UMcvjeVCFs4IE7xkE bVWUJVW8JwACjcxG0xvY0x0EwIxGrwACI402YVCY1x02628vn2kIc2xKxwCY1x0262kKe7 AKxVW8ZVWrXwCF04k20xvY0x0EwIxGrwCFx2IqxVCFs4IE7xkEbVWUJVW8JwC20s026c02 F40E14v26r1j6r18MI8I3I0E7480Y4vE14v26r106r1rMI8E67AF67kF1VAFwI0_GFv_Wr ylIxkGc2Ij64vIr41lIxAIcVC0I7IYx2IY67AKxVWUJVWUCwCI42IY6xIIjxv20xvEc7Cj xVAFwI0_Gr1j6F4UJwCI42IY6xAIw20EY4v20xvaj40_Jr0_JF4lIxAIcVC2z280aVAFwI 0_Jr0_Gr1lIxAIcVC2z280aVCY1x0267AKxVW8Jr0_Cr1UYxBIdaVFxhVjvjDU0xZFpf9x 07jxCztUUUUU= X-CM-SenderInfo: purev21wro2thvvxqx5xdzvxpfor3voofrz/1tbiAgATBF1jj4asxgAEsM X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org X-Patchwork-Delegate: bpf@iogearbox.net From: Roberto Sassu Move bpfilter_process_sockopt() to sockopt.c, and call umd_mgmt_send_recv() instead of umd_send_recv(), so that it has the original capability of bpfilter_mbox_request() to request the loading of the kernel module containing the user mode driver. Move also the connection test originally in start_umh() in bpfilter.c, to sockopt.c. Create the new function bpfilter_post_start_umh() with the moved code. Directly call bpfilter_process_sockopt() from bpfilter_ip_set_sockopt() and bpfilter_ip_get_sockopt(), which now it is equivalent to bpfilter_mbox_request(). Remove the struct bpfilter_umh_ops definition, and declare the global variable bpfilter_ops as a umd_mgmt structure. Set kmod to 'bpfilter', kmod_loaded to false and the new function bpfilter_post_start_umh() as the post_start method for bpfilter_ops. Replace load_umh() and fini_umh() in bpfilter.c respectively with umd_mgmt_load() and umd_mgmt_unload(). Finally, remove the remaining functions, as their job is done by the user mode driver management. Signed-off-by: Roberto Sassu --- include/linux/bpfilter.h | 12 +---- net/bpfilter/bpfilter_kern.c | 98 ++---------------------------------- net/ipv4/bpfilter/sockopt.c | 67 ++++++++++++++---------- 3 files changed, 45 insertions(+), 132 deletions(-) diff --git a/include/linux/bpfilter.h b/include/linux/bpfilter.h index 2ae3c8e1d83..655e6ec6e9d 100644 --- a/include/linux/bpfilter.h +++ b/include/linux/bpfilter.h @@ -3,7 +3,7 @@ #define _LINUX_BPFILTER_H #include -#include +#include #include struct sock; @@ -13,13 +13,5 @@ int bpfilter_ip_get_sockopt(struct sock *sk, int optname, char __user *optval, int __user *optlen); void bpfilter_umh_cleanup(struct umd_info *info); -struct bpfilter_umh_ops { - struct umd_info info; - /* since ip_getsockopt() can run in parallel, serialize access to umh */ - struct mutex lock; - int (*sockopt)(struct sock *sk, int optname, sockptr_t optval, - unsigned int optlen, bool is_set); - int (*start)(void); -}; -extern struct bpfilter_umh_ops bpfilter_ops; +extern struct umd_mgmt bpfilter_ops; #endif diff --git a/net/bpfilter/bpfilter_kern.c b/net/bpfilter/bpfilter_kern.c index 17d4df5f8fe..f2137d889c9 100644 --- a/net/bpfilter/bpfilter_kern.c +++ b/net/bpfilter/bpfilter_kern.c @@ -1,113 +1,21 @@ // SPDX-License-Identifier: GPL-2.0 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt -#include #include -#include #include -#include -#include -#include -#include #include "msgfmt.h" extern char bpfilter_umh_start; extern char bpfilter_umh_end; -static void shutdown_umh(void) -{ - struct umd_info *info = &bpfilter_ops.info; - struct pid *tgid = info->tgid; - - if (tgid) { - kill_pid(tgid, SIGKILL, 1); - wait_event(tgid->wait_pidfd, thread_group_exited(tgid)); - bpfilter_umh_cleanup(info); - } -} - -static int bpfilter_process_sockopt(struct sock *sk, int optname, - sockptr_t optval, unsigned int optlen, - bool is_set) -{ - struct mbox_request req = { - .is_set = is_set, - .pid = current->pid, - .cmd = optname, - .addr = (uintptr_t)optval.user, - .len = optlen, - }; - struct mbox_reply reply; - int err; - - if (sockptr_is_kernel(optval)) { - pr_err("kernel access not supported\n"); - return -EFAULT; - } - err = umd_send_recv(&bpfilter_ops.info, &req, sizeof(req), &reply, - sizeof(reply)); - if (err) { - shutdown_umh(); - return err; - } - - return reply.status; -} - -static int start_umh(void) -{ - struct mbox_request req = { .pid = current->pid }; - struct mbox_reply reply; - int err; - - /* fork usermode process */ - err = fork_usermode_driver(&bpfilter_ops.info); - if (err) - return err; - pr_info("Loaded bpfilter_umh pid %d\n", pid_nr(bpfilter_ops.info.tgid)); - - /* health check that usermode process started correctly */ - if (umd_send_recv(&bpfilter_ops.info, &req, sizeof(req), &reply, - sizeof(reply)) != 0 || reply.status != 0) { - shutdown_umh(); - return -EFAULT; - } - - return 0; -} - static int __init load_umh(void) { - int err; - - err = umd_load_blob(&bpfilter_ops.info, - &bpfilter_umh_start, - &bpfilter_umh_end - &bpfilter_umh_start); - if (err) - return err; - - mutex_lock(&bpfilter_ops.lock); - err = start_umh(); - if (!err && IS_ENABLED(CONFIG_INET)) { - bpfilter_ops.sockopt = &bpfilter_process_sockopt; - bpfilter_ops.start = &start_umh; - } - mutex_unlock(&bpfilter_ops.lock); - if (err) - umd_unload_blob(&bpfilter_ops.info); - return err; + return umd_mgmt_load(&bpfilter_ops, &bpfilter_umh_start, + &bpfilter_umh_end); } static void __exit fini_umh(void) { - mutex_lock(&bpfilter_ops.lock); - if (IS_ENABLED(CONFIG_INET)) { - shutdown_umh(); - bpfilter_ops.start = NULL; - bpfilter_ops.sockopt = NULL; - } - mutex_unlock(&bpfilter_ops.lock); - - umd_unload_blob(&bpfilter_ops.info); + umd_mgmt_unload(&bpfilter_ops); } module_init(load_umh); module_exit(fini_umh); diff --git a/net/ipv4/bpfilter/sockopt.c b/net/ipv4/bpfilter/sockopt.c index 1b34cb9a770..491f5042612 100644 --- a/net/ipv4/bpfilter/sockopt.c +++ b/net/ipv4/bpfilter/sockopt.c @@ -8,8 +8,9 @@ #include #include #include +#include "../../bpfilter/msgfmt.h" -struct bpfilter_umh_ops bpfilter_ops; +struct umd_mgmt bpfilter_ops; EXPORT_SYMBOL_GPL(bpfilter_ops); void bpfilter_umh_cleanup(struct umd_info *info) @@ -21,40 +22,49 @@ void bpfilter_umh_cleanup(struct umd_info *info) } EXPORT_SYMBOL_GPL(bpfilter_umh_cleanup); -static int bpfilter_mbox_request(struct sock *sk, int optname, sockptr_t optval, - unsigned int optlen, bool is_set) +static int bpfilter_process_sockopt(struct sock *sk, int optname, + sockptr_t optval, unsigned int optlen, + bool is_set) { + struct mbox_request req = { + .is_set = is_set, + .pid = current->pid, + .cmd = optname, + .addr = (uintptr_t)optval.user, + .len = optlen, + }; + struct mbox_reply reply; int err; - mutex_lock(&bpfilter_ops.lock); - if (!bpfilter_ops.sockopt) { - mutex_unlock(&bpfilter_ops.lock); - request_module("bpfilter"); - mutex_lock(&bpfilter_ops.lock); - if (!bpfilter_ops.sockopt) { - err = -ENOPROTOOPT; - goto out; - } + if (sockptr_is_kernel(optval)) { + pr_err("kernel access not supported\n"); + return -EFAULT; } - if (bpfilter_ops.info.tgid && - thread_group_exited(bpfilter_ops.info.tgid)) - bpfilter_umh_cleanup(&bpfilter_ops.info); + err = umd_mgmt_send_recv(&bpfilter_ops, &req, sizeof(req), &reply, + sizeof(reply)); + if (err) + return err; - if (!bpfilter_ops.info.tgid) { - err = bpfilter_ops.start(); - if (err) - goto out; - } - err = bpfilter_ops.sockopt(sk, optname, optval, optlen, is_set); -out: - mutex_unlock(&bpfilter_ops.lock); - return err; + return reply.status; +} + +static int bpfilter_post_start_umh(struct umd_mgmt *mgmt) +{ + struct mbox_request req = { .pid = current->pid }; + struct mbox_reply reply; + + /* health check that usermode process started correctly */ + if (umd_send_recv(&bpfilter_ops.info, &req, sizeof(req), &reply, + sizeof(reply)) != 0 || reply.status != 0) + return -EFAULT; + + return 0; } int bpfilter_ip_set_sockopt(struct sock *sk, int optname, sockptr_t optval, unsigned int optlen) { - return bpfilter_mbox_request(sk, optname, optval, optlen, true); + return bpfilter_process_sockopt(sk, optname, optval, optlen, true); } int bpfilter_ip_get_sockopt(struct sock *sk, int optname, char __user *optval, @@ -65,8 +75,8 @@ int bpfilter_ip_get_sockopt(struct sock *sk, int optname, char __user *optval, if (get_user(len, optlen)) return -EFAULT; - return bpfilter_mbox_request(sk, optname, USER_SOCKPTR(optval), len, - false); + return bpfilter_process_sockopt(sk, optname, USER_SOCKPTR(optval), len, + false); } static int __init bpfilter_sockopt_init(void) @@ -74,6 +84,9 @@ static int __init bpfilter_sockopt_init(void) mutex_init(&bpfilter_ops.lock); bpfilter_ops.info.tgid = NULL; bpfilter_ops.info.driver_name = "bpfilter_umh"; + bpfilter_ops.post_start = bpfilter_post_start_umh; + bpfilter_ops.kmod = "bpfilter"; + bpfilter_ops.kmod_loaded = false; return 0; } From patchwork Fri Mar 17 14:52:39 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Roberto Sassu X-Patchwork-Id: 13179213 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 75773C76195 for ; Fri, 17 Mar 2023 15:33:37 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230451AbjCQPdf (ORCPT ); Fri, 17 Mar 2023 11:33:35 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:39958 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230212AbjCQPde (ORCPT ); Fri, 17 Mar 2023 11:33:34 -0400 Received: from frasgout12.his.huawei.com (frasgout12.his.huawei.com [14.137.139.154]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 594C0C3CEB; Fri, 17 Mar 2023 08:33:04 -0700 (PDT) Received: from mail02.huawei.com (unknown [172.18.147.228]) by frasgout12.his.huawei.com (SkyGuard) with ESMTP id 4PdRkC08qjz9xGYt; Fri, 17 Mar 2023 22:45:07 +0800 (CST) Received: from huaweicloud.com (unknown [10.204.63.22]) by APP2 (Coremail) with SMTP id GxC2BwBnOWDafhRkaQemAQ--.41316S6; Fri, 17 Mar 2023 15:54:17 +0100 (CET) From: Roberto Sassu To: corbet@lwn.net, ast@kernel.org, daniel@iogearbox.net, andrii@kernel.org, martin.lau@linux.dev, song@kernel.org, yhs@fb.com, john.fastabend@gmail.com, kpsingh@kernel.org, sdf@google.com, haoluo@google.com, jolsa@kernel.org, davem@davemloft.net, edumazet@google.com, kuba@kernel.org, pabeni@redhat.com, dsahern@kernel.org, shuah@kernel.org, brauner@kernel.org Cc: linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, bpf@vger.kernel.org, netdev@vger.kernel.org, linux-kselftest@vger.kernel.org, ebiederm@xmission.com, mcgrof@kernel.org, Roberto Sassu Subject: [PATCH 4/5] selftests/umd_mgmt: Add selftests for UMD management library Date: Fri, 17 Mar 2023 15:52:39 +0100 Message-Id: <20230317145240.363908-5-roberto.sassu@huaweicloud.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20230317145240.363908-1-roberto.sassu@huaweicloud.com> References: <20230317145240.363908-1-roberto.sassu@huaweicloud.com> MIME-Version: 1.0 X-CM-TRANSID: GxC2BwBnOWDafhRkaQemAQ--.41316S6 X-Coremail-Antispam: 1UD129KBjvAXoWfXr17tr4rXF4UGw1kAFyUAwb_yoW8JFyfuo ZxGrs8Wr409347Aw13Wr4xJrWxW393KF17JF1rW3yrJF9rAayYkryUCw13Zr4Svr4rZa40 vF1qva1xJayrXr1kn29KB7ZKAUJUUUU8529EdanIXcx71UUUUU7v73VFW2AGmfu7bjvjm3 AaLaJ3UjIYCTnIWjp_UUUOo7kC6x804xWl14x267AKxVWrJVCq3wAFc2x0x2IEx4CE42xK 8VAvwI8IcIk0rVWrJVCq3wAFIxvE14AKwVWUJVWUGwA2048vs2IY020E87I2jVAFwI0_JF 0E3s1l82xGYIkIc2x26xkF7I0E14v26ryj6s0DM28lY4IEw2IIxxk0rwA2F7IY1VAKz4vE j48ve4kI8wA2z4x0Y4vE2Ix0cI8IcVAFwI0_Jr0_JF4l84ACjcxK6xIIjxv20xvEc7CjxV AFwI0_Gr1j6F4UJwA2z4x0Y4vEx4A2jsIE14v26r4j6F4UM28EF7xvwVC2z280aVCY1x02 67AKxVW8Jr0_Cr1UM2AIxVAIcxkEcVAq07x20xvEncxIr21l5I8CrVACY4xI64kE6c02F4 0Ex7xfMcIj6xIIjxv20xvE14v26r1j6r18McIj6I8E87Iv67AKxVWUJVW8JwAm72CE4IkC 6x0Yz7v_Jr0_Gr1lF7xvr2IYc2Ij64vIr41lFIxGxcIEc7CjxVA2Y2ka0xkIwI1lc7CjxV Aaw2AFwI0_GFv_Wryl42xK82IYc2Ij64vIr41l4I8I3I0E4IkC6x0Yz7v_Jr0_Gr1lx2Iq xVAqx4xG67AKxVWUJVWUGwC20s026x8GjcxK67AKxVWUGVWUWwC2zVAF1VAY17CE14v26r 4a6rW5MIIYrxkI7VAKI48JMIIF0xvE2Ix0cI8IcVAFwI0_Jr0_JF4lIxAIcVC0I7IYx2IY 6xkF7I0E14v26r4UJVWxJr1lIxAIcVCF04k26cxKx2IYs7xG6r1j6r1xMIIF0xvEx4A2js IE14v26r4j6F4UMIIF0xvEx4A2jsIEc7CjxVAFwI0_Gr1j6F4UJbIYCTnIWIevJa73UjIF yTuYvjxUI-eODUUUU X-CM-SenderInfo: purev21wro2thvvxqx5xdzvxpfor3voofrz/1tbiAgATBF1jj4asxgAFsN X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org From: Roberto Sassu Introduce a simple UMD driver using the management library, for testing purposes. UMD Manager: sample_mgr.c UMD Loader: sample_loader.c UMD Handler: sample_handler.c The UMD Manager exposes /sys/kernel/security/sample_umd and accepts an offset between 0-128K. It invokes the UMD Loader to start the UMD Handler and passes to the latter the offset at which it sets the byte of the response buffer to 1. The UMD Manager verifies that and returns the number of bytes written on success, a negative value on failure. Signed-off-by: Roberto Sassu --- MAINTAINERS | 1 + tools/testing/selftests/Makefile | 1 + tools/testing/selftests/umd_mgmt/.gitignore | 1 + tools/testing/selftests/umd_mgmt/Makefile | 14 ++ tools/testing/selftests/umd_mgmt/config | 1 + .../selftests/umd_mgmt/sample_umd/Makefile | 22 ++++ .../selftests/umd_mgmt/sample_umd/msgfmt.h | 13 ++ .../umd_mgmt/sample_umd/sample_binary_blob.S | 7 + .../umd_mgmt/sample_umd/sample_handler.c | 81 ++++++++++++ .../umd_mgmt/sample_umd/sample_loader.c | 28 ++++ .../umd_mgmt/sample_umd/sample_mgr.c | 124 ++++++++++++++++++ tools/testing/selftests/umd_mgmt/umd_mgmt.sh | 40 ++++++ 12 files changed, 333 insertions(+) create mode 100644 tools/testing/selftests/umd_mgmt/.gitignore create mode 100644 tools/testing/selftests/umd_mgmt/Makefile create mode 100644 tools/testing/selftests/umd_mgmt/config create mode 100644 tools/testing/selftests/umd_mgmt/sample_umd/Makefile create mode 100644 tools/testing/selftests/umd_mgmt/sample_umd/msgfmt.h create mode 100644 tools/testing/selftests/umd_mgmt/sample_umd/sample_binary_blob.S create mode 100644 tools/testing/selftests/umd_mgmt/sample_umd/sample_handler.c create mode 100644 tools/testing/selftests/umd_mgmt/sample_umd/sample_loader.c create mode 100644 tools/testing/selftests/umd_mgmt/sample_umd/sample_mgr.c create mode 100755 tools/testing/selftests/umd_mgmt/umd_mgmt.sh diff --git a/MAINTAINERS b/MAINTAINERS index 7b27435fd20..a0cd161843e 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -11251,6 +11251,7 @@ L: linux-kernel@vger.kernel.org S: Maintained F: include/linux/usermode_driver_mgmt.h F: kernel/usermode_driver_mgmt.c +F: tools/testing/selftests/umd_mgmt/* KERNEL VIRTUAL MACHINE (KVM) M: Paolo Bonzini diff --git a/tools/testing/selftests/Makefile b/tools/testing/selftests/Makefile index 13a6837a0c6..84202d5b4fb 100644 --- a/tools/testing/selftests/Makefile +++ b/tools/testing/selftests/Makefile @@ -84,6 +84,7 @@ TARGETS += timers endif TARGETS += tmpfs TARGETS += tpm2 +TARGETS += umd_mgmt TARGETS += user TARGETS += vDSO TARGETS += mm diff --git a/tools/testing/selftests/umd_mgmt/.gitignore b/tools/testing/selftests/umd_mgmt/.gitignore new file mode 100644 index 00000000000..215c17d13e9 --- /dev/null +++ b/tools/testing/selftests/umd_mgmt/.gitignore @@ -0,0 +1 @@ +/sample_umd/sample_umh diff --git a/tools/testing/selftests/umd_mgmt/Makefile b/tools/testing/selftests/umd_mgmt/Makefile new file mode 100644 index 00000000000..f1d47eec04e --- /dev/null +++ b/tools/testing/selftests/umd_mgmt/Makefile @@ -0,0 +1,14 @@ +# SPDX-License-Identifier: GPL-2.0 +TEST_GEN_PROGS_EXTENDED = sample_umd.ko + +$(OUTPUT)/%.ko: $(wildcard sample_umd/Makefile sample_umd/*.[ch]) + $(call msg,MOD,,$@) + $(Q)$(MAKE) -C sample_umd install + +OVERRIDE_TARGETS := 1 +override define CLEAN + $(call msg,CLEAN) + $(Q)$(MAKE) -C sample_umd clean +endef + +include ../lib.mk diff --git a/tools/testing/selftests/umd_mgmt/config b/tools/testing/selftests/umd_mgmt/config new file mode 100644 index 00000000000..71a078a3ac0 --- /dev/null +++ b/tools/testing/selftests/umd_mgmt/config @@ -0,0 +1 @@ +CONFIG_BPFILTER=y diff --git a/tools/testing/selftests/umd_mgmt/sample_umd/Makefile b/tools/testing/selftests/umd_mgmt/sample_umd/Makefile new file mode 100644 index 00000000000..6d950e05f3d --- /dev/null +++ b/tools/testing/selftests/umd_mgmt/sample_umd/Makefile @@ -0,0 +1,22 @@ +KDIR ?= ../../../../.. + +userprogs := sample_umh +sample_umh-objs := sample_handler.o +userccflags += -I $(srctree) + +$(obj)/sample_binary_blob.o: $(obj)/sample_umh + +MODULES = sample_loader_kmod.ko sample_mgr.ko + +obj-m += sample_loader_kmod.o sample_mgr.o + +sample_loader_kmod-objs = sample_loader.o sample_binary_blob.o + +all: + +$(Q)$(MAKE) -C $(KDIR) M=$$PWD modules + +clean: + +$(Q)$(MAKE) -C $(KDIR) M=$$PWD clean + +install: all + +$(Q)$(MAKE) -C $(KDIR) M=$$PWD modules_install diff --git a/tools/testing/selftests/umd_mgmt/sample_umd/msgfmt.h b/tools/testing/selftests/umd_mgmt/sample_umd/msgfmt.h new file mode 100644 index 00000000000..34a62d72cde --- /dev/null +++ b/tools/testing/selftests/umd_mgmt/sample_umd/msgfmt.h @@ -0,0 +1,13 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef _SAMPLE_UMH_MSGFMT_H +#define _SAMPLE_UMH_MSGFMT_H + +struct sample_request { + uint32_t offset; +}; + +struct sample_reply { + uint8_t data[128 * 1024]; +}; + +#endif diff --git a/tools/testing/selftests/umd_mgmt/sample_umd/sample_binary_blob.S b/tools/testing/selftests/umd_mgmt/sample_umd/sample_binary_blob.S new file mode 100644 index 00000000000..3687dd13973 --- /dev/null +++ b/tools/testing/selftests/umd_mgmt/sample_umd/sample_binary_blob.S @@ -0,0 +1,7 @@ +/* SPDX-License-Identifier: GPL-2.0 */ + .section .init.rodata, "a" + .global sample_umh_start +sample_umh_start: + .incbin "tools/testing/selftests/umd_mgmt/sample_umd/sample_umh" + .global sample_umh_end +sample_umh_end: diff --git a/tools/testing/selftests/umd_mgmt/sample_umd/sample_handler.c b/tools/testing/selftests/umd_mgmt/sample_umd/sample_handler.c new file mode 100644 index 00000000000..94ea6d99bbc --- /dev/null +++ b/tools/testing/selftests/umd_mgmt/sample_umd/sample_handler.c @@ -0,0 +1,81 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright (C) 2023 Huawei Technologies Duesseldorf GmbH + * + * Author: Roberto Sassu + * + * Implement the UMD Handler. + */ +#include +#include +#include + +#include "msgfmt.h" + +FILE *debug_f; + +static void loop(void) +{ + struct sample_request *req = NULL; + struct sample_reply *reply = NULL; + + req = calloc(1, sizeof(*req)); + if (!req) + return; + + reply = calloc(1, sizeof(*reply)); + if (!reply) + goto out; + + while (1) { + int n, len, offset; + + offset = 0; + len = sizeof(*req); + + while (len) { + n = read(0, ((void *)req) + offset, len); + if (n <= 0) { + fprintf(debug_f, "invalid request %d\n", n); + goto out; + } + + len -= n; + offset += n; + } + + if (req->offset < sizeof(reply->data)) + reply->data[req->offset] = 1; + + offset = 0; + len = sizeof(*reply); + + while (len) { + n = write(1, ((void *)reply) + offset, len); + if (n <= 0) { + fprintf(debug_f, "reply failed %d\n", n); + goto out; + } + + len -= n; + offset += n; + } + + if (req->offset < sizeof(reply->data)) + reply->data[req->offset] = 0; + } +out: + free(req); + free(reply); +} + +int main(void) +{ + debug_f = fopen("/dev/kmsg", "w"); + setvbuf(debug_f, 0, _IOLBF, 0); + fprintf(debug_f, "<5>Started sample_umh\n"); + loop(); + fclose(debug_f); + + return 0; +} diff --git a/tools/testing/selftests/umd_mgmt/sample_umd/sample_loader.c b/tools/testing/selftests/umd_mgmt/sample_umd/sample_loader.c new file mode 100644 index 00000000000..36c0e69e3f7 --- /dev/null +++ b/tools/testing/selftests/umd_mgmt/sample_umd/sample_loader.c @@ -0,0 +1,28 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright (C) 2023 Huawei Technologies Duesseldorf GmbH + * + * Author: Roberto Sassu + * + * Implement the UMD Loader (credits: bpfilter). + */ +#include +#include + +extern char sample_umh_start; +extern char sample_umh_end; +extern struct umd_mgmt sample_mgmt_ops; + +static int __init load_umh(void) +{ + return umd_mgmt_load(&sample_mgmt_ops, &sample_umh_start, + &sample_umh_end); +} + +static void __exit fini_umh(void) +{ + umd_mgmt_unload(&sample_mgmt_ops); +} +module_init(load_umh); +module_exit(fini_umh); +MODULE_LICENSE("GPL"); diff --git a/tools/testing/selftests/umd_mgmt/sample_umd/sample_mgr.c b/tools/testing/selftests/umd_mgmt/sample_umd/sample_mgr.c new file mode 100644 index 00000000000..75c572f9849 --- /dev/null +++ b/tools/testing/selftests/umd_mgmt/sample_umd/sample_mgr.c @@ -0,0 +1,124 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright (C) 2023 Huawei Technologies Duesseldorf GmbH + * + * Author: Roberto Sassu + * + * Implement the UMD Manager. + */ +#include +#include +#include +#include + +#include "msgfmt.h" + +struct umd_mgmt sample_mgmt_ops; +EXPORT_SYMBOL_GPL(sample_mgmt_ops); + +struct dentry *sample_umd_dentry; + +static int sample_write_common(u32 offset, bool test) +{ + struct sample_request *req; + struct sample_reply *reply; + int ret; + + req = kzalloc(sizeof(*req), GFP_KERNEL); + if (!req) { + ret = -ENOMEM; + goto out; + } + + reply = kzalloc(sizeof(*reply), GFP_KERNEL); + if (!reply) { + ret = -ENOMEM; + goto out; + } + + req->offset = offset; + + if (test) + /* Lock is already taken. */ + ret = umd_send_recv(&sample_mgmt_ops.info, req, sizeof(*req), + reply, sizeof(*reply)); + else + ret = umd_mgmt_send_recv(&sample_mgmt_ops, req, sizeof(*req), + reply, sizeof(*reply)); + if (ret < 0) + goto out; + + if (reply->data[req->offset] != 1) { + ret = -EINVAL; + goto out; + } +out: + kfree(req); + kfree(reply); + + return ret; +} + +static ssize_t sample_umd_write(struct file *file, const char __user *buf, + size_t datalen, loff_t *ppos) +{ + char offset_str[8]; + u32 offset; + int ret; + + if (datalen >= sizeof(offset_str)) + return -EINVAL; + + ret = copy_from_user(offset_str, buf, datalen); + if (ret < 0) + return ret; + + offset_str[datalen] = '\0'; + + ret = kstrtou32(offset_str, 10, &offset); + if (ret < 0) + return ret; + + if (offset >= sizeof(((struct sample_reply *)0)->data)) + return -EINVAL; + + ret = sample_write_common(offset, false); + if (ret < 0) + return ret; + + return datalen; +} + +static const struct file_operations sample_umd_file_ops = { + .write = sample_umd_write, +}; + +static int sample_post_start_umh(struct umd_mgmt *mgmt) +{ + return sample_write_common(0, true); +} + +static int __init load_umh(void) +{ + mutex_init(&sample_mgmt_ops.lock); + sample_mgmt_ops.info.tgid = NULL; + sample_mgmt_ops.info.driver_name = "sample_umh"; + sample_mgmt_ops.post_start = sample_post_start_umh; + sample_mgmt_ops.kmod = "sample_loader_kmod"; + sample_mgmt_ops.kmod_loaded = false; + + sample_umd_dentry = securityfs_create_file("sample_umd", 0200, NULL, + NULL, &sample_umd_file_ops); + if (IS_ERR(sample_umd_dentry)) + return PTR_ERR(sample_umd_dentry); + + return 0; +} + +static void __exit fini_umh(void) +{ + securityfs_remove(sample_umd_dentry); +} +module_init(load_umh); +module_exit(fini_umh); +MODULE_LICENSE("GPL"); diff --git a/tools/testing/selftests/umd_mgmt/umd_mgmt.sh b/tools/testing/selftests/umd_mgmt/umd_mgmt.sh new file mode 100755 index 00000000000..9b90d737fec --- /dev/null +++ b/tools/testing/selftests/umd_mgmt/umd_mgmt.sh @@ -0,0 +1,40 @@ +#!/bin/bash +# SPDX-License-Identifier: GPL-2.0-only +# +# Copyright (C) 2023 Huawei Technologies Duesseldorf GmbH +# +# Author: Roberto Sassu +# +# Script to test the UMD management library. + +# Kselftest framework defines: ksft_pass=0, ksft_fail=1, ksft_skip=4 +ksft_pass=0 +ksft_fail=1 +ksft_skip=4 + +if ! /sbin/modprobe -q sample_mgr; then + echo "umd_mgmt: module sample_mgr is not found [SKIP]" + exit $ksft_skip +fi + +if [ ! -f /sys/kernel/security/sample_umd ]; then + echo "umd_mgmt: kernel interface is not found [SKIP]" + exit $ksft_skip +fi + +i=0 + +while [ $i -lt 500 ]; do + if ! echo $(( RANDOM % 128 * 1024 )) > /sys/kernel/security/sample_umd; then + echo "umd_mgmt: test failed" + exit $ksft_fail + fi + + if [ $(( i % 50 )) -eq 0 ]; then + rmmod sample_loader_kmod + fi + + (( i++ )) +done + +exit $ksft_pass From patchwork Fri Mar 17 14:52:40 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Roberto Sassu X-Patchwork-Id: 13179144 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 71343C76196 for ; Fri, 17 Mar 2023 14:55:05 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231327AbjCQOzD (ORCPT ); Fri, 17 Mar 2023 10:55:03 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:36740 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230196AbjCQOzC (ORCPT ); Fri, 17 Mar 2023 10:55:02 -0400 Received: from frasgout11.his.huawei.com (frasgout11.his.huawei.com [14.137.139.23]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 0F6C6559C1; Fri, 17 Mar 2023 07:54:53 -0700 (PDT) Received: from mail02.huawei.com (unknown [172.18.147.228]) by frasgout11.his.huawei.com (SkyGuard) with ESMTP id 4PdRl72Zggz9xqck; Fri, 17 Mar 2023 22:45:55 +0800 (CST) Received: from huaweicloud.com (unknown [10.204.63.22]) by APP2 (Coremail) with SMTP id GxC2BwBnOWDafhRkaQemAQ--.41316S7; Fri, 17 Mar 2023 15:54:29 +0100 (CET) From: Roberto Sassu To: corbet@lwn.net, ast@kernel.org, daniel@iogearbox.net, andrii@kernel.org, martin.lau@linux.dev, song@kernel.org, yhs@fb.com, john.fastabend@gmail.com, kpsingh@kernel.org, sdf@google.com, haoluo@google.com, jolsa@kernel.org, davem@davemloft.net, edumazet@google.com, kuba@kernel.org, pabeni@redhat.com, dsahern@kernel.org, shuah@kernel.org, brauner@kernel.org Cc: linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, bpf@vger.kernel.org, netdev@vger.kernel.org, linux-kselftest@vger.kernel.org, ebiederm@xmission.com, mcgrof@kernel.org, Roberto Sassu Subject: [PATCH 5/5] doc: Add documentation for the User Mode Driver management library Date: Fri, 17 Mar 2023 15:52:40 +0100 Message-Id: <20230317145240.363908-6-roberto.sassu@huaweicloud.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20230317145240.363908-1-roberto.sassu@huaweicloud.com> References: <20230317145240.363908-1-roberto.sassu@huaweicloud.com> MIME-Version: 1.0 X-CM-TRANSID: GxC2BwBnOWDafhRkaQemAQ--.41316S7 X-Coremail-Antispam: 1UD129KBjvJXoW3Gw4Utr4kKFWrKrWrGw18AFb_yoW7AFW8pF Z3JrWft3WkJryavr1fJw17uryrZas7Ja15GFn3Kw1rZwn8Zrn0yr1Ut3WFqFyUGryFyrW5 tr15Jr1UCw1DAr7anT9S1TB71UUUUU7qnTZGkaVYY2UrUUUUjbIjqfuFe4nvWSU5nxnvy2 9KBjDU0xBIdaVrnRJUUUPlb4IE77IF4wAFF20E14v26rWj6s0DM7CY07I20VC2zVCF04k2 6cxKx2IYs7xG6rWj6s0DM7CIcVAFz4kK6r1j6r18M28IrcIa0xkI8VA2jI8067AKxVWUAV Cq3wA2048vs2IY020Ec7CjxVAFwI0_Xr0E3s1l8cAvFVAK0II2c7xJM28CjxkF64kEwVA0 rcxSw2x7M28EF7xvwVC0I7IYx2IY67AKxVWUCVW8JwA2z4x0Y4vE2Ix0cI8IcVCY1x0267 AKxVW8Jr0_Cr1UM28EF7xvwVC2z280aVAFwI0_Gr0_Cr1l84ACjcxK6I8E87Iv6xkF7I0E 14v26r4UJVWxJr1le2I262IYc4CY6c8Ij28IcVAaY2xG8wAqx4xG64xvF2IEw4CE5I8CrV C2j2WlYx0E2Ix0cI8IcVAFwI0_Jr0_Jr4lYx0Ex4A2jsIE14v26r1j6r4UMcvjeVCFs4IE 7xkEbVWUJVW8JwACjcxG0xvY0x0EwIxGrwACI402YVCY1x02628vn2kIc2xKxwCY1x0262 kKe7AKxVW8ZVWrXwCF04k20xvY0x0EwIxGrwCFx2IqxVCFs4IE7xkEbVWUJVW8JwC20s02 6c02F40E14v26r1j6r18MI8I3I0E7480Y4vE14v26r106r1rMI8E67AF67kF1VAFwI0_GF v_WrylIxkGc2Ij64vIr41lIxAIcVC0I7IYx2IY67AKxVWUCVW8JwCI42IY6xIIjxv20xvE c7CjxVAFwI0_Gr1j6F4UJwCI42IY6xAIw20EY4v20xvaj40_Jr0_JF4lIxAIcVC2z280aV AFwI0_Gr0_Cr1lIxAIcVC2z280aVCY1x0267AKxVW8Jr0_Cr1UYxBIdaVFxhVjvjDU0xZF pf9x07jIPfQUUUUU= X-CM-SenderInfo: purev21wro2thvvxqx5xdzvxpfor3voofrz/1tbiAQATBF1jj4qqgQAAsG X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org From: Roberto Sassu Add a documentation, to explain the motivation behind the new component, to describe the software architecture, the API and an example used for testing. Signed-off-by: Roberto Sassu Reviewed-by: Bagas Sanjaya --- Documentation/driver-api/index.rst | 1 + Documentation/driver-api/umd_mgmt.rst | 99 +++++++++++++++++++++++++++ MAINTAINERS | 1 + 3 files changed, 101 insertions(+) create mode 100644 Documentation/driver-api/umd_mgmt.rst diff --git a/Documentation/driver-api/index.rst b/Documentation/driver-api/index.rst index ff9aa1afdc6..ad42cd968dc 100644 --- a/Documentation/driver-api/index.rst +++ b/Documentation/driver-api/index.rst @@ -113,6 +113,7 @@ available subsections can be seen below. xillybus zorro hte/index + umd_mgmt .. only:: subproject and html diff --git a/Documentation/driver-api/umd_mgmt.rst b/Documentation/driver-api/umd_mgmt.rst new file mode 100644 index 00000000000..7dbb50b3643 --- /dev/null +++ b/Documentation/driver-api/umd_mgmt.rst @@ -0,0 +1,99 @@ +.. SPDX-License-Identifier: GPL-2.0 + +=================================== +User Mode Driver Management Library +=================================== + +:Author: Roberto Sassu, Huawei Technologies Duesseldorf GmbH +:Date: 2023-03-16 + +Introduction +============ + +The idea of moving code away from the kernel and running it in user space +is not new. For example, the User Space I/O driver model allows developers +to implement most of the driver logic in user space, and keep only a small +part in a kernel module, for example to handle interrupts. + +The User Mode Driver (UMD) is a more specialized solution, primarily used +by bpfilter, consisting of a user space process running from code embedded +in a kernel module, communicating only through a pipe with the kernel. + +The kernel makes a request, possibly originated by the user of the system, +and sends it to the user space process. The latter handles the kernel +request, and sends the response back to the kernel. Finally, the kernel +eventually forwards the result to the user. + +This usage model is particularly interesting for security. The kernel can +offload to user space workloads that could introduce possible threats, for +example parsing unknown and possibly malicious data. While the kernel +already does that, it is important to limit to the minimum the chances of +an attacker to exploit a vulnerability in the kernel code. + +If a user space process becomes corrupted, it can still send malicious data +to the kernel, but it won't be able to directly corrupt the kernel memory. +In addition, if the communication protocol between the user space process +and the kernel is simple enough, malicious data can be effectively +sanitized. + +The purpose of this library is simply to facilitate developers to create +UMDs and to help them customize the UMDs to their needs. + + + +Architecture +============ + +The architecture of the UMD library is as follows: + +:: + + +-----------+ +---------------+ + | UMD | 2. request module | UMD Loader | + | Manager |------------------->| (kmod + | + | |------+ | user binary) | + +-----------+ | +---------------+ + ^ | | kernel space + -------------------------------------------------------------------------- + | | 4. send/ v 3. fork/execve/pipe user space + | | receive +-------------+ + 1. user request +------------>| UMD Handler | + | (exec user | + | binary) | + +-------------+ + +The `UMD Manager` is the frontend interface to any user or +kernel-originated request. It invokes the `UMD Loader` to start the +`UMD Handler`, and communicates with the latter to satisfy the request. + +The `UMD Loader` is merely responsible to extract the `user binary` from +the kernel module, copy it to a tmpfs filesystem, fork the current process, +start the `UMD Handler`, and create a pipe for the communication between +the `UMD Manager` and the `UMD Handler`. + +The `UMD Handler` reads requests from the `UMD Manager`, processes them +internally, and sends the response to it. + + +API +=== + +.. kernel-doc:: include/linux/usermode_driver_mgmt.h + +.. kernel-doc:: kernel/usermode_driver_mgmt.c + + +Example +======= + +An example of usage of the UMD management library can be found in +tools/testing/selftests/umd_mgmt/sample_umd. + +sample_mgr.c implements the `UMD Manager`, sample_loader.c implements the +`UMD Loader` and, finally, sample_handler.c implements the `UMD Handler`. + +The `UMD Manager` exposes /sys/kernel/security/sample_umd and accepts a +number between 0-128K intended as an offset in the response buffer, at +which the `UMD Handler` sets the byte to 1. The `UMD Manager` verifies +that. If the byte is not set to 1, the `UMD Manager` rejects the write, so +that the failure can be reported by the test. diff --git a/MAINTAINERS b/MAINTAINERS index a0cd161843e..4b9d251259d 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -11249,6 +11249,7 @@ KERNEL USERMODE DRIVER MANAGEMENT M: Roberto Sassu L: linux-kernel@vger.kernel.org S: Maintained +F: Documentation/driver-api/umd_mgmt.rst F: include/linux/usermode_driver_mgmt.h F: kernel/usermode_driver_mgmt.c F: tools/testing/selftests/umd_mgmt/*