From nobody Fri Dec 19 20:42:16 2025 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 0D135C6FA89 for ; Thu, 15 Sep 2022 15:07:53 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230497AbiIOPHt (ORCPT ); Thu, 15 Sep 2022 11:07:49 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:46788 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230388AbiIOPG1 (ORCPT ); Thu, 15 Sep 2022 11:06:27 -0400 Received: from mail-ej1-x64a.google.com (mail-ej1-x64a.google.com [IPv6:2a00:1450:4864:20::64a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 41EB08F940 for ; Thu, 15 Sep 2022 08:05:24 -0700 (PDT) Received: by mail-ej1-x64a.google.com with SMTP id qk37-20020a1709077fa500b00730c2d975a0so7695630ejc.13 for ; Thu, 15 Sep 2022 08:05:24 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20210112; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:from:to:cc:subject:date; bh=uEBXmIOJ/jVJ62g3MgOZ1PWj/PPm6Zng9ZXCGF8oCGQ=; b=d96TG3Hxv6sIG0D9GCl0RiC+uFhT+JLVK6sevFTTg2cGiOmsNKa0agzQa6C6xzYpgB KrER5gjEWJxrUVaZFexycRUvOwztcaivd+5Ql+JyY3mBj0Ia9jZkUxSEK4PULX7m/EV6 XWACNEeJZDhm241z1k7FPfy66U38FvMA/gORPAoDPIW41/YFRIqK1uT63SaSHtWW0R0x q4TO7avKYTsOs8uhvI820+846g4n5hZBN5ENyr4KQ8lx22/A9EtRnuyzFUnVUEdfkMx/ sfWQuT3tK6ZVt0bBZuCbUoQf0lkYauyM3gSJyZgZsuanpkHtxDrS16OPGAfrdP3wp1IT m86g== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:x-gm-message-state:from:to:cc:subject:date; bh=uEBXmIOJ/jVJ62g3MgOZ1PWj/PPm6Zng9ZXCGF8oCGQ=; b=8NZEdmMJPmeXIhT0/pQmRzcnZpykt4lg37wrb/LE1dsgbri9W6wdW3uNOYl64vMpjS OBeOepMz2p8gmYmxONzJqsD8O06oUegBOU4nNnt1/ogUjopejNonxJ58IEjENRQeD5hF vN9MDsTea0zYbKNKbkeFX4GqG2V0IBaYFu1lnJH50Qm2fv9mTSYt+JIkWY2BqNHg2uDj s3DgsNF4hLsMixyyaD8jimbvXmdxxKmbHp8DcY5zdgDA8AnQrk6v7CdCIU0LsUEuyNmz T3Iebu457QJb854rEQ2TRJtLprmYXzxi9N4egNe4cgRUu6jOtPpj2IZDhfgWylZS31G0 HH3A== X-Gm-Message-State: ACrzQf1waW/lZANCrWRIYyHMaha5eyDTaKQjvdG/5L0xfUQ7GoRod/bU /McxfRTrB5YprjV+fj+3xFzm2T5mRUM= X-Google-Smtp-Source: AMsMyM4p9q4a8kwSPLQHupWtxmE8sSfLUWhBeeePGlfGtCaz1sm2ZmFR06/jzES7F9GL5jloyYk/aerrGvE= X-Received: from glider.muc.corp.google.com ([2a00:79e0:9c:201:686d:27b5:495:85b7]) (user=glider job=sendgmr) by 2002:a17:907:7215:b0:780:3153:cca2 with SMTP id dr21-20020a170907721500b007803153cca2mr279565ejc.427.1663254322378; Thu, 15 Sep 2022 08:05:22 -0700 (PDT) Date: Thu, 15 Sep 2022 17:03:50 +0200 In-Reply-To: <20220915150417.722975-1-glider@google.com> Mime-Version: 1.0 References: <20220915150417.722975-1-glider@google.com> X-Mailer: git-send-email 2.37.2.789.g6183377224-goog Message-ID: <20220915150417.722975-17-glider@google.com> Subject: [PATCH v7 16/43] kmsan: handle task creation and exiting From: Alexander Potapenko To: glider@google.com Cc: Alexander Viro , Alexei Starovoitov , Andrew Morton , Andrey Konovalov , Andy Lutomirski , Arnd Bergmann , Borislav Petkov , Christoph Hellwig , Christoph Lameter , David Rientjes , Dmitry Vyukov , Eric Biggers , Eric Dumazet , Greg Kroah-Hartman , Herbert Xu , Ilya Leoshkevich , Ingo Molnar , Jens Axboe , Joonsoo Kim , Kees Cook , Marco Elver , Mark Rutland , Matthew Wilcox , "Michael S. Tsirkin" , Pekka Enberg , Peter Zijlstra , Petr Mladek , Stephen Rothwell , Steven Rostedt , Thomas Gleixner , Vasily Gorbik , Vegard Nossum , Vlastimil Babka , kasan-dev@googlegroups.com, linux-mm@kvack.org, linux-arch@vger.kernel.org, linux-kernel@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" Tell KMSAN that a new task is created, so the tool creates a backing metadata structure for that task. Signed-off-by: Alexander Potapenko --- v2: -- move implementation of kmsan_task_create() and kmsan_task_exit() here v4: -- change sizeof(type) to sizeof(*ptr) v5: -- do not export KMSAN hooks that are not called from modules -- minor comment fix Link: https://linux-review.googlesource.com/id/I0f41c3a1c7d66f7e14aabcfdfc7= c69addb945805 --- include/linux/kmsan.h | 21 +++++++++++++++++++++ kernel/exit.c | 2 ++ kernel/fork.c | 2 ++ mm/kmsan/core.c | 10 ++++++++++ mm/kmsan/hooks.c | 17 +++++++++++++++++ mm/kmsan/kmsan.h | 2 ++ 6 files changed, 54 insertions(+) diff --git a/include/linux/kmsan.h b/include/linux/kmsan.h index 5c4e0079054e6..354aee6f7b1a2 100644 --- a/include/linux/kmsan.h +++ b/include/linux/kmsan.h @@ -15,9 +15,22 @@ =20 struct page; struct kmem_cache; +struct task_struct; =20 #ifdef CONFIG_KMSAN =20 +/** + * kmsan_task_create() - Initialize KMSAN state for the task. + * @task: task to initialize. + */ +void kmsan_task_create(struct task_struct *task); + +/** + * kmsan_task_exit() - Notify KMSAN that a task has exited. + * @task: task about to finish. + */ +void kmsan_task_exit(struct task_struct *task); + /** * kmsan_alloc_page() - Notify KMSAN about an alloc_pages() call. * @page: struct page pointer returned by alloc_pages(). @@ -139,6 +152,14 @@ void kmsan_iounmap_page_range(unsigned long start, uns= igned long end); =20 #else =20 +static inline void kmsan_task_create(struct task_struct *task) +{ +} + +static inline void kmsan_task_exit(struct task_struct *task) +{ +} + static inline int kmsan_alloc_page(struct page *page, unsigned int order, gfp_t flags) { diff --git a/kernel/exit.c b/kernel/exit.c index 84021b24f79e3..f5d620c315662 100644 --- a/kernel/exit.c +++ b/kernel/exit.c @@ -60,6 +60,7 @@ #include #include #include +#include #include #include #include @@ -741,6 +742,7 @@ void __noreturn do_exit(long code) WARN_ON(tsk->plug); =20 kcov_task_exit(tsk); + kmsan_task_exit(tsk); =20 coredump_task_exit(tsk); ptrace_event(PTRACE_EVENT_EXIT, code); diff --git a/kernel/fork.c b/kernel/fork.c index 8a9e92068b150..a438f5ee3aed5 100644 --- a/kernel/fork.c +++ b/kernel/fork.c @@ -37,6 +37,7 @@ #include #include #include +#include #include #include #include @@ -1026,6 +1027,7 @@ static struct task_struct *dup_task_struct(struct tas= k_struct *orig, int node) tsk->worker_private =3D NULL; =20 kcov_task_init(tsk); + kmsan_task_create(tsk); kmap_local_fork(tsk); =20 #ifdef CONFIG_FAULT_INJECTION diff --git a/mm/kmsan/core.c b/mm/kmsan/core.c index 5330138fda5bc..112dce135c7f6 100644 --- a/mm/kmsan/core.c +++ b/mm/kmsan/core.c @@ -37,6 +37,16 @@ bool kmsan_enabled __read_mostly; */ DEFINE_PER_CPU(struct kmsan_ctx, kmsan_percpu_ctx); =20 +void kmsan_internal_task_create(struct task_struct *task) +{ + struct kmsan_ctx *ctx =3D &task->kmsan_ctx; + struct thread_info *info =3D current_thread_info(); + + __memset(ctx, 0, sizeof(*ctx)); + ctx->allow_reporting =3D true; + kmsan_internal_unpoison_memory(info, sizeof(*info), false); +} + void kmsan_internal_poison_memory(void *address, size_t size, gfp_t flags, unsigned int poison_flags) { diff --git a/mm/kmsan/hooks.c b/mm/kmsan/hooks.c index 000703c563a4d..6f3e64b0b61f8 100644 --- a/mm/kmsan/hooks.c +++ b/mm/kmsan/hooks.c @@ -27,6 +27,23 @@ * skipping effects of functions like memset() inside instrumented code. */ =20 +void kmsan_task_create(struct task_struct *task) +{ + kmsan_enter_runtime(); + kmsan_internal_task_create(task); + kmsan_leave_runtime(); +} + +void kmsan_task_exit(struct task_struct *task) +{ + struct kmsan_ctx *ctx =3D &task->kmsan_ctx; + + if (!kmsan_enabled || kmsan_in_runtime()) + return; + + ctx->allow_reporting =3D false; +} + void kmsan_slab_alloc(struct kmem_cache *s, void *object, gfp_t flags) { if (unlikely(object =3D=3D NULL)) diff --git a/mm/kmsan/kmsan.h b/mm/kmsan/kmsan.h index 97d48b45dba58..77ee068c04ae9 100644 --- a/mm/kmsan/kmsan.h +++ b/mm/kmsan/kmsan.h @@ -180,6 +180,8 @@ void kmsan_internal_set_shadow_origin(void *address, si= ze_t size, int b, u32 origin, bool checked); depot_stack_handle_t kmsan_internal_chain_origin(depot_stack_handle_t id); =20 +void kmsan_internal_task_create(struct task_struct *task); + bool kmsan_metadata_is_contiguous(void *addr, size_t size); void kmsan_internal_check_memory(void *addr, size_t size, const void *user= _addr, int reason); --=20 2.37.2.789.g6183377224-goog