From mboxrd@z Thu Jan 1 00:00:00 1970 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 kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id 0946BC00140 for ; Tue, 2 Aug 2022 15:48:26 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 6A1308E0001; Tue, 2 Aug 2022 11:48:26 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 64EF96B0072; Tue, 2 Aug 2022 11:48:26 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 4C9408E0001; Tue, 2 Aug 2022 11:48:26 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0017.hostedemail.com [216.40.44.17]) by kanga.kvack.org (Postfix) with ESMTP id 3AA8A6B0071 for ; Tue, 2 Aug 2022 11:48:26 -0400 (EDT) Received: from smtpin09.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay09.hostedemail.com (Postfix) with ESMTP id 026588133C for ; Tue, 2 Aug 2022 15:48:25 +0000 (UTC) X-FDA: 79755084612.09.B51D82D Received: from mail-wr1-f46.google.com (mail-wr1-f46.google.com [209.85.221.46]) by imf15.hostedemail.com (Postfix) with ESMTP id 9A6B8A0103 for ; Tue, 2 Aug 2022 15:48:25 +0000 (UTC) Received: by mail-wr1-f46.google.com with SMTP id z16so18351546wrh.12 for ; Tue, 02 Aug 2022 08:48:25 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20210112; h=cc:to:subject:message-id:date:from:in-reply-to:references :mime-version:from:to:cc; bh=At7GobCcr6Y9heni/Yduc1l7sWHbyaA1znBRmpamTcU=; b=k0qIjj7CJX3r48zFSSvRSE7fKJFlSgjDIhA8mzTd0ZcpMPn12XJ6fIc2KYUaTigCd4 YTisP+v+bOYKSmD39f3LvDFr2wmoBrlXjEjnEd1DcEx1/IqfjINPjtUZ1BFHlx4j0Jmz LkMV6go6TkzA0Dxo8MRefBSAf8hO5p80YdxlJUhRzLS/CU3z/Ia60UibzxP6Bg6YSTQn +zDdo7F+GVJagu52I/SHqEOVJFdD2+28QTwXq6Ao1VL+DUTX45ePo6q0GGNYWwWYdZ5R g+0wA7U+Jy12i61t6eA5aow37U8Z0u+DjFYtVziFw3KpTKwXYg33h4L/SJGumTZPW654 1v3g== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=cc:to:subject:message-id:date:from:in-reply-to:references :mime-version:x-gm-message-state:from:to:cc; bh=At7GobCcr6Y9heni/Yduc1l7sWHbyaA1znBRmpamTcU=; b=PB927r0+rAMcwK41tK7DzEFLqhvdPvg3DbmndJgYqwajoRLrJXjFe7DNfJ3bRQ+klI DeXG4UOaEB1NZiyiVTSFINk/rJFRUDTIkLFoLmYVHqNQhI+rDdHYXmHEZOM3ceVyrTD5 EhpbknK1DbkazkTIROq/9WNhlT+hiOnpCQ86SgLFhEbMc8u1diyliZl0b9cLvzt2plre diZZJXC8B0xaxWLf0DCyK7D/tUkkdyzZayGmlyAGLEkJQNtVUWIAvH7oonNRAD+OMNKq 95+0k7fCf2LGEaucwNN3g8SGhnds1xEflmUbdtV+0eV4kplnJ+iQVRmFiDsU0DYtlM5K LTyw== X-Gm-Message-State: ACgBeo17JcTnzEMbBVlFpDL9LfEbxUnRZrDlnw/BAKDF3+8cG5nLm7DH 1wJbZOgTnlwY8IZHI060NdWqvkTCcG4Un6x2L9hw7A== X-Google-Smtp-Source: AA6agR7sJpNI3jbui+JxLBQdGVQkDKwSDyZdyGBwAfJb7lo5F2di5P6ZlWKItvxslBAeDMYE4hWgwQfIZ27Du4ierS8= X-Received: by 2002:a05:6000:2c1:b0:220:5f91:62de with SMTP id o1-20020a05600002c100b002205f9162demr8238093wry.715.1659455304037; Tue, 02 Aug 2022 08:48:24 -0700 (PDT) MIME-Version: 1.0 References: <20220701142310.2188015-1-glider@google.com> <20220701142310.2188015-17-glider@google.com> In-Reply-To: From: Alexander Potapenko Date: Tue, 2 Aug 2022 17:47:47 +0200 Message-ID: Subject: Re: [PATCH v4 16/45] kmsan: handle task creation and exiting To: Marco Elver Cc: Alexander Viro , Alexei Starovoitov , Andrew Morton , Andrey Konovalov , Andy Lutomirski , Arnd Bergmann , Borislav Petkov , Christoph Hellwig , Christoph Lameter , David Rientjes , Dmitry Vyukov , Eric Dumazet , Greg Kroah-Hartman , Herbert Xu , Ilya Leoshkevich , Ingo Molnar , Jens Axboe , Joonsoo Kim , Kees Cook , Mark Rutland , Matthew Wilcox , "Michael S. Tsirkin" , Pekka Enberg , Peter Zijlstra , Petr Mladek , Steven Rostedt , Thomas Gleixner , Vasily Gorbik , Vegard Nossum , Vlastimil Babka , kasan-dev , Linux Memory Management List , Linux-Arch , LKML Content-Type: text/plain; charset="UTF-8" ARC-Authentication-Results: i=1; imf15.hostedemail.com; dkim=pass header.d=google.com header.s=20210112 header.b=k0qIjj7C; spf=pass (imf15.hostedemail.com: domain of glider@google.com designates 209.85.221.46 as permitted sender) smtp.mailfrom=glider@google.com; dmarc=pass (policy=reject) header.from=google.com ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1659455305; a=rsa-sha256; cv=none; b=ICCsSPvt94GhhLx5x4SKyH4rH2KaKnNBAWZLTrLRjJMZwxb6fDeANeHp1SJjwKAVOtGKcK HmztD2IRwqTnXoYKwOjJ4iDil8E1ekXciAovoXPZhCQK8/7NPFadjFVDQ3+FEPoYjfQq8P EZKF14QUNmKv8maTCSxzPmg6wOydJxU= ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1659455305; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=At7GobCcr6Y9heni/Yduc1l7sWHbyaA1znBRmpamTcU=; b=Bm+xtCfZpw6VtSyLWVuuBKS9823NUaz6OhIBPOHW07Mw5yP6HkASuM92rk74joAYZjYXQA 0cNP8JUS1LNMiY1cB5R/v5k/Zt5FFzJFLTbYm+uV/FYlW2Knm/TG8i6u1STqpT4RthwsjE wxxqUeXFRgl3EA1ojdue4rOYykNooc8= X-Stat-Signature: moa4bcnhm1t4ni5zs4uoccwqsg7c5sft X-Rspamd-Queue-Id: 9A6B8A0103 Authentication-Results: imf15.hostedemail.com; dkim=pass header.d=google.com header.s=20210112 header.b=k0qIjj7C; spf=pass (imf15.hostedemail.com: domain of glider@google.com designates 209.85.221.46 as permitted sender) smtp.mailfrom=glider@google.com; dmarc=pass (policy=reject) header.from=google.com X-Rspam-User: X-Rspamd-Server: rspam12 X-HE-Tag: 1659455305-470595 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Tue, Jul 12, 2022 at 3:18 PM Marco Elver wrote: > > On Fri, 1 Jul 2022 at 16:24, 'Alexander Potapenko' via kasan-dev > wrote: > > > > 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) > > > > Link: https://linux-review.googlesource.com/id/I0f41c3a1c7d66f7e14aabcfdfc7c69addb945805 > > --- > > include/linux/kmsan.h | 17 +++++++++++++++++ > > kernel/exit.c | 2 ++ > > kernel/fork.c | 2 ++ > > mm/kmsan/core.c | 10 ++++++++++ > > mm/kmsan/hooks.c | 19 +++++++++++++++++++ > > mm/kmsan/kmsan.h | 2 ++ > > 6 files changed, 52 insertions(+) > > > > diff --git a/include/linux/kmsan.h b/include/linux/kmsan.h > > index fd76cea338878..b71e2032222e9 100644 > > --- a/include/linux/kmsan.h > > +++ b/include/linux/kmsan.h > > @@ -16,6 +16,7 @@ > > > > struct page; > > struct kmem_cache; > > +struct task_struct; > > > > #ifdef CONFIG_KMSAN > > > > @@ -42,6 +43,14 @@ struct kmsan_ctx { > > bool allow_reporting; > > }; > > > > +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(). > > @@ -163,6 +172,14 @@ void kmsan_iounmap_page_range(unsigned long start, unsigned long end); > > > > #else > > > > +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 f072959fcab7f..1784b7a741ddd 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); > > > > kcov_task_exit(tsk); > > + kmsan_task_exit(tsk); > > > > coredump_task_exit(tsk); > > ptrace_event(PTRACE_EVENT_EXIT, code); > > diff --git a/kernel/fork.c b/kernel/fork.c > > index 9d44f2d46c696..6dfca6f00ec82 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 task_struct *orig, int node) > > tsk->worker_private = NULL; > > > > kcov_task_init(tsk); > > + kmsan_task_create(tsk); > > kmap_local_fork(tsk); > > > > #ifdef CONFIG_FAULT_INJECTION > > diff --git a/mm/kmsan/core.c b/mm/kmsan/core.c > > index 16fb8880a9c6d..7eabed03ed10b 100644 > > --- a/mm/kmsan/core.c > > +++ b/mm/kmsan/core.c > > @@ -44,6 +44,16 @@ bool kmsan_enabled __read_mostly; > > */ > > DEFINE_PER_CPU(struct kmsan_ctx, kmsan_percpu_ctx); > > > > +void kmsan_internal_task_create(struct task_struct *task) > > +{ > > + struct kmsan_ctx *ctx = &task->kmsan_ctx; > > + struct thread_info *info = current_thread_info(); > > + > > + __memset(ctx, 0, sizeof(*ctx)); > > + ctx->allow_reporting = 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 052e17b7a717d..43a529569053d 100644 > > --- a/mm/kmsan/hooks.c > > +++ b/mm/kmsan/hooks.c > > @@ -26,6 +26,25 @@ > > * skipping effects of functions like memset() inside instrumented code. > > */ > > > > +void kmsan_task_create(struct task_struct *task) > > +{ > > + kmsan_enter_runtime(); > > + kmsan_internal_task_create(task); > > + kmsan_leave_runtime(); > > +} > > +EXPORT_SYMBOL(kmsan_task_create); > > + > > +void kmsan_task_exit(struct task_struct *task) > > +{ > > + struct kmsan_ctx *ctx = &task->kmsan_ctx; > > + > > + if (!kmsan_enabled || kmsan_in_runtime()) > > + return; > > + > > + ctx->allow_reporting = false; > > +} > > +EXPORT_SYMBOL(kmsan_task_exit); > > Why are these EXPORT_SYMBOL? Will they be used from some kernel module? You're right, most of them will not. Will fix.