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Tsirkin" , Pekka Enberg , Peter Zijlstra , Petr Mladek , 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 Content-Type: text/plain; charset="UTF-8" ARC-Authentication-Results: i=1; imf09.hostedemail.com; dkim=pass header.d=google.com header.s=20210112 header.b=fBcmdT6+; dmarc=pass (policy=reject) header.from=google.com; spf=pass (imf09.hostedemail.com: domain of elver@google.com designates 209.85.128.182 as permitted sender) smtp.mailfrom=elver@google.com ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1657631909; 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=yN+yeyjG1qKP+1Pj2TR7+x/fenSy0T+ddQvCTNkV1Ls=; b=a3KMynWaFYQJGXF/j/SsadKxbuEFZOpVMCIkRJhmrEEnuMbhrQXwqg8fFOmWMPd4m2NcQk fEvMkAwygG5LLN5Z2x/RPwOy64IsLqrnGby9EZB4FnNBWqGFYCdudNuwEhmg8JcPr2RMqP Vc9DiuF2/Pf1U8UfV83X6N8ZaHlUkrU= ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1657631909; a=rsa-sha256; cv=none; b=zEgxzerB+j48JRbBSSTb2LUkKS69jiVVnSSujGNYwzwaX3iKU7bK5cpCJc6dMwztyRBy4F tIy69X/wFeQBphMT+L/KrfcTkQzv/ithDHATYIO2ZdB2Kdfduu9ggfQ4CZYR1YB/41ETA5 pFqvy/MIedoo/jb8s9IYzq+pD3BayoQ= X-Rspamd-Server: rspam04 X-Rspamd-Queue-Id: BA1B8140079 X-Stat-Signature: niegmnw1qu6ahd58bey64tfs6is3h1jj Authentication-Results: imf09.hostedemail.com; dkim=pass header.d=google.com header.s=20210112 header.b=fBcmdT6+; dmarc=pass (policy=reject) header.from=google.com; spf=pass (imf09.hostedemail.com: domain of elver@google.com designates 209.85.128.182 as permitted sender) smtp.mailfrom=elver@google.com X-Rspam-User: X-HE-Tag: 1657631909-544351 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 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?