From: Catalin Marinas <catalin.marinas@arm.com> To: Konstantin Khlebnikov <khlebnikov@yandex-team.ru> Cc: linux-mm@kvack.org, Andrew Morton <akpm@linux-foundation.org>, linux-kernel@vger.kernel.org, Andy Lutomirski <luto@kernel.org> Subject: Re: [PATCH] kmemleak: clear stale pointers from task stacks Date: Fri, 6 Oct 2017 15:02:29 +0100 [thread overview] Message-ID: <20171006140229.p5be6n6peafqasgl@armageddon.cambridge.arm.com> (raw) In-Reply-To: <150728990124.744199.8403409836394318684.stgit@buzz> On Fri, Oct 06, 2017 at 02:38:21PM +0300, Konstantin Khlebnikov wrote: > Kmemleak considers any pointers as task stacks as references. ^^ on > This patch clears newly allocated and reused vmap stacks. > > Signed-off-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru> > --- > include/linux/thread_info.h | 2 +- > kernel/fork.c | 4 ++++ > 2 files changed, 5 insertions(+), 1 deletion(-) > > diff --git a/include/linux/thread_info.h b/include/linux/thread_info.h > index 905d769d8ddc..5f7eeab990fe 100644 > --- a/include/linux/thread_info.h > +++ b/include/linux/thread_info.h > @@ -42,7 +42,7 @@ enum { > #define THREAD_ALIGN THREAD_SIZE > #endif > > -#ifdef CONFIG_DEBUG_STACK_USAGE > +#if IS_ENABLED(CONFIG_DEBUG_STACK_USAGE) || IS_ENABLED(CONFIG_DEBUG_KMEMLEAK) > # define THREADINFO_GFP (GFP_KERNEL_ACCOUNT | __GFP_NOTRACK | \ > __GFP_ZERO) > #else > diff --git a/kernel/fork.c b/kernel/fork.c > index c4ff0303b7c5..53e3b6f8a3bf 100644 > --- a/kernel/fork.c > +++ b/kernel/fork.c > @@ -213,6 +213,10 @@ static unsigned long *alloc_thread_stack_node(struct task_struct *tsk, int node) > if (!s) > continue; > > +#ifdef CONFIG_DEBUG_KMEMLEAK > + /* Clear stale pointers from reused stack. */ > + memset(s->addr, 0, THREAD_SIZE); > +#endif > tsk->stack_vm_area = s; > return s->addr; > } Acked-by: Catalin Marinas <catalin.marinas@arm.com>
WARNING: multiple messages have this Message-ID (diff)
From: Catalin Marinas <catalin.marinas@arm.com> To: Konstantin Khlebnikov <khlebnikov@yandex-team.ru> Cc: linux-mm@kvack.org, Andrew Morton <akpm@linux-foundation.org>, linux-kernel@vger.kernel.org, Andy Lutomirski <luto@kernel.org> Subject: Re: [PATCH] kmemleak: clear stale pointers from task stacks Date: Fri, 6 Oct 2017 15:02:29 +0100 [thread overview] Message-ID: <20171006140229.p5be6n6peafqasgl@armageddon.cambridge.arm.com> (raw) In-Reply-To: <150728990124.744199.8403409836394318684.stgit@buzz> On Fri, Oct 06, 2017 at 02:38:21PM +0300, Konstantin Khlebnikov wrote: > Kmemleak considers any pointers as task stacks as references. ^^ on > This patch clears newly allocated and reused vmap stacks. > > Signed-off-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru> > --- > include/linux/thread_info.h | 2 +- > kernel/fork.c | 4 ++++ > 2 files changed, 5 insertions(+), 1 deletion(-) > > diff --git a/include/linux/thread_info.h b/include/linux/thread_info.h > index 905d769d8ddc..5f7eeab990fe 100644 > --- a/include/linux/thread_info.h > +++ b/include/linux/thread_info.h > @@ -42,7 +42,7 @@ enum { > #define THREAD_ALIGN THREAD_SIZE > #endif > > -#ifdef CONFIG_DEBUG_STACK_USAGE > +#if IS_ENABLED(CONFIG_DEBUG_STACK_USAGE) || IS_ENABLED(CONFIG_DEBUG_KMEMLEAK) > # define THREADINFO_GFP (GFP_KERNEL_ACCOUNT | __GFP_NOTRACK | \ > __GFP_ZERO) > #else > diff --git a/kernel/fork.c b/kernel/fork.c > index c4ff0303b7c5..53e3b6f8a3bf 100644 > --- a/kernel/fork.c > +++ b/kernel/fork.c > @@ -213,6 +213,10 @@ static unsigned long *alloc_thread_stack_node(struct task_struct *tsk, int node) > if (!s) > continue; > > +#ifdef CONFIG_DEBUG_KMEMLEAK > + /* Clear stale pointers from reused stack. */ > + memset(s->addr, 0, THREAD_SIZE); > +#endif > tsk->stack_vm_area = s; > return s->addr; > } Acked-by: Catalin Marinas <catalin.marinas@arm.com> -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>
next prev parent reply other threads:[~2017-10-06 14:02 UTC|newest] Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top 2017-10-06 11:38 [PATCH] kmemleak: clear stale pointers from task stacks Konstantin Khlebnikov 2017-10-06 11:38 ` Konstantin Khlebnikov 2017-10-06 14:02 ` Catalin Marinas [this message] 2017-10-06 14:02 ` Catalin Marinas
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