Messages in this thread | | | Date | Fri, 6 Oct 2017 15:02:29 +0100 | From | Catalin Marinas <> | Subject | Re: [PATCH] kmemleak: clear stale pointers from task stacks |
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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>
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