diff options
| author | Konstantin Khlebnikov <khlebnikov@yandex-team.ru> | 2017-10-13 15:58:22 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2017-10-13 16:18:33 -0700 |
| commit | ca182551857cc2c1e6a2b7f1e72090a137a15008 (patch) | |
| tree | 2811f50f3d352d6f82f453e05a76489637b2d1b0 | |
| parent | 7e86600606cef21beec725039d70377fb364f881 (diff) | |
| download | lwn-ca182551857cc2c1e6a2b7f1e72090a137a15008.tar.gz lwn-ca182551857cc2c1e6a2b7f1e72090a137a15008.zip | |
kmemleak: clear stale pointers from task stacks
Kmemleak considers any pointers on task stacks as references. This
patch clears newly allocated and reused vmap stacks.
Link: http://lkml.kernel.org/r/150728990124.744199.8403409836394318684.stgit@buzz
Signed-off-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| -rw-r--r-- | include/linux/thread_info.h | 2 | ||||
| -rw-r--r-- | kernel/fork.c | 4 |
2 files changed, 5 insertions, 1 deletions
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 e702cb9ffbd8..07cc743698d3 100644 --- a/kernel/fork.c +++ b/kernel/fork.c @@ -215,6 +215,10 @@ 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; } |