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| author | Konstantin Khlebnikov <khlebnikov@yandex-team.ru> | 2017-10-13 15:58:22 -0700 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2018-08-09 12:18:00 +0200 |
| commit | 885b49b4f31fdec212e6c5e9ad0845fab266d3cf (patch) | |
| tree | 83beefc835f79706bc9ee19eb9dc9a00b2044f7d | |
| parent | 36ee106e844187e3fc612c9b87f12e5e23e9d8a5 (diff) | |
| download | linux-rt-885b49b4f31fdec212e6c5e9ad0845fab266d3cf.tar.gz | |
kmemleak: clear stale pointers from task stacks
commit ca182551857cc2c1e6a2b7f1e72090a137a15008 upstream.
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>
[ Srivatsa: Backported to 4.9.y ]
Signed-off-by: Srivatsa S. Bhat <srivatsa@csail.mit.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.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 2873baf5372a..cf87c162f4eb 100644 --- a/include/linux/thread_info.h +++ b/include/linux/thread_info.h @@ -59,7 +59,7 @@ extern long do_no_restart_syscall(struct restart_block *parm); #ifdef __KERNEL__ -#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 70e10cb49be0..c19e6d48d57d 100644 --- a/kernel/fork.c +++ b/kernel/fork.c @@ -184,6 +184,10 @@ static unsigned long *alloc_thread_stack_node(struct task_struct *tsk, int node) continue; this_cpu_write(cached_stacks[i], NULL); +#ifdef CONFIG_DEBUG_KMEMLEAK + /* Clear stale pointers from reused stack. */ + memset(s->addr, 0, THREAD_SIZE); +#endif tsk->stack_vm_area = s; local_irq_enable(); return s->addr; |