lkml.org 
[lkml]   [2018]   [Aug]   [7]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH 4.9 14/17] kmemleak: clear stale pointers from task stacks
Date
4.9-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>

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>
---
include/linux/thread_info.h | 2 +-
kernel/fork.c | 4 ++++
2 files changed, 5 insertions(+), 1 deletion(-)

--- a/include/linux/thread_info.h
+++ b/include/linux/thread_info.h
@@ -59,7 +59,7 @@ extern long do_no_restart_syscall(struct

#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
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -184,6 +184,10 @@ static unsigned long *alloc_thread_stack
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;

\
 
 \ /
  Last update: 2018-08-07 21:06    [W:0.060 / U:1.624 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site