A-Team_Digital_Solutions/android_kernel_motorola_sm6375
Watch
2
0
Fork
You've already forked android_kernel_motorola_sm6375
 0
mirror of https://github.com/BobTheBlinker/android_kernel_motorola_sm6375.git synced 2026-10-28 02:32:09 -04:00
Code Issues Projects Releases Packages Wiki Activity

lockdep, kmemcheck: Annotate ->lock in lockdep_init_map()

Browse source 
Since commit f59de89 ("lockdep: Clear whole lockdep_map on initialization"),
lockdep_init_map() will clear all the struct. But it will break
lock_set_class()/lock_set_subclass(). A typical race condition
is like below:

     CPU A                                   CPU B
lock_set_subclass(lockA);
 lock_set_class(lockA);
   lockdep_init_map(lockA);
     /* lockA->name is cleared */
     memset(lockA);
                                     __lock_acquire(lockA);
                                       /* lockA->class_cache[] is cleared */
                                       register_lock_class(lockA);
                                         look_up_lock_class(lockA);
                                           WARN_ON_ONCE(class->name !=
                                                     lock->name);

     lock->name = name;

So restore to what we have done before commit f59de89 but annotate
->lock with kmemcheck_mark_initialized() to suppress the kmemcheck
warning reported in commit f59de89.

Reported-by: Sergey Senozhatsky <[email protected]>
Reported-by: Borislav Petkov <[email protected]>
Suggested-by: Vegard Nossum <[email protected]>
Signed-off-by: Yong Zhang <[email protected]>
Cc: Tejun Heo <[email protected]>
Cc: David Rientjes <[email protected]>
Cc: <[email protected]>
Signed-off-by: Peter Zijlstra <[email protected]>
Link: http://lkml.kernel.org/r/20111109080451.GB8124@zhy
Signed-off-by: Ingo Molnar <[email protected]>
This commit is contained in:
Yong Zhang 2011-11-09 16:04:51 +08:00 • committed by Ingo Molnar
commit a33caeb118
1 changed files with 7 additions and 1 deletions
Download patch file Download diff file Expand all files Collapse all files

8
kernel/lockdep.c
View file

@ -44,6 +44,7 @@
#include <linux/stringify.h>
#include <linux/bitops.h>
#include <linux/gfp.h>
#include <linux/kmemcheck.h>
#include <asm/sections.h>
@ -2948,7 +2949,12 @@ static int mark_lock(struct task_struct *curr, struct held_lock *this,
void lockdep_init_map(struct lockdep_map *lock, const char *name,
struct lock_class_key *key, int subclass)
{
memset(lock, 0, sizeof(*lock));
int i;
kmemcheck_mark_initialized(lock, sizeof(*lock));
for (i = 0; i < NR_LOCKDEP_CACHING_CLASSES; i++)
lock->class_cache[i] = NULL;
#ifdef CONFIG_LOCK_STAT
lock->cpu = raw_smp_processor_id();