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| author | KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> | 2010-04-06 14:34:42 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2010-04-07 08:38:02 -0700 |
| commit | a3a2e76c77fa22b114e421ac11dec0c56c3503fb (patch) | |
| tree | cc67bbd8d5d364e55ea7a00d0b5ad68d5eac08ac /mm/memory.c | |
| parent | b01d0942c2b7a3026d2b7d38b5773d3d00420e06 (diff) | |
| download | lwn-a3a2e76c77fa22b114e421ac11dec0c56c3503fb.tar.gz lwn-a3a2e76c77fa22b114e421ac11dec0c56c3503fb.zip | |
mm: avoid null-pointer deref in sync_mm_rss()
- We weren't zeroing p->rss_stat[] at fork()
- Consequently sync_mm_rss() was dereferencing tsk->mm for kernel
threads and was oopsing.
- Make __sync_task_rss_stat() static, too.
Addresses https://bugzilla.kernel.org/show_bug.cgi?id=15648
[akpm@linux-foundation.org: remove the BUG_ON(!mm->rss)]
Reported-by: Troels Liebe Bentsen <tlb@rapanden.dk>
Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
"Michael S. Tsirkin" <mst@redhat.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Minchan Kim <minchan.kim@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm/memory.c')
| -rw-r--r-- | mm/memory.c | 3 |
1 files changed, 1 insertions, 2 deletions
diff --git a/mm/memory.c b/mm/memory.c index 1d2ea39260e5..833952d8b74d 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -125,13 +125,12 @@ core_initcall(init_zero_pfn); #if defined(SPLIT_RSS_COUNTING) -void __sync_task_rss_stat(struct task_struct *task, struct mm_struct *mm) +static void __sync_task_rss_stat(struct task_struct *task, struct mm_struct *mm) { int i; for (i = 0; i < NR_MM_COUNTERS; i++) { if (task->rss_stat.count[i]) { - BUG_ON(!mm); add_mm_counter(mm, i, task->rss_stat.count[i]); task->rss_stat.count[i] = 0; } |