diff options
| author | Konstantin Khlebnikov <khlebnikov@openvz.org> | 2012-06-20 21:53:01 +0200 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2012-06-20 23:39:36 +0200 |
| commit | 4fe7efdbdfb1c7e7a7f31decfd831c0f31d37091 (patch) | |
| tree | 5d8fdf353ba3791ef10031ade2d93aa87aa179d3 | |
| parent | mm, thp: print useful information when mmap_sem is unlocked in zap_pmd_range (diff) | |
| download | linux-4fe7efdbdfb1c7e7a7f31decfd831c0f31d37091.tar.xz linux-4fe7efdbdfb1c7e7a7f31decfd831c0f31d37091.zip | |
mm: correctly synchronize rss-counters at exit/exec
do_exit() and exec_mmap() call sync_mm_rss() before mm_release() does
put_user(clear_child_tid) which can update task->rss_stat and thus make
mm->rss_stat inconsistent. This triggers the "BUG:" printk in check_mm().
Let's fix this bug in the safest way, and optimize/cleanup this later.
Reported-by: Markus Trippelsdorf <markus@trippelsdorf.de>
Signed-off-by: Konstantin Khlebnikov <khlebnikov@openvz.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to '')
| -rw-r--r-- | fs/exec.c | 2 | ||||
| -rw-r--r-- | kernel/exit.c | 1 |
2 files changed, 2 insertions, 1 deletions
diff --git a/fs/exec.c b/fs/exec.c index a79786a8d2c8..da27b91ff1e8 100644 --- a/fs/exec.c +++ b/fs/exec.c @@ -819,10 +819,10 @@ static int exec_mmap(struct mm_struct *mm) /* Notify parent that we're no longer interested in the old VM */ tsk = current; old_mm = current->mm; - sync_mm_rss(old_mm); mm_release(tsk, old_mm); if (old_mm) { + sync_mm_rss(old_mm); /* * Make sure that if there is a core dump in progress * for the old mm, we get out and die instead of going diff --git a/kernel/exit.c b/kernel/exit.c index 34867cc5b42a..c0277d3f1aaa 100644 --- a/kernel/exit.c +++ b/kernel/exit.c @@ -643,6 +643,7 @@ static void exit_mm(struct task_struct * tsk) mm_release(tsk, mm); if (!mm) return; + sync_mm_rss(mm); /* * Serialize with any possible pending coredump. * We must hold mmap_sem around checking core_state |