The patch titled
From: Konstantin Khlebnikov <khlebnikov@xxxxxxxxxx>
has been added to the -mm tree. Its filename is
mm-correctly-synchronize-rss-counters-at-exit-exec.patch
Before you just go and hit "reply", please:
a) Consider who else should be cc'ed
b) Prefer to cc a suitable mailing list as well
c) Ideally: find the original patch on the mailing list and do a
reply-to-all to that, adding suitable additional cc's
*** Remember to use Documentation/SubmitChecklist when testing your code ***
The -mm tree is included into linux-next and is updated
there every 3-4 working days
------------------------------------------------------
From: Konstantin Khlebnikov <khlebnikov@xxxxxxxxxx>
Subject: 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@xxxxxxxxxxxxxxx>
Signed-off-by: Konstantin Khlebnikov <khlebnikov@xxxxxxxxxx>
Cc: Oleg Nesterov <oleg@xxxxxxxxxx>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@xxxxxxxxxxxxxx>
Cc: Hugh Dickins <hughd@xxxxxxxxxx>
Cc: <stable@xxxxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
fs/exec.c | 2 +-
kernel/exit.c | 1 +
2 files changed, 2 insertions(+), 1 deletion(-)
diff -puN fs/exec.c~mm-correctly-synchronize-rss-counters-at-exit-exec fs/exec.c
--- a/fs/exec.c~mm-correctly-synchronize-rss-counters-at-exit-exec
+++ a/fs/exec.c
@@ -819,10 +819,10 @@ static int exec_mmap(struct mm_struct *m
/* 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 -puN kernel/exit.c~mm-correctly-synchronize-rss-counters-at-exit-exec kernel/exit.c
--- a/kernel/exit.c~mm-correctly-synchronize-rss-counters-at-exit-exec
+++ a/kernel/exit.c
@@ -643,6 +643,7 @@ static void exit_mm(struct task_struct *
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
_
Subject: From: Konstantin Khlebnikov <khlebnikov@xxxxxxxxxx>
Patches currently in -mm which might be from khlebnikov@xxxxxxxxxx are
linux-next.patch
memcg-fix-use_hierarchy-css_is_ancestor-oops-regression.patch
mm-correctly-synchronize-rss-counters-at-exit-exec.patch
--
To unsubscribe from this list: send the line "unsubscribe mm-commits" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
