The patch titled
     From: Konstantin Khlebnikov <[email protected]>
has been added to the -mm tree.  Its filename is
     mm-correctly-synchronize-rss-counters-at-exit-exec.patch

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------------------------------------------------------
From: Konstantin Khlebnikov <[email protected]>
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 <[email protected]>
Signed-off-by: Konstantin Khlebnikov <[email protected]>
Cc: Oleg Nesterov <[email protected]>
Cc: KAMEZAWA Hiroyuki <[email protected]>
Cc: Hugh Dickins <[email protected]>
Cc: <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
---

 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 <[email protected]>

Patches currently in -mm which might be from [email protected] are

linux-next.patch
memcg-fix-use_hierarchy-css_is_ancestor-oops-regression.patch
mm-correctly-synchronize-rss-counters-at-exit-exec.patch

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