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| author | Ethan Solomita <solo@google.com> | 2007-07-15 23:38:16 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@woody.linux-foundation.org> | 2007-07-16 09:05:36 -0700 |
| commit | 462e00cc7151ed91fba688594436c453c80efb5d (patch) | |
| tree | bf648899ba65f9eb000e9c8163a61c1cb1be9bfe /mm/memory.c | |
| parent | b71636e29823c0602d908a2a62e94c9b57a97491 (diff) | |
| download | lwn-462e00cc7151ed91fba688594436c453c80efb5d.tar.gz lwn-462e00cc7151ed91fba688594436c453c80efb5d.zip | |
oom: stop allocating user memory if TIF_MEMDIE is set
get_user_pages() can try to allocate a nearly unlimited amount of memory on
behalf of a user process, even if that process has been OOM killed. The
OOM kill occurs upon return to user space via a SIGKILL, but
get_user_pages() will try allocate all its memory before returning. Change
get_user_pages() to check for TIF_MEMDIE, and if set then return
immediately.
Signed-off-by: Ethan Solomita <solo@google.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 | 8 |
1 files changed, 8 insertions, 0 deletions
diff --git a/mm/memory.c b/mm/memory.c index ee2925998e2e..cfddcd2075b9 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -1055,6 +1055,14 @@ int get_user_pages(struct task_struct *tsk, struct mm_struct *mm, do { struct page *page; + /* + * If tsk is ooming, cut off its access to large memory + * allocations. It has a pending SIGKILL, but it can't + * be processed until returning to user space. + */ + if (unlikely(test_tsk_thread_flag(tsk, TIF_MEMDIE))) + return -ENOMEM; + if (write) foll_flags |= FOLL_WRITE; |