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author | 2008-07-25 01:47:44 -0700 | |
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committer | 2008-07-25 10:53:40 -0700 | |
commit | b564daf806d492dd4f7afe9b6c83b8d35d137669 (patch) | |
tree | fbd6d186035b9a0a270fca97887da5d6b106a60c /kernel/exit.c | |
parent | coredump: make mm->core_state visible to ->core_dump() (diff) | |
download | linux-b564daf806d492dd4f7afe9b6c83b8d35d137669.tar.gz linux-b564daf806d492dd4f7afe9b6c83b8d35d137669.tar.bz2 linux-b564daf806d492dd4f7afe9b6c83b8d35d137669.zip |
coredump: construct the list of coredumping threads at startup time
binfmt->core_dump() has to iterate over the all threads in system in order
to find the coredumping threads and construct the list using the
GFP_ATOMIC allocations.
With this patch each thread allocates the list node on exit_mm()'s stack and
adds itself to the list.
This allows us to do further changes:
- simplify ->core_dump()
- change exit_mm() to clear ->mm first, then wait for ->core_done.
this makes the coredumping process visible to oom_kill
- kill mm->core_done
Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
Acked-by: Roland McGrath <roland@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'kernel/exit.c')
-rw-r--r-- | kernel/exit.c | 15 |
1 files changed, 12 insertions, 3 deletions
diff --git a/kernel/exit.c b/kernel/exit.c index 63d82957baae..b66f0d55c791 100644 --- a/kernel/exit.c +++ b/kernel/exit.c @@ -664,6 +664,7 @@ assign_new_owner: static void exit_mm(struct task_struct * tsk) { struct mm_struct *mm = tsk->mm; + struct core_state *core_state; mm_release(tsk, mm); if (!mm) @@ -676,11 +677,19 @@ static void exit_mm(struct task_struct * tsk) * group with ->mm != NULL. */ down_read(&mm->mmap_sem); - if (mm->core_state) { + core_state = mm->core_state; + if (core_state) { + struct core_thread self; up_read(&mm->mmap_sem); - if (atomic_dec_and_test(&mm->core_state->nr_threads)) - complete(&mm->core_state->startup); + self.task = tsk; + self.next = xchg(&core_state->dumper.next, &self); + /* + * Implies mb(), the result of xchg() must be visible + * to core_state->dumper. + */ + if (atomic_dec_and_test(&core_state->nr_threads)) + complete(&core_state->startup); wait_for_completion(&mm->core_done); down_read(&mm->mmap_sem); |