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| author | Oleg Nesterov <oleg@redhat.com> | 2012-03-14 19:55:38 +0100 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2012-03-20 14:16:50 -0700 |
| commit | 5f8aadd8b9966d71a77bba52b9d499cc2f38269f (patch) | |
| tree | 229735d79edf0c4cc82ac00ba1abaee63040ff6e | |
| parent | ed378a52dabf77b406b447fd3238f83ea24b71fa (diff) | |
| download | linux-3.10-5f8aadd8b9966d71a77bba52b9d499cc2f38269f.tar.gz linux-3.10-5f8aadd8b9966d71a77bba52b9d499cc2f38269f.tar.bz2 linux-3.10-5f8aadd8b9966d71a77bba52b9d499cc2f38269f.zip | |
CLONE_PARENT shouldn't allow to set ->exit_signal
The child must not control its ->exit_signal, it is the parent who
decides which signal the child should use for notification.
This means that CLONE_PARENT should not use "clone_flags & CSIGNAL",
the forking task is the sibling of the new process and their parent
doesn't control exit_signal in this case.
This patch uses ->exit_signal of the forking process, but perhaps
we should simply use SIGCHLD.
We read group_leader->exit_signal lockless, this can race with the
ORIGINAL_SIGNAL -> SIGCHLD transition, but this is fine.
Potentially this change allows to kill self_exec_id/parent_exec_id.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| -rw-r--r-- | kernel/fork.c | 8 |
1 files changed, 7 insertions, 1 deletions
diff --git a/kernel/fork.c b/kernel/fork.c index 26a7a6707fa..c4f38a84943 100644 --- a/kernel/fork.c +++ b/kernel/fork.c @@ -1340,7 +1340,13 @@ static struct task_struct *copy_process(unsigned long clone_flags, clear_all_latency_tracing(p); /* ok, now we should be set up.. */ - p->exit_signal = (clone_flags & CLONE_THREAD) ? -1 : (clone_flags & CSIGNAL); + if (clone_flags & CLONE_THREAD) + p->exit_signal = -1; + else if (clone_flags & CLONE_PARENT) + p->exit_signal = current->group_leader->exit_signal; + else + p->exit_signal = (clone_flags & CSIGNAL); + p->pdeath_signal = 0; p->exit_state = 0; |