diff options
| author | Oleg Nesterov <oleg@redhat.com> | 2012-01-04 17:29:20 +0100 |
|---|---|---|
| committer | Rohan Somvanshi <rsomvanshi@nvidia.com> | 2012-01-11 10:35:45 -0800 |
| commit | b04a20528569e49bd463a97d978fa50e796edcc8 (patch) | |
| tree | 3867f4ae7e7f36dd0d1caab2f7155fc22ec9d18d /kernel/signal.c | |
| parent | da156cf06a4d3260aa7cfbce976f68d1413c7dd8 (diff) | |
ptrace: ensure JOBCTL_STOP_SIGMASK is not zero after detach
commit 8a88951b5878dc475dcd841cefc767e36397d14e upstream.
This is the temporary simple fix for 3.2, we need more changes in this
area.
1. do_signal_stop() assumes that the running untraced thread in the
stopped thread group is not possible. This was our goal but it is
not yet achieved: a stopped-but-resumed tracee can clone the running
thread which can initiate another group-stop.
Remove WARN_ON_ONCE(!current->ptrace).
2. A new thread always starts with ->jobctl = 0. If it is auto-attached
and this group is stopped, __ptrace_unlink() sets JOBCTL_STOP_PENDING
but JOBCTL_STOP_SIGMASK part is zero, this triggers WANR_ON(!signr)
in do_jobctl_trap() if another debugger attaches.
Change __ptrace_unlink() to set the artificial SIGSTOP for report.
Alternatively we could change ptrace_init_task() to copy signr from
current, but this means we can copy it for no reason and hide the
possible similar problems.
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Change-Id: I2c60e18b07e8e08c7e3b6cc8288b0e04e18844f7
Reviewed-on: http://git-master/r/74233
Reviewed-by: Varun Wadekar <vwadekar@nvidia.com>
Tested-by: Varun Wadekar <vwadekar@nvidia.com>
Diffstat (limited to 'kernel/signal.c')
| -rw-r--r-- | kernel/signal.c | 2 |
1 files changed, 0 insertions, 2 deletions
diff --git a/kernel/signal.c b/kernel/signal.c index 291c9700be75..195331c56ad3 100644 --- a/kernel/signal.c +++ b/kernel/signal.c @@ -1986,8 +1986,6 @@ static bool do_signal_stop(int signr) */ if (!(sig->flags & SIGNAL_STOP_STOPPED)) sig->group_exit_code = signr; - else - WARN_ON_ONCE(!current->ptrace); sig->group_stop_count = 0; |