diff options
Diffstat (limited to 'kernel/signal.c')
| -rw-r--r-- | kernel/signal.c | 23 |
1 files changed, 20 insertions, 3 deletions
diff --git a/kernel/signal.c b/kernel/signal.c index 1e199919ae09..2f2c8f6ee01f 100644 --- a/kernel/signal.c +++ b/kernel/signal.c @@ -1827,10 +1827,27 @@ static int do_signal_stop(int signr) unlikely(signal_group_exit(sig))) return 0; /* - * There is no group stop already in progress. - * We must initiate one now. + * There is no group stop already in progress. We must + * initiate one now. + * + * While ptraced, a task may be resumed while group stop is + * still in effect and then receive a stop signal and + * initiate another group stop. This deviates from the + * usual behavior as two consecutive stop signals can't + * cause two group stops when !ptraced. + * + * The condition can be distinguished by testing whether + * SIGNAL_STOP_STOPPED is already set. Don't generate + * group_exit_code in such case. + * + * This is not necessary for SIGNAL_STOP_CONTINUED because + * an intervening stop signal is required to cause two + * continued events regardless of ptrace. */ - sig->group_exit_code = signr; + if (!(sig->flags & SIGNAL_STOP_STOPPED)) + sig->group_exit_code = signr; + else + WARN_ON_ONCE(!task_ptrace(current)); current->group_stop &= ~GROUP_STOP_SIGMASK; current->group_stop |= signr | gstop; |