From: Oleg Nesterov Based on Pavel Emelyanov's suggestion. Rename __group_complete_signal() to complete_signal() and use it to process the specific signals too. To do this we simply add the "int group" argument. This allows us to greatly simply the signal-sending code and adds a useful behaviour change. We can avoid the unneeded wakeups for the private signals because wants_signal() is more clever than sigismember(blocked), but more importantly we now take into account the fatal specific signals too. The latter allows us to kill some subtle checks in handle_stop_signal() and makes the specific/group signal's behaviour more consistent. For example, currently sigtimedwait(FATAL_SIGNAL) behaves differently depending on was the signal sent by kill() or tkill() if the signal was not blocked. And. This allows us to tweak/fix the behaviour when the specific signal is sent to the dying/dead ->group_leader. Signed-off-by: Pavel Emelyanov Signed-off-by: Oleg Nesterov Cc: Roland McGrath Signed-off-by: Andrew Morton --- kernel/signal.c | 15 ++++++--------- 1 file changed, 6 insertions(+), 9 deletions(-) diff -puN kernel/signal.c~signals-use-__group_complete_signal-for-the-specific-signals-too kernel/signal.c --- a/kernel/signal.c~signals-use-__group_complete_signal-for-the-specific-signals-too +++ a/kernel/signal.c @@ -673,8 +673,7 @@ static inline int wants_signal(int sig, return task_curr(p) || !signal_pending(p); } -static void -__group_complete_signal(int sig, struct task_struct *p) +static void complete_signal(int sig, struct task_struct *p, int group) { struct signal_struct *signal = p->signal; struct task_struct *t; @@ -687,7 +686,7 @@ __group_complete_signal(int sig, struct */ if (wants_signal(sig, p)) t = p; - else if (thread_group_empty(p)) + else if (!group || thread_group_empty(p)) /* * There is just one thread and it does not need to be woken. * It will dequeue unblocked signals before it runs again. @@ -871,8 +870,7 @@ specific_send_sig_info(int sig, struct s if (ret <= 0) return ret; - if (!sigismember(&t->blocked, sig)) - signal_wake_up(t, sig == SIGKILL); + complete_signal(sig, t, 0); return 0; } @@ -930,7 +928,7 @@ __group_send_sig_info(int sig, struct si if (ret <= 0) return ret; - __group_complete_signal(sig, p); + complete_signal(sig, p, 1); return 0; } @@ -1309,8 +1307,7 @@ int send_sigqueue(int sig, struct sigque ret = do_send_sigqueue(sig, q, p, 0); - if (!sigismember(&p->blocked, sig)) - signal_wake_up(p, sig == SIGKILL); + complete_signal(sig, p, 0); unlock_task_sighand(p, &flags); out_err: @@ -1330,7 +1327,7 @@ send_group_sigqueue(int sig, struct sigq ret = do_send_sigqueue(sig, q, p, 1); - __group_complete_signal(sig, p); + complete_signal(sig, p, 1); spin_unlock_irqrestore(&p->sighand->siglock, flags); _