diff options
author | Eric W. Biederman <ebiederm@xmission.com> | 2018-07-20 22:30:23 +0300 |
---|---|---|
committer | Eric W. Biederman <ebiederm@xmission.com> | 2018-07-21 18:43:12 +0300 |
commit | 24122c7f4969adeeaeca3fb1656a31569e9aa59b (patch) | |
tree | 723eaf26f05f49f54df40fc6af0155f5eb880738 /kernel | |
parent | 2118e1f53f6f0973a1d9a6a7dc9296959bf39ec0 (diff) | |
download | linux-24122c7f4969adeeaeca3fb1656a31569e9aa59b.tar.xz |
signal: Pass pid and pid type into send_sigqueue
Make the code more maintainable by performing more of the signal
related work in send_sigqueue.
A quick inspection of do_timer_create will show that this code path
does not lookup a thread group by a thread's pid. Making it safe
to find the task pointed to by it_pid with "pid_task(it_pid, type)";
This supports the changes needed in fork to tell if a signal was sent
to a single process or a group of processes.
Having the pid to task transition in signal.c will also make it easier
to sort out races with de_thread and and the thread group leader
exiting when it comes time to address that.
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Diffstat (limited to 'kernel')
-rw-r--r-- | kernel/signal.c | 14 | ||||
-rw-r--r-- | kernel/time/posix-timers.c | 13 |
2 files changed, 13 insertions, 14 deletions
diff --git a/kernel/signal.c b/kernel/signal.c index 8d8a940422a8..40feb14e276d 100644 --- a/kernel/signal.c +++ b/kernel/signal.c @@ -1664,17 +1664,20 @@ void sigqueue_free(struct sigqueue *q) __sigqueue_free(q); } -int send_sigqueue(struct sigqueue *q, struct task_struct *t, int group) +int send_sigqueue(struct sigqueue *q, struct pid *pid, enum pid_type type) { int sig = q->info.si_signo; struct sigpending *pending; + struct task_struct *t; unsigned long flags; int ret, result; BUG_ON(!(q->flags & SIGQUEUE_PREALLOC)); ret = -1; - if (!likely(lock_task_sighand(t, &flags))) + rcu_read_lock(); + t = pid_task(pid, type); + if (!t || !likely(lock_task_sighand(t, &flags))) goto ret; ret = 1; /* the signal is ignored */ @@ -1696,15 +1699,16 @@ int send_sigqueue(struct sigqueue *q, struct task_struct *t, int group) q->info.si_overrun = 0; signalfd_notify(t, sig); - pending = group ? &t->signal->shared_pending : &t->pending; + pending = (type != PIDTYPE_PID) ? &t->signal->shared_pending : &t->pending; list_add_tail(&q->list, &pending->list); sigaddset(&pending->signal, sig); - complete_signal(sig, t, group); + complete_signal(sig, t, type != PIDTYPE_PID); result = TRACE_SIGNAL_DELIVERED; out: - trace_signal_generate(sig, &q->info, t, group, result); + trace_signal_generate(sig, &q->info, t, type != PIDTYPE_PID, result); unlock_task_sighand(t, &flags); ret: + rcu_read_unlock(); return ret; } diff --git a/kernel/time/posix-timers.c b/kernel/time/posix-timers.c index 2bdf08a2bae9..2d2e739fbc57 100644 --- a/kernel/time/posix-timers.c +++ b/kernel/time/posix-timers.c @@ -332,8 +332,8 @@ void posixtimer_rearm(struct siginfo *info) int posix_timer_event(struct k_itimer *timr, int si_private) { - struct task_struct *task; - int shared, ret = -1; + enum pid_type type; + int ret = -1; /* * FIXME: if ->sigq is queued we can race with * dequeue_signal()->posixtimer_rearm(). @@ -347,13 +347,8 @@ int posix_timer_event(struct k_itimer *timr, int si_private) */ timr->sigq->info.si_sys_private = si_private; - rcu_read_lock(); - task = pid_task(timr->it_pid, PIDTYPE_PID); - if (task) { - shared = !(timr->it_sigev_notify & SIGEV_THREAD_ID); - ret = send_sigqueue(timr->sigq, task, shared); - } - rcu_read_unlock(); + type = !(timr->it_sigev_notify & SIGEV_THREAD_ID) ? PIDTYPE_TGID : PIDTYPE_PID; + ret = send_sigqueue(timr->sigq, timr->it_pid, type); /* If we failed to send the signal the timer stops. */ return ret > 0; } |