The patch titled
signals: unify send_sigqueue/send_group_sigqueue completely
has been added to the -mm tree. Its filename is
signals-unify-send_sigqueue-send_group_sigqueue-completely.patch
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See http://www.zip.com.au/~akpm/linux/patches/stuff/added-to-mm.txt to find
out what to do about this
The current -mm tree may be found at http://userweb.kernel.org/~akpm/mmotm/
------------------------------------------------------
Subject: signals: unify send_sigqueue/send_group_sigqueue completely
From: Oleg Nesterov <oleg@xxxxxxxxxx>
Suggested by Pavel Emelyanov.
send_sigqueue/send_group_sigqueue are only differ in how they lock ->siglock.
Unify them. send_group_sigqueue() uses spin_lock() because it knows the task
can't exit, but in that case lock_task_sighand() can't fail and doesn't hurt.
Note that the "sig" argument is ignored, it is always equal to ->si_signo.
Signed-off-by: Pavel Emelyanov <xemul@xxxxxxxxxx>
Signed-off-by: Oleg Nesterov <oleg@xxxxxxxxxx>
Cc: Roland McGrath <roland@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
kernel/signal.c | 58 ++++++++++++++++------------------------------
1 file changed, 21 insertions(+), 37 deletions(-)
diff -puN kernel/signal.c~signals-unify-send_sigqueue-send_group_sigqueue-completely kernel/signal.c
--- a/kernel/signal.c~signals-unify-send_sigqueue-send_group_sigqueue-completely
+++ a/kernel/signal.c
@@ -1240,14 +1240,27 @@ void sigqueue_free(struct sigqueue *q)
__sigqueue_free(q);
}
-static int do_send_sigqueue(int sig, struct sigqueue *q, struct task_struct *t,
+static int do_send_sigqueue(struct sigqueue *q, struct task_struct *t,
int group)
{
+ int sig = q->info.si_signo;
struct sigpending *pending;
+ unsigned long flags;
+ int ret;
BUG_ON(!(q->flags & SIGQUEUE_PREALLOC));
+
+ ret = -1;
+ if (!likely(lock_task_sighand(t, &flags)))
+ goto ret;
+
handle_stop_signal(sig, t);
+ ret = 1;
+ if (sig_ignored(t, sig))
+ goto out;
+
+ ret = 0;
if (unlikely(!list_empty(&q->list))) {
/*
* If an SI_TIMER entry is already queue just increment
@@ -1256,58 +1269,29 @@ static int do_send_sigqueue(int sig, str
BUG_ON(q->info.si_code != SI_TIMER);
q->info.si_overrun++;
- return 0;
+ goto out;
}
- if (sig_ignored(t, sig))
- return 1;
-
signalfd_notify(t, sig);
pending = group ? &t->signal->shared_pending : &t->pending;
list_add_tail(&q->list, &pending->list);
sigaddset(&pending->signal, sig);
complete_signal(sig, t, group);
-
- return 0;
+out:
+ unlock_task_sighand(t, &flags);
+ret:
+ return ret;
}
int send_sigqueue(int sig, struct sigqueue *q, struct task_struct *p)
{
- unsigned long flags;
- int ret = -1;
-
- /*
- * The rcu based delayed sighand destroy makes it possible to
- * run this without tasklist lock held. The task struct itself
- * cannot go away as create_timer did get_task_struct().
- *
- * We return -1, when the task is marked exiting, so
- * posix_timer_event can redirect it to the group leader
- */
- if (!likely(lock_task_sighand(p, &flags)))
- goto out_err;
-
- ret = do_send_sigqueue(sig, q, p, 0);
-
- unlock_task_sighand(p, &flags);
-out_err:
- return ret;
+ return do_send_sigqueue(q, p, 0);
}
int
send_group_sigqueue(int sig, struct sigqueue *q, struct task_struct *p)
{
- unsigned long flags;
- int ret;
-
- /* Since it_lock is held, p->sighand cannot be NULL. */
- spin_lock_irqsave(&p->sighand->siglock, flags);
-
- ret = do_send_sigqueue(sig, q, p, 1);
-
- spin_unlock_irqrestore(&p->sighand->siglock, flags);
-
- return ret;
+ return do_send_sigqueue(q, p, 1);
}
/*
_
Patches currently in -mm which might be from oleg@xxxxxxxxxx are
git-hrt.patch
kthread-call-wake_up_process-without-the-lock-being-held.patch
mmap_region-cleanup-the-final-vma_merge-related-code.patch
remove-unused-variable-from-send_signal.patch
turn-legacy_queue-macro-into-static-inline-function.patch
consolidate-checking-for-ignored-legacy-signals.patch
consolidate-checking-for-ignored-legacy-signals-simplify.patch
signals-do_signal_stop-use-signal_group_exit.patch
signals-do_group_exit-use-signal_group_exit-more-consistently.patch
lock_task_sighand-add-rcu-lock-unlock.patch
k_getrusage-dont-take-rcu_read_lock.patch
do_task_stat-dont-take-rcu_read_lock.patch
signals-consolidate-checks-for-whether-or-not-to-ignore-a-signal.patch
signals-clean-dequeue_signal-from-excess-checks-and-assignments.patch
signals-consolidate-send_sigqueue-and-send_group_sigqueue.patch
signals-cleanup-security_task_kill-usage-implementation.patch
signals-re-assign-cld_continued-notification-from-the-sender-to-reciever.patch
kill_pid_info-dont-take-now-unneeded-tasklist_lock.patch
handle_stop_signal-unify-partial-full-stop-handling.patch
handle_stop_signal-use-the-cached-p-signal-value.patch
get_signal_to_deliver-use-the-cached-signal-sighand-values.patch
signals-send_sigqueue-dont-take-rcu-lock.patch
signals-send_sigqueue-dont-forget-about-handle_stop_signal.patch
signals-__group_complete_signal-cache-the-value-of-p-signal.patch
signals-send_group_sigqueue-dont-take-tasklist_lock.patch
signals-move-handle_stop_signal-into-send_signal.patch
signals-do_tkill-dont-use-tasklist_lock.patch
signals-do_tkill-dont-use-tasklist_lock-comment.patch
signals-send_sig_info-dont-take-tasklist_lock.patch
signals-microoptimize-the-usage-of-curr_target.patch
signals-move-the-definition-of-__group_complete_signal-up.patch
signals-change-send_signal-do_send_sigqueue-to-take-boolean-group-parameter.patch
signals-use-__group_complete_signal-for-the-specific-signals-too.patch
signals-fold-complete_signal-into-send_signal-do_send_sigqueue.patch
signals-unify-send_sigqueue-send_group_sigqueue-completely.patch
signals-join-send_sigqueue-with-send_group_sigqueue.patch
ptrace-introduce-task_detached-helper.patch
reparent_thread-use-same_thread_group.patch
document-de_thread-with-exit_notify-connection.patch
ptrace-introduce-ptrace_reparented-helper.patch
ptrace-__ptrace_unlink-use-the-ptrace_reparented-helper.patch
workqueues-shrink-cpu_populated_map-when-cpu-dies.patch
workqueues-shrink-cpu_populated_map-when-cpu-dies-fix.patch
cleanup_workqueue_thread-remove-the-unneeded-cpu-parameter.patch
simplify-cpu_hotplug_begin-put_online_cpus.patch
redo-locking-of-tty-pgrp.patch
resume-tty-on-susp-and-fix-crnl-order-in-n_tty-line-discipline.patch
tty_io-fix-remaining-pid-struct-locking.patch
tty_io-fix-remaining-pid-struct-locking-small-cleanup.patch
procfs-task-exe-symlink.patch
procfs-task-exe-symlink-fix.patch
procfs-task-exe-symlink-fix-2.patch
free_pidmap-turn-it-into-free_pidmapstruct-upid.patch
put_pid-make-sure-we-dont-free-the-live-pid.patch
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