[PATCH 2/4] signal: add a helper for dequeuing signals from a specified queue

From: Andrey Vagin
Date: Mon Dec 24 2012 - 03:15:26 EST


Cc: Ingo Molnar <mingo@xxxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Serge Hallyn <serge.hallyn@xxxxxxxxxxxxx>
Cc: Oleg Nesterov <oleg@xxxxxxxxxx>
Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Cc: "Eric W. Biederman" <ebiederm@xxxxxxxxxxxx>
Cc: Al Viro <viro@xxxxxxxxxxxxxxxxxx>
Cc: Pavel Emelyanov <xemul@xxxxxxxxxxxxx>
CC: Cyrill Gorcunov <gorcunov@xxxxxxxxxx>
Signed-off-by: Andrey Vagin <avagin@xxxxxxxxxx>
---
include/linux/sched.h | 9 ++++++++-
kernel/signal.c | 13 +++++++++----
2 files changed, 17 insertions(+), 5 deletions(-)

diff --git a/include/linux/sched.h b/include/linux/sched.h
index 0dd42a0..de9a4bf 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -2159,7 +2159,14 @@ extern void flush_signals(struct task_struct *);
extern void __flush_signals(struct task_struct *);
extern void ignore_signals(struct task_struct *);
extern void flush_signal_handlers(struct task_struct *, int force_default);
-extern int dequeue_signal(struct task_struct *tsk, sigset_t *mask, siginfo_t *info);
+extern int do_dequeue_signal(struct task_struct *tsk,
+ sigset_t *mask, siginfo_t *info, int queue);
+
+static inline int dequeue_signal(struct task_struct *tsk,
+ sigset_t *mask, siginfo_t *info)
+{
+ return do_dequeue_signal(tsk, mask, info, 0);
+}

static inline int dequeue_signal_lock(struct task_struct *tsk, sigset_t *mask, siginfo_t *info)
{
diff --git a/kernel/signal.c b/kernel/signal.c
index 0af8868..91bb76f2 100644
--- a/kernel/signal.c
+++ b/kernel/signal.c
@@ -597,17 +597,22 @@ static int __dequeue_signal(struct sigpending *pending, sigset_t *mask,
* Dequeue a signal and return the element to the caller, which is
* expected to free it.
*
+ * @queue: dequeue from a private queue, if a value is not positive
+ * dequeue from a shared queue, if a value if not negative
+ *
* All callers have to hold the siglock.
*/
-int dequeue_signal(struct task_struct *tsk, sigset_t *mask, siginfo_t *info)
+int do_dequeue_signal(struct task_struct *tsk, sigset_t *mask,
+ siginfo_t *info, int queue)
{
- int signr;
+ int signr = 0;

/* We only dequeue private signals from ourselves, we don't let
* signalfd steal them
*/
- signr = __dequeue_signal(&tsk->pending, mask, info);
- if (!signr) {
+ if (queue <= 0)
+ signr = __dequeue_signal(&tsk->pending, mask, info);
+ if (!signr && queue >= 0) {
signr = __dequeue_signal(&tsk->signal->shared_pending,
mask, info);
/*
--
1.7.11.7

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