Subject: + signals-introduce-kernel_sigaction.patch added to -mm tree
To: oleg@xxxxxxxxxx,dwmw2@xxxxxxxxxxxxx,fweisbec@xxxxxxxxx,geert@xxxxxxxxxxxxxx,mathieu.desnoyers@xxxxxxxxxxxx,mingo@xxxxxxxxxx,peterz@xxxxxxxxxxxxx,richard@xxxxxx,rostedt@xxxxxxxxxxx,tj@xxxxxxxxxx,viro@xxxxxxxxxxxxxxxxxx
From: akpm@xxxxxxxxxxxxxxxxxxxx
Date: Tue, 15 Apr 2014 12:28:57 -0700
The patch titled
Subject: signals: introduce kernel_sigaction()
has been added to the -mm tree. Its filename is
signals-introduce-kernel_sigaction.patch
This patch should soon appear at
http://ozlabs.org/~akpm/mmots/broken-out/signals-introduce-kernel_sigaction.patch
and later at
http://ozlabs.org/~akpm/mmotm/broken-out/signals-introduce-kernel_sigaction.patch
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------------------------------------------------------
From: Oleg Nesterov <oleg@xxxxxxxxxx>
Subject: signals: introduce kernel_sigaction()
Now that allow_signal() is really trivial we can unify it with
disallow_signal(). Add the new helper, kernel_sigaction(), and
reimplement allow_signal/disallow_signal as a trivial wrappers.
This saves one EXPORT_SYMBOL() and the new helper can have more users.
Signed-off-by: Oleg Nesterov <oleg@xxxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Al Viro <viro@xxxxxxxxxxxxxxxxxx>
Cc: David Woodhouse <dwmw2@xxxxxxxxxxxxx>
Cc: Frederic Weisbecker <fweisbec@xxxxxxxxx>
Cc: Geert Uytterhoeven <geert@xxxxxxxxxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxxxxx>
Cc: Mathieu Desnoyers <mathieu.desnoyers@xxxxxxxxxxxx>
Cc: Richard Weinberger <richard@xxxxxx>
Cc: Steven Rostedt <rostedt@xxxxxxxxxxx>
Cc: Tejun Heo <tj@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
include/linux/signal.h | 18 ++++++++++++++++--
kernel/signal.c | 36 ++++++++++++------------------------
2 files changed, 28 insertions(+), 26 deletions(-)
diff -puN include/linux/signal.h~signals-introduce-kernel_sigaction include/linux/signal.h
--- a/include/linux/signal.h~signals-introduce-kernel_sigaction
+++ a/include/linux/signal.h
@@ -284,8 +284,22 @@ extern int get_signal_to_deliver(siginfo
extern void signal_setup_done(int failed, struct ksignal *ksig, int stepping);
extern void signal_delivered(int sig, siginfo_t *info, struct k_sigaction *ka, struct pt_regs *regs, int stepping);
extern void exit_signals(struct task_struct *tsk);
-extern void allow_signal(int);
-extern void disallow_signal(int);
+extern void kernel_sigaction(int, __sighandler_t);
+
+static inline void allow_signal(int sig)
+{
+ /*
+ * Kernel threads handle their own signals. Let the signal code
+ * know it'll be handled, so that they don't get converted to
+ * SIGKILL or just silently dropped.
+ */
+ kernel_sigaction(sig, (__force __sighandler_t)2);
+}
+
+static inline void disallow_signal(int sig)
+{
+ kernel_sigaction(sig, SIG_IGN);
+}
/*
* Eventually that'll replace get_signal_to_deliver(); macro for now,
diff -puN kernel/signal.c~signals-introduce-kernel_sigaction kernel/signal.c
--- a/kernel/signal.c~signals-introduce-kernel_sigaction
+++ a/kernel/signal.c
@@ -3066,37 +3066,25 @@ COMPAT_SYSCALL_DEFINE4(rt_tgsigqueueinfo
#endif
/*
- * Let kernel threads use this to say that they allow a certain signal.
- * Must not be used if kthread was cloned with CLONE_SIGHAND.
+ * For kthreads only, must not be used if cloned with CLONE_SIGHAND
*/
-void allow_signal(int sig)
+void kernel_sigaction(int sig, __sighandler_t action)
{
- /*
- * Kernel threads handle their own signals. Let the signal code
- * know it'll be handled, so that they don't get converted to
- * SIGKILL or just silently dropped.
- */
spin_lock_irq(¤t->sighand->siglock);
- current->sighand->action[(sig)-1].sa.sa_handler = (void __user *)2;
- spin_unlock_irq(¤t->sighand->siglock);
-}
-EXPORT_SYMBOL(allow_signal);
+ current->sighand->action[sig - 1].sa.sa_handler = action;
+ if (action == SIG_IGN) {
+ sigset_t mask;
-void disallow_signal(int sig)
-{
- sigset_t mask;
+ sigemptyset(&mask);
+ sigaddset(&mask, sig);
- sigemptyset(&mask);
- sigaddset(&mask, sig);
-
- spin_lock_irq(¤t->sighand->siglock);
- current->sighand->action[(sig)-1].sa.sa_handler = SIG_IGN;
- flush_sigqueue_mask(&mask, ¤t->signal->shared_pending);
- flush_sigqueue_mask(&mask, ¤t->pending);
- recalc_sigpending();
+ flush_sigqueue_mask(&mask, ¤t->signal->shared_pending);
+ flush_sigqueue_mask(&mask, ¤t->pending);
+ recalc_sigpending();
+ }
spin_unlock_irq(¤t->sighand->siglock);
}
-EXPORT_SYMBOL(disallow_signal);
+EXPORT_SYMBOL(kernel_sigaction);
int do_sigaction(int sig, struct k_sigaction *act, struct k_sigaction *oact)
{
_
Patches currently in -mm which might be from oleg@xxxxxxxxxx are
signals-kill-sigfindinword.patch
signals-s-siginitset-sigemptyset-in-do_sigtimedwait.patch
signals-kill-rm_from_queue-change-prepare_signal-to-use-for_each_thread.patch
signals-rename-rm_from_queue_full-to-flush_sigqueue_mask.patch
signals-cleanup-the-usage-of-t-current-in-do_sigaction.patch
signals-mv-disallow_signal-from-schedh-exitc-to-signal.patch
signals-jffs2-fix-the-wrong-usage-of-disallow_signal.patch
signals-kill-the-obsolete-sigdelset-and-recalc_sigpending-in-allow_signal.patch
signals-disallow_signal-should-flush-the-potentially-pending-signal.patch
signals-introduce-kernel_sigaction.patch
signals-change-wait_for_helper-to-use-kernel_sigaction.patch
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