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authorOleg Nesterov2014-06-06 23:36:53 +0200
committerLinus Torvalds2014-06-07 01:08:11 +0200
commit0341729b4b832e753c5e745c6ba0e797f6198be0 (patch)
tree75e1a7743a1fbf38e27ec1c8e8ece1261fa71dd1 /kernel/signal.c
parentsignals: cleanup the usage of t/current in do_sigaction() (diff)
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signals: mv {dis,}allow_signal() from sched.h/exit.c to signal.[ch]
Move the declaration/definition of allow_signal/disallow_signal to signal.h/signal.c. The new place is more logical and allows to use the static helpers in signal.c (see the next changes). While at it, make them return void and remove the valid_signal() check. Nobody checks the returned value, and in-kernel users must not pass the wrong signal number. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Al Viro <viro@ZenIV.linux.org.uk> Cc: David Woodhouse <dwmw2@infradead.org> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Ingo Molnar <mingo@kernel.org> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: Richard Weinberger <richard@nod.at> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Tejun Heo <tj@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'kernel/signal.c')
-rw-r--r--kernel/signal.c29
1 files changed, 29 insertions, 0 deletions
diff --git a/kernel/signal.c b/kernel/signal.c
index a6d8c3af0ad6..7d6ff8b18509 100644
--- a/kernel/signal.c
+++ b/kernel/signal.c
@@ -3066,6 +3066,35 @@ 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.
+ */
+void allow_signal(int sig)
+{
+ spin_lock_irq(&current->sighand->siglock);
+ /* This is only needed for daemonize()'ed kthreads */
+ sigdelset(&current->blocked, 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.
+ */
+ current->sighand->action[(sig)-1].sa.sa_handler = (void __user *)2;
+ recalc_sigpending();
+ spin_unlock_irq(&current->sighand->siglock);
+}
+EXPORT_SYMBOL(allow_signal);
+
+void disallow_signal(int sig)
+{
+ spin_lock_irq(&current->sighand->siglock);
+ current->sighand->action[(sig)-1].sa.sa_handler = SIG_IGN;
+ recalc_sigpending();
+ spin_unlock_irq(&current->sighand->siglock);
+}
+EXPORT_SYMBOL(disallow_signal);
+
int do_sigaction(int sig, struct k_sigaction *act, struct k_sigaction *oact)
{
struct task_struct *p = current, *t;