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authorRoland McGrath <roland@redhat.com>2008-07-25 22:45:52 -0400
committerLinus Torvalds <torvalds@linux-foundation.org>2008-07-26 15:00:09 -0400
commit445a91d2fe3667fb8fc251433645f686933cf56a (patch)
tree496f0715ba3079f3bf98e9808480fe7f25872b16
parent35de254dc60f91004b3b5ebb1fc7b2c3093d6032 (diff)
tracehook: tracehook_consider_fatal_signal
This defines tracehook_consider_fatal_signal() has a fine-grained hook for deciding to skip the special cases for a fatal signal, as ptrace does. There is no change, only cleanup. Signed-off-by: Roland McGrath <roland@redhat.com> Cc: Oleg Nesterov <oleg@tv-sign.ru> Reviewed-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-rw-r--r--include/linux/tracehook.h21
-rw-r--r--kernel/signal.c9
2 files changed, 26 insertions, 4 deletions
diff --git a/include/linux/tracehook.h b/include/linux/tracehook.h
index 8cffd34f88d5..8b4c15e208fe 100644
--- a/include/linux/tracehook.h
+++ b/include/linux/tracehook.h
@@ -331,4 +331,25 @@ static inline int tracehook_consider_ignored_signal(struct task_struct *task,
331 return (task_ptrace(task) & PT_PTRACED) != 0; 331 return (task_ptrace(task) & PT_PTRACED) != 0;
332} 332}
333 333
334/**
335 * tracehook_consider_fatal_signal - suppress special handling of fatal signal
336 * @task: task receiving the signal
337 * @sig: signal number being sent
338 * @handler: %SIG_DFL or %SIG_IGN
339 *
340 * Return nonzero to prevent special handling of this termination signal.
341 * Normally @handler is %SIG_DFL. It can be %SIG_IGN if @sig is ignored,
342 * in which case force_sig() is about to reset it to %SIG_DFL.
343 * When this returns zero, this signal might cause a quick termination
344 * that does not give the debugger a chance to intercept the signal.
345 *
346 * Called with or without @task->sighand->siglock held.
347 */
348static inline int tracehook_consider_fatal_signal(struct task_struct *task,
349 int sig,
350 void __user *handler)
351{
352 return (task_ptrace(task) & PT_PTRACED) != 0;
353}
354
334#endif /* <linux/tracehook.h> */ 355#endif /* <linux/tracehook.h> */
diff --git a/kernel/signal.c b/kernel/signal.c
index 9efd1cee6d0b..1a942ce32ba0 100644
--- a/kernel/signal.c
+++ b/kernel/signal.c
@@ -300,12 +300,12 @@ flush_signal_handlers(struct task_struct *t, int force_default)
300 300
301int unhandled_signal(struct task_struct *tsk, int sig) 301int unhandled_signal(struct task_struct *tsk, int sig)
302{ 302{
303 void __user *handler = tsk->sighand->action[sig-1].sa.sa_handler;
303 if (is_global_init(tsk)) 304 if (is_global_init(tsk))
304 return 1; 305 return 1;
305 if (tsk->ptrace & PT_PTRACED) 306 if (handler != SIG_IGN && handler != SIG_DFL)
306 return 0; 307 return 0;
307 return (tsk->sighand->action[sig-1].sa.sa_handler == SIG_IGN) || 308 return !tracehook_consider_fatal_signal(tsk, sig, handler);
308 (tsk->sighand->action[sig-1].sa.sa_handler == SIG_DFL);
309} 309}
310 310
311 311
@@ -761,7 +761,8 @@ static void complete_signal(int sig, struct task_struct *p, int group)
761 if (sig_fatal(p, sig) && 761 if (sig_fatal(p, sig) &&
762 !(signal->flags & (SIGNAL_UNKILLABLE | SIGNAL_GROUP_EXIT)) && 762 !(signal->flags & (SIGNAL_UNKILLABLE | SIGNAL_GROUP_EXIT)) &&
763 !sigismember(&t->real_blocked, sig) && 763 !sigismember(&t->real_blocked, sig) &&
764 (sig == SIGKILL || !(t->ptrace & PT_PTRACED))) { 764 (sig == SIGKILL ||
765 !tracehook_consider_fatal_signal(t, sig, SIG_DFL))) {
765 /* 766 /*
766 * This signal will be fatal to the whole group. 767 * This signal will be fatal to the whole group.
767 */ 768 */