[PATCH] sigwait eats blocked default-ignore signals

From: Roland McGrath
Date: Mon Nov 12 2007 - 18:42:43 EST



cf http://bugzilla.kernel.org/show_bug.cgi?id=9347

While a signal is blocked, it must be posted even if its action is
SIG_IGN or is SIG_DFL with the default action to ignore. This works
right most of the time, but is broken when a sigwait (rt_sigtimedwait)
is in progress. This changes the early-discard check to respect
real_blocked. ~blocked is the set to check for "should wake up now",
but ~(blocked|real_blocked) is the set for "blocked" semantics as
defined by POSIX.

Signed-off-by: Roland McGrath <roland@xxxxxxxxxx>
---
kernel/signal.c | 2 +-
1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/kernel/signal.c b/kernel/signal.c
index 0ac614a..9b22790 100644
--- a/kernel/signal.c
+++ b/kernel/signal.c
@@ -55,7 +55,7 @@ static int sig_ignored(struct task_struct *t, int sig)
* signal handler may change by the time it is
* unblocked.
*/
- if (sigismember(&t->blocked, sig))
+ if (sigismember(&t->blocked, sig) || sigismember(&t->real_blocked, sig))
return 0;

/* Is it explicitly or implicitly ignored? */
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/