linux-user: pause() should not pause if signal pending
Fix races between signal handling and the pause syscall by
reimplementing it using block_signals() and sigsuspend().
(Using safe_syscall(pause) would also work, except that the
pause syscall doesn't exist on all architectures.)
Signed-off-by: Timothy Edward Baldwin <T.E.Baldwin99@members.leeds.ac.uk>
Message-id: 1441497448-32489-28-git-send-email-T.E.Baldwin99@members.leeds.ac.uk
[PMM: tweaked commit message]
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Riku Voipio <riku.voipio@linaro.org>
diff --git a/linux-user/syscall.c b/linux-user/syscall.c
index 639b328..aa5517c 100644
--- a/linux-user/syscall.c
+++ b/linux-user/syscall.c
@@ -7059,7 +7059,10 @@
#endif
#ifdef TARGET_NR_pause /* not on alpha */
case TARGET_NR_pause:
- ret = get_errno(pause());
+ if (!block_signals()) {
+ sigsuspend(&((TaskState *)cpu->opaque)->signal_mask);
+ }
+ ret = -TARGET_EINTR;
break;
#endif
#ifdef TARGET_NR_utime
