From e332340a7799cf5681bffac264e3ce90288c037f Mon Sep 17 00:00:00 2001 From: Jean-Christophe Dubois Date: Sun, 17 May 2009 18:38:39 +0200 Subject: [PATCH] Fix NULL alarm_timer pointer at exit This fixes a SIGSEGV error on qemu exit. Here is the valgrind output related to this error ==3648== Process terminating with default action of signal 11 (SIGSEGV) ==3648== Access not within mapped region at address 0x8 ==3648== at 0x40636B: host_alarm_handler (vl.c:1345) ==3648== by 0x52D807F: (within /lib/libpthread-2.9.so) ==3648== by 0x5C0A12E: tcsetattr (in /lib/libc-2.9.so) ==3648== by 0x4DD601: term_exit (qemu-char.c:700) ==3648== by 0x5B636EC: exit (in /lib/libc-2.9.so) ==3648== by 0x5B4B5AC: (below main) (in /lib/libc-2.9.so) This simple fix check for a valid pointer as host_alarm_handler is also called after alarm_timer is released in the exit path. Signed-off-by: Jean-Christophe DUBOIS --- vl.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/vl.c b/vl.c index 40b1d8bf..7034209c 100644 --- a/vl.c +++ b/vl.c @@ -915,7 +915,7 @@ struct qemu_alarm_timer { static inline int alarm_has_dynticks(struct qemu_alarm_timer *t) { - return t->flags & ALARM_FLAG_DYNTICKS; + return t && (t->flags & ALARM_FLAG_DYNTICKS); } static void qemu_rearm_alarm_timer(struct qemu_alarm_timer *t) @@ -1349,7 +1349,7 @@ static void host_alarm_handler(int host_signum) qemu_timer_expired(active_timers[QEMU_TIMER_REALTIME], qemu_get_clock(rt_clock))) { qemu_event_increment(); - alarm_timer->flags |= ALARM_FLAG_EXPIRED; + if (alarm_timer) alarm_timer->flags |= ALARM_FLAG_EXPIRED; #ifndef CONFIG_IOTHREAD if (next_cpu) { -- 2.11.4.GIT