gwj / at91sam9263 · Commits

Commit e332340a7799cf5681bffac264e3ce90288c037f

Authored by Jean-Christophe Dubois
Committed by Anthony Liguori
1 parent e6ade764

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 <jcd@tribudubois.net>
Inline Side-by-side
Showing 1 changed file with 2 additions and 2 deletions
... ... @@ -915,7 +915,7 @@ struct qemu_alarm_timer {
915 915  
916 916 static inline int alarm_has_dynticks(struct qemu_alarm_timer *t)
917 917 {
918   - return t->flags & ALARM_FLAG_DYNTICKS;
  918 + return t && (t->flags & ALARM_FLAG_DYNTICKS);
919 919 }
920 920  
921 921 static void qemu_rearm_alarm_timer(struct qemu_alarm_timer *t)
... ... @@ -1349,7 +1349,7 @@ static void host_alarm_handler(int host_signum)
1349 1349 qemu_timer_expired(active_timers[QEMU_TIMER_REALTIME],
1350 1350 qemu_get_clock(rt_clock))) {
1351 1351 qemu_event_increment();
1352   - alarm_timer->flags |= ALARM_FLAG_EXPIRED;
  1352 + if (alarm_timer) alarm_timer->flags |= ALARM_FLAG_EXPIRED;
1353 1353  
1354 1354 #ifndef CONFIG_IOTHREAD
1355 1355 if (next_cpu) {
... ...