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author | Jan Kiszka <jan.kiszka@siemens.com> | 2014-10-27 14:05:10 +0000 |
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committer | Michael Roth <mdroth@linux.vnet.ibm.com> | 2015-01-06 18:25:45 -0600 |
commit | 5a6af9724369b321f0ae4459403ef76e4a7bd507 (patch) | |
tree | 18e1e702d64655f611073152f497c23859b77454 | |
parent | 90de7a03bbc24d559971248c5530631d9bc27250 (diff) | |
download | qemu-5a6af9724369b321f0ae4459403ef76e4a7bd507.tar.gz |
Make qemu_shutdown_requested signal-safe
qemu_shutdown_requested may be interrupted by qemu_system_killed. If the
latter sets shutdown_requested after qemu_shutdown_requested has read it
but before it was cleared, the shutdown event is lost. Fix this by using
atomic_xchg.
This provides a different fix for the problem which commit 15124e142
attempts to deal with. That commit breaks use of ^C to drop into gdb,
and so this approach is better (and 15124e142 can be reverted).
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Reviewed-by: Gonglei <arei.gonglei@huawei.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
[PMM: commit message tweak]
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
(cherry picked from commit 817ef04db2cfa2df04daffd6917f4ea7605f6403)
Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>
-rw-r--r-- | vl.c | 4 |
1 files changed, 1 insertions, 3 deletions
@@ -1745,9 +1745,7 @@ int qemu_reset_requested_get(void) static int qemu_shutdown_requested(void) { - int r = shutdown_requested; - shutdown_requested = 0; - return r; + return atomic_xchg(&shutdown_requested, 0); } static void qemu_kill_report(void) |