Re: [PATCH] monitor: Fix order in monitor_cleanup()

[Ben Widawsky]

On 20-10-13 14:50:27, Kevin Wolf wrote:
> We can only destroy Monitor objects after we're sure that they are not
> in use by the dispatcher coroutine any more. This fixes crashes like the
> following where we tried to destroy a monitor mutex while the dispatcher
> coroutine still holds it:
> 
>  (gdb) bt
>  #0  0x00007fe541cf4bc5 in raise () at /lib64/libc.so.6
>  #1  0x00007fe541cdd8a4 in abort () at /lib64/libc.so.6
>  #2  0x000055c24e965327 in error_exit (err=16, msg=0x55c24eead3a0 
> <__func__.33> "qemu_mutex_destroy") at ../util/qemu-thread-posix.c:37
>  #3  0x000055c24e9654c3 in qemu_mutex_destroy (mutex=0x55c25133e0f0) at 
> ../util/qemu-thread-posix.c:70
>  #4  0x000055c24e7cfaf1 in monitor_data_destroy_qmp (mon=0x55c25133dfd0) at 
> ../monitor/qmp.c:439
>  #5  0x000055c24e7d23bc in monitor_data_destroy (mon=0x55c25133dfd0) at 
> ../monitor/monitor.c:615
>  #6  0x000055c24e7d253a in monitor_cleanup () at ../monitor/monitor.c:644
>  #7  0x000055c24e6cb002 in qemu_cleanup () at ../softmmu/vl.c:4549
>  #8  0x000055c24e0d259b in main (argc=24, argv=0x7ffff66b0d58, 
> envp=0x7ffff66b0e20) at ../softmmu/main.c:51
> 
> Reported-by: Alex Bennée <alex.bennee@linaro.org>
> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Tested-by: Ben Widawsky <ben.widawsky@intel.com>

[snip]