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| author | Zhimin Feng <fengzhimin1@huawei.com> | 2020-01-10 16:50:19 +0800 |
|---|---|---|
| committer | Juan Quintela <quintela@redhat.com> | 2020-01-29 11:28:59 +0100 |
| commit | 9c4d333c092e9c26d38f740ff3616deb42f21681 (patch) | |
| tree | 0fef119e68639d4b1c0b627d81d2e286f55b3a2a /migration/ram.c | |
| parent | 392d87e21325fdb01210176faa07472b4985ccf0 (diff) | |
migration/multifd: fix nullptr access in multifd_send_terminate_threads
If the multifd_send_threads is not created when migration is failed,
multifd_save_cleanup would be called twice. In this senario, the
multifd_send_state is accessed after it has been released, the result
is that the source VM is crashing down.
Here is the coredump stack:
Program received signal SIGSEGV, Segmentation fault.
0x00005629333a78ef in multifd_send_terminate_threads (err=err@entry=0x0) at migration/ram.c:1012
1012 MultiFDSendParams *p = &multifd_send_state->params[i];
#0 0x00005629333a78ef in multifd_send_terminate_threads (err=err@entry=0x0) at migration/ram.c:1012
#1 0x00005629333ab8a9 in multifd_save_cleanup () at migration/ram.c:1028
#2 0x00005629333abaea in multifd_new_send_channel_async (task=0x562935450e70, opaque=<optimized out>) at migration/ram.c:1202
#3 0x000056293373a562 in qio_task_complete (task=task@entry=0x562935450e70) at io/task.c:196
#4 0x000056293373a6e0 in qio_task_thread_result (opaque=0x562935450e70) at io/task.c:111
#5 0x00007f475d4d75a7 in g_idle_dispatch () from /usr/lib64/libglib-2.0.so.0
#6 0x00007f475d4da9a9 in g_main_context_dispatch () from /usr/lib64/libglib-2.0.so.0
#7 0x0000562933785b33 in glib_pollfds_poll () at util/main-loop.c:219
#8 os_host_main_loop_wait (timeout=<optimized out>) at util/main-loop.c:242
#9 main_loop_wait (nonblocking=nonblocking@entry=0) at util/main-loop.c:518
#10 0x00005629334c5acf in main_loop () at vl.c:1810
#11 0x000056293334d7bb in main (argc=<optimized out>, argv=<optimized out>, envp=<optimized out>) at vl.c:4471
If the multifd_send_threads is not created when migration is failed.
In this senario, we don't call multifd_save_cleanup in multifd_new_send_channel_async.
Signed-off-by: Zhimin Feng <fengzhimin1@huawei.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
Diffstat (limited to 'migration/ram.c')
| -rw-r--r-- | migration/ram.c | 10 |
1 files changed, 9 insertions, 1 deletions
diff --git a/migration/ram.c b/migration/ram.c index 3fd7fdffcf..82c7edb083 100644 --- a/migration/ram.c +++ b/migration/ram.c @@ -1233,7 +1233,15 @@ static void multifd_new_send_channel_async(QIOTask *task, gpointer opaque) trace_multifd_new_send_channel_async(p->id); if (qio_task_propagate_error(task, &local_err)) { migrate_set_error(migrate_get_current(), local_err); - multifd_save_cleanup(); + /* Error happen, we need to tell who pay attention to me */ + qemu_sem_post(&multifd_send_state->channels_ready); + qemu_sem_post(&p->sem_sync); + /* + * Although multifd_send_thread is not created, but main migration + * thread neet to judge whether it is running, so we need to mark + * its status. + */ + p->quit = true; } else { p->c = QIO_CHANNEL(sioc); qio_channel_set_delay(p->c, false); |