migration: fix the compression code
Add judgement in compress_threads_save_cleanup() to check whether the
static CompressParam *comp_param has been allocated. If not, just
return; or else segmentation fault will occur when using the NULL
comp_param's parameters. One test case can reproduce this is: set
the compression on and migrate to a wrong nonexistent host IP address.
Our current code does not judge before handling comp_param[idx]'s quit
and cond that whether they have been initialized. If not initialized,
"qemu_mutex_lock_impl: Assertion `mutex->initialized' failed." will
occur. Fix this by squashing the terminate_compression_threads() into
compress_threads_save_cleanup() and employing the existing judgement
condition. One test case can reproduce this error is: set the
compression on and fail to fully setup the default eight compression
thread in compress_threads_save_setup().
Signed-off-by: Fei Li <fli@suse.com>
Message-Id: <20180925091440.18910-1-fli@suse.com>
Reviewed-by: Peter Xu <peterx@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
diff --git a/migration/ram.c b/migration/ram.c
index 0fdaa8e..408d237 100644
--- a/migration/ram.c
+++ b/migration/ram.c
@@ -431,28 +431,14 @@
return NULL;
}
-static inline void terminate_compression_threads(void)
-{
- int idx, thread_count;
-
- thread_count = migrate_compress_threads();
-
- for (idx = 0; idx < thread_count; idx++) {
- qemu_mutex_lock(&comp_param[idx].mutex);
- comp_param[idx].quit = true;
- qemu_cond_signal(&comp_param[idx].cond);
- qemu_mutex_unlock(&comp_param[idx].mutex);
- }
-}
-
static void compress_threads_save_cleanup(void)
{
int i, thread_count;
- if (!migrate_use_compression()) {
+ if (!migrate_use_compression() || !comp_param) {
return;
}
- terminate_compression_threads();
+
thread_count = migrate_compress_threads();
for (i = 0; i < thread_count; i++) {
/*
@@ -462,6 +448,12 @@
if (!comp_param[i].file) {
break;
}
+
+ qemu_mutex_lock(&comp_param[i].mutex);
+ comp_param[i].quit = true;
+ qemu_cond_signal(&comp_param[i].cond);
+ qemu_mutex_unlock(&comp_param[i].mutex);
+
qemu_thread_join(compress_threads + i);
qemu_mutex_destroy(&comp_param[i].mutex);
qemu_cond_destroy(&comp_param[i].cond);
