[RFC] migration/dirtyrate: check malloc() return

[jianchunfu]

Handling potential memory allocation failures in dirtyrate.

Signed-off-by: jianchunfu <jianchunfu@cmss.chinamobile.com>
---
 migration/dirtyrate.c | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/migration/dirtyrate.c b/migration/dirtyrate.c
index aace12a787..5dd40f32c8 100644
--- a/migration/dirtyrate.c
+++ b/migration/dirtyrate.c
@@ -523,9 +523,17 @@ static void calculate_dirtyrate_dirty_ring(struct 
DirtyRateConfig config)
     }
 
     dirty_pages = malloc(sizeof(*dirty_pages) * nvcpu);
+    if (!dirty_pages) {
+        error_report("malloc dirty pages for vcpus failed.");
+        exit(1);
+    }
 
     DirtyStat.dirty_ring.nvcpu = nvcpu;
     DirtyStat.dirty_ring.rates = malloc(sizeof(DirtyRateVcpu) * nvcpu);
+    if (!DirtyStat.dirty_ring.rates) {
+        error_report("malloc dirty rates for vcpu ring failed.");
+        exit(1);
+    }
 
     dirtyrate_global_dirty_log_start();
 
-- 
2.18.4