vgdb: only queue up to 64 pending signals when waiting for SIGSTOP

We should not queue infinite pending signals so we won't run out of
memory when the SIGSTOP never arrives.

diff --git a/coregrind/vgdb-invoker-ptrace.c b/coregrind/vgdb-invoker-ptrace.c
index 389748960f14d34fd4b05f1eaa49eeb5e38f05aa..07f3400f957c152bd95740375a270d6d6609c6b6 100644 (file)
--- a/coregrind/vgdb-invoker-ptrace.c
+++ b/coregrind/vgdb-invoker-ptrace.c
@@ -300,6 +300,10 @@ Bool waitstopped (pid_t pid, int signal_expected, const char *msg)
 
          // realloc a bigger queue, and store new signal at the end.
          // This is not very efficient but we assume not many sigs are queued.
+         if (signal_queue_sz >= 64) {
+            DEBUG(0, "too many queued signals while waiting for SIGSTOP\n");
+            return False;
+         }
          signal_queue_sz++;
          signal_queue = vrealloc(signal_queue,
                                  sizeof(siginfo_t) * signal_queue_sz);