Fix pg_dump's sigTermHandler() to use _exit() not exit().

sigTermHandler() tried to be careful to invoke only operations that
are safe to do in a signal handler.  But for some reason we forgot
that exit(3) is not among those, because it calls atexit handlers
that might do various random things.  (pg_dump itself installs no
atexit handlers, but e.g. OpenSSL does.)  That led to crashes or
lockups when attempting to terminate a parallel dump or restore
via a signal.

Fix by calling _exit() instead.

Per bug #16199 from Raúl Marín.  Back-patch to all supported branches.

Discussion: https://postgr.es/m/16199-cb2f121146a96f9b@postgresql.org

diff --git a/src/bin/pg_dump/parallel.c b/src/bin/pg_dump/parallel.c
index ce3a06ae816ba2cd8df29f317e2f2935e9352a18..de776a91891ba1421dfe5e17ffc3f410b0282612 100644 (file)
--- a/src/bin/pg_dump/parallel.c
+++ b/src/bin/pg_dump/parallel.c
@@ -573,8 +573,11 @@ sigTermHandler(SIGNAL_ARGS)
        write_stderr("terminated by user\n");
    }
 
-   /* And die. */
-   exit(1);
+   /*
+    * And die, using _exit() not exit() because the latter will invoke atexit
+    * handlers that can fail if we interrupted related code.
+    */
+   _exit(1);
 }
 
 /*