From 26ef5e9b2a6e3b91f0e42689d150c53491fcd4fc Mon Sep 17 00:00:00 2001 From: Tom Lane Date: Sat, 20 Mar 2010 00:58:46 +0000 Subject: [PATCH] Clear error_context_stack and debug_query_string at the beginning of proc_exit, so that we won't try to attach any context printouts to messages that get emitted while exiting. Per report from Dennis Koegel, the context functions won't necessarily work after we've started shutting down the backend, and it seems possible that debug_query_string could be pointing at freed storage as well. The context information doesn't seem particularly relevant to such messages anyway, so there's little lost by suppressing it. Back-patch to all supported branches. I can only demonstrate a crash with log_disconnections messages back to 8.1, but the risk seems real in 8.0 and before anyway. --- src/backend/storage/ipc/ipc.c | 16 +++++++++++++++- 1 file changed, 15 insertions(+), 1 deletion(-) diff --git a/src/backend/storage/ipc/ipc.c b/src/backend/storage/ipc/ipc.c index c917121a38e..89169ed0065 100644 --- a/src/backend/storage/ipc/ipc.c +++ b/src/backend/storage/ipc/ipc.c @@ -13,7 +13,7 @@ * * * IDENTIFICATION - * $Header: /cvsroot/pgsql/src/backend/storage/ipc/ipc.c,v 1.85 2003/08/04 02:40:03 momjian Exp $ + * $Header: /cvsroot/pgsql/src/backend/storage/ipc/ipc.c,v 1.85.4.1 2010/03/20 00:58:46 tgl Exp $ * *------------------------------------------------------------------------- */ @@ -25,6 +25,7 @@ #include "miscadmin.h" #include "storage/ipc.h" +#include "tcop/tcopprot.h" /* @@ -92,6 +93,19 @@ proc_exit(int code) InterruptHoldoffCount = 1; CritSectionCount = 0; + /* + * Also clear the error context stack, to prevent error callbacks + * from being invoked by any elog/ereport calls made during proc_exit. + * Whatever context they might want to offer is probably not relevant, + * and in any case they are likely to fail outright after we've done + * things like aborting any open transaction. (In normal exit scenarios + * the context stack should be empty anyway, but it might not be in the + * case of elog(FATAL) for example.) + */ + error_context_stack = NULL; + /* For the same reason, reset debug_query_string before it's clobbered */ + debug_query_string = NULL; + elog(DEBUG3, "proc_exit(%d)", code); /* do our shared memory exits first */