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| author | Andres Freund <andres@anarazel.de> | 2021-08-19 04:59:06 -0700 |
|---|---|---|
| committer | Andres Freund <andres@anarazel.de> | 2021-08-19 05:07:53 -0700 |
| commit | bed5eac2d50eb86a254861dcdea7b064d10c72cf (patch) | |
| tree | fc7b4ff2f31081812caeeb8be207cf7f26131f93 /src | |
| parent | 4cd7a189687171374ff302ad71c99d39ff6d2bab (diff) | |
| download | postgresql-bed5eac2d50eb86a254861dcdea7b064d10c72cf.tar.gz postgresql-bed5eac2d50eb86a254861dcdea7b064d10c72cf.zip | |
Unset MyBEEntry, making elog.c's call to pgstat_get_my_query_id() safe.
Previously log messages late during shutdown could end up using either another
backend's PgBackendStatus (multi user) or segfault (single user) because
pgstat_get_my_query_id()'s check for !MyBEEntry didn't filter out use after
pgstat_beshutdown_hook().
This became a bug in 4f0b0966c86, but was a bit fishy before. But given
there's no known problematic cases before 14, it doesn't seem worth
backpatching further.
Also fixes a wrong filename in a comment, introduced in e1025044.
Reported-By: Andres Freund <andres@anarazel.de>
Reviewed-By: Julien Rouhaud <rjuju123@gmail.com>
Discussion: https://postgr.es/m/Julien Rouhaud <rjuju123@gmail.com>
Backpatch: 14-
Diffstat (limited to 'src')
| -rw-r--r-- | src/backend/utils/activity/backend_status.c | 5 |
1 files changed, 4 insertions, 1 deletions
diff --git a/src/backend/utils/activity/backend_status.c b/src/backend/utils/activity/backend_status.c index 2901f9f5a9f..e19c4506efa 100644 --- a/src/backend/utils/activity/backend_status.c +++ b/src/backend/utils/activity/backend_status.c @@ -46,7 +46,7 @@ bool pgstat_track_activities = false; int pgstat_track_activity_query_size = 1024; -/* exposed so that progress.c can access it */ +/* exposed so that backend_progress.c can access it */ PgBackendStatus *MyBEEntry = NULL; @@ -469,6 +469,9 @@ pgstat_beshutdown_hook(int code, Datum arg) beentry->st_procpid = 0; /* mark invalid */ PGSTAT_END_WRITE_ACTIVITY(beentry); + + /* so that functions can check if backend_status.c is up via MyBEEntry */ + MyBEEntry = NULL; } /* |