From 31ed3cf746a61538876c66a778ec8a372a3b4ffb Mon Sep 17 00:00:00 2001 From: Tom Lane Date: Mon, 25 Jul 2022 10:27:43 -0400 Subject: Process session_preload_libraries within InitPostgres's transaction. Previously we did this after InitPostgres, at a somewhat randomly chosen place within PostgresMain. However, since commit a0ffa885e doing this outside a transaction can cause a crash, if we need to check permissions while replacing a placeholder GUC. (Besides which, a preloaded library could itself want to do database access within _PG_init.) To avoid needing an additional transaction start/end in every session, move the process_session_preload_libraries call to within InitPostgres's transaction. That requires teaching the code not to call it when InitPostgres is called from somewhere other than PostgresMain, since we don't want session_preload_libraries to affect background workers. The most future-proof solution here seems to be to add an additional flag parameter to InitPostgres; fortunately, we're not yet very worried about API stability for v15. Doing this also exposed the fact that we're currently honoring session_preload_libraries in walsenders, even those not connected to any database. This seems, at minimum, a POLA violation: walsenders are not interactive sessions. Let's stop doing that. (All these comments also apply to local_preload_libraries, of course.) Per report from Gurjeet Singh (thanks also to Nathan Bossart and Kyotaro Horiguchi for review). Backpatch to v15 where a0ffa885e came in. Discussion: https://postgr.es/m/CABwTF4VEpwTHhRQ+q5MiC5ucngN-whN-PdcKeufX7eLSoAfbZA@mail.gmail.com --- src/include/miscadmin.h | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) (limited to 'src/include/miscadmin.h') diff --git a/src/include/miscadmin.h b/src/include/miscadmin.h index 0af130fbc5d..3233278b340 100644 --- a/src/include/miscadmin.h +++ b/src/include/miscadmin.h @@ -457,8 +457,11 @@ extern PGDLLIMPORT AuxProcType MyAuxProcType; /* in utils/init/postinit.c */ extern void pg_split_opts(char **argv, int *argcp, const char *optstr); extern void InitializeMaxBackends(void); -extern void InitPostgres(const char *in_dbname, Oid dboid, const char *username, - Oid useroid, char *out_dbname, bool override_allow_connections); +extern void InitPostgres(const char *in_dbname, Oid dboid, + const char *username, Oid useroid, + bool load_session_libraries, + bool override_allow_connections, + char *out_dbname); extern void BaseInit(void); /* in utils/init/miscinit.c */ -- cgit v1.2.3