From fc737586783a05672ff8eb96e245dfdeeadcd506 Mon Sep 17 00:00:00 2001 From: Heikki Linnakangas Date: Mon, 11 Mar 2024 16:36:37 +0200 Subject: [PATCH 1/1] Disconnect if socket cannot be put into non-blocking mode Commit 387da18874 moved the code to put socket into non-blocking mode from socket_set_nonblocking() into the one-time initialization function, pg_init(). In socket_set_nonblocking(), there indeed was a risk of recursion on failure like the comment said, but in pg_init(), ERROR or FATAL is fine. There's even another elog(FATAL) just after this, if setting FD_CLOEXEC fails. Note that COMMERROR merely logged the error, it did not close the connection, so if putting the socket to non-blocking mode failed we would use the connection anyway. You might not immediately notice, because most socket operations in a regular backend wait for the socket to become readable/writable anyway. But e.g. replication will be quite broken. Backpatch to all supported versions. Discussion: xx --- src/backend/libpq/pqcomm.c | 6 +----- 1 file changed, 1 insertion(+), 5 deletions(-) diff --git a/src/backend/libpq/pqcomm.c b/src/backend/libpq/pqcomm.c index c606bf34473..d9e49ca7028 100644 --- a/src/backend/libpq/pqcomm.c +++ b/src/backend/libpq/pqcomm.c @@ -189,14 +189,10 @@ pq_init(void) * nonblocking mode and use latches to implement blocking semantics if * needed. That allows us to provide safely interruptible reads and * writes. - * - * Use COMMERROR on failure, because ERROR would try to send the error to - * the client, which might require changing the mode again, leading to - * infinite recursion. */ #ifndef WIN32 if (!pg_set_noblock(MyProcPort->sock)) - ereport(COMMERROR, + ereport(FATAL, (errmsg("could not set socket to nonblocking mode: %m"))); #endif -- 2.39.2