From b255493aefe9eea0ba2592d485819aaad21193fb Mon Sep 17 00:00:00 2001
From: Nathan Bossart <nathan@postgresql.org>
Date: Mon, 7 Oct 2024 13:51:03 -0500
Subject: [PATCH] Fix Y2038 issues with MyStartTime.

Several places treat MyStartTime as a "long", which is only 32 bits
wide on some platforms.  In reality, MyStartTime is a pg_time_t,
i.e., a signed 64-bit integer.  This will lead to interesting bugs
on the aforementioned systems in 2038 when signed 32-bit integers
are no longer sufficient to store Unix time (e.g., "pg_ctl start"
hanging).  To fix, ensure that MyStartTime is handled as a 64-bit
value everywhere.  (Of course, users will need to ensure that
time_t is 64 bits wide on their system, too.)

Co-authored-by: Max Johnson
Discussion: https://postgr.es/m/CO1PR07MB905262E8AC270FAAACED66008D682%40CO1PR07MB9052.namprd07.prod.outlook.com
Backpatch-through: 12
---
 src/backend/utils/error/elog.c    | 8 ++++----
 src/backend/utils/init/miscinit.c | 4 ++--
 src/bin/pg_ctl/pg_ctl.c           | 2 +-
 3 files changed, 7 insertions(+), 7 deletions(-)

diff --git a/src/backend/utils/error/elog.c b/src/backend/utils/error/elog.c
index eadfef1078a..31cff62da35 100644
--- a/src/backend/utils/error/elog.c
+++ b/src/backend/utils/error/elog.c
@@ -2455,12 +2455,12 @@ log_line_prefix(StringInfo buf, ErrorData *edata)
 				{
 					char		strfbuf[128];
 
-					snprintf(strfbuf, sizeof(strfbuf) - 1, "%lx.%x",
-							 (long) (MyStartTime), MyProcPid);
+					snprintf(strfbuf, sizeof(strfbuf) - 1, "%" INT64_MODIFIER "x.%x",
+							 MyStartTime, MyProcPid);
 					appendStringInfo(buf, "%*s", padding, strfbuf);
 				}
 				else
-					appendStringInfo(buf, "%lx.%x", (long) (MyStartTime), MyProcPid);
+					appendStringInfo(buf, "%" INT64_MODIFIER "x.%x", MyStartTime, MyProcPid);
 				break;
 			case 'p':
 				if (padding != 0)
@@ -2734,7 +2734,7 @@ write_csvlog(ErrorData *edata)
 	appendStringInfoChar(&buf, ',');
 
 	/* session id */
-	appendStringInfo(&buf, "%lx.%x", (long) MyStartTime, MyProcPid);
+	appendStringInfo(&buf, "%" INT64_MODIFIER "x.%x", MyStartTime, MyProcPid);
 	appendStringInfoChar(&buf, ',');
 
 	/* Line number */
diff --git a/src/backend/utils/init/miscinit.c b/src/backend/utils/init/miscinit.c
index 7828791ed26..0d6d14a2c63 100644
--- a/src/backend/utils/init/miscinit.c
+++ b/src/backend/utils/init/miscinit.c
@@ -1175,10 +1175,10 @@ CreateLockFile(const char *filename, bool amPostmaster,
 	 * both datadir and socket lockfiles; although more stuff may get added to
 	 * the datadir lockfile later.
 	 */
-	snprintf(buffer, sizeof(buffer), "%d\n%s\n%ld\n%d\n%s\n",
+	snprintf(buffer, sizeof(buffer), "%d\n%s\n" INT64_FORMAT "\n%d\n%s\n",
 			 amPostmaster ? (int) my_pid : -((int) my_pid),
 			 DataDir,
-			 (long) MyStartTime,
+			 MyStartTime,
 			 PostPortNumber,
 			 socketDir);
 
diff --git a/src/bin/pg_ctl/pg_ctl.c b/src/bin/pg_ctl/pg_ctl.c
index 091d584d82a..77be073aa45 100644
--- a/src/bin/pg_ctl/pg_ctl.c
+++ b/src/bin/pg_ctl/pg_ctl.c
@@ -624,7 +624,7 @@ wait_for_postmaster_start(pgpid_t pm_pid, bool do_checkpoint)
 			 * Allow 2 seconds slop for possible cross-process clock skew.
 			 */
 			pmpid = atol(optlines[LOCK_FILE_LINE_PID - 1]);
-			pmstart = atol(optlines[LOCK_FILE_LINE_START_TIME - 1]);
+			pmstart = atoll(optlines[LOCK_FILE_LINE_START_TIME - 1]);
 			if (pmstart >= start_time - 2 &&
 #ifndef WIN32
 				pmpid == pm_pid