Fix Y2038 issues with MyStartTime.

nathan-bossart · nathan-bossart · commit 5cea7168dfe6 · 2024-10-07T13:51:03.000-05:00
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
diff --git a/src/backend/utils/error/elog.c b/src/backend/utils/error/elog.c
@@ -2538,12 +2538,12 @@ 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)
@@ -2848,7 +2848,7 @@ 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
@@ -1205,10 +1205,10 @@ 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
@@ -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
