Set progname early in the postmaster/postgres binary, rather than doing

it later.  This fixes a problem where EXEC_BACKEND didn't have progname
set, causing a segfault if log_min_messages was set below debug2 and our
own snprintf.c was being used.

Also alway strdup() progname.

Backpatch to 8.1.X and 8.0.X.

4 files changed, 21 insertions, 23 deletions

diff --git a/src/backend/main/main.c b/src/backend/main/main.c
index db46eb12e8..efbd25a1fa 100644
--- a/src/backend/main/main.c
+++ b/src/backend/main/main.c
@@ -45,7 +45,7 @@
 #include "libpq/pqsignal.h"
 #endif
 
-
+const char *progname;
 
 int
 main(int argc, char *argv[])
@@ -77,6 +77,8 @@ main(int argc, char *argv[])
 	char	   *env_locale;
 #endif
 
+	progname = get_progname(argv[0]);
+
 	/*
 	 * On some platforms, unaligned memory accesses result in a kernel trap;
 	 * the default kernel behavior is to emulate the memory access, but this
@@ -246,7 +248,7 @@ main(int argc, char *argv[])
 	 * possibly first argument) we were called with. The lack of consistency
 	 * here is historical.
 	 */
-	if (strcmp(get_progname(argv[0]), "postmaster") == 0)
+	if (strcmp(progname, "postmaster") == 0)
 	{
 		/* Called as "postmaster" */
 		exit(PostmasterMain(argc, argv));
diff --git a/src/backend/postmaster/postmaster.c b/src/backend/postmaster/postmaster.c
index c24a6bb329..b580851dfd 100644
--- a/src/backend/postmaster/postmaster.c
+++ b/src/backend/postmaster/postmaster.c
@@ -171,9 +171,6 @@ char	   *ListenAddresses;
  */
 int			ReservedBackends;
 
-
-static const char *progname = NULL;
-
 /* The socket(s) we're listening to. */
 #define MAXLISTEN	64
 static int	ListenSocket[MAXLISTEN];
@@ -383,9 +380,6 @@ PostmasterMain(int argc, char *argv[])
 	char	   *userDoption = NULL;
 	int			i;
 
-	/* This will call exit() if strdup() fails. */
-	progname = get_progname(argv[0]);
-
 	MyProcPid = PostmasterPid = getpid();
 
 	IsPostmasterEnvironment = true;
diff --git a/src/include/postmaster/postmaster.h b/src/include/postmaster/postmaster.h
index 38b59e4a2d..27f0bd0a4c 100644
--- a/src/include/postmaster/postmaster.h
+++ b/src/include/postmaster/postmaster.h
@@ -34,6 +34,7 @@ extern char *bonjour_name;
 extern HANDLE PostmasterHandle;
 #endif
 
+extern const char *progname;
 
 extern int	PostmasterMain(int argc, char *argv[]);
 extern void ClosePostmasterPorts(bool am_syslogger);
diff --git a/src/port/path.c b/src/port/path.c
index 2a1853f540..79917629b6 100644
--- a/src/port/path.c
+++ b/src/port/path.c
@@ -388,7 +388,8 @@ path_is_prefix_of_path(const char *path1, const char *path2)
 const char *
 get_progname(const char *argv0)
 {
-	const char *nodir_name;
+	const char  *nodir_name;
+	const char	*progname;
 
 	nodir_name = last_dir_separator(argv0);
 	if (nodir_name)
@@ -396,25 +397,25 @@ get_progname(const char *argv0)
 	else
 		nodir_name = skip_drive(argv0);
 
-#if defined(__CYGWIN__) || defined(WIN32)
-	/* strip .exe suffix, regardless of case */
-	if (strlen(nodir_name) > sizeof(EXE) - 1 &&
-		pg_strcasecmp(nodir_name + strlen(nodir_name) - (sizeof(EXE) - 1), EXE) == 0)
+	/*
+	 *	Make a copy in case argv[0] is modified by ps_status.
+	 *	Leaks memory, but called only once.
+	 */
+	progname = strdup(nodir_name);
+	if (progname == NULL)
 	{
-		char	   *progname;
+		fprintf(stderr, "%s: out of memory\n", nodir_name);
+		exit(1);			/* This could exit the postmaster */
+	}
 
-		progname = strdup(nodir_name);	/* leaks memory, but called only once */
-		if (progname == NULL)
-		{
-			fprintf(stderr, "%s: out of memory\n", nodir_name);
-			exit(1);			/* This could exit the postmaster */
-		}
+#if defined(__CYGWIN__) || defined(WIN32)
+	/* strip ".exe" suffix, regardless of case */
+	if (strlen(progname) > sizeof(EXE) - 1 &&
+		pg_strcasecmp(progname + strlen(progname) - (sizeof(EXE) - 1), EXE) == 0)
 		progname[strlen(progname) - (sizeof(EXE) - 1)] = '\0';
-		nodir_name = progname;
-	}
 #endif
 
-	return nodir_name;
+	return progname;
 }