Change start-stop-daemon's --exec option behaviour on GNU/Linux to

compare the filename pointed by '/proc/<pid>/exe' instead of the inode
and device numbers. Thanks to Vasilis Vasaitis <v.vasaitis@sms.ed.ac.uk>.
Closes: #337942

ChangeLog

@@ -1,3 +1,10 @@
+2006-01-23  Vasilis Vasaitis  <v.vasaitis@sms.ed.ac.uk>
+
+	* utils/start-stop-daemon.c (pid_is_exec) [OSLinux]: Change function
+	prototype to take a constant string instead of a struct stat. Compare
+	the filename pointed by the '/proc/<pid>/exe' symlink, instead of the
+	stat device and inode numbers. Fix all callers.
+
 2006-01-23  Frank Lichtenheld  <djpig@debian.org>
 
 	* scripts/dpkg-shlibdeps.pl: Rewrite of the script

debian/changelog

@@ -90,6 +90,10 @@ dpkg (1.13.12) experimental; urgency=low
   * Add support for architecture wildcards, but for now they will only be
     exposed in debian/control files, not in binary nor source packages.
     Closes: #291939
+  * Change start-stop-daemon's --exec option behaviour on GNU/Linux to
+    compare the filename pointed by '/proc/<pid>/exe' instead of the inode
+    and device numbers. Thanks to Vasilis Vasaitis <v.vasaitis@sms.ed.ac.uk>.
+    Closes: #337942
 
  -- Frank Lichtenheld <djpig@debian.org>  Mon, 23 Jan 2006 14:22:59 +0100
 

utils/start-stop-daemon.c

@@ -174,7 +174,9 @@ static void check(pid_t pid);
 static void do_pidfile(const char *name);
 static void do_stop(int signal_nr, int quietmode,
 		    int *n_killed, int *n_notkilled, int retry_nr);
-#if defined(OSLinux) || defined(OShpux)
+#if defined(OSLinux)
+static int pid_is_exec(pid_t pid, const char *name);
+#elif defined(OShpux)
 static int pid_is_exec(pid_t pid, const struct stat *esb);
 #endif
 
@@ -608,15 +610,29 @@ parse_options(int argc, char * const *argv)
 
 #if defined(OSLinux)
 static int
-pid_is_exec(pid_t pid, const struct stat *esb)
+pid_is_exec(pid_t pid, const char *name)
 {
-	struct stat sb;
-	char buf[32];
-
-	sprintf(buf, "/proc/%d/exe", pid);
-	if (stat(buf, &sb) != 0)
+	char lname[32];
+	char *lcontents;
+	int lcontlen, nread, res;
+
+	/* Allow one extra character for the link contents, which should
+	 * be enough to determine if the file names are the same. */
+	lcontlen = strlen(name) + 1;
+	lcontents = xmalloc(lcontlen);
+	sprintf(lname, "/proc/%d/exe", pid);
+	nread = readlink(lname, lcontents, lcontlen);
+	if (nread == -1) {
+		free(lcontents);
 		return 0;
-	return (sb.st_dev == esb->st_dev && sb.st_ino == esb->st_ino);
+	}
+	if (nread < lcontlen)
+		lcontents[nread] = '\0';
+
+	res = (strncmp(lcontents, name, lcontlen) == 0);
+	free(lcontents);
+
+	return res;
 }
 
 
@@ -746,7 +762,9 @@ pid_is_running(pid_t pid)
 static void
 check(pid_t pid)
 {
-#if defined(OSLinux) || defined(OShpux)
+#if defined(OSLinux)
+	if (execname && !pid_is_exec(pid, execname))
+#elif defined(OShpux)
 	if (execname && !pid_is_exec(pid, &exec_stat))
 #elif defined(OSHURD) || defined(OSFreeBSD) || defined(OSNetBSD)
     /* I will try this to see if it works */