1 files changed, 37 insertions, 36 deletions

diff --git a/lib/libc/gen/setproctitle.c b/lib/libc/gen/setproctitle.c
index 9dff328..cd705fb 100644
--- a/lib/libc/gen/setproctitle.c
+++ b/lib/libc/gen/setproctitle.c
@@ -42,10 +42,9 @@ __FBSDID("$FreeBSD$");
  * 1: old_ps_strings at the very top of the stack.
  * 2: old_ps_strings at SPARE_USRSPACE below the top of the stack.
  * 3: ps_strings at the very top of the stack.
- * We only support a kernel providing #3 style ps_strings.
- *
- * For historical purposes, a definition of the old ps_strings structure
- * and location is preserved below:
+ * This attempts to support a kernel built in the #2 and #3 era.
+ */
+
 struct old_ps_strings {
 	char	*old_ps_argvstr;
 	int	old_ps_nargvstr;
@@ -54,7 +53,6 @@ struct old_ps_strings {
 };
 #define	OLD_PS_STRINGS ((struct old_ps_strings *) \
 	(USRSTACK - SPARE_USRSPACE - sizeof(struct old_ps_strings)))
- */
 
 #include <stdarg.h>
 
@@ -138,38 +136,41 @@ setproctitle(const char *fmt, ...)
 		ps_strings = (struct ps_strings *)ul_ps_strings;
 	}
 
-	/*
-	 * PS_STRINGS points to zeroed memory on a style #2 kernel.
-	 * Should not happen.
-	 */
-	if (ps_strings->ps_argvstr == NULL)
-		return;
-
-	/* style #3 */
-	if (oargc == -1) {
-		/* Record our original args */
-		oargc = ps_strings->ps_nargvstr;
-		oargv = ps_strings->ps_argvstr;
-		for (i = len = 0; i < oargc; i++) {
-			/*
-			 * The program may have scribbled into its
-			 * argv array, e.g., to remove some arguments.
-			 * If that has happened, break out before
-			 * trying to call strlen on a NULL pointer.
-			 */
-			if (oargv[i] == NULL) {
-				oargc = i;
-				break;
+	/* PS_STRINGS points to zeroed memory on a style #2 kernel */
+	if (ps_strings->ps_argvstr) {
+		/* style #3 */
+		if (oargc == -1) {
+			/* Record our original args */
+			oargc = ps_strings->ps_nargvstr;
+			oargv = ps_strings->ps_argvstr;
+			for (i = len = 0; i < oargc; i++) {
+				/*
+				 * The program may have scribbled into its
+				 * argv array, e.g., to remove some arguments.
+				 * If that has happened, break out before
+				 * trying to call strlen on a NULL pointer.
+				 */
+				if (oargv[i] == NULL) {
+					oargc = i;
+					break;
+				}
+				snprintf(obuf + len, SPT_BUFSIZE - len, "%s%s",
+				    len ? " " : "", oargv[i]);
+				if (len)
+					len++;
+				len += strlen(oargv[i]);
+				if (len >= SPT_BUFSIZE)
+					break;
 			}
-			snprintf(obuf + len, SPT_BUFSIZE - len, "%s%s",
-			    len != 0 ? " " : "", oargv[i]);
-			if (len != 0)
-				len++;
-			len += strlen(oargv[i]);
-			if (len >= SPT_BUFSIZE)
-				break;
 		}
+		ps_strings->ps_nargvstr = nargc;
+		ps_strings->ps_argvstr = nargvp;
+	} else {
+		/* style #2 - we can only restore our first arg :-( */
+		if (*obuf == '\0')
+			strncpy(obuf, OLD_PS_STRINGS->old_ps_argvstr,
+			    SPT_BUFSIZE - 1);
+		OLD_PS_STRINGS->old_ps_nargvstr = 1;
+		OLD_PS_STRINGS->old_ps_argvstr = nargvp[0];
 	}
-	ps_strings->ps_nargvstr = nargc;
-	ps_strings->ps_argvstr = nargvp;
 }