Module Name: src
Committed By: christos
Date: Wed Dec 7 22:52:54 UTC 2011
Modified Files:
src/usr.sbin/sup/source: setproctitle.c
Log Message:
be more portable, explain what we are doing, simplify.
To generate a diff of this commit:
cvs rdiff -u -r1.3 -r1.4 src/usr.sbin/sup/source/setproctitle.c
Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.
Modified files:
Index: src/usr.sbin/sup/source/setproctitle.c
diff -u src/usr.sbin/sup/source/setproctitle.c:1.3 src/usr.sbin/sup/source/setproctitle.c:1.4
--- src/usr.sbin/sup/source/setproctitle.c:1.3 Mon Apr 28 16:24:17 2008
+++ src/usr.sbin/sup/source/setproctitle.c Wed Dec 7 17:52:54 2011
@@ -27,10 +27,13 @@
* POSSIBILITY OF SUCH DAMAGE.
*/
+#include <sys/param.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <stdarg.h>
+#include <limits.h>
+#include <unistd.h>
#ifdef NEED_SETPROCTITLE
@@ -42,18 +45,42 @@ setproctitle(const char *fmt, ...)
va_list ap;
char buf[1024];
int len;
- char *pname, *p;
- char **args = __environ - 2;
+ char *pname, *p, *s;
+ /*
+ * Assumes that stack grows down, and than environ has not bee
+ * reallocated because of setenv() required growth. Stack layout:
+ *
+ * argc
+ * argv[0]
+ * ...
+ * argv[n]
+ * NULL
+ * environ[0]
+ * ...
+ * environ[n]
+ * NULL
+ */
+ /* 1 for the first entry, 1 for the NULL */
+ char **args = __environ - 2, *s;
+#ifdef _SC_ARG_MAX
+ s = (char *)sysconf(_SC_ARG_MAX);
+#elifdef ARG_MAX
+ s = (char *)ARG_MAX;
+#elifdef NCARGS
+ s = (char *)NCARGS;
+#else
+ s = (char *)(256 * 1024);
+#endif
/*
* Keep going while it looks like a pointer. We'll stop at argc,
- * Assume that we have < 10K args.
+ * Which is a lot smaller than a pointer, limited by ARG_MAX
*/
- while (*args > (char *)10240)
+ while (*args > s)
args--;
- pname = *++args;
- *(int *)((int *)pname - 1) = 1; /* *argc = 1; */
+ *(int *)args = 1; /* *argc = 1; */
+ pname = *++args; /* pname = argv[0] */
/* Just the last component of the name */
if ((p = strrchr(pname, '/')) != NULL)
