Prevent the wrapper from looping on itself forever, when there

is a symbolic link in the PATH pointing back to /usr/bin/perl.

Change WARNS from 6 to 5 to account for the fact that sys/time.h,
included from sys/stat.h, produces a warning when compiled with
-pedantic.

PR:		bin/42418
Reviewed by:	roberto

2 files changed, 11 insertions, 1 deletions

diff --git a/usr.bin/perl/Makefile b/usr.bin/perl/Makefile
index 0eaf69c..17994de 100644
--- a/usr.bin/perl/Makefile
+++ b/usr.bin/perl/Makefile
@@ -2,7 +2,7 @@
 
 PROG=	perl
 NOMAN=
-WARNS?=	6
+WARNS?=	5
 LINKS=	${BINDIR}/perl ${BINDIR}/perl5 \
 	${BINDIR}/perl ${BINDIR}/perl5.6.1 \
 	${BINDIR}/perl ${BINDIR}/suidperl
diff --git a/usr.bin/perl/perl.c b/usr.bin/perl/perl.c
index cb43457..2bd55e7 100644
--- a/usr.bin/perl/perl.c
+++ b/usr.bin/perl/perl.c
@@ -30,6 +30,7 @@
 __FBSDID("$FreeBSD$");
 
 #include <sys/param.h>
+#include <sys/stat.h>
 #include <sys/sysctl.h>
 
 #include <err.h>
@@ -49,8 +50,13 @@ main(int argc __unused, char *argv[])
 	char path[PATH_MAX], *cp;
 	const char *cmd, *p, *q, *self;
 	size_t len;
+	struct stat self_stat, perl_stat;
 
 	self = argv[0];
+	if (stat (self, &self_stat) != 0) {
+		self_stat.st_dev = makedev (0, 0);
+		self_stat.st_ino = 0;
+	}
 	if ((cmd = strrchr(self, '/')) == NULL)
 		cmd = self;
 	else
@@ -79,6 +85,10 @@ main(int argc __unused, char *argv[])
 		len = snprintf(path, sizeof path, "%.*s/%s", (int)(q - p), p, cmd);
 		if (len >= PATH_MAX || strcmp(path, self) == 0)
 			continue;
+		if (stat (path, &perl_stat) == 0
+		    && self_stat.st_dev == perl_stat.st_dev
+		    && self_stat.st_ino == perl_stat.st_ino)
+			continue;
 		execve(path, argv, environ);
 		if (errno != ENOENT)
 			err(1, "%s", path);