system(3): Unwrap execve()

There is no need to call execl(), which will allocate an array and copy
our arguments into it, when we can use a static array and call execve()
directly.

MFC after:	1 week
Sponsored by:	Klara, Inc.
Reviewed by:	kevans
Differential Revision:	https://reviews.freebsd.org/D55648

1 files changed, 3 insertions, 1 deletions

diff --git a/lib/libc/stdlib/system.c b/lib/libc/stdlib/system.c
index 94f7460c9b68..a2f472502bfd 100644
--- a/lib/libc/stdlib/system.c
+++ b/lib/libc/stdlib/system.c
@@ -60,6 +60,8 @@ __libc_system(const char *command)
 	static struct sigaction ointact, oquitact;
 	struct sigaction ign;
 	sigset_t sigblock, osigblock;
+	char *argv[] = { "sh", "-c", __DECONST(char *, command), NULL };
+	extern char **environ;
 	int pstat = -1, serrno = 0;
 	pid_t pid;
 
@@ -101,7 +103,7 @@ __libc_system(const char *command)
 		/*
 		 * Exec the command.
 		 */
-		execl(_PATH_BSHELL, "sh", "-c", command, NULL);
+		_execve(_PATH_BSHELL, argv, environ);
 		_exit(127);
 	} else {				/* parent */
 		/*