Print error in case execve fails in the trigger program

Signed-off-by: Denis Efremov <denis.e.efremov@oracle.com>

Author: evdenis

Makefile

@@ -12,7 +12,7 @@ check_argc0_lsm.h: check_argc0_lsm.o
 load_check_argc0_lsm: check_argc0_lsm.h load_check_argc0_lsm.c
 	clang -lbpf $@.c -o $@
 
-trigger:
+trigger: trigger.c
 	clang -w $@.c -o $@
 
 clean:

trigger.c

@@ -1,7 +1,10 @@
 #include <unistd.h>
+#include <stdio.h>
+#include <errno.h>
 
 int main(int argc, char *argv[])
 {
 	execve("/usr/bin/pkexec", NULL, NULL);
+	fprintf(stderr, "%s\n", strerror(errno));
 	return 0;
 }