minix/minix/tests/test86.c
David van Moolenbroek 56ac45c10b VFS: check X bit, not R bit, opening executables
For dynamically linked executables, the interpreter is passed a
file descriptor of the binary being executed.  To this end, VFS
opens the target executable, but opening the file fails if it is
not readable, even when it is executable.  With this patch, when
opening the executable, it verifies the X bit rather than the R
bit on the file, thus allowing the execution of dynamically
linked binaries that are executable but not readable.

Add test86 to verify correctness.

Change-Id: If3514add6a33b33d52c05a0a627d757bff118d77
2015-08-31 12:55:55 +00:00

51 lines
1,019 B
C

#include <stdlib.h>
#include <string.h>
#include <limits.h>
#include <fcntl.h>
#include <sys/wait.h>
#include "common.h"
/*
* Test for dynamic executables with no read permissions. This test relies on
* being linked dynamically.
*/
int
main(int argc, char ** argv)
{
char *executable, cp_cmd[PATH_MAX + 9];
int status;
if (strcmp(argv[0], "DO CHECK") == 0)
exit(EXIT_SUCCESS);
start(86);
/* Make a copy of this binary which is executable-only. */
executable = argv[0];
snprintf(cp_cmd, sizeof(cp_cmd), "cp ../%s .", executable);
status = system(cp_cmd);
if (status < 0 || !WIFEXITED(status) ||
WEXITSTATUS(status) != EXIT_SUCCESS) e(0);
if (chmod(executable, S_IXUSR) != 0) e(0);
/* Invoke the changed binary in a child process. */
switch (fork()) {
case -1:
e(0);
case 0:
execl(executable, "DO CHECK", NULL);
exit(EXIT_FAILURE);
default:
if (wait(&status) <= 0) e(0);
if (!WIFEXITED(status) || WEXITSTATUS(status) != EXIT_SUCCESS)
e(0);
}
quit();
/* NOTREACHED */
}