diff options
Diffstat (limited to 'elf/tst-execstack.c')
| -rw-r--r-- | elf/tst-execstack.c | 236 |
1 files changed, 0 insertions, 236 deletions
diff --git a/elf/tst-execstack.c b/elf/tst-execstack.c deleted file mode 100644 index 114f341d76..0000000000 --- a/elf/tst-execstack.c +++ /dev/null @@ -1,236 +0,0 @@ -/* Test program for making nonexecutable stacks executable - on load of a DSO that requires executable stacks. */ - -#include <dlfcn.h> -#include <stdbool.h> -#include <stdio.h> -#include <string.h> -#include <unistd.h> -#include <error.h> -#include <stackinfo.h> - -static void -print_maps (void) -{ -#if 0 - char *cmd = NULL; - asprintf (&cmd, "cat /proc/%d/maps", getpid ()); - system (cmd); - free (cmd); -#endif -} - -static void deeper (void (*f) (void)); - -#if USE_PTHREADS -# include <pthread.h> - -static void * -tryme_thread (void *f) -{ - (*((void (*) (void)) f)) (); - - return 0; -} - -static pthread_barrier_t startup_barrier, go_barrier; -static void * -waiter_thread (void *arg) -{ - void **f = arg; - pthread_barrier_wait (&startup_barrier); - pthread_barrier_wait (&go_barrier); - - (*((void (*) (void)) *f)) (); - - return 0; -} -#endif - -static bool allow_execstack = true; - - -static int -do_test (void) -{ - /* Check whether SELinux is enabled and disallows executable stacks. */ - FILE *fp = fopen ("/selinux/enforce", "r"); - if (fp != NULL) - { - char *line = NULL; - size_t linelen = 0; - - bool enabled = false; - ssize_t n = getline (&line, &linelen, fp); - if (n > 0 && line[0] != '0') - enabled = true; - - fclose (fp); - - if (enabled) - { - fp = fopen ("/selinux/booleans/allow_execstack", "r"); - if (fp != NULL) - { - n = getline (&line, &linelen, fp); - if (n > 0 && line[0] == '0') - allow_execstack = false; - } - - fclose (fp); - } - } - - printf ("executable stacks %sallowed\n", allow_execstack ? "" : "not "); - - static void *f; /* Address of this is used in other threads. */ - -#if USE_PTHREADS - /* Create some threads while stacks are nonexecutable. */ - #define N 5 - pthread_t thr[N]; - - pthread_barrier_init (&startup_barrier, NULL, N + 1); - pthread_barrier_init (&go_barrier, NULL, N + 1); - - for (int i = 0; i < N; ++i) - { - int rc = pthread_create (&thr[i], NULL, &waiter_thread, &f); - if (rc) - error (1, rc, "pthread_create"); - } - - /* Make sure they are all there using their stacks. */ - pthread_barrier_wait (&startup_barrier); - puts ("threads waiting"); -#endif - - print_maps (); - -#if USE_PTHREADS - void *old_stack_addr, *new_stack_addr; - size_t stack_size; - pthread_t me = pthread_self (); - pthread_attr_t attr; - int ret = 0; - - ret = pthread_getattr_np (me, &attr); - if (ret) - { - printf ("before execstack: pthread_getattr_np returned error: %s\n", - strerror (ret)); - return 1; - } - - ret = pthread_attr_getstack (&attr, &old_stack_addr, &stack_size); - if (ret) - { - printf ("before execstack: pthread_attr_getstack returned error: %s\n", - strerror (ret)); - return 1; - } -# if _STACK_GROWS_DOWN - old_stack_addr += stack_size; -# else - old_stack_addr -= stack_size; -# endif -#endif - - /* Loading this module should force stacks to become executable. */ - void *h = dlopen ("tst-execstack-mod.so", RTLD_LAZY); - if (h == NULL) - { - printf ("cannot load: %s\n", dlerror ()); - return allow_execstack; - } - - f = dlsym (h, "tryme"); - if (f == NULL) - { - printf ("symbol not found: %s\n", dlerror ()); - return 1; - } - - /* Test if that really made our stack executable. - The `tryme' function should crash if not. */ - - (*((void (*) (void)) f)) (); - - print_maps (); - -#if USE_PTHREADS - ret = pthread_getattr_np (me, &attr); - if (ret) - { - printf ("after execstack: pthread_getattr_np returned error: %s\n", - strerror (ret)); - return 1; - } - - ret = pthread_attr_getstack (&attr, &new_stack_addr, &stack_size); - if (ret) - { - printf ("after execstack: pthread_attr_getstack returned error: %s\n", - strerror (ret)); - return 1; - } - -# if _STACK_GROWS_DOWN - new_stack_addr += stack_size; -# else - new_stack_addr -= stack_size; -# endif - - /* It is possible that the dlopen'd module may have been mmapped just below - the stack. The stack size is taken as MIN(stack rlimit size, end of last - vma) in pthread_getattr_np. If rlimit is set high enough, it is possible - that the size may have changed. A subsequent call to - pthread_attr_getstack returns the size and (bottom - size) as the - stacksize and stackaddr respectively. If the size changes due to the - above, then both stacksize and stackaddr can change, but the stack bottom - should remain the same, which is computed as stackaddr + stacksize. */ - if (old_stack_addr != new_stack_addr) - { - printf ("Stack end changed, old: %p, new: %p\n", - old_stack_addr, new_stack_addr); - return 1; - } - printf ("Stack address remains the same: %p\n", old_stack_addr); -#endif - - /* Test that growing the stack region gets new executable pages too. */ - deeper ((void (*) (void)) f); - - print_maps (); - -#if USE_PTHREADS - /* Test that a fresh thread now gets an executable stack. */ - { - pthread_t th; - int rc = pthread_create (&th, NULL, &tryme_thread, f); - if (rc) - error (1, rc, "pthread_create"); - } - - puts ("threads go"); - /* The existing threads' stacks should have been changed. - Let them run to test it. */ - pthread_barrier_wait (&go_barrier); - - pthread_exit ((void *) (long int) (! allow_execstack)); -#endif - - return ! allow_execstack; -} - -static void -deeper (void (*f) (void)) -{ - char stack[1100 * 1024]; - memfrob (stack, sizeof stack); - (*f) (); - memfrob (stack, sizeof stack); -} - - -#include <support/test-driver.c> |