diff options
Diffstat (limited to 'elf/tst-execstack.c')
| -rw-r--r-- | elf/tst-execstack.c | 184 |
1 files changed, 77 insertions, 107 deletions
diff --git a/elf/tst-execstack.c b/elf/tst-execstack.c index 560b353..da5fb9e 100644 --- a/elf/tst-execstack.c +++ b/elf/tst-execstack.c @@ -1,30 +1,55 @@ /* Test program for making nonexecutable stacks executable - on load of a DSO that requires executable stacks. */ + on load of a DSO that requires executable stacks. -#include <dlfcn.h> -#include <stdbool.h> -#include <stdio.h> -#include <string.h> -#include <unistd.h> + Copyright (C) 2003-2025 Free Software Foundation, Inc. + This file is part of the GNU C Library. + + The GNU C Library is free software; you can redistribute it and/or + modify it under the terms of the GNU Lesser General Public + License as published by the Free Software Foundation; either + version 2.1 of the License, or (at your option) any later version. + + The GNU C Library is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public + License along with the GNU C Library; if not, see + <https://www.gnu.org/licenses/>. */ + +#include <array_length.h> #include <error.h> #include <stackinfo.h> - +#include <stdbool.h> +#include <string.h> +#include <stdlib.h> +#include <support/xdlfcn.h> +#include <support/xthread.h> +#include <support/check.h> +#include <support/xstdio.h> + +/* The DEFAULT_RWX_STACK controls whether the toolchain enables an executable + stack for the testcase (which does not contain features that might require + an executable stack, such as nested function). + Some ABIs do require an executable stack, even if the toolchain supports + non-executable stack. In this cases the DEFAULT_RWX_STACK can be + overridden. */ +#ifndef DEFAULT_RWX_STACK +# define DEFAULT_RWX_STACK 0 +#else static void -print_maps (void) +deeper (void (*f) (void)) { -#if 0 - char *cmd = NULL; - asprintf (&cmd, "cat /proc/%d/maps", getpid ()); - system (cmd); - free (cmd); -#endif + char stack[1100 * 1024]; + explicit_bzero (stack, sizeof stack); + (*f) (); + memfrob (stack, sizeof stack); } - -static void deeper (void (*f) (void)); +#endif #if USE_PTHREADS -# include <pthread.h> - +# if DEFAULT_RWX_STACK static void * tryme_thread (void *f) { @@ -32,16 +57,21 @@ tryme_thread (void *f) return 0; } +# endif 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); + xpthread_barrier_wait (&startup_barrier); + xpthread_barrier_wait (&go_barrier); +# if DEFAULT_RWX_STACK + void **f = arg; (*((void (*) (void)) *f)) (); +# else + abort (); +# endif return 0; } @@ -83,52 +113,33 @@ do_test (void) printf ("executable stacks %sallowed\n", allow_execstack ? "" : "not "); +#if USE_PTHREADS || DEFAULT_RWX_STACK static void *f; /* Address of this is used in other threads. */ +#endif #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); + xpthread_barrier_init (&startup_barrier, NULL, N + 1); + xpthread_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"); - } + xpthread_create (NULL, &waiter_thread, &f); /* Make sure they are all there using their stacks. */ - pthread_barrier_wait (&startup_barrier); + xpthread_barrier_wait (&startup_barrier); puts ("threads waiting"); #endif - print_maps (); - -#if USE_PTHREADS +#if USE_PTHREADS && DEFAULT_RWX_STACK 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; - } + TEST_VERIFY_EXIT (pthread_getattr_np (me, &attr) == 0); + TEST_VERIFY_EXIT (pthread_attr_getstack (&attr, &old_stack_addr, + &stack_size) == 0); # if _STACK_GROWS_DOWN old_stack_addr += stack_size; # else @@ -143,48 +154,28 @@ do_test (void) const char *soname = "tst-execstack-mod.so"; #endif void *h = dlopen (soname, RTLD_LAZY); - if (h == NULL) - { - printf ("cannot load: %s\n", dlerror ()); - return allow_execstack; - } +#if !DEFAULT_RWX_STACK + TEST_VERIFY_EXIT (h == NULL); +#else + TEST_VERIFY_EXIT (h != NULL); - f = dlsym (h, "tryme"); - if (f == NULL) - { - printf ("symbol not found: %s\n", dlerror ()); - return 1; - } + f = xdlsym (h, "tryme"); /* 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; - } + TEST_VERIFY_EXIT (pthread_getattr_np (me, &attr) == 0); + TEST_VERIFY_EXIT (pthread_attr_getstack (&attr, &new_stack_addr, + &stack_size) == 0); # if _STACK_GROWS_DOWN new_stack_addr += stack_size; -# else +# else new_stack_addr -= stack_size; -# endif +# 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 @@ -194,48 +185,27 @@ do_test (void) 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; - } + TEST_VERIFY_EXIT (old_stack_addr == new_stack_addr); printf ("Stack address remains the same: %p\n", old_stack_addr); -#endif +# endif /* Test that growing the stack region gets new executable pages too. */ deeper ((void (*) (void)) f); - print_maps (); - -#if USE_PTHREADS +# 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"); - } + xpthread_create (NULL, &tryme_thread, f); puts ("threads go"); /* The existing threads' stacks should have been changed. Let them run to test it. */ - pthread_barrier_wait (&go_barrier); + xpthread_barrier_wait (&go_barrier); pthread_exit ((void *) (long int) (! allow_execstack)); +# endif #endif return ! allow_execstack; } -static void -deeper (void (*f) (void)) -{ - char stack[1100 * 1024]; - explicit_bzero (stack, sizeof stack); - (*f) (); - memfrob (stack, sizeof stack); -} - - #include <support/test-driver.c> |