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Diffstat (limited to 'libsigsegv/tests/stackoverflow2.c')
| -rw-r--r-- | libsigsegv/tests/stackoverflow2.c | 198 |
1 files changed, 198 insertions, 0 deletions
diff --git a/libsigsegv/tests/stackoverflow2.c b/libsigsegv/tests/stackoverflow2.c new file mode 100644 index 00000000..2475bf21 --- /dev/null +++ b/libsigsegv/tests/stackoverflow2.c @@ -0,0 +1,198 @@ +/* Test that stack overflow and SIGSEGV are correctly distinguished. + Copyright (C) 2002-2006, 2008 Bruno Haible <bruno@clisp.org> + + This program is free software; you can redistribute it and/or modify + it under the terms of the GNU General Public License as published by + the Free Software Foundation; either version 2, or (at your option) + any later version. + + This program 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 General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program; if not, write to the Free Software Foundation, + Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. */ + +#ifndef _MSC_VER +# include <config.h> +#endif + +#include "sigsegv.h" +#include <stdio.h> +#include <limits.h> + +#if HAVE_STACK_OVERFLOW_RECOVERY && HAVE_SIGSEGV_RECOVERY + +#if defined _WIN32 && !defined __CYGWIN__ + /* Windows doesn't have sigset_t. */ + typedef int sigset_t; +# define sigemptyset(set) +# define sigprocmask(how,set,oldset) +#endif + +#include "mmaputil.h" +#include <stddef.h> /* needed for NULL on SunOS4 */ +#include <stdlib.h> /* for abort, exit */ +#include <signal.h> +#include <setjmp.h> +#if HAVE_SETRLIMIT +# include <sys/types.h> +# include <sys/time.h> +# include <sys/resource.h> +#endif +#ifndef SIGSTKSZ +# define SIGSTKSZ 16384 +#endif + +jmp_buf mainloop; +sigset_t mainsigset; + +volatile int pass = 0; +unsigned long page; + +static void +stackoverflow_handler_continuation (void *arg1, void *arg2, void *arg3) +{ + int arg = (int) (long) arg1; + longjmp (mainloop, arg); +} + +void +stackoverflow_handler (int emergency, stackoverflow_context_t scp) +{ + pass++; + if (pass <= 2) + printf ("Stack overflow %d caught.\n", pass); + else + { + printf ("Segmentation violation misdetected as stack overflow.\n"); + exit (1); + } + sigprocmask (SIG_SETMASK, &mainsigset, NULL); + sigsegv_leave_handler (stackoverflow_handler_continuation, + (void *) (long) (emergency ? -1 : pass), NULL, NULL); +} + +int +sigsegv_handler (void *address, int emergency) +{ + /* This test is necessary to distinguish stack overflow and SIGSEGV. */ + if (!emergency) + return 0; + + pass++; + if (pass <= 2) + { + printf ("Stack overflow %d missed.\n", pass); + exit (1); + } + else + printf ("Segmentation violation correctly detected.\n"); + sigprocmask (SIG_SETMASK, &mainsigset, NULL); + return sigsegv_leave_handler (stackoverflow_handler_continuation, + (void *) (long) pass, NULL, NULL); +} + +volatile int * +recurse_1 (int n, volatile int *p) +{ + if (n < INT_MAX) + *recurse_1 (n + 1, p) += n; + return p; +} + +int +recurse (volatile int n) +{ + return *recurse_1 (n, &n); +} + +int +main () +{ + /* glibc says: Users should use SIGSTKSZ as the size of user-supplied + buffers. */ + char mystack[SIGSTKSZ]; + sigset_t emptyset; + void *p; + +#if HAVE_SETRLIMIT && defined RLIMIT_STACK + /* Before starting the endless recursion, try to be friendly to the user's + machine. On some Linux 2.2.x systems, there is no stack limit for user + processes at all. We don't want to kill such systems. */ + struct rlimit rl; + rl.rlim_cur = rl.rlim_max = 0x100000; /* 1 MB */ + setrlimit (RLIMIT_STACK, &rl); +#endif + + /* Install the stack overflow handler. */ + if (stackoverflow_install_handler (&stackoverflow_handler, + mystack, sizeof (mystack)) + < 0) + exit (2); + + /* Preparations. */ +#if !HAVE_MMAP_ANON && !HAVE_MMAP_ANONYMOUS && HAVE_MMAP_DEVZERO + zero_fd = open ("/dev/zero", O_RDONLY, 0644); +#endif + + /* Setup some mmaped memory. */ + p = mmap_zeromap ((void *) 0x12340000, 0x4000); + if (p == (void *)(-1)) + { + fprintf (stderr, "mmap_zeromap failed.\n"); + exit (2); + } + page = (unsigned long) p; + + /* Make it read-only. */ + if (mprotect ((void *) page, 0x4000, PROT_READ) < 0) + { + fprintf (stderr, "mprotect failed.\n"); + exit (2); + } + + /* Install the SIGSEGV handler. */ + if (sigsegv_install_handler (&sigsegv_handler) < 0) + exit (2); + + /* Save the current signal mask. */ + sigemptyset (&emptyset); + sigprocmask (SIG_BLOCK, &emptyset, &mainsigset); + + /* Provoke two stack overflows in a row. */ + switch (setjmp (mainloop)) + { + case -1: + printf ("emergency exit\n"); exit (1); + case 0: case 1: + printf ("Starting recursion pass %d.\n", pass + 1); + recurse (0); + printf ("no endless recursion?!\n"); exit (1); + case 2: + *(volatile int *) (page + 0x678) = 42; + break; + case 3: + *(volatile int *) 0 = 42; + break; + case 4: + break; + default: + abort (); + } + + printf ("Test passed.\n"); + exit (0); +} + +#else + +int +main () +{ + return 77; +} + +#endif |