| /* This testcase is part of GDB, the GNU debugger. |
| |
| Copyright 2014-2021 Free Software Foundation, Inc. |
| |
| 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 3 of the License, 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, see <http://www.gnu.org/licenses/>. |
| */ |
| |
| #include <sys/mman.h> |
| #include <unistd.h> |
| #include <assert.h> |
| |
| void *global_invalid_ptr = NULL; |
| |
| void |
| func2 (void) |
| { |
| /* Replace the current stack pointer and frame pointer with the invalid |
| pointer. */ |
| asm ("mov %0, %%rsp\n\tmov %0, %%rbp" : : "r" (global_invalid_ptr)); |
| |
| /* Create a label for a breakpoint. */ |
| asm (".global breakpt\nbreakpt:"); |
| } |
| |
| void |
| func1 (void *ptr) |
| { |
| global_invalid_ptr = ptr; |
| func2 (); |
| } |
| |
| /* Finds and returns an invalid pointer, mmaps in a page, grabs a pointer |
| to it then unmaps the page again. This is almost certainly "undefined" |
| behaviour, but should be good enough for this small test program. */ |
| |
| static void * |
| make_invalid_ptr (void) |
| { |
| int page_size, ans; |
| void *ptr; |
| |
| page_size = getpagesize (); |
| ptr = mmap (0, page_size, PROT_NONE, |
| MAP_PRIVATE | MAP_ANONYMOUS, |
| -1, 0); |
| assert (ptr != MAP_FAILED); |
| ans = munmap (ptr, page_size); |
| assert (ans == 0); |
| |
| return ptr; |
| } |
| |
| int |
| main (void) |
| { |
| void *invalid_ptr; |
| |
| invalid_ptr = make_invalid_ptr (); |
| func1 (invalid_ptr); |
| |
| return 0; |
| } |