1 /* This testcase is part of GDB, the GNU debugger. 2 3 Copyright 2014-2023 Free Software Foundation, Inc. 4 5 This program is free software; you can redistribute it and/or modify 6 it under the terms of the GNU General Public License as published by 7 the Free Software Foundation; either version 3 of the License, or 8 (at your option) any later version. 9 10 This program is distributed in the hope that it will be useful, 11 but WITHOUT ANY WARRANTY; without even the implied warranty of 12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 13 GNU General Public License for more details. 14 15 You should have received a copy of the GNU General Public License 16 along with this program. If not, see <http://www.gnu.org/licenses/>. 17 */ 18 19 #include <sys/mman.h> 20 #include <unistd.h> 21 #include <assert.h> 22 23 void 24 breakpt (void) 25 { 26 /* Nothing. */ 27 } 28 29 void 30 func5 (void) 31 { 32 breakpt (); 33 } 34 35 void 36 func4 (void) 37 { 38 func5 (); 39 } 40 41 void 42 func3 (void) 43 { 44 func4 (); 45 } 46 47 void 48 func2 (void *ptr) 49 { 50 func3 (); 51 } 52 53 void 54 func1 (void *ptr) 55 { 56 func2 (ptr); 57 } 58 59 /* Finds and returns an invalid pointer, mmaps in a page, grabs a pointer 60 to it then unmaps the page again. This is almost certainly "undefined" 61 behaviour, but should be good enough for this small test program. */ 62 63 static void * 64 make_invalid_ptr (void) 65 { 66 int page_size, ans; 67 void *ptr; 68 69 page_size = getpagesize (); 70 ptr = mmap (0, page_size, PROT_NONE, 71 MAP_PRIVATE | MAP_ANONYMOUS, 72 -1, 0); 73 assert (ptr != MAP_FAILED); 74 ans = munmap (ptr, page_size); 75 assert (ans == 0); 76 77 return ptr; 78 } 79 80 int 81 main (void) 82 { 83 void *invalid_ptr; 84 85 invalid_ptr = make_invalid_ptr (); 86 func1 (invalid_ptr); 87 88 return 0; 89 } 90