| 1 | /* |
| 2 | * Test that GDB can access PROT_NONE pages. |
| 3 | * |
| 4 | * SPDX-License-Identifier: GPL-2.0-or-later |
| 5 | */ |
| 6 | #include <assert.h> |
| 7 | #include <stdlib.h> |
| 8 | #include <string.h> |
| 9 | #include <sys/mman.h> |
| 10 | #include <unistd.h> |
| 11 | |
| 12 | void break_here(void *q) |
| 13 | { |
| 14 | } |
| 15 | |
| 16 | int main(void) |
| 17 | { |
| 18 | long pagesize = sysconf(_SC_PAGESIZE); |
| 19 | void *p, *q; |
| 20 | int err; |
| 21 | |
| 22 | p = mmap(NULL, pagesize * 2, PROT_READ | PROT_WRITE, |
| 23 | MAP_PRIVATE | MAP_ANONYMOUS, -1, 0); |
| 24 | assert(p != MAP_FAILED); |
| 25 | q = p + pagesize - 1; |
| 26 | strcpy(q, "42"); |
| 27 | |
| 28 | err = mprotect(p, pagesize * 2, PROT_NONE); |
| 29 | assert(err == 0); |
| 30 | |
| 31 | break_here(q); |
| 32 | |
| 33 | err = mprotect(p, pagesize * 2, PROT_READ); |
| 34 | assert(err == 0); |
| 35 | if (getenv("PROT_NONE_PY")) { |
| 36 | assert(strcmp(q, "24") == 0); |
| 37 | } |
| 38 | |
| 39 | return EXIT_SUCCESS; |
| 40 | } |