| 1 | /* |
| 2 | * Test GDB's follow-fork-mode. |
| 3 | * |
| 4 | * fork() a chain of processes. |
| 5 | * Parents sends one byte to their children, and children return their |
| 6 | * position in the chain, in order to prove that they survived GDB's fork() |
| 7 | * handling. |
| 8 | * |
| 9 | * SPDX-License-Identifier: GPL-2.0-or-later |
| 10 | */ |
| 11 | #include <assert.h> |
| 12 | #include <stdlib.h> |
| 13 | #include <sys/wait.h> |
| 14 | #include <unistd.h> |
| 15 | |
| 16 | void break_after_fork(void) |
| 17 | { |
| 18 | } |
| 19 | |
| 20 | int main(void) |
| 21 | { |
| 22 | int depth = 42, err, i, fd[2], status; |
| 23 | pid_t child, pid; |
| 24 | ssize_t n; |
| 25 | char b; |
| 26 | |
| 27 | for (i = 0; i < depth; i++) { |
| 28 | err = pipe(fd); |
| 29 | assert(err == 0); |
| 30 | child = fork(); |
| 31 | break_after_fork(); |
| 32 | assert(child != -1); |
| 33 | if (child == 0) { |
| 34 | close(fd[1]); |
| 35 | |
| 36 | n = read(fd[0], &b, 1); |
| 37 | close(fd[0]); |
| 38 | assert(n == 1); |
| 39 | assert(b == (char)i); |
| 40 | } else { |
| 41 | close(fd[0]); |
| 42 | |
| 43 | b = (char)i; |
| 44 | n = write(fd[1], &b, 1); |
| 45 | close(fd[1]); |
| 46 | assert(n == 1); |
| 47 | |
| 48 | pid = waitpid(child, &status, 0); |
| 49 | assert(pid == child); |
| 50 | assert(WIFEXITED(status)); |
| 51 | return WEXITSTATUS(status) - 1; |
| 52 | } |
| 53 | } |
| 54 | |
| 55 | return depth; |
| 56 | } |