101 lines
3.1 KiB
C
101 lines
3.1 KiB
C
#define _GNU_SOURCE
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#include <stdio.h>
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#include <fcntl.h>
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#include <stdlib.h>
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#include <sys/wait.h>
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#include "test.h"
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// Note: This test intends to test the case that child process directly calls _exit()
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// after vfork. "exit", "_exit" and returning from main function are different.
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// And here the exit function must be "_exit" to prevent undefined bevaviour.
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int test_vfork_exit() {
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pid_t child_pid = vfork();
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if (child_pid == 0) {
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_exit(0);
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} else {
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printf ("Comming back to parent process from child with pid = %d\n", child_pid);
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}
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return 0;
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}
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int test_multiple_vfork_execve() {
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char **child_argv = calloc(1, sizeof(char *) * 2); // "hello_world", NULL
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child_argv[0] = strdup("naughty_child");
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for (int i = 0; i < 3; i++ ) {
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pid_t child_pid = vfork();
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if (child_pid == 0) {
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int ret = execve("/bin/naughty_child", child_argv, NULL);
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if (ret != 0) {
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printf("child process execve error");
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}
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_exit(1);
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} else {
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printf ("Comming back to parent process from child with pid = %d\n", child_pid);
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int ret = waitpid(child_pid, 0, 0);
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if (ret != child_pid) {
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THROW_ERROR("wait child error, child pid = %d\n", child_pid);
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}
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}
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}
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return 0;
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}
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// Create a pipe between parent and child and check file status.
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int test_vfork_isolate_file_table() {
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int pipe_fds[2];
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if (pipe(pipe_fds) < 0) {
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THROW_ERROR("failed to create a pipe");
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}
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pid_t child_pid = vfork();
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if (child_pid == 0) {
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close(pipe_fds[1]); // close write end
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char **child_argv = calloc(1,
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sizeof(char *) * (5 + 1)); // naughty_child -t vfork reader_fd writer_fd
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child_argv[0] = "naughty_child";
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child_argv[1] = "-t";
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child_argv[2] = "vfork";
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if (asprintf(&child_argv[3], "%d", pipe_fds[0]) < 0 ||
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asprintf(&child_argv[4], "%d", pipe_fds[1]) < 0) {
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THROW_ERROR("failed to asprintf");
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}
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int ret = execve("/bin/naughty_child", child_argv, NULL);
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if (ret != 0) {
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printf("child process execve error\n");
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}
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_exit(1);
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} else {
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printf ("Comming back to parent process from child with pid = %d\n", child_pid);
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if (close(pipe_fds[0]) < 0) { // close read end
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printf("close pipe reader error\n");
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goto parent_exit;
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}
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char *greetings = "Hello from parent\n";
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if (write(pipe_fds[1], greetings, strlen(greetings) + 1) < 0) {
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printf("parent write pipe error\n");
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goto parent_exit;
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}
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int ret = waitpid(child_pid, 0, 0);
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if (ret != child_pid) {
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THROW_ERROR("wait child error, child pid = %d\n", child_pid);
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}
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}
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return 0;
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parent_exit:
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kill(child_pid, SIGKILL);
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exit(1);
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}
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static test_case_t test_cases[] = {
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TEST_CASE(test_vfork_exit),
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TEST_CASE(test_multiple_vfork_execve),
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TEST_CASE(test_vfork_isolate_file_table),
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};
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int main() {
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return test_suite_run(test_cases, ARRAY_SIZE(test_cases));
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}
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