// SPDX-License-Identifier: GPL-2.0-only
/* Test that empty argvs are swapped out for a single empty string. */
#include <stdio.h>
#include <unistd.h>
#include <sys/types.h>
#include <sys/wait.h>

#include "kselftest.h"

#define FORK(exec)                              \
do {                                            \
        pid = fork();                           \
        if (pid == 0) {                         \
                /* Child */                     \
                exec; /* Some kind of exec */   \
                perror("# " #exec);             \
                return 1;                       \
        }                                       \
        check_result(pid, #exec);               \
} while (0)

void check_result(pid_t pid, const char *msg)
{
        int wstatus;

        if (pid == (pid_t)-1) {
                perror("# fork");
                ksft_test_result_fail("fork failed: %s\n", msg);
                return;
        }
        if (waitpid(pid, &wstatus, 0) < 0) {
                perror("# waitpid");
                ksft_test_result_fail("waitpid failed: %s\n", msg);
                return;
        }
        if (!WIFEXITED(wstatus)) {
                ksft_test_result_fail("child did not exit: %s\n", msg);
                return;
        }
        if (WEXITSTATUS(wstatus) != 0) {
                ksft_test_result_fail("non-zero exit: %s\n", msg);
                return;
        }
        ksft_test_result_pass("%s\n", msg);
}

int main(int argc, char *argv[], char *envp[])
{
        pid_t pid;
        static char * const args[] = { NULL };
        static char * const str[] = { "", NULL };

        /* argc counting checks */
        if (argc < 1) {
                fprintf(stderr, "# FAIL: saw argc == 0 (old kernel?)\n");
                return 1;
        }
        if (argc != 1) {
                fprintf(stderr, "# FAIL: unknown argc (%d)\n", argc);
                return 1;
        }
        if (argv[0][0] == '\0') {
                /* Good, we found a NULL terminated string at argv[0]! */
                return 0;
        }

        /* Test runner. */
        ksft_print_header();
        ksft_set_plan(5);

        FORK(execve(argv[0], str, NULL));
        FORK(execve(argv[0], NULL, NULL));
        FORK(execve(argv[0], NULL, envp));
        FORK(execve(argv[0], args, NULL));
        FORK(execve(argv[0], args, envp));

        ksft_exit(ksft_cnt.ksft_pass == ksft_plan);
}