[linux-block.git] / tools / testing / selftests / exec / execveat.c

// SPDX-License-Identifier: GPL-2.0-only
/*
 * Copyright (c) 2014 Google, Inc.
 *
 * Selftests for execveat(2).
 */

#ifndef _GNU_SOURCE
#define _GNU_SOURCE  /* to get O_PATH, AT_EMPTY_PATH */
#endif
#include <sys/sendfile.h>
#include <sys/stat.h>
#include <sys/syscall.h>
#include <sys/types.h>
#include <sys/wait.h>
#include <errno.h>
#include <fcntl.h>
#include <limits.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>

#include "../kselftest.h"

#define TESTS_EXPECTED 51
#define TEST_NAME_LEN (PATH_MAX * 4)

static char longpath[2 * PATH_MAX] = "";
static char *envp[] = { "IN_TEST=yes", NULL, NULL };
static char *argv[] = { "execveat", "99", NULL };

static int execveat_(int fd, const char *path, char **argv, char **envp,
		     int flags)
{
#ifdef __NR_execveat
	return syscall(__NR_execveat, fd, path, argv, envp, flags);
#else
	errno = ENOSYS;
	return -1;
#endif
}

#define check_execveat_fail(fd, path, flags, errno)	\
	_check_execveat_fail(fd, path, flags, errno, #errno)
static int _check_execveat_fail(int fd, const char *path, int flags,
				int expected_errno, const char *errno_str)
{
	char test_name[TEST_NAME_LEN];
	int rc;

	errno = 0;
	snprintf(test_name, sizeof(test_name),
		 "Check failure of execveat(%d, '%s', %d) with %s",
		 fd, path?:"(null)", flags, errno_str);
	rc = execveat_(fd, path, argv, envp, flags);

	if (rc > 0) {
		ksft_print_msg("unexpected success from execveat(2)\n");
		ksft_test_result_fail("%s\n", test_name);
		return 1;
	}
	if (errno != expected_errno) {
		ksft_print_msg("expected errno %d (%s) not %d (%s)\n",
			       expected_errno, strerror(expected_errno),
			       errno, strerror(errno));
		ksft_test_result_fail("%s\n", test_name);
		return 1;
	}
	ksft_test_result_pass("%s\n", test_name);
	return 0;
}

static int check_execveat_invoked_rc(int fd, const char *path, int flags,
				     int expected_rc, int expected_rc2)
{
	char test_name[TEST_NAME_LEN];
	int status;
	int rc;
	pid_t child;
	int pathlen = path ? strlen(path) : 0;

	if (pathlen > 40)
		snprintf(test_name, sizeof(test_name),
			 "Check success of execveat(%d, '%.20s...%s', %d)... ",
			 fd, path, (path + pathlen - 20), flags);
	else
		snprintf(test_name, sizeof(test_name),
			 "Check success of execveat(%d, '%s', %d)... ",
			 fd, path?:"(null)", flags);

	child = fork();
	if (child < 0) {
		ksft_perror("fork() failed");
		ksft_test_result_fail("%s\n", test_name);
		return 1;
	}
	if (child == 0) {
		/* Child: do execveat(). */
		rc = execveat_(fd, path, argv, envp, flags);
		ksft_print_msg("child execveat() failed, rc=%d errno=%d (%s)\n",
			       rc, errno, strerror(errno));
		exit(errno);
	}
	/* Parent: wait for & check child's exit status. */
	rc = waitpid(child, &status, 0);
	if (rc != child) {
		ksft_print_msg("waitpid(%d,...) returned %d\n", child, rc);
		ksft_test_result_fail("%s\n", test_name);
		return 1;
	}
	if (!WIFEXITED(status)) {
		ksft_print_msg("child %d did not exit cleanly, status=%08x\n",
			       child, status);
		ksft_test_result_fail("%s\n", test_name);
		return 1;
	}
	if ((WEXITSTATUS(status) != expected_rc) &&
	    (WEXITSTATUS(status) != expected_rc2)) {
		ksft_print_msg("child %d exited with %d not %d nor %d\n",
			       child, WEXITSTATUS(status), expected_rc,
			       expected_rc2);
		ksft_test_result_fail("%s\n", test_name);
		return 1;
	}
	ksft_test_result_pass("%s\n", test_name);
	return 0;
}

static int check_execveat(int fd, const char *path, int flags)
{
	return check_execveat_invoked_rc(fd, path, flags, 99, 99);
}

static char *concat(const char *left, const char *right)
{
	char *result = malloc(strlen(left) + strlen(right) + 1);

	strcpy(result, left);
	strcat(result, right);
	return result;
}

static int open_or_die(const char *filename, int flags)
{
	int fd = open(filename, flags);

	if (fd < 0)
		ksft_exit_fail_msg("Failed to open '%s'; "
			"check prerequisites are available\n", filename);
	return fd;
}

static void exe_cp(const char *src, const char *dest)
{
	int in_fd = open_or_die(src, O_RDONLY);
	int out_fd = open(dest, O_RDWR|O_CREAT|O_TRUNC, 0755);
	struct stat info;

	fstat(in_fd, &info);
	sendfile(out_fd, in_fd, NULL, info.st_size);
	close(in_fd);
	close(out_fd);
}

#define XX_DIR_LEN 200
static int check_execveat_pathmax(int root_dfd, const char *src, int is_script)
{
	int fail = 0;
	int ii, count, len;
	char longname[XX_DIR_LEN + 1];
	int fd;

	if (*longpath == '\0') {
		/* Create a filename close to PATH_MAX in length */
		char *cwd = getcwd(NULL, 0);

		if (!cwd) {
			ksft_perror("Failed to getcwd()");
			return 2;
		}
		strcpy(longpath, cwd);
		strcat(longpath, "/");
		memset(longname, 'x', XX_DIR_LEN - 1);
		longname[XX_DIR_LEN - 1] = '/';
		longname[XX_DIR_LEN] = '\0';
		count = (PATH_MAX - 3 - strlen(cwd)) / XX_DIR_LEN;
		for (ii = 0; ii < count; ii++) {
			strcat(longpath, longname);
			mkdir(longpath, 0755);
		}
		len = (PATH_MAX - 3 - strlen(cwd)) - (count * XX_DIR_LEN);
		if (len <= 0)
			len = 1;
		memset(longname, 'y', len);
		longname[len] = '\0';
		strcat(longpath, longname);
		free(cwd);
	}
	exe_cp(src, longpath);

	/*
	 * Execute as a pre-opened file descriptor, which works whether this is
	 * a script or not (because the interpreter sees a filename like
	 * "/dev/fd/20").
	 */
	fd = open(longpath, O_RDONLY);
	if (fd > 0) {
		ksft_print_msg("Invoke copy of '%s' via filename of length %zu:\n",
			       src, strlen(longpath));
		fail += check_execveat(fd, "", AT_EMPTY_PATH);
	} else {
		ksft_print_msg("Failed to open length %zu filename, errno=%d (%s)\n",
			       strlen(longpath), errno, strerror(errno));
		fail++;
	}

	/*
	 * Execute as a long pathname relative to "/".  If this is a script,
	 * the interpreter will launch but fail to open the script because its
	 * name ("/dev/fd/5/xxx....") is bigger than PATH_MAX.
	 *
	 * The failure code is usually 127 (POSIX: "If a command is not found,
	 * the exit status shall be 127."), but some systems give 126 (POSIX:
	 * "If the command name is found, but it is not an executable utility,
	 * the exit status shall be 126."), so allow either.
	 */
	if (is_script) {
		ksft_print_msg("Invoke script via root_dfd and relative filename\n");
		fail += check_execveat_invoked_rc(root_dfd, longpath + 1, 0,
						  127, 126);
	} else {
		ksft_print_msg("Invoke exec via root_dfd and relative filename\n");
		fail += check_execveat(root_dfd, longpath + 1, 0);
	}

	return fail;
}

static int run_tests(void)
{
	int fail = 0;
	char *fullname = realpath("execveat", NULL);
	char *fullname_script = realpath("script", NULL);
	char *fullname_symlink = concat(fullname, ".symlink");
	int subdir_dfd = open_or_die("subdir", O_DIRECTORY|O_RDONLY);
	int subdir_dfd_ephemeral = open_or_die("subdir.ephemeral",
					       O_DIRECTORY|O_RDONLY);
	int dot_dfd = open_or_die(".", O_DIRECTORY|O_RDONLY);
	int root_dfd = open_or_die("/", O_DIRECTORY|O_RDONLY);
	int dot_dfd_path = open_or_die(".", O_DIRECTORY|O_RDONLY|O_PATH);
	int dot_dfd_cloexec = open_or_die(".", O_DIRECTORY|O_RDONLY|O_CLOEXEC);
	int fd = open_or_die("execveat", O_RDONLY);
	int fd_path = open_or_die("execveat", O_RDONLY|O_PATH);
	int fd_symlink = open_or_die("execveat.symlink", O_RDONLY);
	int fd_denatured = open_or_die("execveat.denatured", O_RDONLY);
	int fd_denatured_path = open_or_die("execveat.denatured",
					    O_RDONLY|O_PATH);
	int fd_script = open_or_die("script", O_RDONLY);
	int fd_ephemeral = open_or_die("execveat.ephemeral", O_RDONLY);
	int fd_ephemeral_path = open_or_die("execveat.path.ephemeral",
					    O_RDONLY|O_PATH);
	int fd_script_ephemeral = open_or_die("script.ephemeral", O_RDONLY);
	int fd_cloexec = open_or_die("execveat", O_RDONLY|O_CLOEXEC);
	int fd_script_cloexec = open_or_die("script", O_RDONLY|O_CLOEXEC);

	/* Check if we have execveat at all, and bail early if not */
	errno = 0;
	execveat_(-1, NULL, NULL, NULL, 0);
	if (errno == ENOSYS) {
		ksft_exit_skip(
			"ENOSYS calling execveat - no kernel support?\n");
	}

	/* Change file position to confirm it doesn't affect anything */
	lseek(fd, 10, SEEK_SET);

	/* Normal executable file: */
	/*   dfd + path */
	fail += check_execveat(subdir_dfd, "../execveat", 0);
	fail += check_execveat(dot_dfd, "execveat", 0);
	fail += check_execveat(dot_dfd_path, "execveat", 0);
	/*   absolute path */
	fail += check_execveat(AT_FDCWD, fullname, 0);
	/*   absolute path with nonsense dfd */
	fail += check_execveat(99, fullname, 0);
	/*   fd + no path */
	fail += check_execveat(fd, "", AT_EMPTY_PATH);
	/*   O_CLOEXEC fd + no path */
	fail += check_execveat(fd_cloexec, "", AT_EMPTY_PATH);
	/*   O_PATH fd */
	fail += check_execveat(fd_path, "", AT_EMPTY_PATH);

	/* Mess with executable file that's already open: */
	/*   fd + no path to a file that's been renamed */
	rename("execveat.ephemeral", "execveat.moved");
	fail += check_execveat(fd_ephemeral, "", AT_EMPTY_PATH);
	/*   fd + no path to a file that's been deleted */
	unlink("execveat.moved"); /* remove the file now fd open */
	fail += check_execveat(fd_ephemeral, "", AT_EMPTY_PATH);

	/* Mess with executable file that's already open with O_PATH */
	/*   fd + no path to a file that's been deleted */
	unlink("execveat.path.ephemeral");
	fail += check_execveat(fd_ephemeral_path, "", AT_EMPTY_PATH);

	/* Invalid argument failures */
	fail += check_execveat_fail(fd, "", 0, ENOENT);
	fail += check_execveat_fail(fd, NULL, AT_EMPTY_PATH, EFAULT);

	/* Symlink to executable file: */
	/*   dfd + path */
	fail += check_execveat(dot_dfd, "execveat.symlink", 0);
	fail += check_execveat(dot_dfd_path, "execveat.symlink", 0);
	/*   absolute path */
	fail += check_execveat(AT_FDCWD, fullname_symlink, 0);
	/*   fd + no path, even with AT_SYMLINK_NOFOLLOW (already followed) */
	fail += check_execveat(fd_symlink, "", AT_EMPTY_PATH);
	fail += check_execveat(fd_symlink, "",
			       AT_EMPTY_PATH|AT_SYMLINK_NOFOLLOW);

	/* Symlink fails when AT_SYMLINK_NOFOLLOW set: */
	/*   dfd + path */
	fail += check_execveat_fail(dot_dfd, "execveat.symlink",
				    AT_SYMLINK_NOFOLLOW, ELOOP);
	fail += check_execveat_fail(dot_dfd_path, "execveat.symlink",
				    AT_SYMLINK_NOFOLLOW, ELOOP);
	/*   absolute path */
	fail += check_execveat_fail(AT_FDCWD, fullname_symlink,
				    AT_SYMLINK_NOFOLLOW, ELOOP);

	/*  Non-regular file failure */
	fail += check_execveat_fail(dot_dfd, "pipe", 0, EACCES);
	unlink("pipe");

	/* Shell script wrapping executable file: */
	/*   dfd + path */
	fail += check_execveat(subdir_dfd, "../script", 0);
	fail += check_execveat(dot_dfd, "script", 0);
	fail += check_execveat(dot_dfd_path, "script", 0);
	/*   absolute path */
	fail += check_execveat(AT_FDCWD, fullname_script, 0);
	/*   fd + no path */
	fail += check_execveat(fd_script, "", AT_EMPTY_PATH);
	fail += check_execveat(fd_script, "",
			       AT_EMPTY_PATH|AT_SYMLINK_NOFOLLOW);
	/*   O_CLOEXEC fd fails for a script (as script file inaccessible) */
	fail += check_execveat_fail(fd_script_cloexec, "", AT_EMPTY_PATH,
				    ENOENT);
	fail += check_execveat_fail(dot_dfd_cloexec, "script", 0, ENOENT);

	/* Mess with script file that's already open: */
	/*   fd + no path to a file that's been renamed */
	rename("script.ephemeral", "script.moved");
	fail += check_execveat(fd_script_ephemeral, "", AT_EMPTY_PATH);
	/*   fd + no path to a file that's been deleted */
	unlink("script.moved"); /* remove the file while fd open */
	fail += check_execveat(fd_script_ephemeral, "", AT_EMPTY_PATH);

	/* Rename a subdirectory in the path: */
	rename("subdir.ephemeral", "subdir.moved");
	fail += check_execveat(subdir_dfd_ephemeral, "../script", 0);
	fail += check_execveat(subdir_dfd_ephemeral, "script", 0);
	/* Remove the subdir and its contents */
	unlink("subdir.moved/script");
	unlink("subdir.moved");
	/* Shell loads via deleted subdir OK because name starts with .. */
	fail += check_execveat(subdir_dfd_ephemeral, "../script", 0);
	fail += check_execveat_fail(subdir_dfd_ephemeral, "script", 0, ENOENT);

	/* Flag values other than AT_SYMLINK_NOFOLLOW => EINVAL */
	fail += check_execveat_fail(dot_dfd, "execveat", 0xFFFF, EINVAL);
	/* Invalid path => ENOENT */
	fail += check_execveat_fail(dot_dfd, "no-such-file", 0, ENOENT);
	fail += check_execveat_fail(dot_dfd_path, "no-such-file", 0, ENOENT);
	fail += check_execveat_fail(AT_FDCWD, "no-such-file", 0, ENOENT);
	/* Attempt to execute directory => EACCES */
	fail += check_execveat_fail(dot_dfd, "", AT_EMPTY_PATH, EACCES);
	/* Attempt to execute non-executable => EACCES */
	fail += check_execveat_fail(dot_dfd, "Makefile", 0, EACCES);
	fail += check_execveat_fail(fd_denatured, "", AT_EMPTY_PATH, EACCES);
	fail += check_execveat_fail(fd_denatured_path, "", AT_EMPTY_PATH,
				    EACCES);
	/* Attempt to execute nonsense FD => EBADF */
	fail += check_execveat_fail(99, "", AT_EMPTY_PATH, EBADF);
	fail += check_execveat_fail(99, "execveat", 0, EBADF);
	/* Attempt to execute relative to non-directory => ENOTDIR */
	fail += check_execveat_fail(fd, "execveat", 0, ENOTDIR);

	fail += check_execveat_pathmax(root_dfd, "execveat", 0);
	fail += check_execveat_pathmax(root_dfd, "script", 1);
	return fail;
}

static void prerequisites(void)
{
	int fd;
	const char *script = "#!/bin/bash\nexit $*\n";

	/* Create ephemeral copies of files */
	exe_cp("execveat", "execveat.ephemeral");
	exe_cp("execveat", "execveat.path.ephemeral");
	exe_cp("script", "script.ephemeral");
	mkdir("subdir.ephemeral", 0755);

	fd = open("subdir.ephemeral/script", O_RDWR|O_CREAT|O_TRUNC, 0755);
	write(fd, script, strlen(script));
	close(fd);

	mkfifo("pipe", 0755);
}

int main(int argc, char **argv)
{
	int ii;
	int rc;
	const char *verbose = getenv("VERBOSE");

	if (argc >= 2) {
		/* If we are invoked with an argument, don't run tests. */
		const char *in_test = getenv("IN_TEST");

		if (verbose) {
			ksft_print_msg("invoked with:\n");
			for (ii = 0; ii < argc; ii++)
				ksft_print_msg("\t[%d]='%s\n'", ii, argv[ii]);
		}

		/* Check expected environment transferred. */
		if (!in_test || strcmp(in_test, "yes") != 0) {
			ksft_print_msg("no IN_TEST=yes in env\n");
			return 1;
		}

		/* Use the final argument as an exit code. */
		rc = atoi(argv[argc - 1]);
		exit(rc);
	} else {
		ksft_print_header();
		ksft_set_plan(TESTS_EXPECTED);
		prerequisites();
		if (verbose)
			envp[1] = "VERBOSE=1";
		rc = run_tests();
		if (rc > 0)
			printf("%d tests failed\n", rc);
		ksft_finished();
	}

	return rc;
}
Commit	Line	Data
4f19048f	1	// SPDX-License-Identifier: GPL-2.0-only
c9b26b81 DD	2	/*
	3	* Copyright (c) 2014 Google, Inc.
	4	*
c9b26b81 DD	5	* Selftests for execveat(2).
	6	*/
	7
61016db1	8	#ifndef _GNU_SOURCE
c9b26b81	9	#define _GNU_SOURCE /* to get O_PATH, AT_EMPTY_PATH */
61016db1	10	#endif
c9b26b81 DD	11	#include <sys/sendfile.h>
	12	#include <sys/stat.h>
	13	#include <sys/syscall.h>
	14	#include <sys/types.h>
	15	#include <sys/wait.h>
	16	#include <errno.h>
	17	#include <fcntl.h>
	18	#include <limits.h>
	19	#include <stdio.h>
	20	#include <stdlib.h>
	21	#include <string.h>
	22	#include <unistd.h>
	23
964224d7 SKSO	24	#include "../kselftest.h"
964224d7 SKSO	25
47903c1d MB	26	#define TESTS_EXPECTED 51
	27	#define TEST_NAME_LEN (PATH_MAX * 4)
	28
c9b26b81 DD	29	static char longpath[2 * PATH_MAX] = "";
	30	static char *envp[] = { "IN_TEST=yes", NULL, NULL };
	31	static char *argv[] = { "execveat", "99", NULL };
	32
	33	static int execveat_(int fd, const char path, char argv, char *envp,
	34	int flags)
	35	{
	36	#ifdef __NR_execveat
	37	return syscall(__NR_execveat, fd, path, argv, envp, flags);
	38	#else
9a0b5745	39	errno = ENOSYS;
c9b26b81 DD	40	return -1;
	41	#endif
	42	}
	43
	44	#define check_execveat_fail(fd, path, flags, errno) \
	45	_check_execveat_fail(fd, path, flags, errno, #errno)
	46	static int _check_execveat_fail(int fd, const char *path, int flags,
	47	int expected_errno, const char *errno_str)
	48	{
47903c1d	49	char test_name[TEST_NAME_LEN];
c9b26b81 DD	50	int rc;
	51
	52	errno = 0;
47903c1d MB	53	snprintf(test_name, sizeof(test_name),
	54	"Check failure of execveat(%d, '%s', %d) with %s",
	55	fd, path?:"(null)", flags, errno_str);
c9b26b81 DD	56	rc = execveat_(fd, path, argv, envp, flags);
	57
	58	if (rc > 0) {
47903c1d MB	59	ksft_print_msg("unexpected success from execveat(2)\n");
47903c1d MB	60	ksft_test_result_fail("%s\n", test_name);
c9b26b81 DD	61	return 1;
	62	}
	63	if (errno != expected_errno) {
47903c1d MB	64	ksft_print_msg("expected errno %d (%s) not %d (%s)\n",
	65	expected_errno, strerror(expected_errno),
	66	errno, strerror(errno));
	67	ksft_test_result_fail("%s\n", test_name);
c9b26b81 DD	68	return 1;
c9b26b81 DD	69	}
47903c1d	70	ksft_test_result_pass("%s\n", test_name);
c9b26b81 DD	71	return 0;
	72	}
	73
	74	static int check_execveat_invoked_rc(int fd, const char *path, int flags,
cd805f36	75	int expected_rc, int expected_rc2)
c9b26b81	76	{
47903c1d	77	char test_name[TEST_NAME_LEN];
c9b26b81 DD	78	int status;
	79	int rc;
	80	pid_t child;
	81	int pathlen = path ? strlen(path) : 0;
	82
	83	if (pathlen > 40)
47903c1d MB	84	snprintf(test_name, sizeof(test_name),
	85	"Check success of execveat(%d, '%.20s...%s', %d)... ",
	86	fd, path, (path + pathlen - 20), flags);
c9b26b81	87	else
47903c1d MB	88	snprintf(test_name, sizeof(test_name),
	89	"Check success of execveat(%d, '%s', %d)... ",
	90	fd, path?:"(null)", flags);
	91
c9b26b81 DD	92	child = fork();
c9b26b81 DD	93	if (child < 0) {
47903c1d MB	94	ksft_perror("fork() failed");
47903c1d MB	95	ksft_test_result_fail("%s\n", test_name);
c9b26b81 DD	96	return 1;
	97	}
	98	if (child == 0) {
	99	/* Child: do execveat(). */
	100	rc = execveat_(fd, path, argv, envp, flags);
0ef58ccb	101	ksft_print_msg("child execveat() failed, rc=%d errno=%d (%s)\n",
47903c1d	102	rc, errno, strerror(errno));
0ef58ccb	103	exit(errno);
c9b26b81 DD	104	}
	105	/* Parent: wait for & check child's exit status. */
	106	rc = waitpid(child, &status, 0);
	107	if (rc != child) {
47903c1d MB	108	ksft_print_msg("waitpid(%d,...) returned %d\n", child, rc);
47903c1d MB	109	ksft_test_result_fail("%s\n", test_name);
c9b26b81 DD	110	return 1;
	111	}
	112	if (!WIFEXITED(status)) {
47903c1d MB	113	ksft_print_msg("child %d did not exit cleanly, status=%08x\n",
	114	child, status);
	115	ksft_test_result_fail("%s\n", test_name);
c9b26b81 DD	116	return 1;
c9b26b81 DD	117	}
cd805f36 DD	118	if ((WEXITSTATUS(status) != expected_rc) &&
cd805f36 DD	119	(WEXITSTATUS(status) != expected_rc2)) {
47903c1d MB	120	ksft_print_msg("child %d exited with %d not %d nor %d\n",
	121	child, WEXITSTATUS(status), expected_rc,
	122	expected_rc2);
	123	ksft_test_result_fail("%s\n", test_name);
c9b26b81 DD	124	return 1;
c9b26b81 DD	125	}
47903c1d	126	ksft_test_result_pass("%s\n", test_name);
c9b26b81 DD	127	return 0;
	128	}
	129
	130	static int check_execveat(int fd, const char *path, int flags)
	131	{
cd805f36	132	return check_execveat_invoked_rc(fd, path, flags, 99, 99);
c9b26b81 DD	133	}
	134
	135	static char concat(const char left, const char *right)
	136	{
	137	char *result = malloc(strlen(left) + strlen(right) + 1);
	138
	139	strcpy(result, left);
	140	strcat(result, right);
	141	return result;
	142	}
	143
	144	static int open_or_die(const char *filename, int flags)
	145	{
	146	int fd = open(filename, flags);
	147
47903c1d MB	148	if (fd < 0)
47903c1d MB	149	ksft_exit_fail_msg("Failed to open '%s'; "
c9b26b81	150	"check prerequisites are available\n", filename);
c9b26b81 DD	151	return fd;
	152	}
	153
	154	static void exe_cp(const char src, const char dest)
	155	{
	156	int in_fd = open_or_die(src, O_RDONLY);
	157	int out_fd = open(dest, O_RDWR\|O_CREAT\|O_TRUNC, 0755);
	158	struct stat info;
	159
	160	fstat(in_fd, &info);
	161	sendfile(out_fd, in_fd, NULL, info.st_size);
	162	close(in_fd);
	163	close(out_fd);
	164	}
	165
	166	#define XX_DIR_LEN 200
2d80c92d	167	static int check_execveat_pathmax(int root_dfd, const char *src, int is_script)
c9b26b81 DD	168	{
	169	int fail = 0;
	170	int ii, count, len;
	171	char longname[XX_DIR_LEN + 1];
	172	int fd;
	173
	174	if (*longpath == '\0') {
	175	/* Create a filename close to PATH_MAX in length */
2d80c92d SM	176	char *cwd = getcwd(NULL, 0);
	177
	178	if (!cwd) {
47903c1d	179	ksft_perror("Failed to getcwd()");
2d80c92d SM	180	return 2;
	181	}
	182	strcpy(longpath, cwd);
	183	strcat(longpath, "/");
c9b26b81 DD	184	memset(longname, 'x', XX_DIR_LEN - 1);
	185	longname[XX_DIR_LEN - 1] = '/';
	186	longname[XX_DIR_LEN] = '\0';
2d80c92d	187	count = (PATH_MAX - 3 - strlen(cwd)) / XX_DIR_LEN;
c9b26b81 DD	188	for (ii = 0; ii < count; ii++) {
	189	strcat(longpath, longname);
	190	mkdir(longpath, 0755);
	191	}
2d80c92d	192	len = (PATH_MAX - 3 - strlen(cwd)) - (count * XX_DIR_LEN);
c9b26b81 DD	193	if (len <= 0)
	194	len = 1;
	195	memset(longname, 'y', len);
	196	longname[len] = '\0';
	197	strcat(longpath, longname);
2d80c92d	198	free(cwd);
c9b26b81 DD	199	}
	200	exe_cp(src, longpath);
	201
	202	/*
	203	* Execute as a pre-opened file descriptor, which works whether this is
	204	* a script or not (because the interpreter sees a filename like
	205	* "/dev/fd/20").
	206	*/
	207	fd = open(longpath, O_RDONLY);
	208	if (fd > 0) {
47903c1d MB	209	ksft_print_msg("Invoke copy of '%s' via filename of length %zu:\n",
47903c1d MB	210	src, strlen(longpath));
c9b26b81 DD	211	fail += check_execveat(fd, "", AT_EMPTY_PATH);
c9b26b81 DD	212	} else {
47903c1d MB	213	ksft_print_msg("Failed to open length %zu filename, errno=%d (%s)\n",
47903c1d MB	214	strlen(longpath), errno, strerror(errno));
c9b26b81 DD	215	fail++;
	216	}
	217
	218	/*
2d80c92d	219	* Execute as a long pathname relative to "/". If this is a script,
c9b26b81 DD	220	* the interpreter will launch but fail to open the script because its
c9b26b81 DD	221	* name ("/dev/fd/5/xxx....") is bigger than PATH_MAX.
cd805f36 DD	222	*
	223	* The failure code is usually 127 (POSIX: "If a command is not found,
	224	* the exit status shall be 127."), but some systems give 126 (POSIX:
	225	* "If the command name is found, but it is not an executable utility,
	226	* the exit status shall be 126."), so allow either.
c9b26b81	227	*/
0ef58ccb KC	228	if (is_script) {
0ef58ccb KC	229	ksft_print_msg("Invoke script via root_dfd and relative filename\n");
2d80c92d	230	fail += check_execveat_invoked_rc(root_dfd, longpath + 1, 0,
cd805f36	231	127, 126);
0ef58ccb KC	232	} else {
0ef58ccb KC	233	ksft_print_msg("Invoke exec via root_dfd and relative filename\n");
2d80c92d	234	fail += check_execveat(root_dfd, longpath + 1, 0);
0ef58ccb	235	}
c9b26b81 DD	236
	237	return fail;
	238	}
	239
	240	static int run_tests(void)
	241	{
	242	int fail = 0;
	243	char *fullname = realpath("execveat", NULL);
	244	char *fullname_script = realpath("script", NULL);
	245	char *fullname_symlink = concat(fullname, ".symlink");
	246	int subdir_dfd = open_or_die("subdir", O_DIRECTORY\|O_RDONLY);
	247	int subdir_dfd_ephemeral = open_or_die("subdir.ephemeral",
	248	O_DIRECTORY\|O_RDONLY);
	249	int dot_dfd = open_or_die(".", O_DIRECTORY\|O_RDONLY);
2d80c92d	250	int root_dfd = open_or_die("/", O_DIRECTORY\|O_RDONLY);
c9b26b81 DD	251	int dot_dfd_path = open_or_die(".", O_DIRECTORY\|O_RDONLY\|O_PATH);
	252	int dot_dfd_cloexec = open_or_die(".", O_DIRECTORY\|O_RDONLY\|O_CLOEXEC);
	253	int fd = open_or_die("execveat", O_RDONLY);
	254	int fd_path = open_or_die("execveat", O_RDONLY\|O_PATH);
	255	int fd_symlink = open_or_die("execveat.symlink", O_RDONLY);
	256	int fd_denatured = open_or_die("execveat.denatured", O_RDONLY);
	257	int fd_denatured_path = open_or_die("execveat.denatured",
	258	O_RDONLY\|O_PATH);
	259	int fd_script = open_or_die("script", O_RDONLY);
	260	int fd_ephemeral = open_or_die("execveat.ephemeral", O_RDONLY);
	261	int fd_ephemeral_path = open_or_die("execveat.path.ephemeral",
	262	O_RDONLY\|O_PATH);
	263	int fd_script_ephemeral = open_or_die("script.ephemeral", O_RDONLY);
	264	int fd_cloexec = open_or_die("execveat", O_RDONLY\|O_CLOEXEC);
	265	int fd_script_cloexec = open_or_die("script", O_RDONLY\|O_CLOEXEC);
	266
9a0b5745 ME	267	/* Check if we have execveat at all, and bail early if not */
	268	errno = 0;
	269	execveat_(-1, NULL, NULL, NULL, 0);
	270	if (errno == ENOSYS) {
964224d7 SKSO	271	ksft_exit_skip(
964224d7 SKSO	272	"ENOSYS calling execveat - no kernel support?\n");
9a0b5745 ME	273	}
9a0b5745 ME	274
c9b26b81 DD	275	/* Change file position to confirm it doesn't affect anything */
	276	lseek(fd, 10, SEEK_SET);
	277
	278	/* Normal executable file: */
	279	/* dfd + path */
	280	fail += check_execveat(subdir_dfd, "../execveat", 0);
	281	fail += check_execveat(dot_dfd, "execveat", 0);
	282	fail += check_execveat(dot_dfd_path, "execveat", 0);
	283	/* absolute path */
	284	fail += check_execveat(AT_FDCWD, fullname, 0);
	285	/* absolute path with nonsense dfd */
	286	fail += check_execveat(99, fullname, 0);
	287	/* fd + no path */
	288	fail += check_execveat(fd, "", AT_EMPTY_PATH);
	289	/* O_CLOEXEC fd + no path */
	290	fail += check_execveat(fd_cloexec, "", AT_EMPTY_PATH);
	291	/* O_PATH fd */
	292	fail += check_execveat(fd_path, "", AT_EMPTY_PATH);
	293
	294	/* Mess with executable file that's already open: */
	295	/* fd + no path to a file that's been renamed */
	296	rename("execveat.ephemeral", "execveat.moved");
	297	fail += check_execveat(fd_ephemeral, "", AT_EMPTY_PATH);
	298	/* fd + no path to a file that's been deleted */
	299	unlink("execveat.moved"); /* remove the file now fd open */
	300	fail += check_execveat(fd_ephemeral, "", AT_EMPTY_PATH);
	301
	302	/* Mess with executable file that's already open with O_PATH */
	303	/* fd + no path to a file that's been deleted */
	304	unlink("execveat.path.ephemeral");
	305	fail += check_execveat(fd_ephemeral_path, "", AT_EMPTY_PATH);
	306
	307	/* Invalid argument failures */
	308	fail += check_execveat_fail(fd, "", 0, ENOENT);
	309	fail += check_execveat_fail(fd, NULL, AT_EMPTY_PATH, EFAULT);
	310
	311	/* Symlink to executable file: */
	312	/* dfd + path */
	313	fail += check_execveat(dot_dfd, "execveat.symlink", 0);
	314	fail += check_execveat(dot_dfd_path, "execveat.symlink", 0);
	315	/* absolute path */
	316	fail += check_execveat(AT_FDCWD, fullname_symlink, 0);
	317	/* fd + no path, even with AT_SYMLINK_NOFOLLOW (already followed) */
	318	fail += check_execveat(fd_symlink, "", AT_EMPTY_PATH);
	319	fail += check_execveat(fd_symlink, "",
	320	AT_EMPTY_PATH\|AT_SYMLINK_NOFOLLOW);
	321
	322	/* Symlink fails when AT_SYMLINK_NOFOLLOW set: */
	323	/* dfd + path */
	324	fail += check_execveat_fail(dot_dfd, "execveat.symlink",
	325	AT_SYMLINK_NOFOLLOW, ELOOP);
	326	fail += check_execveat_fail(dot_dfd_path, "execveat.symlink",
	327	AT_SYMLINK_NOFOLLOW, ELOOP);
	328	/* absolute path */
	329	fail += check_execveat_fail(AT_FDCWD, fullname_symlink,
	330	AT_SYMLINK_NOFOLLOW, ELOOP);
	331
61016db1 KC	332	/* Non-regular file failure */
	333	fail += check_execveat_fail(dot_dfd, "pipe", 0, EACCES);
	334	unlink("pipe");
	335
c9b26b81 DD	336	/* Shell script wrapping executable file: */
	337	/* dfd + path */
	338	fail += check_execveat(subdir_dfd, "../script", 0);
	339	fail += check_execveat(dot_dfd, "script", 0);
	340	fail += check_execveat(dot_dfd_path, "script", 0);
	341	/* absolute path */
	342	fail += check_execveat(AT_FDCWD, fullname_script, 0);
	343	/* fd + no path */
	344	fail += check_execveat(fd_script, "", AT_EMPTY_PATH);
	345	fail += check_execveat(fd_script, "",
	346	AT_EMPTY_PATH\|AT_SYMLINK_NOFOLLOW);
	347	/* O_CLOEXEC fd fails for a script (as script file inaccessible) */
	348	fail += check_execveat_fail(fd_script_cloexec, "", AT_EMPTY_PATH,
	349	ENOENT);
	350	fail += check_execveat_fail(dot_dfd_cloexec, "script", 0, ENOENT);
	351
	352	/* Mess with script file that's already open: */
	353	/* fd + no path to a file that's been renamed */
	354	rename("script.ephemeral", "script.moved");
	355	fail += check_execveat(fd_script_ephemeral, "", AT_EMPTY_PATH);
	356	/* fd + no path to a file that's been deleted */
	357	unlink("script.moved"); /* remove the file while fd open */
	358	fail += check_execveat(fd_script_ephemeral, "", AT_EMPTY_PATH);
	359
	360	/* Rename a subdirectory in the path: */
	361	rename("subdir.ephemeral", "subdir.moved");
	362	fail += check_execveat(subdir_dfd_ephemeral, "../script", 0);
	363	fail += check_execveat(subdir_dfd_ephemeral, "script", 0);
	364	/* Remove the subdir and its contents */
	365	unlink("subdir.moved/script");
	366	unlink("subdir.moved");
	367	/* Shell loads via deleted subdir OK because name starts with .. */
	368	fail += check_execveat(subdir_dfd_ephemeral, "../script", 0);
	369	fail += check_execveat_fail(subdir_dfd_ephemeral, "script", 0, ENOENT);
	370
	371	/* Flag values other than AT_SYMLINK_NOFOLLOW => EINVAL */
	372	fail += check_execveat_fail(dot_dfd, "execveat", 0xFFFF, EINVAL);
	373	/* Invalid path => ENOENT */
	374	fail += check_execveat_fail(dot_dfd, "no-such-file", 0, ENOENT);
	375	fail += check_execveat_fail(dot_dfd_path, "no-such-file", 0, ENOENT);
	376	fail += check_execveat_fail(AT_FDCWD, "no-such-file", 0, ENOENT);
	377	/* Attempt to execute directory => EACCES */
	378	fail += check_execveat_fail(dot_dfd, "", AT_EMPTY_PATH, EACCES);
	379	/* Attempt to execute non-executable => EACCES */
	380	fail += check_execveat_fail(dot_dfd, "Makefile", 0, EACCES);
	381	fail += check_execveat_fail(fd_denatured, "", AT_EMPTY_PATH, EACCES);
	382	fail += check_execveat_fail(fd_denatured_path, "", AT_EMPTY_PATH,
	383	EACCES);
	384	/* Attempt to execute nonsense FD => EBADF */
	385	fail += check_execveat_fail(99, "", AT_EMPTY_PATH, EBADF);
	386	fail += check_execveat_fail(99, "execveat", 0, EBADF);
	387	/* Attempt to execute relative to non-directory => ENOTDIR */
	388	fail += check_execveat_fail(fd, "execveat", 0, ENOTDIR);
	389
2d80c92d SM	390	fail += check_execveat_pathmax(root_dfd, "execveat", 0);
2d80c92d SM	391	fail += check_execveat_pathmax(root_dfd, "script", 1);
c9b26b81 DD	392	return fail;
	393	}
	394
	395	static void prerequisites(void)
	396	{
	397	int fd;
17107429	398	const char script = "#!/bin/bash\nexit $\n";
c9b26b81 DD	399
	400	/* Create ephemeral copies of files */
	401	exe_cp("execveat", "execveat.ephemeral");
	402	exe_cp("execveat", "execveat.path.ephemeral");
	403	exe_cp("script", "script.ephemeral");
	404	mkdir("subdir.ephemeral", 0755);
	405
	406	fd = open("subdir.ephemeral/script", O_RDWR\|O_CREAT\|O_TRUNC, 0755);
	407	write(fd, script, strlen(script));
	408	close(fd);
61016db1 KC	409
61016db1 KC	410	mkfifo("pipe", 0755);
c9b26b81 DD	411	}
	412
	413	int main(int argc, char **argv)
	414	{
	415	int ii;
	416	int rc;
	417	const char *verbose = getenv("VERBOSE");
	418
	419	if (argc >= 2) {
	420	/* If we are invoked with an argument, don't run tests. */
	421	const char *in_test = getenv("IN_TEST");
	422
	423	if (verbose) {
47903c1d	424	ksft_print_msg("invoked with:\n");
c9b26b81	425	for (ii = 0; ii < argc; ii++)
47903c1d	426	ksft_print_msg("\t[%d]='%s\n'", ii, argv[ii]);
c9b26b81 DD	427	}
	428
	429	/* Check expected environment transferred. */
	430	if (!in_test \|\| strcmp(in_test, "yes") != 0) {
47903c1d	431	ksft_print_msg("no IN_TEST=yes in env\n");
c9b26b81 DD	432	return 1;
	433	}
	434
	435	/* Use the final argument as an exit code. */
	436	rc = atoi(argv[argc - 1]);
47903c1d	437	exit(rc);
c9b26b81	438	} else {
47903c1d MB	439	ksft_print_header();
47903c1d MB	440	ksft_set_plan(TESTS_EXPECTED);
c9b26b81 DD	441	prerequisites();
	442	if (verbose)
	443	envp[1] = "VERBOSE=1";
	444	rc = run_tests();
	445	if (rc > 0)
	446	printf("%d tests failed\n", rc);
47903c1d	447	ksft_finished();
c9b26b81	448	}
47903c1d	449
c9b26b81 DD	450	return rc;
c9b26b81 DD	451	}