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/*
* Check decoding of fchmodat2 syscall.
*
* Copyright (c) 2016-2023 The strace developers.
* All rights reserved.
*
* SPDX-License-Identifier: GPL-2.0-or-later
*/
#include "tests.h"
#include "scno.h"
#include "secontext.h"
#include <fcntl.h>
#include <stdio.h>
#include <unistd.h>
#ifndef AT_SYMLINK_NOFOLLOW
# define AT_SYMLINK_NOFOLLOW 0x100
#endif
#ifndef AT_EMPTY_PATH
# define AT_EMPTY_PATH 0x1000
#endif
static const char *errstr;
static long
k_fchmodat2(const unsigned int dfd, const void *path,
const unsigned short mode, const unsigned int flags)
{
const kernel_ulong_t fill = (kernel_ulong_t) 0xbadc0ded00000000ULL;
const kernel_ulong_t fill_short = fill | 0xdead0000ULL;
const kernel_ulong_t arg1 = fill | dfd;
const kernel_ulong_t arg2 = (uintptr_t) path;
const kernel_ulong_t arg3 = fill_short | mode;
const kernel_ulong_t arg4 = fill | flags;
const kernel_ulong_t arg5 = fill | 0xdecaffed;
const kernel_ulong_t arg6 = fill | 0xdeefaced;
const long rc = syscall(__NR_fchmodat2,
arg1, arg2, arg3, arg4, arg5, arg6);
errstr = sprintrc(rc);
return rc;
}
int
main(void)
{
/*
* Make sure the current workdir of the tracee
* is different from the current workdir of the tracer.
*/
create_and_enter_subdir("fchmodat2_subdir");
char *my_secontext = SECONTEXT_PID_MY();
static const char sample[] = "fchmodat2_sample_file";
if (open(sample, O_RDONLY | O_CREAT, 0400) < 0)
perror_msg_and_fail("open");
char *sample_secontext = SECONTEXT_FILE(sample);
/*
* Tests with AT_FDCWD.
*/
k_fchmodat2(-100, sample, 0600, 0);
printf("%s%s(%s, \"%s\"%s, 0600, 0) = %s\n",
my_secontext, "fchmodat2", "AT_FDCWD",
sample, sample_secontext, errstr);
if (unlink(sample))
perror_msg_and_fail("unlink");
k_fchmodat2(-100, sample, 051, AT_SYMLINK_NOFOLLOW);
printf("%s%s(%s, \"%s\", 051, AT_SYMLINK_NOFOLLOW) = %s\n",
my_secontext, "fchmodat2", "AT_FDCWD", sample, errstr);
k_fchmodat2(-100, sample, 0700, AT_SYMLINK_NOFOLLOW | AT_EMPTY_PATH);
printf("%s%s(%s, \"%s\", 0700, AT_SYMLINK_NOFOLLOW|AT_EMPTY_PATH)"
" = %s\n",
my_secontext, "fchmodat2", "AT_FDCWD", sample, errstr);
k_fchmodat2(-100, sample, 004,
-1U & ~(AT_SYMLINK_NOFOLLOW | AT_EMPTY_PATH));
printf("%s%s(%s, \"%s\", 004, 0xffffeeff /* AT_??? */) = %s\n",
my_secontext, "fchmodat2", "AT_FDCWD", sample, errstr);
/*
* Tests with dirfd.
*/
int cwd_fd = get_dir_fd(".");
char *cwd = get_fd_path(cwd_fd);
char *cwd_secontext = SECONTEXT_FILE(".");
char *sample_realpath = xasprintf("%s/%s", cwd, sample);
/* no file */
k_fchmodat2(cwd_fd, sample, 0400, 0);
printf("%s%s(%d%s, \"%s\", 0400, 0) = %s\n",
my_secontext, "fchmodat2",
cwd_fd, cwd_secontext, sample, errstr);
if (open(sample, O_RDONLY | O_CREAT, 0400) < 0)
perror_msg_and_fail("open");
k_fchmodat2(cwd_fd, sample, 0400, AT_SYMLINK_NOFOLLOW);
printf("%s%s(%d%s, \"%s\"%s, 0400, AT_SYMLINK_NOFOLLOW) = %s\n",
my_secontext, "fchmodat2",
cwd_fd, cwd_secontext, sample, sample_secontext, errstr);
/* cwd_fd ignored when path is absolute */
if (chdir("../.."))
perror_msg_and_fail("chdir");
k_fchmodat2(cwd_fd, sample_realpath, 0700, AT_EMPTY_PATH);
printf("%s%s(%d%s, \"%s\"%s, 0700, AT_EMPTY_PATH) = %s\n",
my_secontext, "fchmodat2",
cwd_fd, cwd_secontext,
sample_realpath, sample_secontext, errstr);
if (fchdir(cwd_fd))
perror_msg_and_fail("fchdir");
if (unlink(sample))
perror_msg_and_fail("unlink");
leave_and_remove_subdir();
puts("+++ exited with 0 +++");
return 0;
}
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