1  /*
       2   * Check decoding of fsmount syscall.
       3   *
       4   * Copyright (c) 2019-2021 Dmitry V. Levin <ldv@strace.io>
       5   * All rights reserved.
       6   *
       7   * SPDX-License-Identifier: GPL-2.0-or-later
       8   */
       9  
      10  #include "tests.h"
      11  #include "scno.h"
      12  
      13  #include <fcntl.h>
      14  #include <stdio.h>
      15  #include <stdint.h>
      16  #include <unistd.h>
      17  
      18  static const char *errstr;
      19  
      20  static long
      21  k_fsmount(const unsigned int fs_fd,
      22  	  const unsigned int flags,
      23  	  const unsigned int attr_flags)
      24  {
      25  	const kernel_ulong_t fill = (kernel_ulong_t) 0xdefaced00000000ULL;
      26  	const kernel_ulong_t bad = (kernel_ulong_t) 0xbadc0dedbadc0dedULL;
      27  	const kernel_ulong_t arg1 = fill | fs_fd;
      28  	const kernel_ulong_t arg2 = fill | flags;
      29  	const kernel_ulong_t arg3 = fill | attr_flags;
      30  	const long rc = syscall(__NR_fsmount,
      31  				arg1, arg2, arg3, bad, bad, bad);
      32  	errstr = sprintrc(rc);
      33  	return rc;
      34  }
      35  
      36  int
      37  main(void)
      38  {
      39  	skip_if_unavailable("/proc/self/fd/");
      40  
      41  	static const char path[] = "/dev/full";
      42          int fd = open(path, O_WRONLY);
      43          if (fd < 0)
      44                  perror_msg_and_fail("open: %s", path);
      45  
      46  	struct {
      47  		unsigned int val;
      48  		const char *str;
      49  	} flags[] = {
      50  		{ ARG_STR(0) },
      51  		{ 1, "FSMOUNT_CLOEXEC" },
      52  		{ 2, "0x2 /* FSMOUNT_??? */" },
      53  		{ 0xfffffffe, "0xfffffffe /* FSMOUNT_??? */" },
      54  		{ -1, "FSMOUNT_CLOEXEC|0xfffffffe" }
      55  	},
      56  	attrs[] = {
      57  		{ ARG_STR(0) },
      58  		{ 1, "MOUNT_ATTR_RDONLY" },
      59  		{ 0x10, "MOUNT_ATTR_NOATIME" },
      60  		{ 0xbf, "MOUNT_ATTR_RDONLY|MOUNT_ATTR_NOSUID|MOUNT_ATTR_NODEV"
      61  			"|MOUNT_ATTR_NOEXEC|MOUNT_ATTR_NOATIME"
      62  			"|MOUNT_ATTR_STRICTATIME|MOUNT_ATTR_NODIRATIME" },
      63  		{ 0x40, "0x40 /* MOUNT_ATTR_??? */" },
      64  		{ 0xffffff40, "0xffffff40 /* MOUNT_ATTR_??? */" },
      65  		{ -1, "MOUNT_ATTR_RDONLY|MOUNT_ATTR_NOSUID|MOUNT_ATTR_NODEV"
      66  			"|MOUNT_ATTR_NOEXEC|MOUNT_ATTR_NOATIME"
      67  			"|MOUNT_ATTR_STRICTATIME|MOUNT_ATTR_NODIRATIME"
      68  			"|0xffffff40" }
      69  	};
      70  
      71  	for (unsigned int i = 0; i < ARRAY_SIZE(flags); ++i) {
      72  		for (unsigned int j = 0; j < ARRAY_SIZE(attrs); ++j) {
      73  			k_fsmount(-1, flags[i].val, attrs[j].val);
      74  			printf("fsmount(-1, %s, %s) = %s\n",
      75  			       flags[i].str, attrs[j].str, errstr);
      76  
      77  			k_fsmount(-100, flags[i].val, attrs[j].val);
      78  			printf("fsmount(-100, %s, %s) = %s\n",
      79  			       flags[i].str, attrs[j].str, errstr);
      80  
      81  			k_fsmount(fd, flags[i].val, attrs[j].val);
      82  			printf("fsmount(%d<%s>, %s, %s) = %s\n",
      83  			       fd, path, flags[i].str, attrs[j].str, errstr);
      84  		}
      85  	}
      86  
      87  	puts("+++ exited with 0 +++");
      88  	return 0;
      89  }