glibc/sysdeps/unix/sysv/linux/test-errno-linux.c

/* Test that failing system calls do set errno to the correct value.
   Linux sycalls version.

   Copyright (C) 2017-2025 Free Software Foundation, Inc.
   This file is part of the GNU C Library.

   The GNU C Library is free software; you can redistribute it and/or
   modify it under the terms of the GNU Lesser General Public
   License as published by the Free Software Foundation; either
   version 2.1 of the License, or (at your option) any later version.

   The GNU C Library is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
   Lesser General Public License for more details.

   You should have received a copy of the GNU Lesser General Public
   License along with the GNU C Library; if not, see
   <https://www.gnu.org/licenses/>.  */

#include <array_length.h>
#include <errno.h>
#include <fcntl.h>
#include <mqueue.h>
#include <sched.h>
#include <signal.h>
#include <stdbool.h>
#include <stdio.h>
#include <string.h>
#include <time.h>
#include <unistd.h>
#include <sys/epoll.h>
#include <sys/eventfd.h>
#include <sys/file.h>
#include <sys/fsuid.h>
#include <sys/inotify.h>
#include <sys/mman.h>
#include <sys/poll.h>
#include <sys/quota.h>
#include <sys/resource.h>
#include <sys/select.h>
#include <sys/sendfile.h>
#include <sys/swap.h>
#include <sys/time.h>
#include <sys/types.h>
#include <sys/wait.h>
#include <libc-diag.h>

/* This is not an exhaustive test: only system calls that can be
   persuaded to fail with a consistent error code and no side effects
   are included.  Usually these are failures due to invalid arguments,
   with errno code EBADF or EINVAL.  The order of argument checks is
   unspecified, so we must take care to provide arguments that only
   allow _one_ failure mode.

   Note that all system calls that can fail with EFAULT are permitted
   to deliver a SIGSEGV signal instead, so we avoid supplying invalid
   pointers in general, and we do not attempt to test system calls
   that can only fail with EFAULT (e.g. gettimeofday, gethostname).

   Also note that root-only system calls (e.g. acct, reboot) may, when
   the test is run as an unprivileged user, fail due to insufficient
   privileges before bothering to do argument checks, so those are not
   tested either.

   Also, system calls that take enum or a set of flags as argument is
   not tested if POSIX doesn't specify exact binary values for all
   flags, and so any value passed to flags may become valid.

   Some tests assume "/bin/sh" names a file that exists and is not a
   directory.  */

/* Evaluates to the arguments in a list initializer which can be used
   as a single macro argument.  */
#define LIST(...) { __VA_ARGS__ }

/* This macro is necessary to forward the output of LIST as a macro
   argument.  */
#define LIST_FORWARD(...) __VA_ARGS__

/* Return true if CODE is contained in the array [CODES, CODES +
   COUNT].  */
static bool
check_error_in_list (int code, int *codes, size_t count)
{
  for (size_t i = 0; i < count; ++i)
    if (codes[i] == code)
      return true;
  return false;
}

#define test_wrp_rv(rtype, prtype, experr_list, syscall, ...)	\
  (__extension__ ({						\
    errno = 0xdead;						\
    int experr[] = experr_list;					\
    rtype ret = syscall (__VA_ARGS__);				\
    int err = errno;						\
    int fail;							\
    if ((ret == (rtype) -1)					\
	&& check_error_in_list (err, experr, array_length (experr))) \
      fail = 0;							\
    else							\
      {								\
        fail = 1;						\
        if (ret != (rtype) -1)					\
          printf ("FAIL: " #syscall ": didn't fail as expected"	\
		  " (return "prtype")\n", ret);			\
        else if (err == 0xdead)					\
          puts ("FAIL: " #syscall ": didn't update errno");	\
	else							\
          printf ("FAIL: " #syscall				\
		  ": errno is: %d (%s) expected one of %s\n",	\
		  err, strerror (err), #experr_list);		\
      }								\
    fail;							\
  }))

#define test_wrp(experr, syscall, ...)				\
  test_wrp_rv(int, "%d", LIST (experr), syscall, __VA_ARGS__)

#define test_wrp2(experr, syscall, ...)		\
  test_wrp_rv(int, "%d", LIST_FORWARD (experr), syscall, __VA_ARGS__)

static int
invalid_sigprocmask_how (void)
{
  int n = 0;
  const int how[] = { SIG_BLOCK, SIG_UNBLOCK, SIG_SETMASK };
  for (int i = 0; i < array_length (how); i++)
    if (how[i] == n)
      n++;
  return n;
}

static int
do_test (void)
{
  fd_set rs, ws, es;
  int status;
  off_t off;
  stack_t ss;
  struct dqblk dqblk;
  struct epoll_event epoll_event;
  struct pollfd pollfd;
  struct sched_param sch_param;
  struct timespec ts;
  struct timeval tv;
  sigset_t sigs;
  unsigned char vec[16];
  ss.ss_flags = ~SS_DISABLE;
  ts.tv_sec = -1;

  sigemptyset (&sigs);

  int fails = 0;
  fails |= test_wrp (EINVAL, epoll_create, -1);
  fails |= test_wrp (EINVAL, epoll_create1, EPOLL_CLOEXEC + 1);
  fails |= test_wrp (EBADF, epoll_ctl, -1, EPOLL_CTL_ADD, 0, &epoll_event);
  fails |= test_wrp (EBADF, epoll_wait, -1, &epoll_event, 1, 1);
  fails |= test_wrp (EBADF, fdatasync, -1);
  fails |= test_wrp (EBADF, flock, -1, LOCK_SH);
  fails |= test_wrp (ESRCH, getpgid, -1);
  /* Linux v3.8 (676a0675c) removed the test to check at least one valid
     bit in flags (to return EINVAL).  It was later added back in v3.9
     (04df32fa1).  */
  fails |= test_wrp2 (LIST (EINVAL, EBADF), inotify_add_watch, -1, "/", 0);
  fails |= test_wrp (EINVAL, mincore, (void *) -1, 0, vec);
  /* mlock fails if the result of the addition addr+len was less than addr
     (which indicates final address overflow), however on 32 bits binaries
     running on 64 bits kernels, internal syscall address check won't result
     in an invalid address and thus syscalls fails later in vma
     allocation.  */
  fails |= test_wrp2 (LIST (EINVAL, ENOMEM), mlock, (void *) -1, 1);
  fails |= test_wrp (EINVAL, nanosleep, &ts, &ts);

  DIAG_PUSH_NEEDS_COMMENT;

#if __GNUC_PREREQ (9, 0)
  /* Suppress valid GCC warning:
     'poll' specified size 18446744073709551608 exceeds maximum object size
  */
  DIAG_IGNORE_NEEDS_COMMENT (9, "-Wstringop-overflow=");
#endif
  fails |= test_wrp (EINVAL, poll, &pollfd, -1, 0);
  DIAG_POP_NEEDS_COMMENT;

  /* quotactl returns ENOSYS for kernels not configured with
     CONFIG_QUOTA, and may return EPERM if called within certain types
     of containers.  Linux 5.4 added additional argument validation
     and can return EINVAL.  */
  fails |= test_wrp2 (LIST (ENODEV, ENOSYS, EPERM, EINVAL),
		      quotactl, Q_GETINFO, NULL, -1, (caddr_t) &dqblk);
  fails |= test_wrp (EINVAL, sched_getparam, -1, &sch_param);
  fails |= test_wrp (EINVAL, sched_getscheduler, -1);
  fails |= test_wrp (EINVAL, sched_get_priority_max, -1);
  fails |= test_wrp (EINVAL, sched_get_priority_min, -1);
  fails |= test_wrp (EINVAL, sched_rr_get_interval, -1, &ts);
  fails |= test_wrp (EINVAL, sched_setparam, -1, &sch_param);
  fails |= test_wrp (EINVAL, sched_setscheduler, -1, 0, &sch_param);
  fails |= test_wrp (EINVAL, select, -1, &rs, &ws, &es, &tv);
  fails |= test_wrp (EBADF, sendfile, -1, -1, &off, 0);
  fails |= test_wrp (EINVAL, sigaltstack, &ss, NULL);
  fails |= test_wrp (ECHILD, wait4, -1, &status, 0, NULL);
  /* Austin Group issue #1132 states EINVAL should be returned for invalid
     how argument iff the new set mask is non-null.  And Linux follows the
     standard on this regard.  */
  fails |= test_wrp (EINVAL, sigprocmask, invalid_sigprocmask_how (), &sigs,
		     NULL);

  return fails;
}

#include "support/test-driver.c"