glibc/sysdeps/wordsize-64/tst-writev.c
Siddhesh Poyarekar 30891f35fa Remove "Contributed by" lines
We stopped adding "Contributed by" or similar lines in sources in 2012
in favour of git logs and keeping the Contributors section of the
glibc manual up to date.  Removing these lines makes the license
header a bit more consistent across files and also removes the
possibility of error in attribution when license blocks or files are
copied across since the contributed-by lines don't actually reflect
reality in those cases.

Move all "Contributed by" and similar lines (Written by, Test by,
etc.) into a new file CONTRIBUTED-BY to retain record of these
contributions.  These contributors are also mentioned in
manual/contrib.texi, so we just maintain this additional record as a
courtesy to the earlier developers.

The following scripts were used to filter a list of files to edit in
place and to clean up the CONTRIBUTED-BY file respectively.  These
were not added to the glibc sources because they're not expected to be
of any use in future given that this is a one time task:

https://gist.github.com/siddhesh/b5ecac94eabfd72ed2916d6d8157e7dc
https://gist.github.com/siddhesh/15ea1f5e435ace9774f485030695ee02

Reviewed-by: Carlos O'Donell <carlos@redhat.com>
2021-09-03 22:06:44 +05:30

114 lines
3.3 KiB
C

/* Copyright (C) 2011-2021 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 <fcntl.h>
#include <limits.h>
#include <paths.h>
#include <stdio.h>
#include <stdint.h>
#include <stdlib.h>
#include <unistd.h>
#include <sys/uio.h>
/* The purpose of this test is to verify that the INTERNAL_[V]SYSCALL_NCS
macros on 64-bit platforms don't cast the return type to (int) which would
erroneously sign extend the return value should the high bit of the bottom
half of the word be '1'. */
#if 0
/* Used to test the non power-of-2 code path. */
#undef IOV_MAX
#define IOV_MAX 1000
#endif
/* writev() should report that it has written EXPECTED number of bytes. */
#define EXPECTED ((size_t) INT32_MAX + 1)
static int
do_test (void)
{
struct iovec iv[IOV_MAX];
/* POSIX doesn't guarantee that IOV_MAX is pow of 2 but we're optimistic. */
size_t bufsz = EXPECTED / IOV_MAX;
size_t bufrem = EXPECTED % IOV_MAX;
/* If there's a remainder then IOV_MAX probably isn't a power of 2 and we
need to make bufsz bigger so that the last iovec, iv[IOV_MAX-1], is free
for the remainder. */
if (bufrem)
{
bufsz = bufsz + 1;
bufrem = EXPECTED - (bufsz * (IOV_MAX - 1));
}
/* We writev to /dev/null since we're just testing writev's return value. */
int fd = open (_PATH_DEVNULL, O_WRONLY);
if (fd == -1)
{
printf ("Unable to open /dev/null for writing.\n");
return -1;
}
iv[0].iov_base = malloc (bufsz);
if (iv[0].iov_base == NULL)
{
printf ("malloc (%zu) failed.\n", bufsz);
close (fd);
return -1;
}
iv[0].iov_len = bufsz;
/* We optimistically presume that there isn't a remainder and set all iovec
instances to the same base and len as the first instance. */
for (int i = 1; i < IOV_MAX; i++)
{
/* We don't care what the data is so reuse the allocation from iv[0]; */
iv[i].iov_base = iv[0].iov_base;
iv[i].iov_len = iv[0].iov_len;
}
/* If there is a remainder then we correct the last iov_len. */
if (bufrem)
iv[IOV_MAX - 1].iov_len = bufrem;
/* Write junk to /dev/null with the writev syscall in order to get a return
of INT32_MAX+1 bytes to verify that the INTERNAL_SYSCALL wrappers aren't
mangling the result if the signbit of a 32-bit number is set. */
ssize_t ret = writev (fd, iv, IOV_MAX);
free (iv[0].iov_base);
close (fd);
if (ret != (ssize_t) EXPECTED)
{
#ifdef ARTIFICIAL_LIMIT
if (ret != (ssize_t) ARTIFICIAL_LIMIT)
#endif
{
printf ("writev() return value: %zd != EXPECTED: %zd\n",
ret, EXPECTED);
return 1;
}
}
return 0;
}
#define TEST_FUNCTION do_test ()
#include "../test-skeleton.c"