mirror of
https://sourceware.org/git/glibc.git
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posix: Fix and simplify default p{read,write}v implementation
Currently all architectures but microblaze use wire-up syscall for
p{readv,write}v. Microblaze still uses the syscall emulation using
sysdep/posix/p{readv,writev}.c and it was reported in some ocasions
[1] [2] that it might have some issues with some linux specific
usage (mainly with O_DIRECT and the alignment requirement).
Although it is not an issue for virtually all the system, this
patch refactors the sysdeps/posix p{read,write}v syscall to avoid
such issue (by using posix_memalign on the buffer used on
p{read,write} call) and by refactoring it common files to avoid
the need check on defines to correct set the alias and internal
symbols.
Checked on microblaze-linux-gnu check with run-built-tests=no and
by using the sysdeps/posix implementation on x86_64-linux-gnu (just
for sanity test where it shown no regression).
* sysdeps/posix/preadv.c: Use sysdeps/posix/preadv_common.c.
* sysdeps/posix/preadv64.c: Likewise.
* sysdeps/unix/sysv/linux/preadv.c: Likewise.
* sysdeps/unix/sysv/linux/preadv64.c: Likewise.
* sysdeps/posix/pwritev.c: Use sysdeps/posix/pwritev_common.c.
* sysdeps/posix/pwritev64.c: Likewise.
* sysdeps/unix/sysv/linux/pwritev.c: Likewise.
* sysdeps/unix/sysv/linux/pwritev64.c: Likewise.
* sysdeps/posix/preadv_common.c: New file.
* sysdeps/posix/pwritev_common.c: Likewise.
[1] http://www.mail-archive.com/qemu-devel@nongnu.org/msg25282.html
[2] https://bugzilla.redhat.com/show_bug.cgi?id=563103#c8
This commit is contained in:
Adhemerval Zanella
parent
cdd45522b6
commit
c79a72aa5c
13
ChangeLog
13
ChangeLog
@ -1,3 +1,16 @@
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2017-05-15 Adhemerval Zanella <adhemerval.zanella@linaro.org>
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* sysdeps/posix/preadv.c: Use sysdeps/posix/preadv_common.c.
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* sysdeps/posix/preadv64.c: Likewise.
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* sysdeps/unix/sysv/linux/preadv.c: Likewise.
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* sysdeps/unix/sysv/linux/preadv64.c: Likewise.
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* sysdeps/posix/pwritev.c: Use sysdeps/posix/pwritev_common.c.
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* sysdeps/posix/pwritev64.c: Likewise.
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* sysdeps/unix/sysv/linux/pwritev.c: Likewise.
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* sysdeps/unix/sysv/linux/pwritev64.c: Likewise.
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* sysdeps/posix/preadv_common.c: New file.
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* sysdeps/posix/pwritev_common.c: Likewise.
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2017-05-14 Gabriel F. T. Gomes <gftg@linux.vnet.ibm.com>
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* sysdeps/generic/math-type-macros-float128.h
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@ -1,4 +1,5 @@
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/* Copyright (C) 2009-2017 Free Software Foundation, Inc.
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/* Read data into multiple buffers. Generic version.
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Copyright (C) 2009-2017 Free Software Foundation, Inc.
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This file is part of the GNU C Library.
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The GNU C Library is free software; you can redistribute it and/or
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@ -15,93 +16,15 @@
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License along with the GNU C Library; if not, see
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<http://www.gnu.org/licenses/>. */
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#include <errno.h>
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#include <stdlib.h>
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#include <unistd.h>
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#include <string.h>
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#include <limits.h>
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#include <stdbool.h>
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#include <sys/param.h>
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#if __WORDSIZE == 64 && !defined PREADV
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/* Hide the preadv64 declaration. */
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# define preadv64 __redirect_preadv64
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#endif
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#include <sys/uio.h>
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#include <bits/wordsize.h>
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#include <sys/types.h>
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#ifndef __OFF_T_MATCHES_OFF64_T
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#ifndef PREADV
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# define PREADV preadv
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# define PREAD __pread
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# define OFF_T off_t
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#endif
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static void
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ifree (char **ptrp)
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{
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free (*ptrp);
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}
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/* Read data from file descriptor FD at the given position OFFSET
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without change the file pointer, and put the result in the buffers
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described by VECTOR, which is a vector of COUNT 'struct iovec's.
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The buffers are filled in the order specified. Operates just like
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'pread' (see <unistd.h>) except that data are put in VECTOR instead
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of a contiguous buffer. */
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ssize_t
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PREADV (int fd, const struct iovec *vector, int count, OFF_T offset)
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{
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/* Find the total number of bytes to be read. */
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size_t bytes = 0;
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for (int i = 0; i < count; ++i)
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{
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/* Check for ssize_t overflow. */
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if (SSIZE_MAX - bytes < vector[i].iov_len)
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{
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__set_errno (EINVAL);
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return -1;
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}
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bytes += vector[i].iov_len;
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}
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/* Allocate a temporary buffer to hold the data. We should normally
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use alloca since it's faster and does not require synchronization
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with other threads. But we cannot if the amount of memory
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required is too large. */
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char *buffer;
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char *malloced_buffer __attribute__ ((__cleanup__ (ifree))) = NULL;
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if (__libc_use_alloca (bytes))
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buffer = (char *) __alloca (bytes);
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else
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{
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malloced_buffer = buffer = (char *) malloc (bytes);
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if (buffer == NULL)
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return -1;
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}
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/* Read the data. */
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ssize_t bytes_read = PREAD (fd, buffer, bytes, offset);
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if (bytes_read < 0)
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return -1;
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/* Copy the data from BUFFER into the memory specified by VECTOR. */
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bytes = bytes_read;
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for (int i = 0; i < count; ++i)
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{
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size_t copy = MIN (vector[i].iov_len, bytes);
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(void) memcpy ((void *) vector[i].iov_base, (void *) buffer, copy);
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buffer += copy;
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bytes -= copy;
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if (bytes == 0)
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break;
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}
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return bytes_read;
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}
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#if __WORDSIZE == 64 && defined preadv64
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# undef preadv64
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strong_alias (preadv, preadv64)
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# include <sysdeps/posix/preadv_common.c>
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libc_hidden_def (preadv)
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#endif
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@ -1,9 +1,28 @@
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#include <bits/wordsize.h>
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/* Read data into multiple buffers. Generic LFS version.
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Copyright (C) 2009-2017 Free Software Foundation, Inc.
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This file is part of the GNU C Library.
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#if __WORDSIZE == 32
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# define PREADV preadv64
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# define PREAD __pread64
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# define OFF_T off64_t
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The GNU C Library is free software; you can redistribute it and/or
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modify it under the terms of the GNU Lesser General Public
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License as published by the Free Software Foundation; either
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version 2.1 of the License, or (at your option) any later version.
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# include "preadv.c"
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The GNU C Library is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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Lesser General Public License for more details.
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You should have received a copy of the GNU Lesser General Public
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License along with the GNU C Library; if not, see
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<http://www.gnu.org/licenses/>. */
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#define PREADV preadv64
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#define PREAD __pread64
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#define OFF_T off64_t
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#include <sysdeps/posix/preadv_common.c>
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libc_hidden_def (preadv64)
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#ifdef __OFF_T_MATCHES_OFF64_T
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strong_alias (preadv64, preadv)
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libc_hidden_def (preadv)
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#endif
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83
sysdeps/posix/preadv_common.c
Normal file
83
sysdeps/posix/preadv_common.c
Normal file
@ -0,0 +1,83 @@
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/* Read data into multiple buffers. Base implementation for preadv
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and preadv64.
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Copyright (C) 2017 Free Software Foundation, Inc.
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This file is part of the GNU C Library.
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The GNU C Library is free software; you can redistribute it and/or
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modify it under the terms of the GNU Lesser General Public
|
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License as published by the Free Software Foundation; either
|
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version 2.1 of the License, or (at your option) any later version.
|
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|
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The GNU C Library is distributed in the hope that it will be useful,
|
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but WITHOUT ANY WARRANTY; without even the implied warranty of
|
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
|
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Lesser General Public License for more details.
|
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|
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You should have received a copy of the GNU Lesser General Public
|
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License along with the GNU C Library; if not, see
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<http://www.gnu.org/licenses/>. */
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#include <unistd.h>
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#include <sys/uio.h>
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#include <sys/param.h>
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#include <errno.h>
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#include <malloc.h>
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#include <ldsodefs.h>
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/* Read data from file descriptor FD at the given position OFFSET
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without change the file pointer, and put the result in the buffers
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described by VECTOR, which is a vector of COUNT 'struct iovec's.
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The buffers are filled in the order specified. Operates just like
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'pread' (see <unistd.h>) except that data are put in VECTOR instead
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of a contiguous buffer. */
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ssize_t
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PREADV (int fd, const struct iovec *vector, int count, OFF_T offset)
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{
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/* Find the total number of bytes to be read. */
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size_t bytes = 0;
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for (int i = 0; i < count; ++i)
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{
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/* Check for ssize_t overflow. */
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if (SSIZE_MAX - bytes < vector[i].iov_len)
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{
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__set_errno (EINVAL);
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return -1;
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}
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bytes += vector[i].iov_len;
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}
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/* Allocate a temporary buffer to hold the data. It could be done with a
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stack allocation, but due limitations on some system (Linux with
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O_DIRECT) it aligns the buffer to pagesize. A possible optimization
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would be querying if the syscall would impose any alignment constraint,
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but 1. it is system specific (not meant in generic implementation), and
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2. it would make the implementation more complex, and 3. it will require
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another syscall (fcntl). */
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void *buffer = NULL;
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if (__posix_memalign (&buffer, GLRO(dl_pagesize), bytes) != 0)
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return -1;
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ssize_t bytes_read = PREAD (fd, buffer, bytes, offset);
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if (bytes_read < 0)
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goto end;
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/* Copy the data from BUFFER into the memory specified by VECTOR. */
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bytes = bytes_read;
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void *buf = buffer;
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for (int i = 0; i < count; ++i)
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{
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size_t copy = MIN (vector[i].iov_len, bytes);
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memcpy (vector[i].iov_base, buf, copy);
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buf += copy;
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bytes -= copy;
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if (bytes == 0)
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break;
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}
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end:
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free (buffer);
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return bytes_read;
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}
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@ -1,4 +1,5 @@
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/* Copyright (C) 2009-2017 Free Software Foundation, Inc.
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/* Write data into multiple buffers. Generic version.
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Copyright (C) 2009-2017 Free Software Foundation, Inc.
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This file is part of the GNU C Library.
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The GNU C Library is free software; you can redistribute it and/or
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@ -15,81 +16,15 @@
|
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License along with the GNU C Library; if not, see
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<http://www.gnu.org/licenses/>. */
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#include <errno.h>
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#include <stdlib.h>
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#include <unistd.h>
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#include <string.h>
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#include <limits.h>
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#include <stdbool.h>
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#include <sys/param.h>
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#if __WORDSIZE == 64 && !defined PWRITEV
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/* Hide the pwritev64 declaration. */
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# define pwritev64 __redirect_pwritev64
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#endif
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#include <sys/uio.h>
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#include <bits/wordsize.h>
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#include <sys/types.h>
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#ifndef __OFF_T_MATCHES_OFF64_T
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#ifndef PWRITEV
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# define PWRITEV pwritev
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# define PWRITE __pwrite
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# define OFF_T off_t
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#endif
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static void
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ifree (char **ptrp)
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{
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free (*ptrp);
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}
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|
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|
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/* Write data pointed by the buffers described by IOVEC, which is a
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vector of COUNT 'struct iovec's, to file descriptor FD at the given
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position OFFSET without change the file pointer. The data is
|
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written in the order specified. Operates just like 'write' (see
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<unistd.h>) except that the data are taken from IOVEC instead of a
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contiguous buffer. */
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ssize_t
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PWRITEV (int fd, const struct iovec *vector, int count, OFF_T offset)
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{
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/* Find the total number of bytes to be read. */
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size_t bytes = 0;
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for (int i = 0; i < count; ++i)
|
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{
|
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/* Check for ssize_t overflow. */
|
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if (SSIZE_MAX - bytes < vector[i].iov_len)
|
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{
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__set_errno (EINVAL);
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return -1;
|
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}
|
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bytes += vector[i].iov_len;
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}
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|
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/* Allocate a temporary buffer to hold the data. We should normally
|
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use alloca since it's faster and does not require synchronization
|
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with other threads. But we cannot if the amount of memory
|
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required is too large. */
|
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char *buffer;
|
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char *malloced_buffer __attribute__ ((__cleanup__ (ifree))) = NULL;
|
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if (__libc_use_alloca (bytes))
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buffer = (char *) __alloca (bytes);
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else
|
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{
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malloced_buffer = buffer = (char *) malloc (bytes);
|
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if (buffer == NULL)
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return -1;
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}
|
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/* Copy the data from BUFFER into the memory specified by VECTOR. */
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char *ptr = buffer;
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for (int i = 0; i < count; ++i)
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ptr = __mempcpy ((void *) ptr, (void *) vector[i].iov_base,
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vector[i].iov_len);
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/* Write the data. */
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return PWRITE (fd, buffer, bytes, offset);
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}
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#if __WORDSIZE == 64 && defined pwritev64
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# undef pwritev64
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strong_alias (pwritev, pwritev64)
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# include <sysdeps/posix/pwritev_common.c>
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libc_hidden_def (pwritev)
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|
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#endif
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@ -1,9 +1,28 @@
|
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#include <bits/wordsize.h>
|
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/* Write data into multiple buffers. Generic LFS version.
|
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Copyright (C) 2009-2017 Free Software Foundation, Inc.
|
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This file is part of the GNU C Library.
|
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|
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#if __WORDSIZE == 32
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# define PWRITEV pwritev64
|
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# define PWRITE __pwrite64
|
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# define OFF_T off64_t
|
||||
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.
|
||||
|
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# include "pwritev.c"
|
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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
|
||||
<http://www.gnu.org/licenses/>. */
|
||||
|
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#define PWRITEV pwritev64
|
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#define PWRITE __pwrite64
|
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#define OFF_T off64_t
|
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#include <sysdeps/posix/pwritev_common.c>
|
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|
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libc_hidden_def (pwritev64)
|
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#ifdef __OFF_T_MATCHES_OFF64_T
|
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strong_alias (pwritev64, pwritev)
|
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libc_hidden_def (pwritev)
|
||||
#endif
|
||||
|
||||
72
sysdeps/posix/pwritev_common.c
Normal file
72
sysdeps/posix/pwritev_common.c
Normal file
@ -0,0 +1,72 @@
|
||||
/* Write data into multiple buffers. Base implementation for pwritev
|
||||
and pwritev64.
|
||||
Copyright (C) 2017 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
|
||||
<http://www.gnu.org/licenses/>. */
|
||||
|
||||
#include <unistd.h>
|
||||
#include <sys/uio.h>
|
||||
#include <sys/param.h>
|
||||
#include <errno.h>
|
||||
#include <malloc.h>
|
||||
|
||||
#include <ldsodefs.h>
|
||||
|
||||
/* Write data pointed by the buffers described by IOVEC, which is a
|
||||
vector of COUNT 'struct iovec's, to file descriptor FD at the given
|
||||
position OFFSET without change the file pointer. The data is
|
||||
written in the order specified. Operates just like 'write' (see
|
||||
<unistd.h>) except that the data are taken from IOVEC instead of a
|
||||
contiguous buffer. */
|
||||
ssize_t
|
||||
PWRITEV (int fd, const struct iovec *vector, int count, OFF_T offset)
|
||||
{
|
||||
/* Find the total number of bytes to be read. */
|
||||
size_t bytes = 0;
|
||||
for (int i = 0; i < count; ++i)
|
||||
{
|
||||
/* Check for ssize_t overflow. */
|
||||
if (SSIZE_MAX - bytes < vector[i].iov_len)
|
||||
{
|
||||
__set_errno (EINVAL);
|
||||
return -1;
|
||||
}
|
||||
bytes += vector[i].iov_len;
|
||||
}
|
||||
|
||||
/* Allocate a temporary buffer to hold the data. It could be done with a
|
||||
stack allocation, but due limitations on some system (Linux with
|
||||
O_DIRECT) it aligns the buffer to pagesize. A possible optimization
|
||||
would be querying if the syscall would impose any alignment constraint,
|
||||
but 1. it is system specific (not meant in generic implementation), and
|
||||
2. it would make the implementation more complex, and 3. it will require
|
||||
another syscall (fcntl). */
|
||||
void *buffer = NULL;
|
||||
if (__posix_memalign (&buffer, GLRO(dl_pagesize), bytes) != 0)
|
||||
return -1;
|
||||
|
||||
/* Copy the data from BUFFER into the memory specified by VECTOR. */
|
||||
char *ptr = buffer;
|
||||
for (int i = 0; i < count; ++i)
|
||||
ptr = __mempcpy ((void *) ptr, (void *) vector[i].iov_base,
|
||||
vector[i].iov_len);
|
||||
|
||||
ssize_t ret = PWRITE (fd, buffer, bytes, offset);
|
||||
|
||||
free (buffer);
|
||||
|
||||
return ret;
|
||||
}
|
||||
@ -48,6 +48,6 @@ preadv (int fd, const struct iovec *vector, int count, off_t offset)
|
||||
# define PREADV static internal_function __atomic_preadv_replacement
|
||||
# define PREAD __pread
|
||||
# define OFF_T off_t
|
||||
# include <sysdeps/posix/preadv.c>
|
||||
# include <sysdeps/posix/preadv_common.c>
|
||||
# endif /* __ASSUME_PREADV */
|
||||
#endif
|
||||
|
||||
@ -46,7 +46,7 @@ preadv64 (int fd, const struct iovec *vector, int count, off64_t offset)
|
||||
# define PREADV static internal_function __atomic_preadv64_replacement
|
||||
# define PREAD __pread64
|
||||
# define OFF_T off64_t
|
||||
# include <sysdeps/posix/preadv.c>
|
||||
# include <sysdeps/posix/preadv_common.c>
|
||||
#endif
|
||||
|
||||
#ifdef __OFF_T_MATCHES_OFF64_T
|
||||
|
||||
@ -48,6 +48,6 @@ pwritev (int fd, const struct iovec *vector, int count, off_t offset)
|
||||
# define PWRITEV static internal_function __atomic_pwritev_replacement
|
||||
# define PWRITE __pwrite
|
||||
# define OFF_T off_t
|
||||
# include <sysdeps/posix/pwritev.c>
|
||||
# include <sysdeps/posix/pwritev_common.c>
|
||||
# endif /* __ASSUME_PREADV */
|
||||
#endif
|
||||
|
||||
@ -46,7 +46,7 @@ pwritev64 (int fd, const struct iovec *vector, int count, off64_t offset)
|
||||
# define PWRITEV static internal_function __atomic_pwritev64_replacement
|
||||
# define PWRITE __pwrite64
|
||||
# define OFF_T off64_t
|
||||
# include <sysdeps/posix/pwritev.c>
|
||||
# include <sysdeps/posix/pwritev_common.c>
|
||||
#endif
|
||||
|
||||
#ifdef __OFF_T_MATCHES_OFF64_T
|
||||
|
||||
Loading…
Reference in New Issue
Block a user