From 9710f75d4a4d57fa86f20e011c6dc6e66c590080 Mon Sep 17 00:00:00 2001 From: Ulrich Drepper Date: Sun, 3 Feb 2002 19:39:52 +0000 Subject: Update. 2002-02-03 Andreas Schwab * sysdeps/posix/readv.c: Use ssize_t for bytes_read. * sysdeps/posix/writev.c: Use ssize_t for bytes_written. Fix comment. 2002-02-03 Thorsten Kukuk * sysdeps/posix/writev.c: Check for ssize_t overflow, don't use alloca if the memory reqirements are too high. 2002-02-03 Ulrich Drepper * elf/dl-load.c (decompose_rpath): Avoid using strstr. * elf/dl-minimal.c (_strerror_r): Use _itoa instead of _itoa_word since the former is available anyway and speed isn't important here. * elf/dl-misc.c (_dl_debug_vdprintf): Likewise. * elf/dl-version.c (match_symbol): Likewise. (_dl_check_map_versions): Likewise. * elf/rtld.c (process_envvars): Likewise. (print_statistics): Likewise. * sysdeps/generic/dl-sysdep.c (_dl_show_auxv): Likewise. * elf/dl-minimal.c (_itoa): Always define it. Make it work for all bases. Add assert to catch uses of unimplemented features. (__strsep): Add assert to catch uses of unimplemented features. * elf/dl-object.c (_dl_new_object): Don't use rawmemchr. Use strchr and avoid inline optimization. * elf/rtld.c (process_envvars): Likewise. * elf/dl-open.c: Don't include . * elf/dl-profile.c (_dl_start_profile): Help compiler to avoid ffs. * elf/rtld.c (dl_main): Avoid strsep inline optimization. * stdio-common/_itoa.h: Minor simplifications of the code. * stdio-common/_itoa.c: Likewise. * elf/dl-reloc.c (_dl_relocate_object): Use _dl_debug_printf instead of _dl_printf for debugging info output. * sysdeps/mips/atomicity.h (exchange_and_add): Use branch likely. --- sysdeps/posix/writev.c | 45 ++++++++++++++++++++++++++++++++++++++------- 1 file changed, 38 insertions(+), 7 deletions(-) (limited to 'sysdeps/posix/writev.c') diff --git a/sysdeps/posix/writev.c b/sysdeps/posix/writev.c index f92ff1c19d..dc2c806d66 100644 --- a/sysdeps/posix/writev.c +++ b/sysdeps/posix/writev.c @@ -1,4 +1,4 @@ -/* Copyright (C) 1991, 1992, 1996, 1997 Free Software Foundation, Inc. +/* Copyright (C) 1991, 1992, 1996, 1997, 2002 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 @@ -19,6 +19,9 @@ #include #include #include +#include +#include +#include #include /* Write data pointed by the buffers described by VECTOR, which @@ -35,23 +38,46 @@ __writev (fd, vector, count) char *buffer; register char *bp; size_t bytes, to_copy; + ssize_t bytes_written; int i; + bool use_malloc = false; /* Find the total number of bytes to be written. */ bytes = 0; for (i = 0; i < count; ++i) - bytes += vector[i].iov_len; + { + /* Check for ssize_t overflow. */ + if (SSIZE_MAX - bytes < vector[i].iov_len) + { + errno = EINVAL; + return -1; + } + bytes += vector[i].iov_len; + } - /* Allocate a temporary buffer to hold the data. */ - buffer = (char *) __alloca (bytes); + /* Allocate a temporary buffer to hold the data. We should normally + use alloca since it's faster and does not require synchronization + with other threads. But we cannot if the amount of memory + required is too large. Use 512k as the limit. */ + if (bytes < 512 * 1024) + buffer = (char *) __alloca (bytes); + else + { + buffer = (char *) malloc (bytes); + if (buffer == NULL) + /* XXX I don't know whether it is acceptable to try writing + the data in chunks. Probably not so we just fail here. */ + return -1; + + use_malloc = true; + } /* Copy the data into BUFFER. */ to_copy = bytes; bp = buffer; for (i = 0; i < count; ++i) { -#define min(a, b) ((a) > (b) ? (b) : (a)) - size_t copy = min (vector[i].iov_len, to_copy); + size_t copy = MIN (vector[i].iov_len, to_copy); bp = __mempcpy ((void *) bp, (void *) vector[i].iov_base, copy); @@ -60,7 +86,12 @@ __writev (fd, vector, count) break; } - return __write (fd, buffer, bytes); + bytes_written = __write (fd, buffer, bytes); + + if (use_malloc) + free (buffer); + + return bytes_written; } #ifndef __writev weak_alias (__writev, writev) -- cgit v1.2.3