diff options
| -rw-r--r-- | ChangeLog | 14 | ||||
| -rw-r--r-- | sysdeps/generic/dl-sysdep.c | 4 | ||||
| -rw-r--r-- | sysdeps/posix/readv.c | 42 |
3 files changed, 52 insertions, 8 deletions
@@ -1,3 +1,17 @@ +2002-01-31 Ulrich Drepper <drepper@redhat.com> + + * sysdeps/posix/readv.c: Don't use alloca if the memory requirements + are too high. + +2002-01-31 Andreas Schwab <schwab@suse.de> + + * sysdeps/posix/readv.c: Check for ssize_t overflow. + +2002-01-31 Andreas Schwab <schwab@suse.de> + + * sysdeps/generic/dl-sysdep.c (_dl_sysdep_start): Fix leftover + reference to _dl_pagesize. + 2002-01-30 Ulrich Drepper <drepper@redhat.com> * Versions.def [ld]: Add GLIBC_2.3. diff --git a/sysdeps/generic/dl-sysdep.c b/sysdeps/generic/dl-sysdep.c index 2954b33..f8b8ac1 100644 --- a/sysdeps/generic/dl-sysdep.c +++ b/sysdeps/generic/dl-sysdep.c @@ -168,8 +168,8 @@ _dl_sysdep_start (void **start_argptr, __libc_enable_secure = uid != euid || gid != egid; #ifndef HAVE_AUX_PAGESIZE - if (_dl_pagesize == 0) - _dl_pagesize = __getpagesize (); + if (GL(dl_pagesize) == 0) + GL(dl_pagesize) = __getpagesize (); #endif #ifdef DL_SYSDEP_INIT diff --git a/sysdeps/posix/readv.c b/sysdeps/posix/readv.c index 6349e24..89fe1af 100644 --- a/sysdeps/posix/readv.c +++ b/sysdeps/posix/readv.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 <stdlib.h> #include <unistd.h> #include <string.h> +#include <limits.h> +#include <stdbool.h> +#include <sys/param.h> #include <sys/uio.h> /* Read data from file descriptor FD, and put the result in the @@ -33,17 +36,41 @@ __readv (fd, vector, count) int count; { char *buffer; + char *buffer_start; size_t bytes; int bytes_read; int i; + bool use_malloc = false; /* Find the total number of bytes to be read. */ 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. 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 reading + the data in chunks. Probably not so we just fail here. */ + return -1; - /* Allocate a temporary buffer to hold the data. */ - buffer = (char *) __alloca (bytes); + use_malloc = true; + } /* Read the data. */ bytes_read = __read (fd, buffer, bytes); @@ -52,10 +79,10 @@ __readv (fd, vector, count) /* Copy the data from BUFFER into the memory specified by VECTOR. */ bytes = bytes_read; + buffer_start = buffer; for (i = 0; i < count; ++i) { -#define min(a, b) ((a) > (b) ? (b) : (a)) - size_t copy = min (vector[i].iov_len, bytes); + size_t copy = MIN (vector[i].iov_len, bytes); (void) memcpy ((void *) vector[i].iov_base, (void *) buffer, copy); @@ -65,6 +92,9 @@ __readv (fd, vector, count) break; } + if (use_malloc) + free (buffer_start); + return bytes_read; } #ifndef __readv |