* sysdeps/unix/i386/i686/tempname.c: New file.

	* sysdeps/posix/tempname.c (__gen_tempname): If RANDOM_BITS is
	defined use this macro to get some bits of randomness instead of
	the usual gettimeofday or time calls.

2001-03-16  Paul Eggert  <eggert@twinsun.com>

	* sysdeps/posix/tempname.c (uint64_t): Define to uintmax_t if
	not defined, and if UINT64_MAX is not defined.

2001-03-19  Ulrich Drepper  <drepper@redhat.com>
This commit is contained in:
Ulrich Drepper 2001-03-19 23:34:54 +00:00
parent 96c0d65dc3
commit f2615995a7
4 changed files with 66 additions and 2 deletions

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@ -1,3 +1,16 @@
2001-03-19 Ulrich Drepper <drepper@redhat.com>
* sysdeps/unix/i386/i686/tempname.c: New file.
* sysdeps/posix/tempname.c (__gen_tempname): If RANDOM_BITS is
defined use this macro to get some bits of randomness instead of
the usual gettimeofday or time calls.
2001-03-16 Paul Eggert <eggert@twinsun.com>
* sysdeps/posix/tempname.c (uint64_t): Define to uintmax_t if
not defined, and if UINT64_MAX is not defined.
2001-03-19 Ulrich Drepper <drepper@redhat.com>
* elf/cache.c: Mark and have translated a few more messages.

View File

@ -1445,6 +1445,9 @@ c = 0xb = 11
but they can also be changed by the user. @code{m} is of course 2^48
since the state consists of a 48-bit array.
The prototypes for these functions are in @file{stdlib.h}.
@pindex stdlib.h
@comment stdlib.h
@comment SVID

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@ -107,6 +107,15 @@
# define __secure_getenv getenv
#endif
/* Use the widest available unsigned type if uint64_t is not
available. The algorithm below extracts a number less than 62**6
(approximately 2**35.725) from uint64_t, so ancient hosts where
uintmax_t is only 32 bits lose about 3.725 bits of randomness,
which is better than not having mkstemp at all. */
#if !defined UINT64_MAX && !defined uint64_t
# define uint64_t uintmax_t
#endif
/* Return nonzero if DIR is an existent directory. */
static int
direxists (const char *dir)
@ -218,14 +227,18 @@ __gen_tempname (char *tmpl, int kind)
XXXXXX = &tmpl[len - 6];
/* Get some more or less random data. */
#if HAVE_GETTIMEOFDAY || _LIBC
#ifdef RANDOM_BITS
RANDOM_BITS (random_time_bits);
#else
# if HAVE_GETTIMEOFDAY || _LIBC
{
struct timeval tv;
__gettimeofday (&tv, NULL);
random_time_bits = ((uint64_t) tv.tv_usec << 16) ^ tv.tv_sec;
}
#else
# else
random_time_bits = time (NULL);
# endif
#endif
value += random_time_bits ^ __getpid ();

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@ -0,0 +1,35 @@
/* Copyright (C) 2001 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 Library General Public License as
published by the Free Software Foundation; either version 2 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
Library General Public License for more details.
You should have received a copy of the GNU Library General Public
License along with the GNU C Library; see the file COPYING.LIB. If not,
write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
Boston, MA 02111-1307, USA. */
/* For i686 and up we have a better and faster source of random bits in the
form of the time stamp counter. */
#define RANDOM_BITS(Var) \
if (__builtin_expect (value == UINT64_C (0), 0)) \
{ \
/* If this is the first time this function is used initialize \
the variable we accumulate the value in to some somewhat \
random value. If we'd not do this programs at startup time \
might have a reduced set of possible names, at least on slow \
machines. */ \
struct timeval tv; \
__gettimeofday (&tv, NULL); \
value = ((uint64_t) tv.tv_usec << 16) ^ tv.tv_sec; \
} \
__asm__ __volatile__ ("rdtsc" : "=A" (Var))
#include_next <tempname.c>