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authorUlrich Drepper <drepper@redhat.com>2001-03-19 23:34:54 +0000
committerUlrich Drepper <drepper@redhat.com>2001-03-19 23:34:54 +0000
commitf2615995a753b80dd8d9fce55f5e87e8105f2d82 (patch)
tree3a5196fcebde20a334b70bd82fbbfb9a2269576c
parent96c0d65dc3644467a0521cc4084274be073fb5e0 (diff)
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Update.
* 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>
-rw-r--r--ChangeLog13
-rw-r--r--manual/math.texi3
-rw-r--r--sysdeps/posix/tempname.c17
-rw-r--r--sysdeps/unix/i386/i686/tempname.c35
4 files changed, 66 insertions, 2 deletions
diff --git a/ChangeLog b/ChangeLog
index 18e8725..99e55f7 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,18 @@
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.
2001-03-19 Martin Schwidefsky <schwidefsky@de.ibm.com>
diff --git a/manual/math.texi b/manual/math.texi
index a7d6c88..1ec5977 100644
--- a/manual/math.texi
+++ b/manual/math.texi
@@ -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
diff --git a/sysdeps/posix/tempname.c b/sysdeps/posix/tempname.c
index ae22f10..088da95 100644
--- a/sysdeps/posix/tempname.c
+++ b/sysdeps/posix/tempname.c
@@ -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 ();
diff --git a/sysdeps/unix/i386/i686/tempname.c b/sysdeps/unix/i386/i686/tempname.c
new file mode 100644
index 0000000..3d2476e
--- /dev/null
+++ b/sysdeps/unix/i386/i686/tempname.c
@@ -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>