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Fix some minor races in hosts lacking mkostemp.

Browse Source 
Gnulib's emulation of mkostemp doesn't have races that Emacs's does.
* configure.ac (mkostemp): Remove check for this function;
gnulib does the check now.
(mkstemp): Remove check for this no-longer-used function.
* lib/mkostemp.c, lib/secure_getenv.c, lib/tempname.c, lib/tempname.h:
* m4/mkostemp.m4, m4/secure_getenv.m4, m4/tempname.m4:
New files, copied from Gnulib.
* lib/gnulib.mk, m4/gnulib-comp.m4: Regenerate.
* admin/merge-gnulib (GNULIB_MODULES): Add mkostemp.
* lib-src/movemail.c (main):
* lib-src/update-game-score.c (write_scores):
Use mkostemp (which now works on all platforms, due to changes
in the portability layer) rather than mktemp (which has a race)
or mkstemp (which we no longer bother with).
* src/callproc.c (create_temp_file):
* src/filelock.c (create_lock_file):
Assume mkostemp, since it's now provided by Gnulib.

Fixes: debbugs:15015
This commit is contained in:
Paul Eggert 2013-08-04 09:56:56 -07:00
parent 484ab23924
commit e0fdb69430
19 changed files with 632 additions and 52 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

12
ChangeLog
View File

@ -1,3 +1,15 @@
2013-08-04 Paul Eggert <eggert@cs.ucla.edu>
Fix some minor races in hosts lacking mkostemp (Bug#15015).
Gnulib's emulation of mkostemp doesn't have races that Emacs's does.
* configure.ac (mkostemp): Remove check for this function;
gnulib does the check now.
(mkstemp): Remove check for this no-longer-used function.
* lib/mkostemp.c, lib/secure_getenv.c, lib/tempname.c, lib/tempname.h:
* m4/mkostemp.m4, m4/secure_getenv.m4, m4/tempname.m4:
New files, copied from Gnulib.
* lib/gnulib.mk, m4/gnulib-comp.m4: Regenerate.
2013-07-29 Michael Albinus <michael.albinus@gmx.de>
* INSTALL (DETAILED BUILDING AND INSTALLATION): Add

5
admin/ChangeLog
View File

@ -1,3 +1,8 @@
2013-08-04 Paul Eggert <eggert@cs.ucla.edu>
Fix some minor races in hosts lacking mkostemp (Bug#15015).
* merge-gnulib (GNULIB_MODULES): Add mkostemp.
2013-07-12 Glenn Morris <rgm@gnu.org>
* admin.el (manual-style-string): Use non-abbreviated url.

2
admin/merge-gnulib
View File

@ -32,7 +32,7 @@ GNULIB_MODULES='
fcntl fcntl-h fdatasync fdopendir filemode fstatat fsync
getloadavg getopt-gnu gettime gettimeofday
intprops largefile lstat
manywarnings memrchr mktime
manywarnings memrchr mkostemp mktime
pipe2 pselect pthread_sigmask putenv qacl readlink readlinkat
sig2str socklen stat-time stdalign stdarg stdbool stdio
strftime strtoimax strtoumax symlink sys_stat

2
configure.ac
View File

@ -3277,7 +3277,7 @@ select getpagesize setlocale \
getrlimit setrlimit shutdown getaddrinfo \
strsignal setitimer \
sendto recvfrom getsockname getpeername getifaddrs freeifaddrs \
gai_strerror mkostemp mkstemp getline getdelim sync \
gai_strerror getline getdelim sync \
difftime posix_memalign \
getpwent endpwent getgrent endgrent \
touchlock \

9
lib-src/ChangeLog
View File

@ -1,3 +1,12 @@
2013-08-04 Paul Eggert <eggert@cs.ucla.edu>
Fix some minor races in hosts lacking mkostemp (Bug#15015).
* movemail.c (main):
* update-game-score.c (write_scores):
Use mkostemp (which now works on all platforms, due to changes
in the portability layer) rather than mktemp (which has a race)
or mkstemp (which we no longer bother with).
2013-07-10 Paul Eggert <eggert@cs.ucla.edu>
Port to C89.

17
lib-src/movemail.c
View File

@ -304,24 +304,13 @@ main (int argc, char **argv)
memcpy (tempname, inname, inname_dirlen);
strcpy (tempname + inname_dirlen, "EXXXXXX");
#ifdef HAVE_MKSTEMP
desc = mkstemp (tempname);
#else
mktemp (tempname);
if (!*tempname)
desc = -1;
else
{
unlink (tempname);
desc = open (tempname, O_WRONLY | O_CREAT | O_EXCL, 0600);
}
#endif
desc = mkostemp (tempname, 0);
if (desc < 0)
{
int mkstemp_errno = errno;
int mkostemp_errno = errno;
error ("error while creating what would become the lock file",
0, 0);
errno = mkstemp_errno;
errno = mkostemp_errno;
pfatal_with_name (tempname);
}
close (desc);

12
lib-src/update-game-score.c
View File

@ -383,6 +383,7 @@ sort_scores (struct score_entry *scores, int count, int reverse)
static int
write_scores (const char *filename, const struct score_entry *scores, int count)
{
int fd;
FILE *f;
int i;
char *tempfile = malloc (strlen (filename) + strlen (".tempXXXXXX") + 1);
@ -390,12 +391,11 @@ write_scores (const char *filename, const struct score_entry *scores, int count)
return -1;
strcpy (tempfile, filename);
strcat (tempfile, ".tempXXXXXX");
#ifdef HAVE_MKSTEMP
if (mkstemp (tempfile) < 0
#else
if (mktemp (tempfile) != tempfile
#endif
|| !(f = fopen (tempfile, "w")))
fd = mkostemp (tempfile, 0);
if (fd < 0)
return -1;
f = fdopen (fd, "w");
if (! f)
return -1;
for (i = 0; i < count; i++)
if (fprintf (f, "%ld %s %s\n", scores[i].score, scores[i].username,

32
lib/gnulib.mk
View File

@ -21,7 +21,7 @@
# the same distribution terms as the rest of that program.
#
# Generated by gnulib-tool.
# Reproduce by: gnulib-tool --import --dir=. --lib=libgnu --source-base=lib --m4-base=m4 --doc-base=doc --tests-base=tests --aux-dir=build-aux --avoid=close --avoid=dup --avoid=fchdir --avoid=fstat --avoid=malloc-posix --avoid=msvc-inval --avoid=msvc-nothrow --avoid=open --avoid=openat-die --avoid=opendir --avoid=raise --avoid=save-cwd --avoid=select --avoid=sigprocmask --avoid=sys_types --avoid=threadlib --makefile-name=gnulib.mk --conditional-dependencies --no-libtool --macro-prefix=gl --no-vc-files alloca-opt c-ctype c-strcase careadlinkat close-stream crypto/md5 crypto/sha1 crypto/sha256 crypto/sha512 dtoastr dtotimespec dup2 environ execinfo faccessat fcntl fcntl-h fdatasync fdopendir filemode fstatat fsync getloadavg getopt-gnu gettime gettimeofday intprops largefile lstat manywarnings memrchr mktime pipe2 pselect pthread_sigmask putenv qacl readlink readlinkat sig2str socklen stat-time stdalign stdarg stdbool stdio strftime strtoimax strtoumax symlink sys_stat sys_time time timer-time timespec-add timespec-sub unsetenv utimens warnings
# Reproduce by: gnulib-tool --import --dir=. --lib=libgnu --source-base=lib --m4-base=m4 --doc-base=doc --tests-base=tests --aux-dir=build-aux --avoid=close --avoid=dup --avoid=fchdir --avoid=fstat --avoid=malloc-posix --avoid=msvc-inval --avoid=msvc-nothrow --avoid=open --avoid=openat-die --avoid=opendir --avoid=raise --avoid=save-cwd --avoid=select --avoid=sigprocmask --avoid=sys_types --avoid=threadlib --makefile-name=gnulib.mk --conditional-dependencies --no-libtool --macro-prefix=gl --no-vc-files alloca-opt c-ctype c-strcase careadlinkat close-stream crypto/md5 crypto/sha1 crypto/sha256 crypto/sha512 dtoastr dtotimespec dup2 environ execinfo faccessat fcntl fcntl-h fdatasync fdopendir filemode fstatat fsync getloadavg getopt-gnu gettime gettimeofday intprops largefile lstat manywarnings memrchr mkostemp mktime pipe2 pselect pthread_sigmask putenv qacl readlink readlinkat sig2str socklen stat-time stdalign stdarg stdbool stdio strftime strtoimax strtoumax symlink sys_stat sys_time time timer-time timespec-add timespec-sub unsetenv utimens warnings
MOSTLYCLEANFILES += core *.stackdump
@ -560,6 +560,15 @@ EXTRA_libgnu_a_SOURCES += memrchr.c
## end gnulib module memrchr
## begin gnulib module mkostemp
EXTRA_DIST += mkostemp.c
EXTRA_libgnu_a_SOURCES += mkostemp.c
## end gnulib module mkostemp
## begin gnulib module mktime
@ -657,6 +666,17 @@ EXTRA_DIST += root-uid.h
## end gnulib module root-uid
## begin gnulib module secure_getenv
if gl_GNULIB_ENABLED_secure_getenv
endif
EXTRA_DIST += secure_getenv.c
EXTRA_libgnu_a_SOURCES += secure_getenv.c
## end gnulib module secure_getenv
## begin gnulib module sig2str
@ -1480,6 +1500,16 @@ EXTRA_DIST += sys_time.in.h
## end gnulib module sys_time
## begin gnulib module tempname
if gl_GNULIB_ENABLED_tempname
libgnu_a_SOURCES += tempname.c
endif
EXTRA_DIST += tempname.h
## end gnulib module tempname
## begin gnulib module time
BUILT_SOURCES += time.h

46
lib/mkostemp.c Normal file
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@ -0,0 +1,46 @@
/* Copyright (C) 1998-1999, 2001, 2005-2007, 2009-2013 Free Software
Foundation, Inc.
This file is derived from the one in the GNU C Library.
This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 3 of the License, or
(at your option) any later version.
This program 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 General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program. If not, see <http://www.gnu.org/licenses/>. */
#if !_LIBC
# include <config.h>
#endif
#include <stdlib.h>
#if !_LIBC
# include "tempname.h"
# define __gen_tempname gen_tempname
# ifndef __GTFILE
# define __GT_FILE GT_FILE
# endif
#endif
#include <stdio.h>
#ifndef __GT_FILE
# define __GT_FILE 0
#endif
/* Generate a unique temporary file name from XTEMPLATE.
The last six characters of XTEMPLATE must be "XXXXXX";
they are replaced with a string that makes the file name unique.
Then open the file and return a fd. */
int
mkostemp (char *xtemplate, int flags)
{
return __gen_tempname (xtemplate, 0, flags, __GT_FILE);
}

41
lib/secure_getenv.c Normal file
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@ -0,0 +1,41 @@
/* Look up an environment variable more securely.
Copyright 2013 Free Software Foundation, Inc.
This program is free software: you can redistribute it and/or modify it
under the terms of the GNU General Public License as published
by the Free Software Foundation; either version 3 of the License, or
(at your option) any later version.
This program 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
General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program. If not, see <http://www.gnu.org/licenses/>. */
#include <config.h>
#include <stdlib.h>
#if !HAVE___SECURE_GETENV
# if HAVE_ISSETUGID
# include <unistd.h>
# else
# undef issetugid
# define issetugid() 1
# endif
#endif
char *
secure_getenv (char const *name)
{
#if HAVE___SECURE_GETENV
return __secure_getenv (name);
#else
if (issetugid ())
return 0;
return getenv (name);
#endif
}

306
lib/tempname.c Normal file
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@ -0,0 +1,306 @@
/* tempname.c - generate the name of a temporary file.
Copyright (C) 1991-2003, 2005-2007, 2009-2013 Free Software Foundation, Inc.
This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 3 of the License, or
(at your option) any later version.
This program 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 General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program. If not, see <http://www.gnu.org/licenses/>. */
/* Extracted from glibc sysdeps/posix/tempname.c. See also tmpdir.c. */
#if !_LIBC
# include <config.h>
# include "tempname.h"
#endif
#include <sys/types.h>
#include <assert.h>
#include <errno.h>
#ifndef __set_errno
# define __set_errno(Val) errno = (Val)
#endif
#include <stdio.h>
#ifndef P_tmpdir
# define P_tmpdir "/tmp"
#endif
#ifndef TMP_MAX
# define TMP_MAX 238328
#endif
#ifndef __GT_FILE
# define __GT_FILE 0
# define __GT_DIR 1
# define __GT_NOCREATE 2
#endif
#if !_LIBC && (GT_FILE != __GT_FILE || GT_DIR != __GT_DIR \
|| GT_NOCREATE != __GT_NOCREATE)
# error report this to bug-gnulib@gnu.org
#endif
#include <stddef.h>
#include <stdlib.h>
#include <string.h>
#include <fcntl.h>
#include <sys/time.h>
#include <stdint.h>
#include <unistd.h>
#include <sys/stat.h>
#if _LIBC
# define struct_stat64 struct stat64
#else
# define struct_stat64 struct stat
# define __gen_tempname gen_tempname
# define __getpid getpid
# define __gettimeofday gettimeofday
# define __mkdir mkdir
# define __open open
# define __lxstat64(version, file, buf) lstat (file, buf)
# define __secure_getenv secure_getenv
#endif
#ifdef _LIBC
# include <hp-timing.h>
# if HP_TIMING_AVAIL
# 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; \
} \
HP_TIMING_NOW (Var)
# endif
#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
#if _LIBC
/* Return nonzero if DIR is an existent directory. */
static int
direxists (const char *dir)
{
struct_stat64 buf;
return __xstat64 (_STAT_VER, dir, &buf) == 0 && S_ISDIR (buf.st_mode);
}
/* Path search algorithm, for tmpnam, tmpfile, etc. If DIR is
non-null and exists, uses it; otherwise uses the first of $TMPDIR,
P_tmpdir, /tmp that exists. Copies into TMPL a template suitable
for use with mk[s]temp. Will fail (-1) if DIR is non-null and
doesn't exist, none of the searched dirs exists, or there's not
enough space in TMPL. */
int
__path_search (char *tmpl, size_t tmpl_len, const char *dir, const char *pfx,
int try_tmpdir)
{
const char *d;
size_t dlen, plen;
if (!pfx || !pfx[0])
{
pfx = "file";
plen = 4;
}
else
{
plen = strlen (pfx);
if (plen > 5)
plen = 5;
}
if (try_tmpdir)
{
d = __secure_getenv ("TMPDIR");
if (d != NULL && direxists (d))
dir = d;
else if (dir != NULL && direxists (dir))
/* nothing */ ;
else
dir = NULL;
}
if (dir == NULL)
{
if (direxists (P_tmpdir))
dir = P_tmpdir;
else if (strcmp (P_tmpdir, "/tmp") != 0 && direxists ("/tmp"))
dir = "/tmp";
else
{
__set_errno (ENOENT);
return -1;
}
}
dlen = strlen (dir);
while (dlen > 1 && dir[dlen - 1] == '/')
dlen--; /* remove trailing slashes */
/* check we have room for "${dir}/${pfx}XXXXXX\0" */
if (tmpl_len < dlen + 1 + plen + 6 + 1)
{
__set_errno (EINVAL);
return -1;
}
sprintf (tmpl, "%.*s/%.*sXXXXXX", (int) dlen, dir, (int) plen, pfx);
return 0;
}
#endif /* _LIBC */
/* These are the characters used in temporary file names. */
static const char letters[] =
"abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789";
/* Generate a temporary file name based on TMPL. TMPL must match the
rules for mk[s]temp (i.e. end in "XXXXXX", possibly with a suffix).
The name constructed does not exist at the time of the call to
__gen_tempname. TMPL is overwritten with the result.
KIND may be one of:
__GT_NOCREATE: simply verify that the name does not exist
at the time of the call.
__GT_FILE: create the file using open(O_CREAT|O_EXCL)
and return a read-write fd. The file is mode 0600.
__GT_DIR: create a directory, which will be mode 0700.
We use a clever algorithm to get hard-to-predict names. */
int
__gen_tempname (char *tmpl, int suffixlen, int flags, int kind)
{
int len;
char *XXXXXX;
static uint64_t value;
uint64_t random_time_bits;
unsigned int count;
int fd = -1;
int save_errno = errno;
struct_stat64 st;
/* A lower bound on the number of temporary files to attempt to
generate. The maximum total number of temporary file names that
can exist for a given template is 62**6. It should never be
necessary to try all of these combinations. Instead if a reasonable
number of names is tried (we define reasonable as 62**3) fail to
give the system administrator the chance to remove the problems. */
#define ATTEMPTS_MIN (62 * 62 * 62)
/* The number of times to attempt to generate a temporary file. To
conform to POSIX, this must be no smaller than TMP_MAX. */
#if ATTEMPTS_MIN < TMP_MAX
unsigned int attempts = TMP_MAX;
#else
unsigned int attempts = ATTEMPTS_MIN;
#endif
len = strlen (tmpl);
if (len < 6 + suffixlen || memcmp (&tmpl[len - 6 - suffixlen], "XXXXXX", 6))
{
__set_errno (EINVAL);
return -1;
}
/* This is where the Xs start. */
XXXXXX = &tmpl[len - 6 - suffixlen];
/* Get some more or less random data. */
#ifdef RANDOM_BITS
RANDOM_BITS (random_time_bits);
#else
{
struct timeval tv;
__gettimeofday (&tv, NULL);
random_time_bits = ((uint64_t) tv.tv_usec << 16) ^ tv.tv_sec;
}
#endif
value += random_time_bits ^ __getpid ();
for (count = 0; count < attempts; value += 7777, ++count)
{
uint64_t v = value;
/* Fill in the random bits. */
XXXXXX[0] = letters[v % 62];
v /= 62;
XXXXXX[1] = letters[v % 62];
v /= 62;
XXXXXX[2] = letters[v % 62];
v /= 62;
XXXXXX[3] = letters[v % 62];
v /= 62;
XXXXXX[4] = letters[v % 62];
v /= 62;
XXXXXX[5] = letters[v % 62];
switch (kind)
{
case __GT_FILE:
fd = __open (tmpl,
(flags & ~O_ACCMODE)
| O_RDWR | O_CREAT | O_EXCL, S_IRUSR | S_IWUSR);
break;
case __GT_DIR:
fd = __mkdir (tmpl, S_IRUSR | S_IWUSR | S_IXUSR);
break;
case __GT_NOCREATE:
/* This case is backward from the other three. __gen_tempname
succeeds if __xstat fails because the name does not exist.
Note the continue to bypass the common logic at the bottom
of the loop. */
if (__lxstat64 (_STAT_VER, tmpl, &st) < 0)
{
if (errno == ENOENT)
{
__set_errno (save_errno);
return 0;
}
else
/* Give up now. */
return -1;
}
continue;
default:
assert (! "invalid KIND in __gen_tempname");
abort ();
}
if (fd >= 0)
{
__set_errno (save_errno);
return fd;
}
else if (errno != EEXIST)
return -1;
}
/* We got out of the loop because we ran out of combinations to try. */
__set_errno (EEXIST);
return -1;
}

50
lib/tempname.h Normal file
View File

@ -0,0 +1,50 @@
/* Create a temporary file or directory.
Copyright (C) 2006, 2009-2013 Free Software Foundation, Inc.
This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 3 of the License, or
(at your option) any later version.
This program 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 General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program. If not, see <http://www.gnu.org/licenses/>. */
/* header written by Eric Blake */
#ifndef GL_TEMPNAME_H
# define GL_TEMPNAME_H
# include <stdio.h>
# ifdef __GT_FILE
# define GT_FILE __GT_FILE
# define GT_DIR __GT_DIR
# define GT_NOCREATE __GT_NOCREATE
# else
# define GT_FILE 0
# define GT_DIR 1
# define GT_NOCREATE 2
# endif
/* Generate a temporary file name based on TMPL. TMPL must match the
rules for mk[s]temp (i.e. end in "XXXXXX", possibly with a suffix).
The name constructed does not exist at the time of the call to
gen_tempname. TMPL is overwritten with the result.
KIND may be one of:
GT_NOCREATE: simply verify that the name does not exist
at the time of the call.
GT_FILE: create a large file using open(O_CREAT|O_EXCL)
and return a read-write fd. The file is mode 0600.
GT_DIR: create a directory, which will be mode 0700.
We use a clever algorithm to get hard-to-predict names. */
extern int gen_tempname (char *tmpl, int suffixlen, int flags, int kind);
#endif /* GL_TEMPNAME_H */

44
m4/gnulib-comp.m4
View File

@ -89,6 +89,7 @@ AC_DEFUN([gl_EARLY],
# Code from module lstat:
# Code from module manywarnings:
# Code from module memrchr:
# Code from module mkostemp:
# Code from module mktime:
# Code from module multiarch:
# Code from module nocrash:
@ -102,6 +103,7 @@ AC_DEFUN([gl_EARLY],
# Code from module readlink:
# Code from module readlinkat:
# Code from module root-uid:
# Code from module secure_getenv:
# Code from module sig2str:
# Code from module signal-h:
# Code from module snippet/_Noreturn:
@ -134,6 +136,7 @@ AC_DEFUN([gl_EARLY],
# Code from module sys_select:
# Code from module sys_stat:
# Code from module sys_time:
# Code from module tempname:
# Code from module time:
# Code from module time_r:
# Code from module timer-time:
@ -274,6 +277,13 @@ AC_DEFUN([gl_INIT],
gl_PREREQ_MEMRCHR
fi
gl_STRING_MODULE_INDICATOR([memrchr])
gl_FUNC_MKOSTEMP
if test $HAVE_MKOSTEMP = 0; then
AC_LIBOBJ([mkostemp])
gl_PREREQ_MKOSTEMP
fi
gl_MODULE_INDICATOR([mkostemp])
gl_STDLIB_MODULE_INDICATOR([mkostemp])
gl_FUNC_MKTIME
if test $REPLACE_MKTIME = 1; then
AC_LIBOBJ([mktime])
@ -381,9 +391,11 @@ AC_DEFUN([gl_INIT],
gl_gnulib_enabled_03e0aaad4cb89ca757653bd367a6ccb7=false
gl_gnulib_enabled_pathmax=false
gl_gnulib_enabled_6099e9737f757db36c47fa9d9f02e88c=false
gl_gnulib_enabled_secure_getenv=false
gl_gnulib_enabled_stat=false
gl_gnulib_enabled_strtoll=false
gl_gnulib_enabled_strtoull=false
gl_gnulib_enabled_tempname=false
gl_gnulib_enabled_682e609604ccaac6be382e4ee3a4eaec=false
func_gl_gnulib_m4code_260941c0e5dc67ec9e87d1fb321c300b ()
{
@ -485,6 +497,18 @@ AC_DEFUN([gl_INIT],
gl_gnulib_enabled_6099e9737f757db36c47fa9d9f02e88c=true
fi
}
func_gl_gnulib_m4code_secure_getenv ()
{
if ! $gl_gnulib_enabled_secure_getenv; then
gl_FUNC_SECURE_GETENV
if test $HAVE_SECURE_GETENV = 0; then
AC_LIBOBJ([secure_getenv])
gl_PREREQ_SECURE_GETENV
fi
gl_STDLIB_MODULE_INDICATOR([secure_getenv])
gl_gnulib_enabled_secure_getenv=true
fi
}
func_gl_gnulib_m4code_stat ()
{
if ! $gl_gnulib_enabled_stat; then
@ -527,6 +551,14 @@ AC_DEFUN([gl_INIT],
gl_gnulib_enabled_strtoull=true
fi
}
func_gl_gnulib_m4code_tempname ()
{
if ! $gl_gnulib_enabled_tempname; then
gl_FUNC_GEN_TEMPNAME
gl_gnulib_enabled_tempname=true
func_gl_gnulib_m4code_secure_getenv
fi
}
func_gl_gnulib_m4code_682e609604ccaac6be382e4ee3a4eaec ()
{
if ! $gl_gnulib_enabled_682e609604ccaac6be382e4ee3a4eaec; then
@ -569,6 +601,9 @@ AC_DEFUN([gl_INIT],
if test $REPLACE_LSTAT = 1; then
func_gl_gnulib_m4code_stat
fi
if test $HAVE_MKOSTEMP = 0; then
func_gl_gnulib_m4code_tempname
fi
if test $HAVE_READLINK = 0 || test $REPLACE_READLINK = 1; then
func_gl_gnulib_m4code_stat
fi
@ -598,9 +633,11 @@ AC_DEFUN([gl_INIT],
AM_CONDITIONAL([gl_GNULIB_ENABLED_03e0aaad4cb89ca757653bd367a6ccb7], [$gl_gnulib_enabled_03e0aaad4cb89ca757653bd367a6ccb7])
AM_CONDITIONAL([gl_GNULIB_ENABLED_pathmax], [$gl_gnulib_enabled_pathmax])
AM_CONDITIONAL([gl_GNULIB_ENABLED_6099e9737f757db36c47fa9d9f02e88c], [$gl_gnulib_enabled_6099e9737f757db36c47fa9d9f02e88c])
AM_CONDITIONAL([gl_GNULIB_ENABLED_secure_getenv], [$gl_gnulib_enabled_secure_getenv])
AM_CONDITIONAL([gl_GNULIB_ENABLED_stat], [$gl_gnulib_enabled_stat])
AM_CONDITIONAL([gl_GNULIB_ENABLED_strtoll], [$gl_gnulib_enabled_strtoll])
AM_CONDITIONAL([gl_GNULIB_ENABLED_strtoull], [$gl_gnulib_enabled_strtoull])
AM_CONDITIONAL([gl_GNULIB_ENABLED_tempname], [$gl_gnulib_enabled_tempname])
AM_CONDITIONAL([gl_GNULIB_ENABLED_682e609604ccaac6be382e4ee3a4eaec], [$gl_gnulib_enabled_682e609604ccaac6be382e4ee3a4eaec])
# End of code from modules
m4_ifval(gl_LIBSOURCES_LIST, [
@ -806,6 +843,7 @@ AC_DEFUN([gl_FILE_LIST], [
lib/md5.c
lib/md5.h
lib/memrchr.c
lib/mkostemp.c
lib/mktime-internal.h
lib/mktime.c
lib/openat-priv.h
@ -821,6 +859,7 @@ AC_DEFUN([gl_FILE_LIST], [
lib/readlink.c
lib/readlinkat.c
lib/root-uid.h
lib/secure_getenv.c
lib/sha1.c
lib/sha1.h
lib/sha256.c
@ -853,6 +892,8 @@ AC_DEFUN([gl_FILE_LIST], [
lib/sys_select.in.h
lib/sys_stat.in.h
lib/sys_time.in.h
lib/tempname.c
lib/tempname.h
lib/time.in.h
lib/time_r.c
lib/timespec-add.c
@ -908,6 +949,7 @@ AC_DEFUN([gl_FILE_LIST], [
m4/manywarnings.m4
m4/md5.m4
m4/memrchr.m4
m4/mkostemp.m4
m4/mktime.m4
m4/multiarch.m4
m4/nocrash.m4
@ -919,6 +961,7 @@ AC_DEFUN([gl_FILE_LIST], [
m4/putenv.m4
m4/readlink.m4
m4/readlinkat.m4
m4/secure_getenv.m4
m4/setenv.m4
m4/sha1.m4
m4/sha256.m4
@ -948,6 +991,7 @@ AC_DEFUN([gl_FILE_LIST], [
m4/sys_socket_h.m4
m4/sys_stat_h.m4
m4/sys_time_h.m4
m4/tempname.m4
m4/time_h.m4
m4/time_r.m4
m4/timer_time.m4

23
m4/mkostemp.m4 Normal file
View File

@ -0,0 +1,23 @@
# mkostemp.m4 serial 2
dnl Copyright (C) 2009-2013 Free Software Foundation, Inc.
dnl This file is free software; the Free Software Foundation
dnl gives unlimited permission to copy and/or distribute it,
dnl with or without modifications, as long as this notice is preserved.
AC_DEFUN([gl_FUNC_MKOSTEMP],
[
AC_REQUIRE([gl_STDLIB_H_DEFAULTS])
dnl Persuade glibc <stdlib.h> to declare mkostemp().
AC_REQUIRE([AC_USE_SYSTEM_EXTENSIONS])
AC_CHECK_FUNCS_ONCE([mkostemp])
if test $ac_cv_func_mkostemp != yes; then
HAVE_MKOSTEMP=0
fi
])
# Prerequisites of lib/mkostemp.c.
AC_DEFUN([gl_PREREQ_MKOSTEMP],
[
])

25
m4/secure_getenv.m4 Normal file
View File

@ -0,0 +1,25 @@
# Look up an environment variable more securely.
dnl Copyright 2013 Free Software Foundation, Inc.
dnl This file is free software; the Free Software Foundation
dnl gives unlimited permission to copy and/or distribute it,
dnl with or without modifications, as long as this notice is preserved.
AC_DEFUN([gl_FUNC_SECURE_GETENV],
[
dnl Persuade glibc <stdlib.h> to declare secure_getenv().
AC_REQUIRE([AC_USE_SYSTEM_EXTENSIONS])
AC_REQUIRE([gl_STDLIB_H_DEFAULTS])
AC_CHECK_FUNCS_ONCE([secure_getenv])
if test $ac_cv_func_secure_getenv = no; then
HAVE_SECURE_GETENV=0
fi
])
# Prerequisites of lib/secure_getenv.c.
AC_DEFUN([gl_PREREQ_SECURE_GETENV], [
AC_CHECK_FUNCS([__secure_getenv])
if test $ac_cv_func___secure_getenv = no; then
AC_CHECK_FUNCS([issetugid])
fi
])

19
m4/tempname.m4 Normal file
View File

@ -0,0 +1,19 @@
#serial 5
# Copyright (C) 2006-2007, 2009-2013 Free Software Foundation, Inc.
# This file is free software; the Free Software Foundation
# gives unlimited permission to copy and/or distribute it,
# with or without modifications, as long as this notice is preserved.
# glibc provides __gen_tempname as a wrapper for mk[ds]temp. Expose
# it as a public API, and provide it on systems that are lacking.
AC_DEFUN([gl_FUNC_GEN_TEMPNAME],
[
gl_PREREQ_TEMPNAME
])
# Prerequisites of lib/tempname.c.
AC_DEFUN([gl_PREREQ_TEMPNAME],
[
:
])

7
src/ChangeLog
View File

@ -1,3 +1,10 @@
2013-08-04 Paul Eggert <eggert@cs.ucla.edu>
Fix some minor races in hosts lacking mkostemp (Bug#15015).
* callproc.c (create_temp_file):
* filelock.c (create_lock_file):
Assume mkostemp, since it's now provided by Gnulib.
2013-08-04 Eli Zaretskii <eliz@gnu.org>
* w32.c (mkostemp): New function.

14
src/callproc.c
View File

@ -1009,23 +1009,11 @@ create_temp_file (ptrdiff_t nargs, Lisp_Object *args)
tempfile = SSDATA (filename_string);
{
int fd;
#ifdef HAVE_MKOSTEMP
fd = mkostemp (tempfile, O_CLOEXEC);
#elif defined HAVE_MKSTEMP
fd = mkstemp (tempfile);
#else
errno = EEXIST;
mktemp (tempfile);
fd = *tempfile ? 0 : -1;
#endif
int fd = mkostemp (tempfile, O_CLOEXEC);
if (fd < 0)
report_file_error ("Failed to open temporary file using pattern",
pattern);
#if defined HAVE_MKOSTEMP || defined HAVE_MKSTEMP
emacs_close (fd);
#endif
}
record_unwind_protect (delete_temp_file, filename_string);

18
src/filelock.c
View File

@ -411,28 +411,14 @@ create_lock_file (char *lfname, char *lock_info_str, bool force)
memcpy (nonce, lfname, lfdirlen);
strcpy (nonce + lfdirlen, nonce_base);
#if HAVE_MKOSTEMP
/* Prefer mkostemp to mkstemp, as it avoids a window where FD is
temporarily open without close-on-exec. */
fd = mkostemp (nonce, O_BINARY | O_CLOEXEC);
#elif HAVE_MKSTEMP
/* Prefer mkstemp to mktemp, as it avoids a race between
mktemp and emacs_open. */
fd = mkstemp (nonce);
#else
mktemp (nonce);
fd = emacs_open (nonce, O_WRONLY | O_CREAT | O_EXCL | O_BINARY,
S_IRUSR | S_IWUSR);
#endif
if (fd < 0)
err = errno;
else
{
ptrdiff_t lock_info_len;
#if ! (HAVE_MKOSTEMP && O_CLOEXEC)
fcntl (fd, F_SETFD, FD_CLOEXEC);
#endif
if (! O_CLOEXEC)
fcntl (fd, F_SETFD, FD_CLOEXEC);
lock_info_len = strlen (lock_info_str);
err = 0;
/* Use 'write', not 'emacs_write', as garbage collection