mirror of
https://sourceware.org/git/glibc.git
synced 2025-01-03 08:11:08 +00:00
Distinguish ELOOP diagnosis threshold from SYMLOOP_MAX.
This commit is contained in:
Roland McGrath
parent
0c41943a4d
commit
4f75b7a09a
13
ChangeLog
13
ChangeLog
@ -1,3 +1,16 @@
|
||||
2012-08-03 Roland McGrath <roland@hack.frob.com>
|
||||
|
||||
* sysdeps/mach/hurd/sys/param.h (MAXSYMLINKS): Macro removed.
|
||||
* sysdeps/mach/hurd/bits/local_lim.h (SYMLOOP_MAX): Macro removed.
|
||||
* sysdeps/mach/hurd/eloop-threshold.h: New file.
|
||||
* hurd/lookup-retry.c (__hurd_file_name_lookup_retry): Use
|
||||
__eloop_threshold instead of SYMLOOP_MAX.
|
||||
|
||||
* sysdeps/generic/eloop-threshold.h: New file.
|
||||
* stdlib/canonicalize.c (__realpath): Use __eloop_threshold instead
|
||||
of MAXSYMLINKS.
|
||||
* elf/chroot_canon.c (chroot_canon): Likewise.
|
||||
|
||||
2012-08-03 Joseph Myers <joseph@codesourcery.com>
|
||||
|
||||
[BZ #13717]
|
||||
|
||||
@ -1,6 +1,5 @@
|
||||
/* Return the canonical absolute name of a given file inside chroot.
|
||||
Copyright (C) 1996,1997,1998,1999,2000,2001,2004,2005,2010,2011
|
||||
Free Software Foundation, Inc.
|
||||
Copyright (C) 1996-2012 Free Software Foundation, Inc.
|
||||
This file is part of the GNU C Library.
|
||||
|
||||
This program is free software; you can redistribute it and/or modify
|
||||
@ -20,12 +19,12 @@
|
||||
#include <string.h>
|
||||
#include <unistd.h>
|
||||
#include <limits.h>
|
||||
#include <sys/param.h>
|
||||
#include <sys/stat.h>
|
||||
#include <errno.h>
|
||||
#include <stddef.h>
|
||||
#include <stdint.h>
|
||||
|
||||
#include <eloop-threshold.h>
|
||||
#include <ldconfig.h>
|
||||
|
||||
#ifndef PATH_MAX
|
||||
@ -127,7 +126,7 @@ chroot_canon (const char *chroot, const char *name)
|
||||
char *buf = alloca (PATH_MAX);
|
||||
size_t len;
|
||||
|
||||
if (++num_links > MAXSYMLINKS)
|
||||
if (++num_links > __eloop_threshold ())
|
||||
{
|
||||
__set_errno (ELOOP);
|
||||
goto error;
|
||||
|
||||
@ -24,6 +24,7 @@
|
||||
#include <fcntl.h>
|
||||
#include <string.h>
|
||||
#include <_itoa.h>
|
||||
#include <eloop-threshold.h>
|
||||
|
||||
/* Translate the error from dir_lookup into the error the user sees. */
|
||||
static inline error_t
|
||||
@ -103,7 +104,7 @@ __hurd_file_name_lookup_retry (error_t (*use_init_port)
|
||||
/* Fall through. */
|
||||
|
||||
case FS_RETRY_NORMAL:
|
||||
if (nloops++ >= SYMLOOP_MAX)
|
||||
if (nloops++ >= __eloop_threshold ())
|
||||
{
|
||||
__mach_port_deallocate (__mach_task_self (), *result);
|
||||
return ELOOP;
|
||||
@ -180,7 +181,7 @@ __hurd_file_name_lookup_retry (error_t (*use_init_port)
|
||||
dirport = INIT_PORT_CRDIR;
|
||||
if (*result != MACH_PORT_NULL)
|
||||
__mach_port_deallocate (__mach_task_self (), *result);
|
||||
if (nloops++ >= SYMLOOP_MAX)
|
||||
if (nloops++ >= __eloop_threshold ())
|
||||
return ELOOP;
|
||||
file_name = &retryname[1];
|
||||
break;
|
||||
|
||||
@ -1,5 +1,5 @@
|
||||
/* Return the canonical absolute name of a given file.
|
||||
Copyright (C) 1996-2002,2004,2005,2006,2008 Free Software Foundation, Inc.
|
||||
Copyright (C) 1996-2012 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
|
||||
@ -21,11 +21,11 @@
|
||||
#include <string.h>
|
||||
#include <unistd.h>
|
||||
#include <limits.h>
|
||||
#include <sys/param.h>
|
||||
#include <sys/stat.h>
|
||||
#include <errno.h>
|
||||
#include <stddef.h>
|
||||
|
||||
#include <eloop-threshold.h>
|
||||
#include <shlib-compat.h>
|
||||
|
||||
/* Return the canonical absolute name of file NAME. A canonical name
|
||||
@ -166,7 +166,7 @@ __realpath (const char *name, char *resolved)
|
||||
char *buf = __alloca (path_max);
|
||||
size_t len;
|
||||
|
||||
if (++num_links > MAXSYMLINKS)
|
||||
if (++num_links > __eloop_threshold ())
|
||||
{
|
||||
__set_errno (ELOOP);
|
||||
goto error;
|
||||
|
||||
72
sysdeps/generic/eloop-threshold.h
Normal file
72
sysdeps/generic/eloop-threshold.h
Normal file
@ -0,0 +1,72 @@
|
||||
/* Threshold at which to diagnose ELOOP. Generic version.
|
||||
Copyright (C) 2012 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 Lesser General Public
|
||||
License as published by the Free Software Foundation; either
|
||||
version 2.1 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
|
||||
Lesser General Public License for more details.
|
||||
|
||||
You should have received a copy of the GNU Lesser General Public
|
||||
License along with the GNU C Library; if not, see
|
||||
<http://www.gnu.org/licenses/>. */
|
||||
|
||||
#ifndef _ELOOP_THRESHOLD_H
|
||||
#define _ELOOP_THRESHOLD_H 1
|
||||
|
||||
#include <limits.h>
|
||||
#include <sys/param.h>
|
||||
|
||||
/* POSIX specifies SYMLOOP_MAX as the "Maximum number of symbolic
|
||||
links that can be reliably traversed in the resolution of a
|
||||
pathname in the absence of a loop." This makes it a minimum that
|
||||
we should certainly accept. But it leaves open the possibility
|
||||
that more might sometimes work--just not "reliably".
|
||||
|
||||
For example, Linux implements a complex policy whereby there is a
|
||||
small limit on the number of direct symlink traversals (a symlink
|
||||
to a symlink to a symlink), but larger limit on the total number of
|
||||
symlink traversals overall. Hence the SYMLOOP_MAX number should be
|
||||
the small one, but the limit library functions enforce on users
|
||||
should be the larger one.
|
||||
|
||||
So, we use the larger of the reported SYMLOOP_MAX (if any) and our
|
||||
own constant MIN_ELOOP_THRESHOLD, below. This constant should be
|
||||
large enough that it never rules out a file name and directory tree
|
||||
that the underlying system (i.e. calls to 'open' et al) would
|
||||
resolve successfully. It should be small enough that actual loops
|
||||
are detected without a huge number of iterations. */
|
||||
|
||||
#ifndef MIN_ELOOP_THRESHOLD
|
||||
# define MIN_ELOOP_THRESHOLD 40
|
||||
#endif
|
||||
|
||||
/* Return the maximum number of symlink traversals to permit
|
||||
before diagnosing ELOOP. */
|
||||
static inline unsigned int __attribute__ ((const))
|
||||
__eloop_threshold (void)
|
||||
{
|
||||
#ifdef SYMLOOP_MAX
|
||||
const int symloop_max = SYMLOOP_MAX;
|
||||
#else
|
||||
/* The function is marked 'const' even though we use memory and
|
||||
call a function, because sysconf is required to return the
|
||||
same value in every call and so it must always be safe to
|
||||
call __eloop_threshold exactly once and reuse the value. */
|
||||
static long int sysconf_symloop_max;
|
||||
if (sysconf_symloop_max == 0)
|
||||
sysconf_symloop_max = __sysconf (_SC_SYMLOOP_MAX);
|
||||
const unsigned int symloop_max = (sysconf_symloop_max <= 0
|
||||
? _POSIX_SYMLOOP_MAX
|
||||
: sysconf_symloop_max);
|
||||
#endif
|
||||
|
||||
return MAX (symloop_max, MIN_ELOOP_THRESHOLD);
|
||||
}
|
||||
|
||||
#endif /* eloop-threshold.h */
|
||||
@ -1,5 +1,5 @@
|
||||
/* Minimum guaranteed maximum values for system limits. Hurd version.
|
||||
Copyright (C) 1993,94,96,98,2002 Free Software Foundation, Inc.
|
||||
Copyright (C) 1993-2012 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
|
||||
@ -32,14 +32,3 @@
|
||||
suitable, and `sysconf' will return a number at least as large. */
|
||||
|
||||
#define NGROUPS_MAX 256
|
||||
|
||||
/* The maximum number of symbolic links that are allowed in a single file
|
||||
name resolution. When a further link is encountered, the call returns
|
||||
ELOOP. This name is a GNU extension; POSIX.1 has no such limit, and BSD
|
||||
calls it MAXSYMLINKS in <sys/param.h>. (We define the name under
|
||||
_BSD_SOURCE even without _GNU_SOURCE because our <sys/param.h> uses it
|
||||
to define MAXSYMLINKS.) */
|
||||
|
||||
#if defined __USE_GNU || defined __USE_BSD /* 1003.1a defines this */
|
||||
#define SYMLOOP_MAX 8
|
||||
#endif
|
||||
|
||||
37
sysdeps/mach/hurd/eloop-threshold.h
Normal file
37
sysdeps/mach/hurd/eloop-threshold.h
Normal file
@ -0,0 +1,37 @@
|
||||
/* Threshold at which to diagnose ELOOP. Hurd version.
|
||||
Copyright (C) 2012 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 Lesser General Public
|
||||
License as published by the Free Software Foundation; either
|
||||
version 2.1 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
|
||||
Lesser General Public License for more details.
|
||||
|
||||
You should have received a copy of the GNU Lesser General Public
|
||||
License along with the GNU C Library; if not, see
|
||||
<http://www.gnu.org/licenses/>. */
|
||||
|
||||
#ifndef _ELOOP_THRESHOLD_H
|
||||
#define _ELOOP_THRESHOLD_H 1
|
||||
|
||||
/* Return the maximum number of symlink traversals to permit
|
||||
before diagnosing ELOOP.
|
||||
|
||||
In the Hurd version, here we are actually setting the only policy
|
||||
there is on the system. We use a literal number here rather than
|
||||
defining SYMLOOP_MAX so that programs don't compile in a number
|
||||
but instead use sysconf and the number can be changed here to
|
||||
affect sysconf's result. */
|
||||
|
||||
static inline unsigned int __attribute__ ((const))
|
||||
__eloop_threshold (void)
|
||||
{
|
||||
return 32;
|
||||
}
|
||||
|
||||
#endif /* eloop-threshold.h */
|
||||
@ -1,4 +1,4 @@
|
||||
/* Copyright (C) 1993,1994,1995,1997,1999,2011 Free Software Foundation, Inc.
|
||||
/* Copyright (C) 1993-2012 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
|
||||
@ -83,7 +83,6 @@
|
||||
|
||||
#define NBBY CHAR_BIT
|
||||
#define NGROUPS NGROUPS_MAX
|
||||
#define MAXSYMLINKS SYMLOOP_MAX
|
||||
#define CANBSIZ MAX_CANON /* XXX ? */
|
||||
|
||||
/* ARG_MAX is unlimited, but we define NCARGS for BSD programs that want to
|
||||
|
||||
26
sysdeps/mach/hurd/sysconf.c
Normal file
26
sysdeps/mach/hurd/sysconf.c
Normal file
@ -0,0 +1,26 @@
|
||||
/* Return values of system parameters. Hurd version.
|
||||
Copyright (C) 2012 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 Lesser General Public
|
||||
License as published by the Free Software Foundation; either
|
||||
version 2.1 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
|
||||
Lesser General Public License for more details.
|
||||
|
||||
You should have received a copy of the GNU Lesser General Public
|
||||
License along with the GNU C Library; if not, see
|
||||
<http://www.gnu.org/licenses/>. */
|
||||
|
||||
#include <limits.h>
|
||||
#include <unistd.h>
|
||||
|
||||
#include <eloop-threshold.h>
|
||||
|
||||
#define SYMLOOP_MAX (__eloop_threshold ())
|
||||
|
||||
#include <sysdeps/posix/sysconf.c>
|
||||
Loading…
Reference in New Issue
Block a user