glibc/sysdeps/generic/dl-cache.c
Ulrich Drepper a986484f67 Update.
2001-03-12  Jakub Jelinek  <jakub@redhat.com>

	* csu/Makefile (abi-tag.h): Define OS and version separately, allow
	version to be overriden from config.h.
	* csu/abi-note.S: Use OS and version separately, include config.h.
	* elf/dl-load.c (_dl_osversion): New.
	(_dl_map_object_from_fd): Kill some warnings.
	(open_verify): Check .note.ABI-tag of the library if present.
	* elf/Makefile (CPPFLAGS-dl-load.c): Add -I$(csu-objpfx).
	* elf/cache.c (struct cache_entry): Add osversion.
	(print_entry): Print osversion.
	(print_cache): Pass osversion to it.
	(compare): Sort according to osversion.
	(save_cache): Set osversion.
	(add_to_cache): Add osversion argument.
	* sysdeps/generic/ldconfig.h (add_to_cache, process_file,
	process_elf_file): Add osversion argument.
	* elf/readlib.c (process_file): Likewise.
	* sysdeps/generic/readelflib.c (process_elf_file): Likewise.
	* sysdeps/unix/sysv/linux/ia64/readelflib.c (process_elf_file,
	process_elf32_file, process_elf64_file): Likewise.
	* sysdeps/unix/sysv/linux/i386/readelflib.c (process_elf_file,
	process_elf32_file, process_elf64_file): Likewise.
	* sysdeps/unix/sysv/linux/sparc/readelflib.c (process_elf_file,
	process_elf32_file, process_elf64_file): Likewise.
	* elf/ldconfig.c (manual_link): Pass it.
	(search_dir): Issue diagnostic if two libs with the same soname in
	the same directory have different .note.ABI-tag.  Record osversion in
	dlib_entry and use it from there.
	(struct lib_entry): Remove.
	(struct dlib_entry): Add osversion.
	* sysdeps/generic/dl-cache.c (_dl_load_cache_lookup): Check
	osversion.
	* sysdeps/generic/dl-cache.h (struct file_entry_new): Replace __unused
	field with osversion.
	* sysdeps/generic/ldsodefs.h (_dl_osversion): Declare.
	* sysdeps/unix/sysv/linux/init-first.c: Include ldsodefs.h.
	* sysdeps/unix/sysv/linux/dl-osinfo.h (DL_SYSDEP_OSCHECK): Save kernel
	version in _dl_osversion.
	* sysdeps/unix/sysv/linux/configure.in: Define __ABI_TAG_VERSION.
	* Makerules (build-shlib-helper, build-module-helper): New.
	(build-shlib, build-module-helper): Make sure .note.ABI-tag comes
	early.
	* config.h.in (__ABI_TAG_VERSION): Add.
	* elf/dl-minimal.c (__strtoul_internal): Set endptr on return.
	* sysdeps/unix/sysv/linux/i386/dl-librecon.h (EXTRA_LD_ENVVARS):
	Handle LD_ASSUME_KERNEL.
	* sysdeps/unix/sysv/linux/dl-librecon.h: New.
2001-03-16 07:40:05 +00:00

278 lines
8.6 KiB
C

/* Support for reading /etc/ld.so.cache files written by Linux ldconfig.
Copyright (C) 1996,1997,1998,1999,2000,2001 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. */
#include <assert.h>
#include <unistd.h>
#include <ldsodefs.h>
#include <sys/mman.h>
#include <dl-cache.h>
#include <dl-procinfo.h>
#include <stdio-common/_itoa.h>
extern const char *_dl_platform;
#ifndef _DL_PLATFORMS_COUNT
# define _DL_PLATFORMS_COUNT 0
#endif
/* This is the starting address and the size of the mmap()ed file. */
static struct cache_file *cache;
static struct cache_file_new *cache_new;
static size_t cachesize;
/* 1 if cache_data + PTR points into the cache. */
#define _dl_cache_verify_ptr(ptr) (ptr < cache_data_size)
/* This is the cache ID we expect. Normally it is 3 for glibc linked
binaries. */
int _dl_correct_cache_id = _DL_CACHE_DEFAULT_ID;
#define SEARCH_CACHE(cache) \
/* We use binary search since the table is sorted in the cache file. \
The first matching entry in the table is returned. \
It is important to use the same algorithm as used while generating \
the cache file. */ \
do \
{ \
left = 0; \
right = cache->nlibs - 1; \
middle = (left + right) / 2; \
cmpres = 1; \
\
while (left <= right) \
{ \
/* Make sure string table indices are not bogus before using \
them. */ \
if (! _dl_cache_verify_ptr (cache->libs[middle].key)) \
{ \
cmpres = 1; \
break; \
} \
\
/* Actually compare the entry with the key. */ \
cmpres = _dl_cache_libcmp (name, \
cache_data + cache->libs[middle].key); \
if (cmpres == 0) \
/* Found it. */ \
break; \
\
if (cmpres < 0) \
left = middle + 1; \
else \
right = middle - 1; \
\
middle = (left + right) / 2; \
} \
\
if (cmpres == 0) \
{ \
/* LEFT now marks the last entry for which we know the name is \
correct. */ \
left = middle; \
\
/* There might be entries with this name before the one we \
found. So we have to find the beginning. */ \
while (middle > 0 \
/* Make sure string table indices are not bogus before \
using them. */ \
&& _dl_cache_verify_ptr (cache->libs[middle - 1].key) \
/* Actually compare the entry. */ \
&& (_dl_cache_libcmp (name, \
cache_data \
+ cache->libs[middle - 1].key) \
== 0)) \
--middle; \
\
do \
{ \
int flags; \
\
/* Only perform the name test if necessary. */ \
if (middle > left \
/* We haven't seen this string so far. Test whether the \
index is ok and whether the name matches. Otherwise \
we are done. */ \
&& (! _dl_cache_verify_ptr (cache->libs[middle].key) \
|| (_dl_cache_libcmp (name, \
cache_data \
+ cache->libs[middle].key) \
!= 0))) \
break; \
\
flags = cache->libs[middle].flags; \
if (_dl_cache_check_flags (flags) \
&& _dl_cache_verify_ptr (cache->libs[middle].value)) \
{ \
if (best == NULL || flags == _dl_correct_cache_id) \
{ \
HWCAP_CHECK; \
best = cache_data + cache->libs[middle].value; \
\
if (flags == _dl_correct_cache_id) \
/* We've found an exact match for the shared \
object and no general `ELF' release. Stop \
searching. */ \
break; \
} \
} \
} \
while (++middle <= right); \
} \
} \
while (0)
/* Look up NAME in ld.so.cache and return the file name stored there,
or null if none is found. */
const char *
internal_function
_dl_load_cache_lookup (const char *name)
{
int left, right, middle;
int cmpres;
const char *cache_data;
uint32_t cache_data_size;
const char *best;
/* Print a message if the loading of libs is traced. */
if (__builtin_expect (_dl_debug_mask & DL_DEBUG_LIBS, 0))
_dl_debug_printf (" search cache=%s\n", LD_SO_CACHE);
if (cache == NULL)
{
/* Read the contents of the file. */
void *file = _dl_sysdep_read_whole_file (LD_SO_CACHE, &cachesize,
PROT_READ);
/* We can handle three different cache file formats here:
- the old libc5/glibc2.0/2.1 format
- the old format with the new format in it
- only the new format
The following checks if the cache contains any of these formats. */
if (file != NULL && cachesize > sizeof *cache
&& memcmp (file, CACHEMAGIC, sizeof CACHEMAGIC - 1) == 0)
{
size_t offset;
/* Looks ok. */
cache = file;
/* Check for new version. */
offset = ALIGN_CACHE (sizeof (struct cache_file)
+ cache->nlibs * sizeof (struct file_entry));
cache_new = (struct cache_file_new *) ((void *) cache + offset);
if (cachesize < (offset + sizeof (struct cache_file_new))
|| memcmp (cache_new->magic, CACHEMAGIC_VERSION_NEW,
sizeof CACHEMAGIC_VERSION_NEW - 1) != 0)
cache_new = (void *) -1;
}
else if (file != NULL && cachesize > sizeof *cache_new
&& memcmp (file, CACHEMAGIC_VERSION_NEW,
sizeof CACHEMAGIC_VERSION_NEW - 1) == 0)
{
cache_new = file;
cache = file;
}
else
{
if (file != NULL)
__munmap (file, cachesize);
cache = (void *) -1;
}
assert (cache != NULL);
}
if (cache == (void *) -1)
/* Previously looked for the cache file and didn't find it. */
return NULL;
best = NULL;
if (cache_new != (void *) -1)
{
/* This file ends in static libraries where we don't have a hwcap. */
unsigned long int *hwcap;
uint64_t platform;
weak_extern (_dl_hwcap);
/* This is where the strings start. */
cache_data = (const char *) cache_new;
/* Now we can compute how large the string table is. */
cache_data_size = (const char *) cache + cachesize - cache_data;
hwcap = &_dl_hwcap;
platform = _dl_string_platform (_dl_platform);
if (platform != -1)
platform = 1ULL << platform;
/* Only accept hwcap if it's for the right platform. */
#define HWCAP_CHECK \
if (_dl_osversion && cache_new->libs[middle].osversion > _dl_osversion) \
continue; \
if (_DL_PLATFORMS_COUNT && platform != -1 \
&& (cache_new->libs[middle].hwcap & _DL_HWCAP_PLATFORM) != 0 \
&& (cache_new->libs[middle].hwcap & _DL_HWCAP_PLATFORM) != platform) \
continue; \
if (hwcap \
&& ((cache_new->libs[middle].hwcap & *hwcap & ~_DL_HWCAP_PLATFORM) \
> *hwcap)) \
continue
SEARCH_CACHE (cache_new);
}
else
{
/* This is where the strings start. */
cache_data = (const char *) &cache->libs[cache->nlibs];
/* Now we can compute how large the string table is. */
cache_data_size = (const char *) cache + cachesize - cache_data;
#undef HWCAP_CHECK
#define HWCAP_CHECK do {} while (0)
SEARCH_CACHE (cache);
}
/* Print our result if wanted. */
if (__builtin_expect (_dl_debug_mask & DL_DEBUG_LIBS, 0) && best != NULL)
_dl_debug_printf (" trying file=%s\n", best);
return best;
}
#ifndef MAP_COPY
/* If the system does not support MAP_COPY we cannot leave the file open
all the time since this would create problems when the file is replaced.
Therefore we provide this function to close the file and open it again
once needed. */
void
_dl_unload_cache (void)
{
if (cache != NULL && cache != (struct cache_file *) -1)
{
__munmap (cache, cachesize);
cache = NULL;
}
}
#endif