[thirdparty/glibc.git] / sysdeps / generic / dl-cache.h

/* Support for reading /etc/ld.so.cache files written by Linux ldconfig.
   Copyright (C) 1999-2023 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
   <https://www.gnu.org/licenses/>.  */

#ifndef _DL_CACHE_H
#define _DL_CACHE_H

#include <endian.h>
#include <stdbool.h>
#include <stddef.h>
#include <stdint.h>
#include <string.h>

#ifndef _DL_CACHE_DEFAULT_ID
# define _DL_CACHE_DEFAULT_ID	3
#endif

#ifndef _dl_cache_check_flags
# define _dl_cache_check_flags(flags)			\
  ((flags) == 1 || (flags) == _DL_CACHE_DEFAULT_ID)
#endif

#ifndef LD_SO_CACHE
# define LD_SO_CACHE SYSCONFDIR "/ld.so.cache"
#endif

#ifndef add_system_dir
# define add_system_dir(dir) add_dir (dir)
#endif

#define CACHEMAGIC "ld.so-1.7.0"

/* libc5 and glibc 2.0/2.1 use the same format.  For glibc 2.2 another
   format has been added in a compatible way:
   The beginning of the string table is used for the new table:
	old_magic
	nlibs
	libs[0]
	...
	libs[nlibs-1]
	pad, new magic needs to be aligned
	     - this is string[0] for the old format
	new magic - this is string[0] for the new format
	newnlibs
	...
	newlibs[0]
	...
	newlibs[newnlibs-1]
	string 1
	string 2
	...
*/
struct file_entry
{
  int32_t flags;		/* This is 1 for an ELF library.  */
  uint32_t key, value;		/* String table indices.  */
};

struct cache_file
{
  char magic[sizeof CACHEMAGIC - 1];
  unsigned int nlibs;
  struct file_entry libs[0];
};

#define CACHEMAGIC_NEW "glibc-ld.so.cache"
#define CACHE_VERSION "1.1"
#define CACHEMAGIC_VERSION_NEW CACHEMAGIC_NEW CACHE_VERSION


struct file_entry_new
{
  union
  {
    /* Fields shared with struct file_entry.  */
    struct file_entry entry;
    /* Also expose these fields directly.  */
    struct
    {
      int32_t flags;		/* This is 1 for an ELF library.  */
      uint32_t key, value;	/* String table indices.  */
    };
  };
  uint32_t osversion_unused;	/* Required OS version (unused).  */
  uint64_t hwcap;		/* Hwcap entry.	 */
};

/* This bit in the hwcap field of struct file_entry_new indicates that
   the lower 32 bits contain an index into the
   cache_extension_tag_glibc_hwcaps section.  Older glibc versions do
   not know about this HWCAP bit, so they will ignore these
   entries.  */
#define DL_CACHE_HWCAP_EXTENSION (1ULL << 62)

/* The number of the ISA level bits in the upper 32 bits of the hwcap
   field.  */
#define DL_CACHE_HWCAP_ISA_LEVEL_COUNT 10

/* The mask of the ISA level bits in the hwcap field.  */
#define DL_CACHE_HWCAP_ISA_LEVEL_MASK \
  ((1 << DL_CACHE_HWCAP_ISA_LEVEL_COUNT) -1)

/* Return true if the ENTRY->hwcap value indicates that
   DL_CACHE_HWCAP_EXTENSION is used.  */
static inline bool
dl_cache_hwcap_extension (struct file_entry_new *entry)
{
  /* This is an hwcap extension if only the DL_CACHE_HWCAP_EXTENSION bit
     is set, ignoring the lower 32 bits as well as the ISA level bits in
     the upper 32 bits.  */
  return (((entry->hwcap >> 32) & ~DL_CACHE_HWCAP_ISA_LEVEL_MASK)
	  == (DL_CACHE_HWCAP_EXTENSION >> 32));
}

/* See flags member of struct cache_file_new below.  */
enum
  {
    /* No endianness information available.  An old ldconfig version
       without endianness support wrote the file.  */
    cache_file_new_flags_endian_unset = 0,

    /* Cache is invalid and should be ignored.  */
    cache_file_new_flags_endian_invalid = 1,

    /* Cache format is little endian.  */
    cache_file_new_flags_endian_little = 2,

    /* Cache format is big endian.  */
    cache_file_new_flags_endian_big = 3,

    /* Bit mask to extract the cache_file_new_flags_endian_*
       values.  */
    cache_file_new_flags_endian_mask = 3,

    /* Expected value of the endian bits in the flags member for the
       current architecture.  */
    cache_file_new_flags_endian_current
      = (__BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__
	 ? cache_file_new_flags_endian_little
	 : cache_file_new_flags_endian_big),
  };

struct cache_file_new
{
  char magic[sizeof CACHEMAGIC_NEW - 1];
  char version[sizeof CACHE_VERSION - 1];
  uint32_t nlibs;		/* Number of entries.  */
  uint32_t len_strings;		/* Size of string table. */

  /* flags & cache_file_new_flags_endian_mask is one of the values
     cache_file_new_flags_endian_unset, cache_file_new_flags_endian_invalid,
     cache_file_new_flags_endian_little, cache_file_new_flags_endian_big.

     The remaining bits are unused and should be generated as zero and
     ignored by readers.  */
  uint8_t flags;

  uint8_t padding_unsed[3];	/* Not used, for future extensions.  */

  /* File offset of the extension directory.  See struct
     cache_extension below.  Must be a multiple of four.  */
  uint32_t extension_offset;

  uint32_t unused[3];		/* Leave space for future extensions
				   and align to 8 byte boundary.  */
  struct file_entry_new libs[0]; /* Entries describing libraries.  */
  /* After this the string table of size len_strings is found.	*/
};
_Static_assert (sizeof (struct cache_file_new) == 48,
		"size of struct cache_file_new");

/* Returns false if *CACHE has the wrong endianness for this
   architecture, and true if the endianness matches (or is
   unknown).  */
static inline bool
cache_file_new_matches_endian (const struct cache_file_new *cache)
{
  /* A zero value for cache->flags means that no endianness
     information is available.  */
  return cache->flags == 0
    || ((cache->flags & cache_file_new_flags_endian_big)
	== cache_file_new_flags_endian_current);
}


/* Randomly chosen magic value, which allows for additional
   consistency verification.  */
enum { cache_extension_magic = (uint32_t) -358342284 };

/* Tag values for different kinds of extension sections.  Similar to
   SHT_* constants.  */
enum cache_extension_tag
  {
   /* Array of bytes containing the glibc version that generated this
      cache file.  */
   cache_extension_tag_generator,

   /* glibc-hwcaps subdirectory information.  An array of uint32_t
      values, which are indices into the string table.  The strings
      are sorted lexicographically (according to strcmp).  The extra
      level of indirection (instead of using string table indices
      directly) allows the dynamic loader to compute the preference
      order of the hwcaps names more efficiently.

      For this section, 4-byte alignment is required, and the section
      size must be a multiple of 4.  */
   cache_extension_tag_glibc_hwcaps,

   /* Total number of known cache extension tags.  */
   cache_extension_count
  };

/* Element in the array following struct cache_extension.  Similar to
   an ELF section header.  */
struct cache_extension_section
{
  /* Type of the extension section.  A enum cache_extension_tag value.  */
  uint32_t tag;

  /* Extension-specific flags.  Currently generated as zero.  */
  uint32_t flags;

  /* Offset from the start of the file for the data in this extension
     section.  Specific extensions can have alignment constraints.  */
  uint32_t offset;

  /* Length in bytes of the extension data.  Specific extensions may
     have size requirements.  */
  uint32_t size;
};

/* The extension directory in the cache.  An array of struct
   cache_extension_section entries.  */
struct cache_extension
{
  uint32_t magic;		/* Always cache_extension_magic.  */
  uint32_t count;		/* Number of following entries.  */

  /* count section descriptors of type struct cache_extension_section
     follow.  */
  struct cache_extension_section sections[];
};

/* A relocated version of struct cache_extension_section.  */
struct cache_extension_loaded
{
  /* Address and size of this extension section.  base is NULL if the
     section is missing from the file.  */
  const void *base;
  size_t size;

  /* Flags from struct cache_extension_section.  */
  uint32_t flags;
};

/* All supported extension sections, relocated.  Filled in by
   cache_extension_load below.  */
struct cache_extension_all_loaded
{
  struct cache_extension_loaded sections[cache_extension_count];
};

/* Performs basic data validation based on section tag, and removes
   the sections which are invalid.  */
static void
cache_extension_verify (struct cache_extension_all_loaded *loaded)
{
  {
    /* Section must not be empty, it must be aligned at 4 bytes, and
       the size must be a multiple of 4.  */
    struct cache_extension_loaded *hwcaps
      = &loaded->sections[cache_extension_tag_glibc_hwcaps];
    if (hwcaps->size == 0
	|| ((uintptr_t) hwcaps->base % 4) != 0
	|| (hwcaps->size % 4) != 0)
      {
	hwcaps->base = NULL;
	hwcaps->size = 0;
	hwcaps->flags = 0;
      }
  }
}

static bool __attribute__ ((unused))
cache_extension_load (const struct cache_file_new *cache,
		      const void *file_base, size_t file_size,
		      struct cache_extension_all_loaded *loaded)
{
  memset (loaded, 0, sizeof (*loaded));
  if (cache->extension_offset == 0)
    /* No extensions present.  This is not a format error.  */
    return true;
  if ((cache->extension_offset % 4) != 0)
    /* Extension offset is misaligned.  */
    return false;
  size_t size_tmp;
  if (__builtin_add_overflow (cache->extension_offset,
			      sizeof (struct cache_extension), &size_tmp)
      || size_tmp > file_size)
    /* Extension extends beyond the end of the file.  */
    return false;
  const struct cache_extension *ext = file_base + cache->extension_offset;
  if (ext->magic != cache_extension_magic)
    return false;
  if (__builtin_mul_overflow (ext->count,
			      sizeof (struct cache_extension_section),
			      &size_tmp)
      || __builtin_add_overflow (cache->extension_offset
				 + sizeof (struct cache_extension), size_tmp,
				 &size_tmp)
      || size_tmp > file_size)
    /* Extension array extends beyond the end of the file.  */
    return false;
  for (uint32_t i = 0; i < ext->count; ++i)
    {
      if (__builtin_add_overflow (ext->sections[i].offset,
				  ext->sections[i].size, &size_tmp)
	  || size_tmp > file_size)
	/* Extension data extends beyond the end of the file.  */
	return false;

      uint32_t tag = ext->sections[i].tag;
      if (tag >= cache_extension_count)
	/* Tag is out of range and unrecognized.  */
	continue;
      loaded->sections[tag].base = file_base + ext->sections[i].offset;
      loaded->sections[tag].size = ext->sections[i].size;
      loaded->sections[tag].flags = ext->sections[i].flags;
    }
  cache_extension_verify (loaded);
  return true;
}

/* Used to align cache_file_new.  */
#define ALIGN_CACHE(addr)				\
(((addr) + __alignof__ (struct cache_file_new) -1)	\
 & (~(__alignof__ (struct cache_file_new) - 1)))

extern int _dl_cache_libcmp (const char *p1, const char *p2) attribute_hidden;

#endif /* _DL_CACHE_H */
Commit	Line	Data
c41baa79	1	/* Support for reading /etc/ld.so.cache files written by Linux ldconfig.
6d7e8eda	2	Copyright (C) 1999-2023 Free Software Foundation, Inc.
c41baa79 UD	3	This file is part of the GNU C Library.
	4
	5	The GNU C Library is free software; you can redistribute it and/or
41bdb6e2 AJ	6	modify it under the terms of the GNU Lesser General Public
	7	License as published by the Free Software Foundation; either
	8	version 2.1 of the License, or (at your option) any later version.
c41baa79 UD	9
	10	The GNU C Library is distributed in the hope that it will be useful,
	11	but WITHOUT ANY WARRANTY; without even the implied warranty of
	12	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
41bdb6e2	13	Lesser General Public License for more details.
c41baa79	14
41bdb6e2	15	You should have received a copy of the GNU Lesser General Public
59ba27a6	16	License along with the GNU C Library; if not, see
5a82c748	17	<https://www.gnu.org/licenses/>. */
c41baa79	18
84ba719b FW	19	#ifndef _DL_CACHE_H
	20	#define _DL_CACHE_H
	21
	22	#include <endian.h>
	23	#include <stdbool.h>
dfb3f101	24	#include <stddef.h>
a8fd59b0	25	#include <stdint.h>
dfb3f101	26	#include <string.h>
a8fd59b0	27
e25054c4 AJ	28	#ifndef _DL_CACHE_DEFAULT_ID
	29	# define _DL_CACHE_DEFAULT_ID 3
	30	#endif
c41baa79	31
e25054c4 AJ	32	#ifndef _dl_cache_check_flags
e25054c4 AJ	33	# define _dl_cache_check_flags(flags) \
c41baa79	34	((flags) == 1 \|\| (flags) == _DL_CACHE_DEFAULT_ID)
e25054c4	35	#endif
45eca4d1 UD	36
45eca4d1 UD	37	#ifndef LD_SO_CACHE
8ca91b36	38	# define LD_SO_CACHE SYSCONFDIR "/ld.so.cache"
45eca4d1 UD	39	#endif
45eca4d1 UD	40
bd89c0b5 UD	41	#ifndef add_system_dir
	42	# define add_system_dir(dir) add_dir (dir)
	43	#endif
	44
45eca4d1 UD	45	#define CACHEMAGIC "ld.so-1.7.0"
	46
	47	/* libc5 and glibc 2.0/2.1 use the same format. For glibc 2.2 another
	48	format has been added in a compatible way:
	49	The beginning of the string table is used for the new table:
e25054c4	50	old_magic
45eca4d1 UD	51	nlibs
	52	libs[0]
	53	...
	54	libs[nlibs-1]
e25054c4 AJ	55	pad, new magic needs to be aligned
	56	- this is string[0] for the old format
	57	new magic - this is string[0] for the new format
45eca4d1 UD	58	newnlibs
	59	...
	60	newlibs[0]
	61	...
	62	newlibs[newnlibs-1]
	63	string 1
	64	string 2
	65	...
	66	*/
	67	struct file_entry
	68	{
de1a9197 FW	69	int32_t flags; /* This is 1 for an ELF library. */
de1a9197 FW	70	uint32_t key, value; /* String table indices. */
45eca4d1 UD	71	};
	72
	73	struct cache_file
	74	{
	75	char magic[sizeof CACHEMAGIC - 1];
	76	unsigned int nlibs;
	77	struct file_entry libs[0];
	78	};
	79
	80	#define CACHEMAGIC_NEW "glibc-ld.so.cache"
a8fd59b0	81	#define CACHE_VERSION "1.1"
ea029468	82	#define CACHEMAGIC_VERSION_NEW CACHEMAGIC_NEW CACHE_VERSION
45eca4d1 UD	83
	84
	85	struct file_entry_new
	86	{
de1a9197 FW	87	union
	88	{
	89	/* Fields shared with struct file_entry. */
	90	struct file_entry entry;
	91	/* Also expose these fields directly. */
	92	struct
	93	{
	94	int32_t flags; /* This is 1 for an ELF library. */
	95	uint32_t key, value; /* String table indices. */
	96	};
	97	};
c628c229	98	uint32_t osversion_unused; /* Required OS version (unused). */
a8fd59b0	99	uint64_t hwcap; /* Hwcap entry. */
45eca4d1 UD	100	};
45eca4d1 UD	101
b44ac4f4 FW	102	/* This bit in the hwcap field of struct file_entry_new indicates that
	103	the lower 32 bits contain an index into the
	104	cache_extension_tag_glibc_hwcaps section. Older glibc versions do
	105	not know about this HWCAP bit, so they will ignore these
	106	entries. */
	107	#define DL_CACHE_HWCAP_EXTENSION (1ULL << 62)
	108
efbbd9c3 L	109	/* The number of the ISA level bits in the upper 32 bits of the hwcap
	110	field. */
	111	#define DL_CACHE_HWCAP_ISA_LEVEL_COUNT 10
	112
	113	/* The mask of the ISA level bits in the hwcap field. */
	114	#define DL_CACHE_HWCAP_ISA_LEVEL_MASK \
	115	((1 << DL_CACHE_HWCAP_ISA_LEVEL_COUNT) -1)
	116
b44ac4f4 FW	117	/* Return true if the ENTRY->hwcap value indicates that
	118	DL_CACHE_HWCAP_EXTENSION is used. */
	119	static inline bool
	120	dl_cache_hwcap_extension (struct file_entry_new *entry)
	121	{
efbbd9c3 L	122	/* This is an hwcap extension if only the DL_CACHE_HWCAP_EXTENSION bit
	123	is set, ignoring the lower 32 bits as well as the ISA level bits in
	124	the upper 32 bits. */
	125	return (((entry->hwcap >> 32) & ~DL_CACHE_HWCAP_ISA_LEVEL_MASK)
	126	== (DL_CACHE_HWCAP_EXTENSION >> 32));
b44ac4f4 FW	127	}
b44ac4f4 FW	128
84ba719b FW	129	/* See flags member of struct cache_file_new below. */
	130	enum
	131	{
	132	/* No endianness information available. An old ldconfig version
	133	without endianness support wrote the file. */
	134	cache_file_new_flags_endian_unset = 0,
	135
	136	/* Cache is invalid and should be ignored. */
	137	cache_file_new_flags_endian_invalid = 1,
	138
	139	/* Cache format is little endian. */
	140	cache_file_new_flags_endian_little = 2,
	141
	142	/* Cache format is big endian. */
	143	cache_file_new_flags_endian_big = 3,
	144
	145	/* Bit mask to extract the cache_file_new_flags_endian_*
	146	values. */
	147	cache_file_new_flags_endian_mask = 3,
	148
	149	/* Expected value of the endian bits in the flags member for the
	150	current architecture. */
	151	cache_file_new_flags_endian_current
	152	= (__BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__
	153	? cache_file_new_flags_endian_little
	154	: cache_file_new_flags_endian_big),
	155	};
	156
45eca4d1 UD	157	struct cache_file_new
	158	{
	159	char magic[sizeof CACHEMAGIC_NEW - 1];
	160	char version[sizeof CACHE_VERSION - 1];
a8fd59b0 AJ	161	uint32_t nlibs; /* Number of entries. */
a8fd59b0 AJ	162	uint32_t len_strings; /* Size of string table. */
84ba719b FW	163
	164	/* flags & cache_file_new_flags_endian_mask is one of the values
	165	cache_file_new_flags_endian_unset, cache_file_new_flags_endian_invalid,
	166	cache_file_new_flags_endian_little, cache_file_new_flags_endian_big.
	167
	168	The remaining bits are unused and should be generated as zero and
	169	ignored by readers. */
	170	uint8_t flags;
	171
	172	uint8_t padding_unsed[3]; /* Not used, for future extensions. */
	173
dfb3f101 FW	174	/* File offset of the extension directory. See struct
	175	cache_extension below. Must be a multiple of four. */
	176	uint32_t extension_offset;
	177
	178	uint32_t unused[3]; /* Leave space for future extensions
a8fd59b0	179	and align to 8 byte boundary. */
45eca4d1	180	struct file_entry_new libs[0]; /* Entries describing libraries. */
a8fd59b0	181	/* After this the string table of size len_strings is found. */
45eca4d1	182	};
84ba719b FW	183	_Static_assert (sizeof (struct cache_file_new) == 48,
	184	"size of struct cache_file_new");
	185
	186	/* Returns false if *CACHE has the wrong endianness for this
	187	architecture, and true if the endianness matches (or is
	188	unknown). */
	189	static inline bool
	190	cache_file_new_matches_endian (const struct cache_file_new *cache)
	191	{
	192	/* A zero value for cache->flags means that no endianness
	193	information is available. */
	194	return cache->flags == 0
	195	\|\| ((cache->flags & cache_file_new_flags_endian_big)
	196	== cache_file_new_flags_endian_current);
	197	}
	198
45eca4d1	199
dfb3f101 FW	200	/* Randomly chosen magic value, which allows for additional
	201	consistency verification. */
	202	enum { cache_extension_magic = (uint32_t) -358342284 };
	203
	204	/* Tag values for different kinds of extension sections. Similar to
	205	SHT_* constants. */
	206	enum cache_extension_tag
	207	{
	208	/* Array of bytes containing the glibc version that generated this
	209	cache file. */
	210	cache_extension_tag_generator,
	211
b44ac4f4 FW	212	/* glibc-hwcaps subdirectory information. An array of uint32_t
	213	values, which are indices into the string table. The strings
	214	are sorted lexicographically (according to strcmp). The extra
	215	level of indirection (instead of using string table indices
	216	directly) allows the dynamic loader to compute the preference
	217	order of the hwcaps names more efficiently.
	218
	219	For this section, 4-byte alignment is required, and the section
	220	size must be a multiple of 4. */
	221	cache_extension_tag_glibc_hwcaps,
	222
dfb3f101 FW	223	/* Total number of known cache extension tags. */
	224	cache_extension_count
	225	};
	226
	227	/* Element in the array following struct cache_extension. Similar to
	228	an ELF section header. */
	229	struct cache_extension_section
	230	{
	231	/* Type of the extension section. A enum cache_extension_tag value. */
	232	uint32_t tag;
	233
	234	/* Extension-specific flags. Currently generated as zero. */
	235	uint32_t flags;
	236
	237	/* Offset from the start of the file for the data in this extension
	238	section. Specific extensions can have alignment constraints. */
	239	uint32_t offset;
	240
	241	/* Length in bytes of the extension data. Specific extensions may
	242	have size requirements. */
	243	uint32_t size;
	244	};
	245
	246	/* The extension directory in the cache. An array of struct
	247	cache_extension_section entries. */
	248	struct cache_extension
	249	{
	250	uint32_t magic; /* Always cache_extension_magic. */
	251	uint32_t count; /* Number of following entries. */
	252
	253	/* count section descriptors of type struct cache_extension_section
	254	follow. */
	255	struct cache_extension_section sections[];
	256	};
	257
	258	/* A relocated version of struct cache_extension_section. */
	259	struct cache_extension_loaded
	260	{
	261	/* Address and size of this extension section. base is NULL if the
	262	section is missing from the file. */
	263	const void *base;
	264	size_t size;
	265
	266	/* Flags from struct cache_extension_section. */
	267	uint32_t flags;
	268	};
	269
	270	/* All supported extension sections, relocated. Filled in by
	271	cache_extension_load below. */
	272	struct cache_extension_all_loaded
	273	{
	274	struct cache_extension_loaded sections[cache_extension_count];
	275	};
	276
b44ac4f4 FW	277	/* Performs basic data validation based on section tag, and removes
	278	the sections which are invalid. */
	279	static void
	280	cache_extension_verify (struct cache_extension_all_loaded *loaded)
	281	{
	282	{
	283	/* Section must not be empty, it must be aligned at 4 bytes, and
	284	the size must be a multiple of 4. */
	285	struct cache_extension_loaded *hwcaps
	286	= &loaded->sections[cache_extension_tag_glibc_hwcaps];
	287	if (hwcaps->size == 0
	288	\|\| ((uintptr_t) hwcaps->base % 4) != 0
	289	\|\| (hwcaps->size % 4) != 0)
	290	{
	291	hwcaps->base = NULL;
	292	hwcaps->size = 0;
	293	hwcaps->flags = 0;
	294	}
	295	}
	296	}
	297
dfb3f101 FW	298	static bool __attribute__ ((unused))
	299	cache_extension_load (const struct cache_file_new *cache,
	300	const void *file_base, size_t file_size,
	301	struct cache_extension_all_loaded *loaded)
	302	{
	303	memset (loaded, 0, sizeof (*loaded));
	304	if (cache->extension_offset == 0)
	305	/* No extensions present. This is not a format error. */
	306	return true;
	307	if ((cache->extension_offset % 4) != 0)
	308	/* Extension offset is misaligned. */
	309	return false;
	310	size_t size_tmp;
	311	if (__builtin_add_overflow (cache->extension_offset,
	312	sizeof (struct cache_extension), &size_tmp)
	313	\|\| size_tmp > file_size)
	314	/* Extension extends beyond the end of the file. */
	315	return false;
	316	const struct cache_extension *ext = file_base + cache->extension_offset;
	317	if (ext->magic != cache_extension_magic)
	318	return false;
	319	if (__builtin_mul_overflow (ext->count,
	320	sizeof (struct cache_extension_section),
	321	&size_tmp)
	322	\|\| __builtin_add_overflow (cache->extension_offset
	323	+ sizeof (struct cache_extension), size_tmp,
	324	&size_tmp)
	325	\|\| size_tmp > file_size)
	326	/* Extension array extends beyond the end of the file. */
	327	return false;
	328	for (uint32_t i = 0; i < ext->count; ++i)
	329	{
	330	if (__builtin_add_overflow (ext->sections[i].offset,
	331	ext->sections[i].size, &size_tmp)
	332	\|\| size_tmp > file_size)
	333	/* Extension data extends beyond the end of the file. */
	334	return false;
	335
	336	uint32_t tag = ext->sections[i].tag;
	337	if (tag >= cache_extension_count)
	338	/* Tag is out of range and unrecognized. */
	339	continue;
	340	loaded->sections[tag].base = file_base + ext->sections[i].offset;
	341	loaded->sections[tag].size = ext->sections[i].size;
	342	loaded->sections[tag].flags = ext->sections[i].flags;
	343	}
b44ac4f4	344	cache_extension_verify (loaded);
dfb3f101 FW	345	return true;
	346	}
	347
e25054c4 AJ	348	/* Used to align cache_file_new. */
	349	#define ALIGN_CACHE(addr) \
	350	(((addr) + __alignof__ (struct cache_file_new) -1) \
	351	& (~(__alignof__ (struct cache_file_new) - 1)))
	352
17e00cc6	353	extern int _dl_cache_libcmp (const char p1, const char p2) attribute_hidden;
84ba719b FW	354
84ba719b FW	355	#endif /* _DL_CACHE_H */