diff options
Diffstat (limited to 'sysdeps/generic/dl-cache.h')
| -rw-r--r-- | sysdeps/generic/dl-cache.h | 64 |
1 files changed, 63 insertions, 1 deletions
diff --git a/sysdeps/generic/dl-cache.h b/sysdeps/generic/dl-cache.h index 4ddd96b005..4c77cd0c1b 100644 --- a/sysdeps/generic/dl-cache.h +++ b/sysdeps/generic/dl-cache.h @@ -16,6 +16,11 @@ 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 <stdint.h> #ifndef _DL_CACHE_DEFAULT_ID @@ -92,17 +97,72 @@ struct file_entry_new uint64_t hwcap; /* Hwcap entry. */ }; +/* 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. */ - uint32_t unused[5]; /* Leave space for future extensions + + /* 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. */ + + uint32_t unused[4]; /* 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); +} + /* Used to align cache_file_new. */ #define ALIGN_CACHE(addr) \ @@ -110,3 +170,5 @@ struct cache_file_new & (~(__alignof__ (struct cache_file_new) - 1))) extern int _dl_cache_libcmp (const char *p1, const char *p2) attribute_hidden; + +#endif /* _DL_CACHE_H */ |