[23/28] elf: Unify old and new format cache handling code in ld.so
Commit Message
struct file_entry_new starts with the fields of struct file_entry,
so the code can be shared if the size computation is made dynamic.
---
elf/dl-cache.c | 287 +++++++++++++++++++------------------
sysdeps/generic/dl-cache.h | 17 ++-
2 files changed, 158 insertions(+), 146 deletions(-)
Comments
On 01/10/2020 13:34, Florian Weimer via Libc-alpha wrote:
> struct file_entry_new starts with the fields of struct file_entry,
> so the code can be shared if the size computation is made dynamic.
LGTM, with some nits below.
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
> ---
> elf/dl-cache.c | 287 +++++++++++++++++++------------------
> sysdeps/generic/dl-cache.h | 17 ++-
> 2 files changed, 158 insertions(+), 146 deletions(-)
>
> diff --git a/elf/dl-cache.c b/elf/dl-cache.c
> index 3aa8ed6c13..02c46ffb0c 100644
> --- a/elf/dl-cache.c
> +++ b/elf/dl-cache.c
> @@ -35,103 +35,141 @@ 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)
> -
> -#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; \
> - \
> - while (left <= right) \
> - { \
> - __typeof__ (cache->libs[0].key) key; \
> - \
> - middle = (left + right) / 2; \
> - \
> - key = cache->libs[middle].key; \
> - \
> - /* Make sure string table indices are not bogus before using \
> - them. */ \
> - if (! _dl_cache_verify_ptr (key)) \
> - { \
> - cmpres = 1; \
> - break; \
> - } \
> - \
> - /* Actually compare the entry with the key. */ \
> - cmpres = _dl_cache_libcmp (name, cache_data + key); \
> - if (__glibc_unlikely (cmpres == 0)) \
> - { \
> - /* Found it. 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) \
> - { \
> - __typeof__ (cache->libs[0].key) key; \
> - \
> - key = cache->libs[middle - 1].key; \
> - /* Make sure string table indices are not bogus before \
> - using them. */ \
> - if (! _dl_cache_verify_ptr (key) \
> - /* Actually compare the entry. */ \
> - || _dl_cache_libcmp (name, cache_data + key) != 0) \
> - break; \
> - --middle; \
> - } \
> - \
> - do \
> - { \
> - int flags; \
> - __typeof__ (cache->libs[0]) *lib = &cache->libs[middle]; \
> - \
> - /* 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 (lib->key) \
> - || (_dl_cache_libcmp (name, cache_data + lib->key) \
> - != 0))) \
> - break; \
> - \
> - flags = lib->flags; \
> - if (_dl_cache_check_flags (flags) \
> - && _dl_cache_verify_ptr (lib->value)) \
> - { \
> - if (best == NULL || flags == GLRO(dl_correct_cache_id)) \
> - { \
> - HWCAP_CHECK; \
> - best = cache_data + lib->value; \
> - \
> - if (flags == GLRO(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); \
> - break; \
> - } \
> - \
> - if (cmpres < 0) \
> - left = middle + 1; \
> - else \
> - right = middle - 1; \
> - } \
> - } \
> -while (0)
Ok.
> +/* True if PTR is a valid string table index. */
> +static inline bool
> +_dl_cache_verify_ptr (uint32_t ptr, size_t string_table_size)
> +{
> + return ptr < string_table_size;
> +}
> +
Ok.
> +/* Compute the address of the element INDEX of the array at LIBS.
> + Conceptually, this is &LIBS[INDEX], but use ENTRY_SIZE for the size
> + of *LIBS. */
> +static inline const struct file_entry *
> +_dl_cache_file_entry (const struct file_entry *libs, size_t entry_size,
> + size_t index)
> +{
> + return (const void *) libs + index * entry_size;
> +}
> +
Although pointer arithmetic with void *is valid for gcc, I think we should
use uintptr_t here.
> +/* 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.
> + STRING_TABLE_SIZE indicates the maximum offset in STRING_TABLE at
> + which data is mapped; it is not exact. */
> +static const char *
> +search_cache (const char *string_table, uint32_t string_table_size,
> + struct file_entry *libs, uint32_t nlibs, uint32_t entry_size,
> + const char *name)
> +{
> + /* Used by the HWCAP check in the struct file_entry_new case. */
> + uint64_t platform = _dl_string_platform (GLRO (dl_platform));
> + if (platform != (uint64_t) -1)
> + platform = 1ULL << platform;
Maybe UINT64_C(1) << platform?
> + uint64_t hwcap_mask = GET_HWCAP_MASK ();
> +#define _DL_HWCAP_TLS_MASK (1LL << 63)
Same as before.
> + uint64_t hwcap_exclude = ~((GLRO (dl_hwcap) & hwcap_mask)
> + | _DL_HWCAP_PLATFORM | _DL_HWCAP_TLS_MASK);
> +
> + int left = 0;
> + int right = nlibs - 1;
> + const char *best = NULL;
> +
> + while (left <= right)
> + {
> + int middle = (left + right) / 2;
> + uint32_t key = _dl_cache_file_entry (libs, entry_size, middle)->key;
> +
> + /* Make sure string table indices are not bogus before using
> + them. */
> + if (!_dl_cache_verify_ptr (key, string_table_size))
> + return NULL;
>
> + /* Actually compare the entry with the key. */
> + int cmpres = _dl_cache_libcmp (name, string_table + key);
> + if (__glibc_unlikely (cmpres == 0))
> + {
> + /* Found it. 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)
> + {
> + key = _dl_cache_file_entry (libs, entry_size, middle - 1)->key;
> + /* Make sure string table indices are not bogus before
> + using them. */
> + if (!_dl_cache_verify_ptr (key, string_table_size)
> + /* Actually compare the entry. */
> + || _dl_cache_libcmp (name, string_table + key) != 0)
> + break;
> + --middle;
> + }
> +
> + do
> + {
> + int flags;
> + const struct file_entry *lib
> + = _dl_cache_file_entry (libs, entry_size, middle);
> +
> + /* 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 (lib->key, string_table_size)
> + || (_dl_cache_libcmp (name, string_table + lib->key)
> + != 0)))
> + break;
> +
> + flags = lib->flags;
> + if (_dl_cache_check_flags (flags)
> + && _dl_cache_verify_ptr (lib->value, string_table_size))
> + {
> + if (best == NULL || flags == GLRO (dl_correct_cache_id))
> + {
> + if (entry_size >= sizeof (struct file_entry_new))
> + {
> + /* The entry is large enough to include
> + HWCAP data. Check it. */
> + struct file_entry_new *libnew
> + = (struct file_entry_new *) lib;
> +
> + if (libnew->hwcap & hwcap_exclude)
> + continue;
> + if (GLRO (dl_osversion)
> + && libnew->osversion > GLRO (dl_osversion))
> + continue;
> + if (_DL_PLATFORMS_COUNT
> + && (libnew->hwcap & _DL_HWCAP_PLATFORM) != 0
> + && ((libnew->hwcap & _DL_HWCAP_PLATFORM)
> + != platform))
> + continue;
> + }
Ok, this is HWCAP_CHECK expanded.
> +
> + best = string_table + lib->value;
> +
> + if (flags == GLRO (dl_correct_cache_id))
> + /* We've found an exact match for the shared
> + object and no general `ELF' release. Stop
Should we replace the grave accent with apostrophe in this case?
> + searching. */
> + break;
> + }
> + }
> + }
> + while (++middle <= right);
> + break;
> + }
> +
> + if (cmpres < 0)
> + left = middle + 1;
> + else
> + right = middle - 1;
> + }
> +
> + return best;
> +}
>
> int
> _dl_cache_libcmp (const char *p1, const char *p2)
Ok.
> @@ -182,12 +220,6 @@ _dl_cache_libcmp (const char *p1, const char *p2)
> char *
> _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 (__glibc_unlikely (GLRO(dl_debug_mask) & DL_DEBUG_LIBS))
> _dl_debug_printf (" search cache=%s\n", LD_SO_CACHE);
Ok.
> @@ -265,51 +297,22 @@ _dl_load_cache_lookup (const char *name)
> /* Previously looked for the cache file and didn't find it. */
> return NULL;
>
> - best = NULL;
> -
> + const char *best;
> if (cache_new != (void *) -1)
> {
> - uint64_t platform;
> -
> - /* 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;
> -
> - platform = _dl_string_platform (GLRO(dl_platform));
> - if (platform != (uint64_t) -1)
> - platform = 1ULL << platform;
> -
> - uint64_t hwcap_mask = GET_HWCAP_MASK();
> -
> -#define _DL_HWCAP_TLS_MASK (1LL << 63)
> - uint64_t hwcap_exclude = ~((GLRO(dl_hwcap) & hwcap_mask)
> - | _DL_HWCAP_PLATFORM | _DL_HWCAP_TLS_MASK);
> -
> - /* Only accept hwcap if it's for the right platform. */
> -#define HWCAP_CHECK \
> - if (lib->hwcap & hwcap_exclude) \
> - continue; \
> - if (GLRO(dl_osversion) && lib->osversion > GLRO(dl_osversion)) \
> - continue; \
> - if (_DL_PLATFORMS_COUNT \
> - && (lib->hwcap & _DL_HWCAP_PLATFORM) != 0 \
> - && (lib->hwcap & _DL_HWCAP_PLATFORM) != platform) \
> - continue
> - SEARCH_CACHE (cache_new);
> + const char *string_table = (const char *) cache_new;
> + best = search_cache (string_table, cachesize,
> + &cache_new->libs[0].entry, cache_new->nlibs,
> + sizeof (cache_new->libs[0]), name);
> }
Ok.
> 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);
> + const char *string_table = (const char *) &cache->libs[cache->nlibs];
> + uint32_t string_table_size
> + = (const char *) cache + cachesize - string_table;
> + best = search_cache (string_table, string_table_size,
> + &cache->libs[0], cache->nlibs,
> + sizeof (cache->libs[0]), name);
> }
>
> /* Print our result if wanted. */
Ok.
> diff --git a/sysdeps/generic/dl-cache.h b/sysdeps/generic/dl-cache.h
> index b154740da9..fec209509d 100644
> --- a/sysdeps/generic/dl-cache.h
> +++ b/sysdeps/generic/dl-cache.h
> @@ -66,8 +66,8 @@
> */
> struct file_entry
> {
> - int flags; /* This is 1 for an ELF library. */
> - unsigned int key, value; /* String table indices. */
> + int32_t flags; /* This is 1 for an ELF library. */
> + uint32_t key, value; /* String table indices. */
> };
>
Ok, although not sure if our code guidelines allows multiple fields in the
same line.
> struct cache_file
> @@ -84,8 +84,17 @@ struct cache_file
>
> struct file_entry_new
> {
> - int32_t flags; /* This is 1 for an ELF library. */
> - uint32_t key, value; /* String table indices. */
> + 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; /* Required OS version. */
> uint64_t hwcap; /* Hwcap entry. */
> };
>
Ok.
* Adhemerval Zanella via Libc-alpha:
>> +/* Compute the address of the element INDEX of the array at LIBS.
>> + Conceptually, this is &LIBS[INDEX], but use ENTRY_SIZE for the size
>> + of *LIBS. */
>> +static inline const struct file_entry *
>> +_dl_cache_file_entry (const struct file_entry *libs, size_t entry_size,
>> + size_t index)
>> +{
>> + return (const void *) libs + index * entry_size;
>> +}
>> +
>
> Although pointer arithmetic with void *is valid for gcc, I think we should
> use uintptr_t here.
Do you mean char *? It will need another cast for the result. I don't
think it clarifies matters.
>> +{
>> + /* Used by the HWCAP check in the struct file_entry_new case. */
>> + uint64_t platform = _dl_string_platform (GLRO (dl_platform));
>> + if (platform != (uint64_t) -1)
>> + platform = 1ULL << platform;
>
> Maybe UINT64_C(1) << platform?
1ULL needs to be at least 64 bits, so this should be fine.
>> +
>> + best = string_table + lib->value;
>> +
>> + if (flags == GLRO (dl_correct_cache_id))
>> + /* We've found an exact match for the shared
>> + object and no general `ELF' release. Stop
>
> Should we replace the grave accent with apostrophe in this case?
I want to minimize the changes in this refactoring.
>> diff --git a/sysdeps/generic/dl-cache.h b/sysdeps/generic/dl-cache.h
>> index b154740da9..fec209509d 100644
>> --- a/sysdeps/generic/dl-cache.h
>> +++ b/sysdeps/generic/dl-cache.h
>> @@ -66,8 +66,8 @@
>> */
>> struct file_entry
>> {
>> - int flags; /* This is 1 for an ELF library. */
>> - unsigned int key, value; /* String table indices. */
>> + int32_t flags; /* This is 1 for an ELF library. */
>> + uint32_t key, value; /* String table indices. */
>> };
>>
>
> Ok, although not sure if our code guidelines allows multiple fields in the
> same line.
Likewise.
I'll assume your Reviewed-by: stands and push this separately.
Thanks,
Florian
On 30/10/2020 10:22, Florian Weimer wrote:
> * Adhemerval Zanella via Libc-alpha:
>
>>> +/* Compute the address of the element INDEX of the array at LIBS.
>>> + Conceptually, this is &LIBS[INDEX], but use ENTRY_SIZE for the size
>>> + of *LIBS. */
>>> +static inline const struct file_entry *
>>> +_dl_cache_file_entry (const struct file_entry *libs, size_t entry_size,
>>> + size_t index)
>>> +{
>>> + return (const void *) libs + index * entry_size;
>>> +}
>>> +
>>
>> Although pointer arithmetic with void *is valid for gcc, I think we should
>> use uintptr_t here.
>
> Do you mean char *? It will need another cast for the result. I don't
> think it clarifies matters.
I don't have a strong opinion in fact, it just is might not be straightforward
for a reader not used with GNU C extensions.
>
>>> +{
>>> + /* Used by the HWCAP check in the struct file_entry_new case. */
>>> + uint64_t platform = _dl_string_platform (GLRO (dl_platform));
>>> + if (platform != (uint64_t) -1)
>>> + platform = 1ULL << platform;
>>
>> Maybe UINT64_C(1) << platform?
>
> 1ULL needs to be at least 64 bits, so this should be fine.
>
>>> +
>>> + best = string_table + lib->value;
>>> +
>>> + if (flags == GLRO (dl_correct_cache_id))
>>> + /* We've found an exact match for the shared
>>> + object and no general `ELF' release. Stop
>>
>> Should we replace the grave accent with apostrophe in this case?
>
> I want to minimize the changes in this refactoring.
But git shows this as new lines anyway, so I see no good reason to
not replace it with an apostrophe.
>
>>> diff --git a/sysdeps/generic/dl-cache.h b/sysdeps/generic/dl-cache.h
>>> index b154740da9..fec209509d 100644
>>> --- a/sysdeps/generic/dl-cache.h
>>> +++ b/sysdeps/generic/dl-cache.h
>>> @@ -66,8 +66,8 @@
>>> */
>>> struct file_entry
>>> {
>>> - int flags; /* This is 1 for an ELF library. */
>>> - unsigned int key, value; /* String table indices. */
>>> + int32_t flags; /* This is 1 for an ELF library. */
>>> + uint32_t key, value; /* String table indices. */
>>> };
>>>
>>
>> Ok, although not sure if our code guidelines allows multiple fields in the
>> same line.
>
> Likewise.
>
> I'll assume your Reviewed-by: stands and push this separately.
LGTM.
@@ -35,103 +35,141 @@ 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)
-
-#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; \
- \
- while (left <= right) \
- { \
- __typeof__ (cache->libs[0].key) key; \
- \
- middle = (left + right) / 2; \
- \
- key = cache->libs[middle].key; \
- \
- /* Make sure string table indices are not bogus before using \
- them. */ \
- if (! _dl_cache_verify_ptr (key)) \
- { \
- cmpres = 1; \
- break; \
- } \
- \
- /* Actually compare the entry with the key. */ \
- cmpres = _dl_cache_libcmp (name, cache_data + key); \
- if (__glibc_unlikely (cmpres == 0)) \
- { \
- /* Found it. 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) \
- { \
- __typeof__ (cache->libs[0].key) key; \
- \
- key = cache->libs[middle - 1].key; \
- /* Make sure string table indices are not bogus before \
- using them. */ \
- if (! _dl_cache_verify_ptr (key) \
- /* Actually compare the entry. */ \
- || _dl_cache_libcmp (name, cache_data + key) != 0) \
- break; \
- --middle; \
- } \
- \
- do \
- { \
- int flags; \
- __typeof__ (cache->libs[0]) *lib = &cache->libs[middle]; \
- \
- /* 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 (lib->key) \
- || (_dl_cache_libcmp (name, cache_data + lib->key) \
- != 0))) \
- break; \
- \
- flags = lib->flags; \
- if (_dl_cache_check_flags (flags) \
- && _dl_cache_verify_ptr (lib->value)) \
- { \
- if (best == NULL || flags == GLRO(dl_correct_cache_id)) \
- { \
- HWCAP_CHECK; \
- best = cache_data + lib->value; \
- \
- if (flags == GLRO(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); \
- break; \
- } \
- \
- if (cmpres < 0) \
- left = middle + 1; \
- else \
- right = middle - 1; \
- } \
- } \
-while (0)
+/* True if PTR is a valid string table index. */
+static inline bool
+_dl_cache_verify_ptr (uint32_t ptr, size_t string_table_size)
+{
+ return ptr < string_table_size;
+}
+
+/* Compute the address of the element INDEX of the array at LIBS.
+ Conceptually, this is &LIBS[INDEX], but use ENTRY_SIZE for the size
+ of *LIBS. */
+static inline const struct file_entry *
+_dl_cache_file_entry (const struct file_entry *libs, size_t entry_size,
+ size_t index)
+{
+ return (const void *) libs + index * entry_size;
+}
+
+/* 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.
+ STRING_TABLE_SIZE indicates the maximum offset in STRING_TABLE at
+ which data is mapped; it is not exact. */
+static const char *
+search_cache (const char *string_table, uint32_t string_table_size,
+ struct file_entry *libs, uint32_t nlibs, uint32_t entry_size,
+ const char *name)
+{
+ /* Used by the HWCAP check in the struct file_entry_new case. */
+ uint64_t platform = _dl_string_platform (GLRO (dl_platform));
+ if (platform != (uint64_t) -1)
+ platform = 1ULL << platform;
+ uint64_t hwcap_mask = GET_HWCAP_MASK ();
+#define _DL_HWCAP_TLS_MASK (1LL << 63)
+ uint64_t hwcap_exclude = ~((GLRO (dl_hwcap) & hwcap_mask)
+ | _DL_HWCAP_PLATFORM | _DL_HWCAP_TLS_MASK);
+
+ int left = 0;
+ int right = nlibs - 1;
+ const char *best = NULL;
+
+ while (left <= right)
+ {
+ int middle = (left + right) / 2;
+ uint32_t key = _dl_cache_file_entry (libs, entry_size, middle)->key;
+
+ /* Make sure string table indices are not bogus before using
+ them. */
+ if (!_dl_cache_verify_ptr (key, string_table_size))
+ return NULL;
+ /* Actually compare the entry with the key. */
+ int cmpres = _dl_cache_libcmp (name, string_table + key);
+ if (__glibc_unlikely (cmpres == 0))
+ {
+ /* Found it. 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)
+ {
+ key = _dl_cache_file_entry (libs, entry_size, middle - 1)->key;
+ /* Make sure string table indices are not bogus before
+ using them. */
+ if (!_dl_cache_verify_ptr (key, string_table_size)
+ /* Actually compare the entry. */
+ || _dl_cache_libcmp (name, string_table + key) != 0)
+ break;
+ --middle;
+ }
+
+ do
+ {
+ int flags;
+ const struct file_entry *lib
+ = _dl_cache_file_entry (libs, entry_size, middle);
+
+ /* 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 (lib->key, string_table_size)
+ || (_dl_cache_libcmp (name, string_table + lib->key)
+ != 0)))
+ break;
+
+ flags = lib->flags;
+ if (_dl_cache_check_flags (flags)
+ && _dl_cache_verify_ptr (lib->value, string_table_size))
+ {
+ if (best == NULL || flags == GLRO (dl_correct_cache_id))
+ {
+ if (entry_size >= sizeof (struct file_entry_new))
+ {
+ /* The entry is large enough to include
+ HWCAP data. Check it. */
+ struct file_entry_new *libnew
+ = (struct file_entry_new *) lib;
+
+ if (libnew->hwcap & hwcap_exclude)
+ continue;
+ if (GLRO (dl_osversion)
+ && libnew->osversion > GLRO (dl_osversion))
+ continue;
+ if (_DL_PLATFORMS_COUNT
+ && (libnew->hwcap & _DL_HWCAP_PLATFORM) != 0
+ && ((libnew->hwcap & _DL_HWCAP_PLATFORM)
+ != platform))
+ continue;
+ }
+
+ best = string_table + lib->value;
+
+ if (flags == GLRO (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);
+ break;
+ }
+
+ if (cmpres < 0)
+ left = middle + 1;
+ else
+ right = middle - 1;
+ }
+
+ return best;
+}
int
_dl_cache_libcmp (const char *p1, const char *p2)
@@ -182,12 +220,6 @@ _dl_cache_libcmp (const char *p1, const char *p2)
char *
_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 (__glibc_unlikely (GLRO(dl_debug_mask) & DL_DEBUG_LIBS))
_dl_debug_printf (" search cache=%s\n", LD_SO_CACHE);
@@ -265,51 +297,22 @@ _dl_load_cache_lookup (const char *name)
/* Previously looked for the cache file and didn't find it. */
return NULL;
- best = NULL;
-
+ const char *best;
if (cache_new != (void *) -1)
{
- uint64_t platform;
-
- /* 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;
-
- platform = _dl_string_platform (GLRO(dl_platform));
- if (platform != (uint64_t) -1)
- platform = 1ULL << platform;
-
- uint64_t hwcap_mask = GET_HWCAP_MASK();
-
-#define _DL_HWCAP_TLS_MASK (1LL << 63)
- uint64_t hwcap_exclude = ~((GLRO(dl_hwcap) & hwcap_mask)
- | _DL_HWCAP_PLATFORM | _DL_HWCAP_TLS_MASK);
-
- /* Only accept hwcap if it's for the right platform. */
-#define HWCAP_CHECK \
- if (lib->hwcap & hwcap_exclude) \
- continue; \
- if (GLRO(dl_osversion) && lib->osversion > GLRO(dl_osversion)) \
- continue; \
- if (_DL_PLATFORMS_COUNT \
- && (lib->hwcap & _DL_HWCAP_PLATFORM) != 0 \
- && (lib->hwcap & _DL_HWCAP_PLATFORM) != platform) \
- continue
- SEARCH_CACHE (cache_new);
+ const char *string_table = (const char *) cache_new;
+ best = search_cache (string_table, cachesize,
+ &cache_new->libs[0].entry, cache_new->nlibs,
+ sizeof (cache_new->libs[0]), name);
}
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);
+ const char *string_table = (const char *) &cache->libs[cache->nlibs];
+ uint32_t string_table_size
+ = (const char *) cache + cachesize - string_table;
+ best = search_cache (string_table, string_table_size,
+ &cache->libs[0], cache->nlibs,
+ sizeof (cache->libs[0]), name);
}
/* Print our result if wanted. */
@@ -66,8 +66,8 @@
*/
struct file_entry
{
- int flags; /* This is 1 for an ELF library. */
- unsigned int key, value; /* String table indices. */
+ int32_t flags; /* This is 1 for an ELF library. */
+ uint32_t key, value; /* String table indices. */
};
struct cache_file
@@ -84,8 +84,17 @@ struct cache_file
struct file_entry_new
{
- int32_t flags; /* This is 1 for an ELF library. */
- uint32_t key, value; /* String table indices. */
+ 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; /* Required OS version. */
uint64_t hwcap; /* Hwcap entry. */
};