rpms
/
glibc
20
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity
You can not select more than 25 topics Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
Branches Tags
${ item.name }
Create tag ${ searchTerm }
Create branch ${ searchTerm }
from '5462dd1bb7'
${ noResults }
glibc/SOURCES/glibc-rh1817513-108.patch

365 lines
12 KiB
Raw Blame History

commit de1a9197af7f67a89f929dcadb8ceca8c3846b1c
Author: Florian Weimer <fweimer@redhat.com>
Date: Fri Oct 30 11:57:59 2020 +0100
elf: Unify old and new format cache handling code in ld.so
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.
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
diff --git a/elf/dl-cache.c b/elf/dl-cache.c
index ef37ca18fa9fb6e0..366a051dfcd26132 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)
+/* 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);
@@ -247,51 +279,22 @@ _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. */
diff --git a/sysdeps/generic/dl-cache.h b/sysdeps/generic/dl-cache.h
index cf43f1cf3b441bc7..3c5730dfe42c7c88 100644
--- a/sysdeps/generic/dl-cache.h
+++ b/sysdeps/generic/dl-cache.h
@@ -59,8 +59,8 @@
*/
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
@@ -77,8 +77,17 @@ 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. */
};
Reference in new issue View Git Blame Copy Permalink