/* Look up a symbol in the loaded objects.
- Copyright (C) 1995-2020 Free Software Foundation, Inc.
+ Copyright (C) 1995-2022 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
#include <ldsodefs.h>
#include <dl-hash.h>
#include <dl-machine.h>
+#include <dl-protected.h>
#include <sysdep-cancel.h>
#include <libc-lock.h>
#include <tls.h>
in the unique symbol table, creating a new entry if necessary.
Return the matching symbol in RESULT. */
static void
-do_lookup_unique (const char *undef_name, uint_fast32_t new_hash,
+do_lookup_unique (const char *undef_name, unsigned int new_hash,
struct link_map *map, struct sym_val *result,
int type_class, const ElfW(Sym) *sym, const char *strtab,
const ElfW(Sym) *ref, const struct link_map *undef_map,
assert (!RTLD_CHECK_FOREIGN_CALL);
#endif
-#ifdef SHARED
- /* If tab->entries is NULL, but tab->size is not, it means
- this is the second, conflict finding, lookup for
- LD_TRACE_PRELINKING in _dl_debug_bindings. Don't
- allocate anything and don't enter anything into the
- hash table. */
- if (__glibc_unlikely (tab->size))
- {
- assert (GLRO(dl_debug_mask) & DL_DEBUG_PRELINK);
- goto success;
- }
-#endif
-
#define INITIAL_NUNIQUE_SYM_TABLE 31
size = INITIAL_NUNIQUE_SYM_TABLE;
entries = calloc (sizeof (struct unique_sym), size);
}
++tab->n_elements;
-#ifdef SHARED
- success:
-#endif
__rtld_lock_unlock_recursive (tab->lock);
result->s = sym;
something bad happened. */
static int
__attribute_noinline__
-do_lookup_x (const char *undef_name, uint_fast32_t new_hash,
+do_lookup_x (const char *undef_name, unsigned int new_hash,
unsigned long int *old_hash, const ElfW(Sym) *ref,
struct sym_val *result, struct r_scope_elem *scope, size_t i,
const struct r_found_version *const version, int flags,
if (__glibc_unlikely (dl_symbol_visibility_binds_local_p (sym)))
goto skip;
+ if (ELFW(ST_VISIBILITY) (sym->st_other) == STV_PROTECTED)
+ _dl_check_protected_symbol (undef_name, undef_map, ref, map,
+ type_class);
+
switch (ELFW(ST_BIND) (sym->st_info))
{
case STB_WEAK:
}
-static uint_fast32_t
+static uint32_t
dl_new_hash (const char *s)
{
- uint_fast32_t h = 5381;
+ uint32_t h = 5381;
for (unsigned char c = *s; c != '\0'; c = *++s)
h = h * 33 + c;
- return h & 0xffffffff;
+ return h;
}
goto out;
}
-static void
-_dl_debug_bindings (const char *undef_name, struct link_map *undef_map,
- const ElfW(Sym) **ref, struct sym_val *value,
- const struct r_found_version *version, int type_class,
- int protected);
-
/* Search loaded objects' symbol tables for a definition of the symbol
UNDEF_NAME, perhaps with a requested version for the symbol.
const struct r_found_version *version,
int type_class, int flags, struct link_map *skip_map)
{
- const uint_fast32_t new_hash = dl_new_hash (undef_name);
+ const unsigned int new_hash = dl_new_hash (undef_name);
unsigned long int old_hash = 0xffffffff;
struct sym_val current_value = { NULL, NULL };
struct r_scope_elem **scope = symbol_scope;
if (__glibc_unlikely (current_value.m->l_used == 0))
current_value.m->l_used = 1;
- if (__glibc_unlikely (GLRO(dl_debug_mask)
- & (DL_DEBUG_BINDINGS|DL_DEBUG_PRELINK)))
- _dl_debug_bindings (undef_name, undef_map, ref,
- ¤t_value, version, type_class, protected);
-
*ref = current_value.s;
return LOOKUP_VALUE (current_value.m);
}
-
-
-/* Cache the location of MAP's hash table. */
-
-void
-_dl_setup_hash (struct link_map *map)
-{
- Elf_Symndx *hash;
-
- if (__glibc_likely (map->l_info[ELF_MACHINE_GNU_HASH_ADDRIDX] != NULL))
- {
- Elf32_Word *hash32
- = (void *) D_PTR (map, l_info[ELF_MACHINE_GNU_HASH_ADDRIDX]);
- map->l_nbuckets = *hash32++;
- Elf32_Word symbias = *hash32++;
- Elf32_Word bitmask_nwords = *hash32++;
- /* Must be a power of two. */
- assert ((bitmask_nwords & (bitmask_nwords - 1)) == 0);
- map->l_gnu_bitmask_idxbits = bitmask_nwords - 1;
- map->l_gnu_shift = *hash32++;
-
- map->l_gnu_bitmask = (ElfW(Addr) *) hash32;
- hash32 += __ELF_NATIVE_CLASS / 32 * bitmask_nwords;
-
- map->l_gnu_buckets = hash32;
- hash32 += map->l_nbuckets;
- map->l_gnu_chain_zero = hash32 - symbias;
-
- /* Initialize MIPS xhash translation table. */
- ELF_MACHINE_XHASH_SETUP (hash32, symbias, map);
-
- return;
- }
-
- if (!map->l_info[DT_HASH])
- return;
- hash = (void *) D_PTR (map, l_info[DT_HASH]);
-
- map->l_nbuckets = *hash++;
- /* Skip nchain. */
- hash++;
- map->l_buckets = hash;
- hash += map->l_nbuckets;
- map->l_chain = hash;
-}
-
-
-static void
-_dl_debug_bindings (const char *undef_name, struct link_map *undef_map,
- const ElfW(Sym) **ref, struct sym_val *value,
- const struct r_found_version *version, int type_class,
- int protected)
-{
- const char *reference_name = undef_map->l_name;
-
- if (GLRO(dl_debug_mask) & DL_DEBUG_BINDINGS)
- {
- _dl_debug_printf ("binding file %s [%lu] to %s [%lu]: %s symbol `%s'",
- DSO_FILENAME (reference_name),
- undef_map->l_ns,
- DSO_FILENAME (value->m->l_name),
- value->m->l_ns,
- protected ? "protected" : "normal", undef_name);
- if (version)
- _dl_debug_printf_c (" [%s]\n", version->name);
- else
- _dl_debug_printf_c ("\n");
- }
-#ifdef SHARED
- if (GLRO(dl_debug_mask) & DL_DEBUG_PRELINK)
- {
-/* ELF_RTYPE_CLASS_XXX must match RTYPE_CLASS_XXX used by prelink with
- LD_TRACE_PRELINKING. */
-#define RTYPE_CLASS_VALID 8
-#define RTYPE_CLASS_PLT (8|1)
-#define RTYPE_CLASS_COPY (8|2)
-#define RTYPE_CLASS_TLS (8|4)
-#if ELF_RTYPE_CLASS_PLT != 0 && ELF_RTYPE_CLASS_PLT != 1
-# error ELF_RTYPE_CLASS_PLT must be 0 or 1!
-#endif
-#if ELF_RTYPE_CLASS_COPY != 0 && ELF_RTYPE_CLASS_COPY != 2
-# error ELF_RTYPE_CLASS_COPY must be 0 or 2!
-#endif
- int conflict = 0;
- struct sym_val val = { NULL, NULL };
-
- if ((GLRO(dl_trace_prelink_map) == NULL
- || GLRO(dl_trace_prelink_map) == GL(dl_ns)[LM_ID_BASE]._ns_loaded)
- && undef_map != GL(dl_ns)[LM_ID_BASE]._ns_loaded)
- {
- const uint_fast32_t new_hash = dl_new_hash (undef_name);
- unsigned long int old_hash = 0xffffffff;
- struct unique_sym *saved_entries
- = GL(dl_ns)[LM_ID_BASE]._ns_unique_sym_table.entries;
-
- GL(dl_ns)[LM_ID_BASE]._ns_unique_sym_table.entries = NULL;
- do_lookup_x (undef_name, new_hash, &old_hash, *ref, &val,
- undef_map->l_local_scope[0], 0, version, 0, NULL,
- type_class, undef_map);
- if (val.s != value->s || val.m != value->m)
- conflict = 1;
- else if (__glibc_unlikely (undef_map->l_symbolic_in_local_scope)
- && val.s
- && __glibc_unlikely (ELFW(ST_BIND) (val.s->st_info)
- == STB_GNU_UNIQUE))
- {
- /* If it is STB_GNU_UNIQUE and undef_map's l_local_scope
- contains any DT_SYMBOLIC libraries, unfortunately there
- can be conflicts even if the above is equal. As symbol
- resolution goes from the last library to the first and
- if a STB_GNU_UNIQUE symbol is found in some late DT_SYMBOLIC
- library, it would be the one that is looked up. */
- struct sym_val val2 = { NULL, NULL };
- size_t n;
- struct r_scope_elem *scope = undef_map->l_local_scope[0];
-
- for (n = 0; n < scope->r_nlist; n++)
- if (scope->r_list[n] == val.m)
- break;
-
- for (n++; n < scope->r_nlist; n++)
- if (scope->r_list[n]->l_info[DT_SYMBOLIC] != NULL
- && do_lookup_x (undef_name, new_hash, &old_hash, *ref,
- &val2,
- &scope->r_list[n]->l_symbolic_searchlist,
- 0, version, 0, NULL, type_class,
- undef_map) > 0)
- {
- conflict = 1;
- val = val2;
- break;
- }
- }
- GL(dl_ns)[LM_ID_BASE]._ns_unique_sym_table.entries = saved_entries;
- }
-
- if (value->s)
- {
- /* Keep only ELF_RTYPE_CLASS_PLT and ELF_RTYPE_CLASS_COPY
- bits since since prelink only uses them. */
- type_class &= ELF_RTYPE_CLASS_PLT | ELF_RTYPE_CLASS_COPY;
- if (__glibc_unlikely (ELFW(ST_TYPE) (value->s->st_info)
- == STT_TLS))
- /* Clear the RTYPE_CLASS_VALID bit in RTYPE_CLASS_TLS. */
- type_class = RTYPE_CLASS_TLS & ~RTYPE_CLASS_VALID;
- else if (__glibc_unlikely (ELFW(ST_TYPE) (value->s->st_info)
- == STT_GNU_IFUNC))
- /* Set the RTYPE_CLASS_VALID bit. */
- type_class |= RTYPE_CLASS_VALID;
- }
-
- if (conflict
- || GLRO(dl_trace_prelink_map) == undef_map
- || GLRO(dl_trace_prelink_map) == NULL
- || type_class >= 4)
- {
- _dl_printf ("%s 0x%0*Zx 0x%0*Zx -> 0x%0*Zx 0x%0*Zx ",
- conflict ? "conflict" : "lookup",
- (int) sizeof (ElfW(Addr)) * 2,
- (size_t) undef_map->l_map_start,
- (int) sizeof (ElfW(Addr)) * 2,
- (size_t) (((ElfW(Addr)) *ref) - undef_map->l_map_start),
- (int) sizeof (ElfW(Addr)) * 2,
- (size_t) (value->s ? value->m->l_map_start : 0),
- (int) sizeof (ElfW(Addr)) * 2,
- (size_t) (value->s ? value->s->st_value : 0));
-
- if (conflict)
- _dl_printf ("x 0x%0*Zx 0x%0*Zx ",
- (int) sizeof (ElfW(Addr)) * 2,
- (size_t) (val.s ? val.m->l_map_start : 0),
- (int) sizeof (ElfW(Addr)) * 2,
- (size_t) (val.s ? val.s->st_value : 0));
-
- _dl_printf ("/%x %s\n", type_class, undef_name);
- }
- }
-#endif
-}
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