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-rw-r--r--elf/dl-addr.c193
1 files changed, 114 insertions, 79 deletions
diff --git a/elf/dl-addr.c b/elf/dl-addr.c
index 685cab9..7dbf716 100644
--- a/elf/dl-addr.c
+++ b/elf/dl-addr.c
@@ -1,5 +1,5 @@
/* Locate the shared object symbol nearest a given address.
- Copyright (C) 1996-2003, 2004 Free Software Foundation, Inc.
+ Copyright (C) 1996-2004, 2005, 2006, 2007 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
@@ -22,61 +22,62 @@
#include <ldsodefs.h>
-int
-internal_function
-_dl_addr (const void *address, Dl_info *info,
- struct link_map **mapp, const ElfW(Sym) **symbolp)
+static void
+__attribute ((always_inline))
+determine_info (const ElfW(Addr) addr, struct link_map *match, Dl_info *info,
+ struct link_map **mapp, const ElfW(Sym) **symbolp)
{
- const ElfW(Addr) addr = DL_LOOKUP_ADDRESS (address);
- struct link_map *match;
- const ElfW(Sym) *symtab, *matchsym, *symtabend;
- const char *strtab;
- ElfW(Word) strtabsize;
+ /* Now we know what object the address lies in. */
+ info->dli_fname = match->l_name;
+ info->dli_fbase = (void *) match->l_map_start;
- /* Protect against concurrent loads and unloads. */
- __rtld_lock_lock_recursive (GL(dl_load_lock));
+ /* If this is the main program the information is incomplete. */
+ if (__builtin_expect (match->l_name[0], 'a') == '\0'
+ && match->l_type == lt_executable)
+ info->dli_fname = _dl_argv[0];
- /* Find the highest-addressed object that ADDRESS is not below. */
- match = NULL;
- for (Lmid_t ns = 0; ns < DL_NNS; ++ns)
- for (struct link_map *l = GL(dl_ns)[ns]._ns_loaded; l; l = l->l_next)
- if (addr >= l->l_map_start && addr < l->l_map_end)
+ const ElfW(Sym) *symtab
+ = (const ElfW(Sym) *) D_PTR (match, l_info[DT_SYMTAB]);
+ const char *strtab = (const char *) D_PTR (match, l_info[DT_STRTAB]);
+
+ ElfW(Word) strtabsize = match->l_info[DT_STRSZ]->d_un.d_val;
+
+ const ElfW(Sym) *matchsym = NULL;
+ if (match->l_info[DT_ADDRTAGIDX (DT_GNU_HASH) + DT_NUM + DT_THISPROCNUM
+ + DT_VERSIONTAGNUM + DT_EXTRANUM + DT_VALNUM] != NULL)
+ {
+ /* We look at all symbol table entries referenced by the hash
+ table. */
+ for (Elf_Symndx bucket = 0; bucket < match->l_nbuckets; ++bucket)
{
- /* We know ADDRESS lies within L if in any shared object.
- Make sure it isn't past the end of L's segments. */
- size_t n = l->l_phnum;
- if (n > 0)
+ Elf32_Word symndx = match->l_gnu_buckets[bucket];
+ if (symndx != 0)
{
+ const Elf32_Word *hasharr = &match->l_gnu_chain_zero[symndx];
+
do
- --n;
- while (l->l_phdr[n].p_type != PT_LOAD);
- if (addr >= (l->l_addr +
- l->l_phdr[n].p_vaddr + l->l_phdr[n].p_memsz))
- /* Off the end of the highest-addressed shared object. */
- continue;
+ {
+ /* The hash table never references local symbols so
+ we can omit that test here. */
+ if ((symtab[symndx].st_shndx != SHN_UNDEF
+ || symtab[symndx].st_value != 0)
+#ifdef USE_TLS
+ && ELFW(ST_TYPE) (symtab[symndx].st_info) != STT_TLS
+#endif
+ && DL_ADDR_SYM_MATCH (match, &symtab[symndx],
+ matchsym, addr)
+ && symtab[symndx].st_name < strtabsize)
+ matchsym = (ElfW(Sym) *) &symtab[symndx];
+
+ ++symndx;
+ }
+ while ((*hasharr++ & 1u) == 0);
}
-
- match = l;
- break;
}
-
- int result = 0;
- if (match != NULL)
+ }
+ else
{
- /* Now we know what object the address lies in. */
- info->dli_fname = match->l_name;
- info->dli_fbase = (void *) match->l_map_start;
-
- /* If this is the main program the information is incomplete. */
- if (__builtin_expect (match->l_name[0], 'a') == '\0'
- && match->l_type == lt_executable)
- info->dli_fname = _dl_argv[0];
-
- symtab = (const void *) D_PTR (match, l_info[DT_SYMTAB]);
- strtab = (const void *) D_PTR (match, l_info[DT_STRTAB]);
-
- strtabsize = match->l_info[DT_STRSZ]->d_un.d_val;
-
+ const ElfW(Sym) *symtabend;
if (match->l_info[DT_HASH] != NULL)
symtabend = (symtab
+ ((Elf_Symndx *) D_PTR (match, l_info[DT_HASH]))[1]);
@@ -87,49 +88,83 @@ _dl_addr (const void *address, Dl_info *info,
the string table which generally follows the symbol table. */
symtabend = (const ElfW(Sym) *) strtab;
- /* We assume that the string table follows the symbol table,
- because there is no way in ELF to know the size of the
- dynamic symbol table!! */
- for (matchsym = NULL; (void *) symtab < (void *) symtabend; ++symtab)
- if (addr >= match->l_addr + symtab->st_value
-#if defined USE_TLS
+ for (; (void *) symtab < (void *) symtabend; ++symtab)
+ if ((ELFW(ST_BIND) (symtab->st_info) == STB_GLOBAL
+ || ELFW(ST_BIND) (symtab->st_info) == STB_WEAK)
+#ifdef USE_TLS
&& ELFW(ST_TYPE) (symtab->st_info) != STT_TLS
#endif
- && ((symtab->st_size == 0
- && addr == match->l_addr + symtab->st_value)
- || addr < match->l_addr + symtab->st_value + symtab->st_size)
- && symtab->st_name < strtabsize
- && (matchsym == NULL || matchsym->st_value < symtab->st_value)
- && (ELFW(ST_BIND) (symtab->st_info) == STB_GLOBAL
- || ELFW(ST_BIND) (symtab->st_info) == STB_WEAK))
+ && (symtab->st_shndx != SHN_UNDEF
+ || symtab->st_value != 0)
+ && DL_ADDR_SYM_MATCH (match, symtab, matchsym, addr)
+ && symtab->st_name < strtabsize)
matchsym = (ElfW(Sym) *) symtab;
+ }
- if (mapp)
- *mapp = match;
- if (symbolp)
- *symbolp = matchsym;
+ if (mapp)
+ *mapp = match;
+ if (symbolp)
+ *symbolp = matchsym;
- if (matchsym)
- {
- /* We found a symbol close by. Fill in its name and exact
- address. */
- lookup_t matchl = LOOKUP_VALUE (match);
+ if (matchsym)
+ {
+ /* We found a symbol close by. Fill in its name and exact
+ address. */
+ lookup_t matchl = LOOKUP_VALUE (match);
- info->dli_sname = strtab + matchsym->st_name;
- info->dli_saddr = DL_SYMBOL_ADDRESS (matchl, matchsym);
- }
- else
+ info->dli_sname = strtab + matchsym->st_name;
+ info->dli_saddr = DL_SYMBOL_ADDRESS (matchl, matchsym);
+ }
+ else
+ {
+ /* No symbol matches. We return only the containing object. */
+ info->dli_sname = NULL;
+ info->dli_saddr = NULL;
+ }
+}
+
+
+int
+internal_function
+_dl_addr (const void *address, Dl_info *info,
+ struct link_map **mapp, const ElfW(Sym) **symbolp)
+{
+ const ElfW(Addr) addr = DL_LOOKUP_ADDRESS (address);
+ int result = 0;
+
+ /* Protect against concurrent loads and unloads. */
+ __rtld_lock_lock_recursive (GL(dl_load_lock));
+
+ /* Find the highest-addressed object that ADDRESS is not below. */
+ for (Lmid_t ns = 0; ns < DL_NNS; ++ns)
+ for (struct link_map *l = GL(dl_ns)[ns]._ns_loaded; l; l = l->l_next)
+ if (addr >= l->l_map_start && addr < l->l_map_end
+ && (l->l_contiguous || _dl_addr_inside_object (l, addr)))
{
- /* No symbol matches. We return only the containing object. */
- info->dli_sname = NULL;
- info->dli_saddr = NULL;
+ determine_info (addr, l, info, mapp, symbolp);
+ result = 1;
+ goto out;
}
- result = 1;
- }
-
+ out:
__rtld_lock_unlock_recursive (GL(dl_load_lock));
return result;
}
libc_hidden_def (_dl_addr)
+
+/* Return non-zero if ADDR lies within one of L's segments. */
+int
+internal_function
+_dl_addr_inside_object (struct link_map *l, const ElfW(Addr) addr)
+{
+ int n = l->l_phnum;
+ const ElfW(Addr) reladdr = addr - l->l_addr;
+
+ while (--n >= 0)
+ if (l->l_phdr[n].p_type == PT_LOAD
+ && reladdr - l->l_phdr[n].p_vaddr >= 0
+ && reladdr - l->l_phdr[n].p_vaddr < l->l_phdr[n].p_memsz)
+ return 1;
+ return 0;
+}