2007-05-06  Ulrich Drepper  <drepper@redhat.com>
	[BZ #4131]
	* elf/dl-addr.c (_dl_addr): Compare address with actual segment
	boundaries to work around systems with overlapping binary loading.
	Based on a patch by Suzuki <suzuki@in.ibm.com>.
This commit is contained in:
Ulrich Drepper 2007-05-06 21:01:32 +00:00
parent 30b323ab4e
commit ffecd39b9c
2 changed files with 122 additions and 115 deletions

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@ -1,3 +1,10 @@
2007-05-06 Ulrich Drepper <drepper@redhat.com>
[BZ #4131]
* elf/dl-addr.c (_dl_addr): Compare address with actual segment
boundaries to work around systems with overlapping binary loading.
Based on a patch by Suzuki <suzuki@in.ibm.com>.
2007-05-04 Ulrich Drepper <drepper@redhat.com>
* stdio-common/vfprintf.c (process_string_arg): Adjust call to

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@ -1,5 +1,5 @@
/* Locate the shared object symbol nearest a given address.
Copyright (C) 1996-2004, 2005, 2006 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
@ -22,137 +22,137 @@
#include <ldsodefs.h>
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)
{
/* 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];
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)
{
Elf32_Word symndx = match->l_gnu_buckets[bucket];
if (symndx != 0)
{
const Elf32_Word *hasharr = &match->l_gnu_chain_zero[symndx];
do
{
/* 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)
&& ELFW(ST_TYPE) (symtab[symndx].st_info) != STT_TLS
&& DL_ADDR_SYM_MATCH (match, &symtab[symndx],
matchsym, addr)
&& symtab[symndx].st_name < strtabsize)
matchsym = (ElfW(Sym) *) &symtab[symndx];
++symndx;
}
while ((*hasharr++ & 1u) == 0);
}
}
}
else
{
const ElfW(Sym) *symtabend;
if (match->l_info[DT_HASH] != NULL)
symtabend = (symtab
+ ((Elf_Symndx *) D_PTR (match, l_info[DT_HASH]))[1]);
else
/* There is no direct way to determine the number of symbols in the
dynamic symbol table and no hash table is present. The ELF
binary is ill-formed but what shall we do? Use the beginning of
the string table which generally follows the symbol table. */
symtabend = (const ElfW(Sym) *) strtab;
for (; (void *) symtab < (void *) symtabend; ++symtab)
if ((ELFW(ST_BIND) (symtab->st_info) == STB_GLOBAL
|| ELFW(ST_BIND) (symtab->st_info) == STB_WEAK)
&& ELFW(ST_TYPE) (symtab->st_info) != STT_TLS
&& (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 (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
{
/* 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. */
struct link_map *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)
{
/* 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)
{
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;
}
match = l;
break;
/* Make sure it lies within one of L's segments. */
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)
{
if (reladdr - l->l_phdr[n].p_vaddr >= 0
&& reladdr - l->l_phdr[n].p_vaddr < l->l_phdr[n].p_memsz)
{
determine_info (addr, l, info, mapp, symbolp);
result = 1;
goto out;
}
}
}
int result = 0;
if (match != NULL)
{
/* 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];
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)
{
Elf32_Word symndx = match->l_gnu_buckets[bucket];
if (symndx != 0)
{
const Elf32_Word *hasharr = &match->l_gnu_chain_zero[symndx];
do
{
/* 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)
&& ELFW(ST_TYPE) (symtab[symndx].st_info) != STT_TLS
&& DL_ADDR_SYM_MATCH (match, &symtab[symndx],
matchsym, addr)
&& symtab[symndx].st_name < strtabsize)
matchsym = (ElfW(Sym) *) &symtab[symndx];
++symndx;
}
while ((*hasharr++ & 1u) == 0);
}
}
}
else
{
const ElfW(Sym) *symtabend;
if (match->l_info[DT_HASH] != NULL)
symtabend = (symtab
+ ((Elf_Symndx *) D_PTR (match, l_info[DT_HASH]))[1]);
else
/* There is no direct way to determine the number of symbols in the
dynamic symbol table and no hash table is present. The ELF
binary is ill-formed but what shall we do? Use the beginning of
the string table which generally follows the symbol table. */
symtabend = (const ElfW(Sym) *) strtab;
for (; (void *) symtab < (void *) symtabend; ++symtab)
if ((ELFW(ST_BIND) (symtab->st_info) == STB_GLOBAL
|| ELFW(ST_BIND) (symtab->st_info) == STB_WEAK)
&& ELFW(ST_TYPE) (symtab->st_info) != STT_TLS
&& (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 (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
{
/* No symbol matches. We return only the containing object. */
info->dli_sname = NULL;
info->dli_saddr = NULL;
}
result = 1;
}
out:
__rtld_lock_unlock_recursive (GL(dl_load_lock));
return result;