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2.5-18.1

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This commit is contained in:
Jakub Jelinek
2007-07-12 18:26:36 +00:00
parent 7d58530341
commit 0ecb606cb6
6215 changed files with 494638 additions and 305010 deletions
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320
elf/dl-runtime.c
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@ -1,5 +1,5 @@
/* On-demand PLT fixup for shared objects.
Copyright (C) 1995-2002, 2003, 2004 Free Software Foundation, Inc.
Copyright (C) 1995-2006, 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
@ -22,8 +22,12 @@
#include <alloca.h>
#include <stdlib.h>
#include <unistd.h>
#include <sys/param.h>
#include <ldsodefs.h>
#include <sysdep-cancel.h>
#include "dynamic-link.h"
#include <tls.h>
#if (!defined ELF_MACHINE_NO_RELA && !defined ELF_MACHINE_PLT_REL) \
|| ELF_MACHINE_NO_REL
@ -51,15 +55,15 @@
function. */
#ifndef ELF_MACHINE_NO_PLT
static ElfW(Addr)
__attribute ((used, noinline)) ARCH_FIXUP_ATTRIBUTE
fixup (
DL_FIXUP_VALUE_TYPE
__attribute ((noinline)) ARCH_FIXUP_ATTRIBUTE
_dl_fixup (
# ifdef ELF_MACHINE_RUNTIME_FIXUP_ARGS
ELF_MACHINE_RUNTIME_FIXUP_ARGS,
ELF_MACHINE_RUNTIME_FIXUP_ARGS,
# endif
/* GKM FIXME: Fix trampoline to pass bounds so we can do
without the `__unbounded' qualifier. */
struct link_map *__unbounded l, ElfW(Word) reloc_offset)
/* GKM FIXME: Fix trampoline to pass bounds so we can do
without the `__unbounded' qualifier. */
struct link_map *__unbounded l, ElfW(Word) reloc_offset)
{
const ElfW(Sym) *const symtab
= (const void *) D_PTR (l, l_info[DT_SYMTAB]);
@ -70,7 +74,7 @@ fixup (
const ElfW(Sym) *sym = &symtab[ELFW(R_SYM) (reloc->r_info)];
void *const rel_addr = (void *)(l->l_addr + reloc->r_offset);
lookup_t result;
ElfW(Addr) value;
DL_FIXUP_VALUE_TYPE value;
/* Sanity check that we're really looking at a PLT relocation. */
assert (ELFW(R_TYPE)(reloc->r_info) == ELF_MACHINE_JMP_SLOT);
@ -80,8 +84,6 @@ fixup (
if (__builtin_expect (ELFW(ST_VISIBILITY) (sym->st_other), 0) == 0)
{
const struct r_found_version *version = NULL;
// XXX Why exactly do we have the differentiation of the flags here?
int flags = DL_LOOKUP_ADD_DEPENDENCY;
if (l->l_info[VERSYMIDX (DT_VERSYM)] != NULL)
{
@ -91,27 +93,35 @@ fixup (
version = &l->l_versions[ndx];
if (version->hash == 0)
version = NULL;
else
flags = 0;
}
result = _dl_lookup_symbol_x (strtab + sym->st_name, l, &sym,
l->l_scope, version, ELF_RTYPE_CLASS_PLT,
DL_LOOKUP_ADD_DEPENDENCY, NULL);
/* We need to keep the scope around so do some locking. This is
not necessary for objects which cannot be unloaded or when
we are not using any threads (yet). */
int flags = DL_LOOKUP_ADD_DEPENDENCY;
if (!RTLD_SINGLE_THREAD_P)
THREAD_GSCOPE_SET_FLAG ();
result = _dl_lookup_symbol_x (strtab + sym->st_name, l, &sym, l->l_scope,
version, ELF_RTYPE_CLASS_PLT, flags, NULL);
/* We are done with the global scope. */
if (!RTLD_SINGLE_THREAD_P)
THREAD_GSCOPE_RESET_FLAG ();
/* Currently result contains the base load address (or link map)
of the object that defines sym. Now add in the symbol
offset. */
value = (sym ? LOOKUP_VALUE_ADDRESS (result) + sym->st_value : 0);
value = DL_FIXUP_MAKE_VALUE (result,
sym ? (LOOKUP_VALUE_ADDRESS (result)
+ sym->st_value) : 0);
}
else
{
/* We already found the symbol. The module (and therefore its load
address) is also known. */
value = l->l_addr + sym->st_value;
#ifdef DL_LOOKUP_RETURNS_MAP
value = DL_FIXUP_MAKE_VALUE (l, l->l_addr + sym->st_value);
result = l;
#endif
}
/* And now perhaps the relocation addend. */
@ -127,45 +137,45 @@ fixup (
#if !defined PROF && !defined ELF_MACHINE_NO_PLT && !__BOUNDED_POINTERS__
static ElfW(Addr)
__attribute ((used, noinline)) ARCH_FIXUP_ATTRIBUTE
profile_fixup (
DL_FIXUP_VALUE_TYPE
__attribute ((noinline)) ARCH_FIXUP_ATTRIBUTE
_dl_profile_fixup (
#ifdef ELF_MACHINE_RUNTIME_FIXUP_ARGS
ELF_MACHINE_RUNTIME_FIXUP_ARGS,
ELF_MACHINE_RUNTIME_FIXUP_ARGS,
#endif
struct link_map *l, ElfW(Word) reloc_offset, ElfW(Addr) retaddr)
struct link_map *l, ElfW(Word) reloc_offset,
ElfW(Addr) retaddr, void *regs, long int *framesizep)
{
void (*mcount_fct) (ElfW(Addr), ElfW(Addr)) = INTUSE(_dl_mcount);
ElfW(Addr) *resultp;
lookup_t result;
ElfW(Addr) value;
/* This is the address in the array where we store the result of previous
relocations. */
resultp = &l->l_reloc_result[reloc_offset / sizeof (PLTREL)];
struct reloc_result *reloc_result
= &l->l_reloc_result[reloc_offset / sizeof (PLTREL)];
DL_FIXUP_VALUE_TYPE *resultp = &reloc_result->addr;
value = *resultp;
if (value == 0)
DL_FIXUP_VALUE_TYPE value = *resultp;
if (DL_FIXUP_VALUE_CODE_ADDR (value) == 0)
{
/* This is the first time we have to relocate this object. */
const ElfW(Sym) *const symtab
= (const void *) D_PTR (l, l_info[DT_SYMTAB]);
const char *strtab = (const void *) D_PTR (l, l_info[DT_STRTAB]);
const char *strtab = (const char *) D_PTR (l, l_info[DT_STRTAB]);
const PLTREL *const reloc
= (const void *) (D_PTR (l, l_info[DT_JMPREL]) + reloc_offset);
const ElfW(Sym) *sym = &symtab[ELFW(R_SYM) (reloc->r_info)];
const ElfW(Sym) *refsym = &symtab[ELFW(R_SYM) (reloc->r_info)];
const ElfW(Sym) *defsym = refsym;
lookup_t result;
/* Sanity check that we're really looking at a PLT relocation. */
assert (ELFW(R_TYPE)(reloc->r_info) == ELF_MACHINE_JMP_SLOT);
/* Look up the target symbol. If the symbol is marked STV_PROTECTED
don't look in the global scope. */
if (__builtin_expect (ELFW(ST_VISIBILITY) (sym->st_other), 0) == 0)
if (__builtin_expect (ELFW(ST_VISIBILITY) (refsym->st_other), 0) == 0)
{
const struct r_found_version *version = NULL;
// XXX Why exactly do we have the differentiation of the flags here?
int flags = DL_LOOKUP_ADD_DEPENDENCY;
if (l->l_info[VERSYMIDX (DT_VERSYM)] != NULL)
{
@ -175,38 +185,208 @@ profile_fixup (
version = &l->l_versions[ndx];
if (version->hash == 0)
version = NULL;
else
flags = 0;
}
result = _dl_lookup_symbol_x (strtab + sym->st_name, l, &sym,
l->l_scope, version,
ELF_RTYPE_CLASS_PLT,
DL_LOOKUP_ADD_DEPENDENCY, NULL);
/* We need to keep the scope around so do some locking. This is
not necessary for objects which cannot be unloaded or when
we are not using any threads (yet). */
int flags = DL_LOOKUP_ADD_DEPENDENCY;
if (!RTLD_SINGLE_THREAD_P)
THREAD_GSCOPE_SET_FLAG ();
result = _dl_lookup_symbol_x (strtab + refsym->st_name, l,
&defsym, l->l_scope, version,
ELF_RTYPE_CLASS_PLT, flags, NULL);
/* We are done with the global scope. */
if (!RTLD_SINGLE_THREAD_P)
THREAD_GSCOPE_RESET_FLAG ();
/* Currently result contains the base load address (or link map)
of the object that defines sym. Now add in the symbol
offset. */
value = (sym ? LOOKUP_VALUE_ADDRESS (result) + sym->st_value : 0);
value = DL_FIXUP_MAKE_VALUE (result,
defsym != NULL
? LOOKUP_VALUE_ADDRESS (result)
+ defsym->st_value : 0);
}
else
{
/* We already found the symbol. The module (and therefore its load
address) is also known. */
value = l->l_addr + sym->st_value;
#ifdef DL_LOOKUP_RETURNS_MAP
value = DL_FIXUP_MAKE_VALUE (l, l->l_addr + refsym->st_value);
result = l;
#endif
}
/* And now perhaps the relocation addend. */
value = elf_machine_plt_value (l, reloc, value);
#ifdef SHARED
/* Auditing checkpoint: we have a new binding. Provide the
auditing libraries the possibility to change the value and
tell us whether further auditing is wanted. */
if (defsym != NULL && GLRO(dl_naudit) > 0)
{
reloc_result->bound = result;
/* Compute index of the symbol entry in the symbol table of
the DSO with the definition. */
reloc_result->boundndx = (defsym
- (ElfW(Sym) *) D_PTR (result,
l_info[DT_SYMTAB]));
/* Determine whether any of the two participating DSOs is
interested in auditing. */
if ((l->l_audit_any_plt | result->l_audit_any_plt) != 0)
{
unsigned int altvalue = 0;
struct audit_ifaces *afct = GLRO(dl_audit);
/* Synthesize a symbol record where the st_value field is
the result. */
ElfW(Sym) sym = *defsym;
sym.st_value = DL_FIXUP_VALUE_ADDR (value);
/* Keep track whether there is any interest in tracing
the call in the lower two bits. */
assert (DL_NNS * 2 <= sizeof (reloc_result->flags) * 8);
assert ((LA_SYMB_NOPLTENTER | LA_SYMB_NOPLTEXIT) == 3);
reloc_result->enterexit = LA_SYMB_NOPLTENTER | LA_SYMB_NOPLTEXIT;
const char *strtab2 = (const void *) D_PTR (result,
l_info[DT_STRTAB]);
for (unsigned int cnt = 0; cnt < GLRO(dl_naudit); ++cnt)
{
/* XXX Check whether both DSOs must request action or
only one */
if ((l->l_audit[cnt].bindflags & LA_FLG_BINDFROM) != 0
&& (result->l_audit[cnt].bindflags & LA_FLG_BINDTO) != 0)
{
unsigned int flags = altvalue;
if (afct->symbind != NULL)
{
uintptr_t new_value
= afct->symbind (&sym, reloc_result->boundndx,
&l->l_audit[cnt].cookie,
&result->l_audit[cnt].cookie,
&flags,
strtab2 + defsym->st_name);
if (new_value != (uintptr_t) sym.st_value)
{
altvalue = LA_SYMB_ALTVALUE;
sym.st_value = new_value;
}
}
/* Remember the results for every audit library and
store a summary in the first two bits. */
reloc_result->enterexit
&= flags & (LA_SYMB_NOPLTENTER | LA_SYMB_NOPLTEXIT);
reloc_result->enterexit
|= ((flags & (LA_SYMB_NOPLTENTER | LA_SYMB_NOPLTEXIT))
<< ((cnt + 1) * 2));
}
else
/* If the bind flags say this auditor is not interested,
set the bits manually. */
reloc_result->enterexit
|= ((LA_SYMB_NOPLTENTER | LA_SYMB_NOPLTEXIT)
<< ((cnt + 1) * 2));
afct = afct->next;
}
reloc_result->flags = altvalue;
value = DL_FIXUP_ADDR_VALUE (sym.st_value);
}
else
/* Set all bits since this symbol binding is not interesting. */
reloc_result->enterexit = (1u << DL_NNS) - 1;
}
#endif
/* Store the result for later runs. */
if (__builtin_expect (! GLRO(dl_bind_not), 1))
*resultp = value;
}
(*mcount_fct) (retaddr, value);
/* By default we do not call the pltexit function. */
long int framesize = -1;
#ifdef SHARED
/* Auditing checkpoint: report the PLT entering and allow the
auditors to change the value. */
if (DL_FIXUP_VALUE_CODE_ADDR (value) != 0 && GLRO(dl_naudit) > 0
/* Don't do anything if no auditor wants to intercept this call. */
&& (reloc_result->enterexit & LA_SYMB_NOPLTENTER) == 0)
{
ElfW(Sym) *defsym = ((ElfW(Sym) *) D_PTR (reloc_result->bound,
l_info[DT_SYMTAB])
+ reloc_result->boundndx);
/* Set up the sym parameter. */
ElfW(Sym) sym = *defsym;
sym.st_value = DL_FIXUP_VALUE_ADDR (value);
/* Get the symbol name. */
const char *strtab = (const void *) D_PTR (reloc_result->bound,
l_info[DT_STRTAB]);
const char *symname = strtab + sym.st_name;
/* Keep track of overwritten addresses. */
unsigned int altvalue = reloc_result->flags;
struct audit_ifaces *afct = GLRO(dl_audit);
for (unsigned int cnt = 0; cnt < GLRO(dl_naudit); ++cnt)
{
if (afct->ARCH_LA_PLTENTER != NULL
&& (reloc_result->enterexit
& (LA_SYMB_NOPLTENTER << (2 * (cnt + 1)))) == 0)
{
unsigned int flags = altvalue;
long int new_framesize = -1;
uintptr_t new_value
= afct->ARCH_LA_PLTENTER (&sym, reloc_result->boundndx,
&l->l_audit[cnt].cookie,
&reloc_result->bound->l_audit[cnt].cookie,
regs, &flags, symname,
&new_framesize);
if (new_value != (uintptr_t) sym.st_value)
{
altvalue = LA_SYMB_ALTVALUE;
sym.st_value = new_value;
}
/* Remember the results for every audit library and
store a summary in the first two bits. */
reloc_result->enterexit
|= ((flags & (LA_SYMB_NOPLTENTER | LA_SYMB_NOPLTEXIT))
<< (2 * (cnt + 1)));
if ((reloc_result->enterexit & (LA_SYMB_NOPLTEXIT
<< (2 * (cnt + 1))))
== 0 && new_framesize != -1 && framesize != -2)
{
/* If this is the first call providing information,
use it. */
if (framesize == -1)
framesize = new_framesize;
/* If two pltenter calls provide conflicting information,
use the larger value. */
else if (new_framesize != framesize)
framesize = MAX (new_framesize, framesize);
}
}
afct = afct->next;
}
value = DL_FIXUP_ADDR_VALUE (sym.st_value);
}
#endif
/* Store the frame size information. */
*framesizep = framesize;
(*mcount_fct) (retaddr, DL_FIXUP_VALUE_CODE_ADDR (value));
return value;
}
@ -214,9 +394,45 @@ profile_fixup (
#endif /* PROF && ELF_MACHINE_NO_PLT */
/* This macro is defined in dl-machine.h to define the entry point called
by the PLT. The `fixup' function above does the real work, but a little
more twiddling is needed to get the stack right and jump to the address
finally resolved. */
#include <stdio.h>
void
ARCH_FIXUP_ATTRIBUTE
_dl_call_pltexit (struct link_map *l, ElfW(Word) reloc_offset,
const void *inregs, void *outregs)
{
#ifdef SHARED
/* This is the address in the array where we store the result of previous
relocations. */
// XXX Maybe the bound information must be stored on the stack since
// XXX with bind_not a new value could have been stored in the meantime.
struct reloc_result *reloc_result
= &l->l_reloc_result[reloc_offset / sizeof (PLTREL)];
ElfW(Sym) *defsym = ((ElfW(Sym) *) D_PTR (reloc_result->bound,
l_info[DT_SYMTAB])
+ reloc_result->boundndx);
ELF_MACHINE_RUNTIME_TRAMPOLINE
/* Set up the sym parameter. */
ElfW(Sym) sym = *defsym;
/* Get the symbol name. */
const char *strtab = (const void *) D_PTR (reloc_result->bound,
l_info[DT_STRTAB]);
const char *symname = strtab + sym.st_name;
struct audit_ifaces *afct = GLRO(dl_audit);
for (unsigned int cnt = 0; cnt < GLRO(dl_naudit); ++cnt)
{
if (afct->ARCH_LA_PLTEXIT != NULL
&& (reloc_result->enterexit
& (LA_SYMB_NOPLTEXIT >> (2 * cnt))) == 0)
{
afct->ARCH_LA_PLTEXIT (&sym, reloc_result->boundndx,
&l->l_audit[cnt].cookie,
&reloc_result->bound->l_audit[cnt].cookie,
inregs, outregs, symname);
}
afct = afct->next;
}
#endif
}