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Merge "Refactoring: move mips reloc to separate method"

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This commit is contained in:
Dmitriy Ivanov 2015-01-15 17:56:36 +00:00 committed by Gerrit Code Review
commit fcc6fd35df
5 changed files with 197 additions and 123 deletions
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4
linker/Android.mk
View File

@ -16,8 +16,8 @@ LOCAL_SRC_FILES_arm := arch/arm/begin.S
LOCAL_SRC_FILES_arm64 := arch/arm64/begin.S
LOCAL_SRC_FILES_x86 := arch/x86/begin.c
LOCAL_SRC_FILES_x86_64 := arch/x86_64/begin.S
LOCAL_SRC_FILES_mips := arch/mips/begin.S
LOCAL_SRC_FILES_mips64 := arch/mips64/begin.S
LOCAL_SRC_FILES_mips := arch/mips/begin.S linker_mips.cpp
LOCAL_SRC_FILES_mips64 := arch/mips64/begin.S linker_mips.cpp
LOCAL_LDFLAGS := \
-shared \

139
linker/linker.cpp
View File

@ -122,14 +122,6 @@ __LIBC_HIDDEN__ int g_ld_debug_verbosity;
__LIBC_HIDDEN__ abort_msg_t* g_abort_message = nullptr; // For debuggerd.
enum RelocationKind {
kRelocAbsolute = 0,
kRelocRelative,
kRelocCopy,
kRelocSymbol,
kRelocMax
};
#if STATS
struct linker_stats_t {
int count[kRelocMax];
@ -137,30 +129,16 @@ struct linker_stats_t {
static linker_stats_t linker_stats;
static void count_relocation(RelocationKind kind) {
void count_relocation(RelocationKind kind) {
++linker_stats.count[kind];
}
#else
static void count_relocation(RelocationKind) {
void count_relocation(RelocationKind) {
}
#endif
#if COUNT_PAGES
static unsigned bitmask[4096];
#if defined(__LP64__)
#define MARK(offset) \
do { \
if ((((offset) >> 12) >> 5) < 4096) \
bitmask[((offset) >> 12) >> 5] |= (1 << (((offset) >> 12) & 31)); \
} while (0)
#else
#define MARK(offset) \
do { \
bitmask[((offset) >> 12) >> 3] |= (1 << (((offset) >> 12) & 7)); \
} while (0)
#endif
#else
#define MARK(x) do {} while (0)
uint32_t bitmask[4096];
#endif
// You shouldn't try to call memory-allocating functions in the dynamic linker.
@ -539,7 +517,7 @@ uint32_t SymbolName::gnu_hash() {
return gnu_hash_;
}
static ElfW(Sym)* soinfo_do_lookup(soinfo* si_from, const char* name, soinfo** si_found_in,
ElfW(Sym)* soinfo_do_lookup(soinfo* si_from, const char* name, soinfo** si_found_in,
const soinfo::soinfo_list_t& global_group, const soinfo::soinfo_list_t& local_group) {
SymbolName symbol_name(name);
ElfW(Sym)* s = nullptr;
@ -1292,10 +1270,9 @@ static ElfW(Addr) get_addend(ElfW(Rel)* rel, ElfW(Addr) reloc_addr) {
return 0;
}
#endif
#endif
template<typename ElfRelT>
int soinfo::relocate(ElfRelT* rel, unsigned count, const soinfo_list_t& global_group, const soinfo_list_t& local_group) {
bool soinfo::relocate(ElfRelT* rel, unsigned count, const soinfo_list_t& global_group, const soinfo_list_t& local_group) {
for (size_t idx = 0; idx < count; ++idx, ++rel) {
ElfW(Word) type = ELFW(R_TYPE)(rel->r_info);
ElfW(Word) sym = ELFW(R_SYM)(rel->r_info);
@ -1303,11 +1280,9 @@ int soinfo::relocate(ElfRelT* rel, unsigned count, const soinfo_list_t& global_g
ElfW(Addr) reloc = static_cast<ElfW(Addr)>(rel->r_offset + load_bias);
ElfW(Addr) sym_addr = 0;
const char* sym_name = nullptr;
#if !defined(__mips__)
ElfW(Addr) addend = get_addend(rel, reloc);
#endif
DEBUG("Processing '%s' relocation at index %zd", name, idx);
DEBUG("Processing '%s' relocation at index %zd", this->name, idx);
if (type == R_GENERIC_NONE) {
continue;
}
@ -1323,7 +1298,7 @@ int soinfo::relocate(ElfRelT* rel, unsigned count, const soinfo_list_t& global_g
s = &symtab_[sym];
if (ELF_ST_BIND(s->st_info) != STB_WEAK) {
DL_ERR("cannot locate symbol \"%s\" referenced by \"%s\"...", sym_name, name);
return -1;
return false;
}
/* IHI0044C AAELF 4.5.1.1:
@ -1339,7 +1314,6 @@ int soinfo::relocate(ElfRelT* rel, unsigned count, const soinfo_list_t& global_g
*/
switch (type) {
#if !defined(__mips__)
case R_GENERIC_JUMP_SLOT:
case R_GENERIC_GLOB_DAT:
case R_GENERIC_RELATIVE:
@ -1370,11 +1344,10 @@ int soinfo::relocate(ElfRelT* rel, unsigned count, const soinfo_list_t& global_g
case R_386_PC32:
sym_addr = reloc;
break;
#endif
#endif
default:
DL_ERR("unknown weak reloc type %d @ %p (%zu)", type, rel, idx);
return -1;
return false;
}
} else {
// We got a definition.
@ -1384,7 +1357,6 @@ int soinfo::relocate(ElfRelT* rel, unsigned count, const soinfo_list_t& global_g
}
switch (type) {
#if !defined(__mips__)
case R_GENERIC_JUMP_SLOT:
count_relocation(kRelocAbsolute);
MARK(rel->r_offset);
@ -1418,7 +1390,6 @@ int soinfo::relocate(ElfRelT* rel, unsigned count, const soinfo_list_t& global_g
reinterpret_cast<void*>(base + addend));
*reinterpret_cast<ElfW(Addr)*>(reloc) = call_ifunc_resolver(base + addend);
break;
#endif
#if defined(__aarch64__)
case R_AARCH64_ABS64:
@ -1441,7 +1412,7 @@ int soinfo::relocate(ElfRelT* rel, unsigned count, const soinfo_list_t& global_g
(*reinterpret_cast<ElfW(Addr)*>(reloc) + (sym_addr + addend)),
static_cast<ElfW(Addr)>(INT32_MIN),
static_cast<ElfW(Addr)>(UINT32_MAX));
return -1;
return false;
}
break;
case R_AARCH64_ABS16:
@ -1457,7 +1428,7 @@ int soinfo::relocate(ElfRelT* rel, unsigned count, const soinfo_list_t& global_g
(*reinterpret_cast<ElfW(Addr)*>(reloc) + (sym_addr + addend)),
static_cast<ElfW(Addr)>(INT16_MIN),
static_cast<ElfW(Addr)>(UINT16_MAX));
return -1;
return false;
}
break;
case R_AARCH64_PREL64:
@ -1480,7 +1451,7 @@ int soinfo::relocate(ElfRelT* rel, unsigned count, const soinfo_list_t& global_g
(*reinterpret_cast<ElfW(Addr)*>(reloc) + ((sym_addr + addend) - rel->r_offset)),
static_cast<ElfW(Addr)>(INT32_MIN),
static_cast<ElfW(Addr)>(UINT32_MAX));
return -1;
return false;
}
break;
case R_AARCH64_PREL16:
@ -1496,7 +1467,7 @@ int soinfo::relocate(ElfRelT* rel, unsigned count, const soinfo_list_t& global_g
(*reinterpret_cast<ElfW(Addr)*>(reloc) + ((sym_addr + addend) - rel->r_offset)),
static_cast<ElfW(Addr)>(INT16_MIN),
static_cast<ElfW(Addr)>(UINT16_MAX));
return -1;
return false;
}
break;
@ -1511,7 +1482,7 @@ int soinfo::relocate(ElfRelT* rel, unsigned count, const soinfo_list_t& global_g
* set to ET_EXEC.
*/
DL_ERR("%s R_AARCH64_COPY relocations are not supported", name);
return -1;
return false;
case R_AARCH64_TLS_TPREL64:
TRACE_TYPE(RELO, "RELO TLS_TPREL64 *** %16llx <- %16llx - %16llx\n",
reloc, (sym_addr + addend), rel->r_offset);
@ -1568,7 +1539,7 @@ int soinfo::relocate(ElfRelT* rel, unsigned count, const soinfo_list_t& global_g
* set to ET_EXEC.
*/
DL_ERR("%s R_ARM_COPY relocations are not supported", name);
return -1;
return false;
#elif defined(__i386__)
case R_386_32:
count_relocation(kRelocRelative);
@ -1583,87 +1554,15 @@ int soinfo::relocate(ElfRelT* rel, unsigned count, const soinfo_list_t& global_g
reloc, (sym_addr - reloc), sym_addr, reloc, sym_name);
*reinterpret_cast<ElfW(Addr)*>(reloc) += (sym_addr - reloc);
break;
#elif defined(__mips__)
case R_MIPS_REL32:
#if defined(__LP64__)
// MIPS Elf64_Rel entries contain compound relocations
// We only handle the R_MIPS_NONE|R_MIPS_64|R_MIPS_REL32 case
if (ELF64_R_TYPE2(rel->r_info) != R_MIPS_64 ||
ELF64_R_TYPE3(rel->r_info) != R_MIPS_NONE) {
DL_ERR("Unexpected compound relocation type:%d type2:%d type3:%d @ %p (%zu)",
type, (unsigned)ELF64_R_TYPE2(rel->r_info),
(unsigned)ELF64_R_TYPE3(rel->r_info), rel, idx);
return -1;
}
#endif
count_relocation(kRelocAbsolute);
MARK(rel->r_offset);
TRACE_TYPE(RELO, "RELO REL32 %08zx <- %08zx %s", static_cast<size_t>(reloc),
static_cast<size_t>(sym_addr), sym_name ? sym_name : "*SECTIONHDR*");
if (s) {
*reinterpret_cast<ElfW(Addr)*>(reloc) += sym_addr;
} else {
*reinterpret_cast<ElfW(Addr)*>(reloc) += base;
}
break;
#endif
default:
DL_ERR("unknown reloc type %d @ %p (%zu)", type, rel, idx);
return -1;
}
}
return 0;
}
#if defined(__mips__)
bool soinfo::mips_relocate_got(const soinfo_list_t& global_group, const soinfo_list_t& local_group) {
ElfW(Addr)** got = plt_got_;
if (got == nullptr) {
return true;
}
// got[0] is the address of the lazy resolver function.
// got[1] may be used for a GNU extension.
// Set it to a recognizable address in case someone calls it (should be _rtld_bind_start).
// FIXME: maybe this should be in a separate routine?
if ((flags_ & FLAG_LINKER) == 0) {
size_t g = 0;
got[g++] = reinterpret_cast<ElfW(Addr)*>(0xdeadbeef);
if (reinterpret_cast<intptr_t>(got[g]) < 0) {
got[g++] = reinterpret_cast<ElfW(Addr)*>(0xdeadfeed);
}
// Relocate the local GOT entries.
for (; g < mips_local_gotno_; g++) {
got[g] = reinterpret_cast<ElfW(Addr)*>(reinterpret_cast<uintptr_t>(got[g]) + load_bias);
}
}
// Now for the global GOT entries...
ElfW(Sym)* sym = symtab_ + mips_gotsym_;
got = plt_got_ + mips_local_gotno_;
for (size_t g = mips_gotsym_; g < mips_symtabno_; g++, sym++, got++) {
// This is an undefined reference... try to locate it.
const char* sym_name = get_string(sym->st_name);
soinfo* lsi = nullptr;
ElfW(Sym)* s = soinfo_do_lookup(this, sym_name, &lsi, global_group, local_group);
if (s == nullptr) {
// We only allow an undefined symbol if this is a weak reference.
s = &symtab_[g];
if (ELF_ST_BIND(s->st_info) != STB_WEAK) {
DL_ERR("cannot locate \"%s\"...", sym_name);
return false;
}
*got = 0;
} else {
// FIXME: is this sufficient?
// For reference see NetBSD link loader
// http://cvsweb.netbsd.org/bsdweb.cgi/src/libexec/ld.elf_so/arch/mips/mips_reloc.c?rev=1.53&content-type=text/x-cvsweb-markup
*got = reinterpret_cast<ElfW(Addr)*>(lsi->resolve_symbol_address(s));
}
}
return true;
}
#endif
#endif // !defined(__mips__)
void soinfo::call_array(const char* array_name __unused, linker_function_t* functions, size_t count, bool reverse) {
if (functions == nullptr) {
@ -2352,26 +2251,26 @@ bool soinfo::link_image(const soinfo_list_t& global_group, const soinfo_list_t&
#if defined(USE_RELA)
if (rela_ != nullptr) {
DEBUG("[ relocating %s ]", name);
if (relocate(rela_, rela_count_, global_group, local_group)) {
if (!relocate(rela_, rela_count_, global_group, local_group)) {
return false;
}
}
if (plt_rela_ != nullptr) {
DEBUG("[ relocating %s plt ]", name);
if (relocate(plt_rela_, plt_rela_count_, global_group, local_group)) {
if (!relocate(plt_rela_, plt_rela_count_, global_group, local_group)) {
return false;
}
}
#else
if (rel_ != nullptr) {
DEBUG("[ relocating %s ]", name);
if (relocate(rel_, rel_count_, global_group, local_group)) {
if (!relocate(rel_, rel_count_, global_group, local_group)) {
return false;
}
}
if (plt_rel_ != nullptr) {
DEBUG("[ relocating %s plt ]", name);
if (relocate(plt_rel_, plt_rel_count_, global_group, local_group)) {
if (!relocate(plt_rel_, plt_rel_count_, global_group, local_group)) {
return false;
}
}

15
linker/linker.h
View File

@ -287,7 +287,7 @@ struct soinfo {
void call_array(const char* array_name, linker_function_t* functions, size_t count, bool reverse);
void call_function(const char* function_name, linker_function_t function);
template<typename ElfRelT>
int relocate(ElfRelT* rel, unsigned count, const soinfo_list_t& global_group, const soinfo_list_t& local_group);
bool relocate(ElfRelT* rel, unsigned count, const soinfo_list_t& global_group, const soinfo_list_t& local_group);
private:
// This part of the structure is only available
@ -318,6 +318,19 @@ struct soinfo {
friend soinfo* get_libdl_info();
};
ElfW(Sym)* soinfo_do_lookup(soinfo* si_from, const char* name, soinfo** si_found_in,
const soinfo::soinfo_list_t& global_group, const soinfo::soinfo_list_t& local_group);
enum RelocationKind {
kRelocAbsolute = 0,
kRelocRelative,
kRelocCopy,
kRelocSymbol,
kRelocMax
};
void count_relocation(RelocationKind kind);
soinfo* get_libdl_info();
void do_android_get_LD_LIBRARY_PATH(char*, size_t);

19
linker/linker_debug.h
View File

@ -82,4 +82,23 @@ __LIBC_HIDDEN__ extern int g_ld_debug_verbosity;
#define TRACE_TYPE(t, x...) do { if (DO_TRACE_##t) { TRACE(x); } } while (0)
#if COUNT_PAGES
extern uint32_t bitmask[];
#if defined(__LP64__)
#define MARK(offset) \
do { \
if ((((offset) >> 12) >> 5) < 4096) \
bitmask[((offset) >> 12) >> 5] |= (1 << (((offset) >> 12) & 31)); \
} while (0)
#else
#define MARK(offset) \
do { \
bitmask[((offset) >> 12) >> 3] |= (1 << (((offset) >> 12) & 7)); \
} while (0)
#endif
#else
#define MARK(x) do {} while (0)
#endif
#endif /* _LINKER_DEBUG_H_ */

143
linker/linker_mips.cpp Normal file
View File

@ -0,0 +1,143 @@
/*
* Copyright (C) 2015 The Android Open Source Project
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* * Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* * Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
* OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
* AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
* OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#include "linker.h"
#include "linker_debug.h"
#include "linker_relocs.h"
template<>
bool soinfo::relocate(ElfW(Rel)* rel, unsigned count, const soinfo_list_t& global_group, const soinfo_list_t& local_group) {
for (size_t idx = 0; idx < count; ++idx, ++rel) {
ElfW(Word) type = ELFW(R_TYPE)(rel->r_info);
ElfW(Word) sym = ELFW(R_SYM)(rel->r_info);
ElfW(Addr) reloc = static_cast<ElfW(Addr)>(rel->r_offset + load_bias);
ElfW(Addr) sym_addr = 0;
const char* sym_name = nullptr;
DEBUG("Processing '%s' relocation at index %zd", this->name, idx);
if (type == R_GENERIC_NONE) {
continue;
}
ElfW(Sym)* s = nullptr;
soinfo* lsi = nullptr;
if (sym != 0) {
sym_name = get_string(symtab_[sym].st_name);
s = soinfo_do_lookup(this, sym_name, &lsi, global_group,local_group);
if (s == nullptr) {
// mips does not support relocation with weak-undefined symbols
DL_ERR("cannot locate symbol \"%s\" referenced by \"%s\"...", sym_name, name);
return false;
} else {
// We got a definition.
sym_addr = lsi->resolve_symbol_address(s);
}
count_relocation(kRelocSymbol);
}
switch (type) {
case R_MIPS_REL32:
#if defined(__LP64__)
// MIPS Elf64_Rel entries contain compound relocations
// We only handle the R_MIPS_NONE|R_MIPS_64|R_MIPS_REL32 case
if (ELF64_R_TYPE2(rel->r_info) != R_MIPS_64 ||
ELF64_R_TYPE3(rel->r_info) != R_MIPS_NONE) {
DL_ERR("Unexpected compound relocation type:%d type2:%d type3:%d @ %p (%zu)",
type, (unsigned)ELF64_R_TYPE2(rel->r_info),
(unsigned)ELF64_R_TYPE3(rel->r_info), rel, idx);
return false;
}
#endif
count_relocation(s == nullptr ? kRelocAbsolute : kRelocRelative);
MARK(rel->r_offset);
TRACE_TYPE(RELO, "RELO REL32 %08zx <- %08zx %s", static_cast<size_t>(reloc),
static_cast<size_t>(sym_addr), sym_name ? sym_name : "*SECTIONHDR*");
if (s != nullptr) {
*reinterpret_cast<ElfW(Addr)*>(reloc) += sym_addr;
} else {
*reinterpret_cast<ElfW(Addr)*>(reloc) += base;
}
break;
default:
DL_ERR("unknown reloc type %d @ %p (%zu)", type, rel, idx);
return false;
}
}
return true;
}
bool soinfo::mips_relocate_got(const soinfo_list_t& global_group, const soinfo_list_t& local_group) {
ElfW(Addr)** got = plt_got_;
if (got == nullptr) {
return true;
}
// got[0] is the address of the lazy resolver function.
// got[1] may be used for a GNU extension.
// Set it to a recognizable address in case someone calls it (should be _rtld_bind_start).
// FIXME: maybe this should be in a separate routine?
if ((flags_ & FLAG_LINKER) == 0) {
size_t g = 0;
got[g++] = reinterpret_cast<ElfW(Addr)*>(0xdeadbeef);
if (reinterpret_cast<intptr_t>(got[g]) < 0) {
got[g++] = reinterpret_cast<ElfW(Addr)*>(0xdeadfeed);
}
// Relocate the local GOT entries.
for (; g < mips_local_gotno_; g++) {
got[g] = reinterpret_cast<ElfW(Addr)*>(reinterpret_cast<uintptr_t>(got[g]) + load_bias);
}
}
// Now for the global GOT entries...
ElfW(Sym)* sym = symtab_ + mips_gotsym_;
got = plt_got_ + mips_local_gotno_;
for (size_t g = mips_gotsym_; g < mips_symtabno_; g++, sym++, got++) {
// This is an undefined reference... try to locate it.
const char* sym_name = get_string(sym->st_name);
soinfo* lsi = nullptr;
ElfW(Sym)* s = soinfo_do_lookup(this, sym_name, &lsi, global_group, local_group);
if (s == nullptr) {
// We only allow an undefined symbol if this is a weak reference.
s = &symtab_[g];
if (ELF_ST_BIND(s->st_info) != STB_WEAK) {
DL_ERR("cannot locate \"%s\"...", sym_name);
return false;
}
*got = 0;
} else {
// FIXME: is this sufficient?
// For reference see NetBSD link loader
// http://cvsweb.netbsd.org/bsdweb.cgi/src/libexec/ld.elf_so/arch/mips/mips_reloc.c?rev=1.53&content-type=text/x-cvsweb-markup
*got = reinterpret_cast<ElfW(Addr)*>(lsi->resolve_symbol_address(s));
}
}
return true;
}