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am 16f6429c: Merge "Add android_dlopen_ext() interface to linker."

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* commit '16f6429c38c24236418cf127a4c11c5d8a2fd47b':
  Add android_dlopen_ext() interface to linker.
This commit is contained in:
Torne (Richard Coles) 2014-04-22 13:32:00 +00:00 committed by Android Git Automerger
commit cf68e0db1f
5 changed files with 70 additions and 16 deletions
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39
libc/include/android/dlext.h Normal file
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@ -0,0 +1,39 @@
/*
* Copyright (C) 2014 The Android Open Source Project
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#ifndef __ANDROID_DLEXT_H__
#define __ANDROID_DLEXT_H__
#include <stddef.h>
#include <sys/cdefs.h>
__BEGIN_DECLS
/* bitfield definitions for android_dlextinfo.flags */
enum {
/* Mask of valid bits */
ANDROID_DLEXT_VALID_FLAG_BITS = 0,
};
typedef struct {
int flags;
} android_dlextinfo;
extern void* android_dlopen_ext(const char* filename, int flag, const android_dlextinfo* extinfo);
__END_DECLS
#endif /* __ANDROID_DLEXT_H__ */

9
libdl/libdl.c
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@ -17,6 +17,7 @@
#include <dlfcn.h>
#include <link.h>
#include <stdlib.h>
#include <android/dlext.h>
// These are stubs for functions that are actually defined
// in the dynamic linker and hijacked at runtime.
@ -27,11 +28,13 @@ void* dlsym(void* handle __unused, const char* symbol __unused) { return 0; }
int dladdr(const void* addr __unused, Dl_info* info __unused) { return 0; }
int dlclose(void* handle __unused) { return 0; }
void android_get_LD_LIBRARY_PATH(char* buffer __unused, size_t buffer_size __unused) { }
void android_update_LD_LIBRARY_PATH(const char* ld_library_path __unused) { }
#if defined(__arm__)
_Unwind_Ptr dl_unwind_find_exidx(_Unwind_Ptr pc __unused, int* pcount __unused) { return 0; }
#endif
int dl_iterate_phdr(int (*cb)(struct dl_phdr_info* info, size_t size, void* data) __unused, void* data __unused) { return 0; }
void android_get_LD_LIBRARY_PATH(char* buffer __unused, size_t buffer_size __unused) { }
void android_update_LD_LIBRARY_PATH(const char* ld_library_path __unused) { }
void* android_dlopen_ext(const char* filename __unused, int flag __unused, const android_dlextinfo* extinfo __unused) { return 0; }

29
linker/dlfcn.cpp
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@ -20,6 +20,7 @@
#include <pthread.h>
#include <stdio.h>
#include <stdlib.h>
#include <android/dlext.h>
#include <bionic/pthread_internal.h>
#include "private/bionic_tls.h"
@ -64,9 +65,10 @@ void android_update_LD_LIBRARY_PATH(const char* ld_library_path) {
do_android_update_LD_LIBRARY_PATH(ld_library_path);
}
void* dlopen(const char* filename, int flags) {
void* android_dlopen_ext(const char* filename, int flags, const android_dlextinfo* extinfo)
{
ScopedPthreadMutexLocker locker(&gDlMutex);
soinfo* result = do_dlopen(filename, flags);
soinfo* result = do_dlopen(filename, flags, extinfo);
if (result == NULL) {
__bionic_format_dlerror("dlopen failed", linker_get_error_buffer());
return NULL;
@ -74,6 +76,10 @@ void* dlopen(const char* filename, int flags) {
return result;
}
void* dlopen(const char* filename, int flags) {
return android_dlopen_ext(filename, flags, NULL);
}
void* dlsym(void* handle, const char* symbol) {
ScopedPthreadMutexLocker locker(&gDlMutex);
@ -168,15 +174,15 @@ int dlclose(void* handle) {
}
#if defined(__arm__)
// 0000000 00011111 111112 22222222 2333333 3333444444444455555555556666666 6667777777777888888888899999 9999900000000001 1
// 0123456 78901234 567890 12345678 9012345 6789012345678901234567890123456 7890123456789012345678901234 5678901234567890 1
// 0000000 00011111 111112 22222222 2333333 3333444444444455555555556666666 6667777777777888888888899999 9999900000000001 1111111112222222222 333333333344444444445
// 0123456 78901234 567890 12345678 9012345 6789012345678901234567890123456 7890123456789012345678901234 5678901234567890 1234567890123456789 012345678901234567890
# define ANDROID_LIBDL_STRTAB \
"dlopen\0dlclose\0dlsym\0dlerror\0dladdr\0android_update_LD_LIBRARY_PATH\0android_get_LD_LIBRARY_PATH\0dl_iterate_phdr\0dl_unwind_find_exidx\0"
"dlopen\0dlclose\0dlsym\0dlerror\0dladdr\0android_update_LD_LIBRARY_PATH\0android_get_LD_LIBRARY_PATH\0dl_iterate_phdr\0android_dlopen_ext\0dl_unwind_find_exidx\0"
#elif defined(__aarch64__) || defined(__i386__) || defined(__mips__) || defined(__x86_64__)
// 0000000 00011111 111112 22222222 2333333 3333444444444455555555556666666 6667777777777888888888899999 9999900000000001 1
// 0123456 78901234 567890 12345678 9012345 6789012345678901234567890123456 7890123456789012345678901234 5678901234567890 1
// 0000000 00011111 111112 22222222 2333333 3333444444444455555555556666666 6667777777777888888888899999 9999900000000001 1111111112222222222
// 0123456 78901234 567890 12345678 9012345 6789012345678901234567890123456 7890123456789012345678901234 5678901234567890 1234567890123456789
# define ANDROID_LIBDL_STRTAB \
"dlopen\0dlclose\0dlsym\0dlerror\0dladdr\0android_update_LD_LIBRARY_PATH\0android_get_LD_LIBRARY_PATH\0dl_iterate_phdr\0"
"dlopen\0dlclose\0dlsym\0dlerror\0dladdr\0android_update_LD_LIBRARY_PATH\0android_get_LD_LIBRARY_PATH\0dl_iterate_phdr\0android_dlopen_ext\0"
#else
# error Unsupported architecture. Only arm, arm64, mips, mips64, x86 and x86_64 are presently supported.
#endif
@ -195,8 +201,9 @@ static ElfW(Sym) gLibDlSymtab[] = {
ELFW(SYM_INITIALIZER)( 36, &android_update_LD_LIBRARY_PATH, 1),
ELFW(SYM_INITIALIZER)( 67, &android_get_LD_LIBRARY_PATH, 1),
ELFW(SYM_INITIALIZER)( 95, &dl_iterate_phdr, 1),
ELFW(SYM_INITIALIZER)(111, &android_dlopen_ext, 1),
#if defined(__arm__)
ELFW(SYM_INITIALIZER)(111, &dl_unwind_find_exidx, 1),
ELFW(SYM_INITIALIZER)(130, &dl_unwind_find_exidx, 1),
#endif
};
@ -213,9 +220,9 @@ static ElfW(Sym) gLibDlSymtab[] = {
// Note that adding any new symbols here requires stubbing them out in libdl.
static unsigned gLibDlBuckets[1] = { 1 };
#if defined(__arm__)
static unsigned gLibDlChains[] = { 0, 2, 3, 4, 5, 6, 7, 8, 9, 0 };
static unsigned gLibDlChains[] = { 0, 2, 3, 4, 5, 6, 7, 8, 9, 10, 0 };
#else
static unsigned gLibDlChains[] = { 0, 2, 3, 4, 5, 6, 7, 8, 0 };
static unsigned gLibDlChains[] = { 0, 2, 3, 4, 5, 6, 7, 8, 9, 0 };
#endif
// This is used by the dynamic linker. Every process gets these symbols for free.

6
linker/linker.cpp
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@ -811,11 +811,15 @@ void do_android_update_LD_LIBRARY_PATH(const char* ld_library_path) {
}
}
soinfo* do_dlopen(const char* name, int flags) {
soinfo* do_dlopen(const char* name, int flags, const android_dlextinfo* extinfo) {
if ((flags & ~(RTLD_NOW|RTLD_LAZY|RTLD_LOCAL|RTLD_GLOBAL)) != 0) {
DL_ERR("invalid flags to dlopen: %x", flags);
return NULL;
}
if (extinfo != NULL && ((extinfo->flags & ~(ANDROID_DLEXT_VALID_FLAG_BITS)) != 0)) {
DL_ERR("invalid extended flags to android_dlopen_ext: %x", extinfo->flags);
return NULL;
}
set_soinfo_pool_protection(PROT_READ | PROT_WRITE);
soinfo* si = find_library(name);
if (si != NULL) {

3
linker/linker.h
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@ -32,6 +32,7 @@
#include <elf.h>
#include <link.h>
#include <unistd.h>
#include <android/dlext.h>
#include "private/libc_logging.h"
@ -192,7 +193,7 @@ extern soinfo libdl_info;
void do_android_get_LD_LIBRARY_PATH(char*, size_t);
void do_android_update_LD_LIBRARY_PATH(const char* ld_library_path);
soinfo* do_dlopen(const char* name, int flags);
soinfo* do_dlopen(const char* name, int flags, const android_dlextinfo* extinfo);
int do_dlclose(soinfo* si);
ElfW(Sym)* dlsym_linear_lookup(const char* name, soinfo** found, soinfo* start);