bda5da074e
this breaks C++ source code in particular. Change-Id: Ie06b5d31d23b5455e6950c470adc64dd5e7784df
276 lines
7.7 KiB
C
276 lines
7.7 KiB
C
/*
|
|
* Copyright (C) 2007 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.
|
|
*/
|
|
#include <dlfcn.h>
|
|
#include <pthread.h>
|
|
#include <stdio.h>
|
|
#include "linker.h"
|
|
#include "linker_format.h"
|
|
|
|
/* This file hijacks the symbols stubbed out in libdl.so. */
|
|
|
|
#define DL_SUCCESS 0
|
|
#define DL_ERR_CANNOT_LOAD_LIBRARY 1
|
|
#define DL_ERR_INVALID_LIBRARY_HANDLE 2
|
|
#define DL_ERR_BAD_SYMBOL_NAME 3
|
|
#define DL_ERR_SYMBOL_NOT_FOUND 4
|
|
#define DL_ERR_SYMBOL_NOT_GLOBAL 5
|
|
|
|
static char dl_err_buf[1024];
|
|
static const char *dl_err_str;
|
|
|
|
static const char *dl_errors[] = {
|
|
[DL_ERR_CANNOT_LOAD_LIBRARY] = "Cannot load library",
|
|
[DL_ERR_INVALID_LIBRARY_HANDLE] = "Invalid library handle",
|
|
[DL_ERR_BAD_SYMBOL_NAME] = "Invalid symbol name",
|
|
[DL_ERR_SYMBOL_NOT_FOUND] = "Symbol not found",
|
|
[DL_ERR_SYMBOL_NOT_GLOBAL] = "Symbol is not global",
|
|
};
|
|
|
|
#define likely(expr) __builtin_expect (expr, 1)
|
|
#define unlikely(expr) __builtin_expect (expr, 0)
|
|
|
|
static pthread_mutex_t dl_lock = PTHREAD_MUTEX_INITIALIZER;
|
|
|
|
static void set_dlerror(int err)
|
|
{
|
|
format_buffer(dl_err_buf, sizeof(dl_err_buf), "%s: %s", dl_errors[err],
|
|
linker_get_error());
|
|
dl_err_str = (const char *)&dl_err_buf[0];
|
|
};
|
|
|
|
void *dlopen(const char *filename, int flag)
|
|
{
|
|
soinfo *ret;
|
|
|
|
pthread_mutex_lock(&dl_lock);
|
|
ret = find_library(filename);
|
|
if (unlikely(ret == NULL)) {
|
|
set_dlerror(DL_ERR_CANNOT_LOAD_LIBRARY);
|
|
} else {
|
|
ret->refcount++;
|
|
}
|
|
pthread_mutex_unlock(&dl_lock);
|
|
return ret;
|
|
}
|
|
|
|
const char *dlerror(void)
|
|
{
|
|
const char *tmp = dl_err_str;
|
|
dl_err_str = NULL;
|
|
return (const char *)tmp;
|
|
}
|
|
|
|
void *dlsym(void *handle, const char *symbol)
|
|
{
|
|
soinfo *found;
|
|
Elf32_Sym *sym;
|
|
unsigned bind;
|
|
|
|
pthread_mutex_lock(&dl_lock);
|
|
|
|
if(unlikely(handle == 0)) {
|
|
set_dlerror(DL_ERR_INVALID_LIBRARY_HANDLE);
|
|
goto err;
|
|
}
|
|
if(unlikely(symbol == 0)) {
|
|
set_dlerror(DL_ERR_BAD_SYMBOL_NAME);
|
|
goto err;
|
|
}
|
|
|
|
if(handle == RTLD_DEFAULT) {
|
|
sym = lookup(symbol, &found, NULL);
|
|
} else if(handle == RTLD_NEXT) {
|
|
void *ret_addr = __builtin_return_address(0);
|
|
soinfo *si = find_containing_library(ret_addr);
|
|
|
|
sym = NULL;
|
|
if(si && si->next) {
|
|
sym = lookup(symbol, &found, si->next);
|
|
}
|
|
} else {
|
|
found = (soinfo*)handle;
|
|
sym = lookup_in_library(found, symbol);
|
|
}
|
|
|
|
if(likely(sym != 0)) {
|
|
bind = ELF32_ST_BIND(sym->st_info);
|
|
|
|
if(likely((bind == STB_GLOBAL) && (sym->st_shndx != 0))) {
|
|
unsigned ret = sym->st_value + found->base;
|
|
pthread_mutex_unlock(&dl_lock);
|
|
return (void*)ret;
|
|
}
|
|
|
|
set_dlerror(DL_ERR_SYMBOL_NOT_GLOBAL);
|
|
}
|
|
else
|
|
set_dlerror(DL_ERR_SYMBOL_NOT_FOUND);
|
|
|
|
err:
|
|
pthread_mutex_unlock(&dl_lock);
|
|
return 0;
|
|
}
|
|
|
|
int dladdr(const void *addr, Dl_info *info)
|
|
{
|
|
int ret = 0;
|
|
|
|
pthread_mutex_lock(&dl_lock);
|
|
|
|
/* Determine if this address can be found in any library currently mapped */
|
|
soinfo *si = find_containing_library(addr);
|
|
|
|
if(si) {
|
|
memset(info, 0, sizeof(Dl_info));
|
|
|
|
info->dli_fname = si->name;
|
|
info->dli_fbase = (void*)si->base;
|
|
|
|
/* Determine if any symbol in the library contains the specified address */
|
|
Elf32_Sym *sym = find_containing_symbol(addr, si);
|
|
|
|
if(sym != NULL) {
|
|
info->dli_sname = si->strtab + sym->st_name;
|
|
info->dli_saddr = (void*)(si->base + sym->st_value);
|
|
}
|
|
|
|
ret = 1;
|
|
}
|
|
|
|
pthread_mutex_unlock(&dl_lock);
|
|
|
|
return ret;
|
|
}
|
|
|
|
int dlclose(void *handle)
|
|
{
|
|
pthread_mutex_lock(&dl_lock);
|
|
(void)unload_library((soinfo*)handle);
|
|
pthread_mutex_unlock(&dl_lock);
|
|
return 0;
|
|
}
|
|
|
|
#if defined(ANDROID_ARM_LINKER)
|
|
// 0000000 00011111 111112 22222222 2333333 333344444444445555555
|
|
// 0123456 78901234 567890 12345678 9012345 678901234567890123456
|
|
#define ANDROID_LIBDL_STRTAB \
|
|
"dlopen\0dlclose\0dlsym\0dlerror\0dladdr\0dl_unwind_find_exidx\0"
|
|
|
|
#elif defined(ANDROID_X86_LINKER)
|
|
// 0000000 00011111 111112 22222222 2333333 3333444444444455
|
|
// 0123456 78901234 567890 12345678 9012345 6789012345678901
|
|
#define ANDROID_LIBDL_STRTAB \
|
|
"dlopen\0dlclose\0dlsym\0dlerror\0dladdr\0dl_iterate_phdr\0"
|
|
|
|
#elif defined(ANDROID_SH_LINKER)
|
|
// 0000000 00011111 111112 22222222 2333333 3333444444444455
|
|
// 0123456 78901234 567890 12345678 9012345 6789012345678901
|
|
#define ANDROID_LIBDL_STRTAB \
|
|
"dlopen\0dlclose\0dlsym\0dlerror\0dladdr\0dl_iterate_phdr\0"
|
|
|
|
#else /* !defined(ANDROID_ARM_LINKER) && !defined(ANDROID_X86_LINKER) */
|
|
#error Unsupported architecture. Only ARM and x86 are presently supported.
|
|
#endif
|
|
|
|
|
|
static Elf32_Sym libdl_symtab[] = {
|
|
// total length of libdl_info.strtab, including trailing 0
|
|
// This is actually the the STH_UNDEF entry. Technically, it's
|
|
// supposed to have st_name == 0, but instead, it points to an index
|
|
// in the strtab with a \0 to make iterating through the symtab easier.
|
|
{ st_name: sizeof(ANDROID_LIBDL_STRTAB) - 1,
|
|
},
|
|
{ st_name: 0, // starting index of the name in libdl_info.strtab
|
|
st_value: (Elf32_Addr) &dlopen,
|
|
st_info: STB_GLOBAL << 4,
|
|
st_shndx: 1,
|
|
},
|
|
{ st_name: 7,
|
|
st_value: (Elf32_Addr) &dlclose,
|
|
st_info: STB_GLOBAL << 4,
|
|
st_shndx: 1,
|
|
},
|
|
{ st_name: 15,
|
|
st_value: (Elf32_Addr) &dlsym,
|
|
st_info: STB_GLOBAL << 4,
|
|
st_shndx: 1,
|
|
},
|
|
{ st_name: 21,
|
|
st_value: (Elf32_Addr) &dlerror,
|
|
st_info: STB_GLOBAL << 4,
|
|
st_shndx: 1,
|
|
},
|
|
{ st_name: 29,
|
|
st_value: (Elf32_Addr) &dladdr,
|
|
st_info: STB_GLOBAL << 4,
|
|
st_shndx: 1,
|
|
},
|
|
#ifdef ANDROID_ARM_LINKER
|
|
{ st_name: 36,
|
|
st_value: (Elf32_Addr) &dl_unwind_find_exidx,
|
|
st_info: STB_GLOBAL << 4,
|
|
st_shndx: 1,
|
|
},
|
|
#elif defined(ANDROID_X86_LINKER)
|
|
{ st_name: 36,
|
|
st_value: (Elf32_Addr) &dl_iterate_phdr,
|
|
st_info: STB_GLOBAL << 4,
|
|
st_shndx: 1,
|
|
},
|
|
#elif defined(ANDROID_SH_LINKER)
|
|
{ st_name: 36,
|
|
st_value: (Elf32_Addr) &dl_iterate_phdr,
|
|
st_info: STB_GLOBAL << 4,
|
|
st_shndx: 1,
|
|
},
|
|
#endif
|
|
};
|
|
|
|
/* Fake out a hash table with a single bucket.
|
|
* A search of the hash table will look through
|
|
* libdl_symtab starting with index [1], then
|
|
* use libdl_chains to find the next index to
|
|
* look at. libdl_chains should be set up to
|
|
* walk through every element in libdl_symtab,
|
|
* and then end with 0 (sentinel value).
|
|
*
|
|
* I.e., libdl_chains should look like
|
|
* { 0, 2, 3, ... N, 0 } where N is the number
|
|
* of actual symbols, or nelems(libdl_symtab)-1
|
|
* (since the first element of libdl_symtab is not
|
|
* a real symbol).
|
|
*
|
|
* (see _elf_lookup())
|
|
*
|
|
* Note that adding any new symbols here requires
|
|
* stubbing them out in libdl.
|
|
*/
|
|
static unsigned libdl_buckets[1] = { 1 };
|
|
static unsigned libdl_chains[7] = { 0, 2, 3, 4, 5, 6, 0 };
|
|
|
|
soinfo libdl_info = {
|
|
name: "libdl.so",
|
|
flags: FLAG_LINKED,
|
|
|
|
strtab: ANDROID_LIBDL_STRTAB,
|
|
symtab: libdl_symtab,
|
|
|
|
nbucket: 1,
|
|
nchain: 7,
|
|
bucket: libdl_buckets,
|
|
chain: libdl_chains,
|
|
};
|
|
|