Browse Source

engine: android: restore dlsym hack for old Android(<5.0)

pull/2/head
Alibek Omarov 6 years ago
parent
commit
e7ddc6d6c5
  1. 94
      engine/platform/android/dlsym-weak.cpp
  2. 21
      engine/platform/android/dlsym-weak.h
  3. 4
      engine/platform/android/lib_android.c
  4. 202
      engine/platform/android/linker.h

94
engine/platform/android/dlsym-weak.cpp

@ -0,0 +1,94 @@ @@ -0,0 +1,94 @@
/*
* Copyright (C) 2008, 2009 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.
*/
#ifdef __ANDROID__
#include <android/log.h>
#include "linker.h"
static Elf_Sym* soinfo_elf_lookup(soinfo* si, unsigned hash, const char* name) {
Elf_Sym* symtab = si->symtab;
const char* strtab = si->strtab;
for (unsigned n = si->bucket[hash % si->nbucket]; n != 0; n = si->chain[n]) {
Elf_Sym* s = symtab + n;
if (strcmp(strtab + s->st_name, name)) continue;
/* only concern ourselves with global and weak symbol definitions */
switch (ELF_ST_BIND(s->st_info)) {
case STB_GLOBAL:
case STB_WEAK:
if (s->st_shndx == SHN_UNDEF) {
continue;
}
return s;
}
}
return NULL;
}
static unsigned elfhash(const char* _name) {
const unsigned char* name = (const unsigned char*) _name;
unsigned h = 0, g;
while(*name) {
h = (h << 4) + *name++;
g = h & 0xf0000000;
h ^= g;
h ^= g >> 24;
}
return h;
}
/* This is used by dlsym(3). It performs symbol lookup only within the
specified soinfo object and not in any of its dependencies.
TODO: Only looking in the specified soinfo seems wrong. dlsym(3) says
that it should do a breadth first search through the dependency
tree. This agrees with the ELF spec (aka System V Application
Binary Interface) where in Chapter 5 it discuss resolving "Shared
Object Dependencies" in breadth first search order.
*/
Elf_Sym* dlsym_handle_lookup(soinfo* si, const char* name) {
return soinfo_elf_lookup(si, elfhash(name), name);
}
extern "C" void* dlsym_weak(void* handle, const char* symbol) {
soinfo* found = NULL;
Elf_Sym* sym = NULL;
found = reinterpret_cast<soinfo*>(handle);
sym = dlsym_handle_lookup(found, symbol);
if (sym != NULL) {
return reinterpret_cast<void*>(sym->st_value + found->base/*load_bias*/);
}
__android_log_print(ANDROID_LOG_ERROR, "dlsym-weak", "Failed when looking up %s\n", symbol);
return NULL;
}
#endif

21
engine/platform/android/dlsym-weak.h

@ -0,0 +1,21 @@ @@ -0,0 +1,21 @@
/*
dlsym-weak.h -- custom dlsym() function to override bionic libc bug on Android <5.0
Copyright (C) 2015-2017 Flying With Gauss
This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
*/
#ifndef DLSYM_WEAH_H
#define DLSYM_WEAK_H
// ------------ dlsym-weak.cpp ------------ //
void* dlsym_weak(void* handle, const char* symbol);
#endif

4
engine/platform/android/lib_android.c

@ -18,8 +18,8 @@ GNU General Public License for more details. @@ -18,8 +18,8 @@ GNU General Public License for more details.
#include "library.h"
#include "filesystem.h"
#include "server.h"
#include "platform/android/android_lib.h"
#include "platform/android/dlsym_weak.h" // Android < 5.0
#include "platform/android/lib_android.h"
#include "platform/android/dlsym-weak.h" // Android < 5.0
void *ANDROID_LoadLibrary( const char *dllname )
{

202
engine/platform/android/linker.h

@ -0,0 +1,202 @@ @@ -0,0 +1,202 @@
/*
* Copyright (C) 2008 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.
*/
#ifndef _LINKER_H_
#define _LINKER_H_
#ifdef __ANDROID__
#include <unistd.h>
#include <sys/types.h>
#include <elf.h>
#include <sys/exec_elf.h>
#include <link.h>
// Returns the address of the page containing address 'x'.
#define PAGE_START(x) ((x) & PAGE_MASK)
// Returns the offset of address 'x' in its page.
#define PAGE_OFFSET(x) ((x) & ~PAGE_MASK)
// Returns the address of the next page after address 'x', unless 'x' is
// itself at the start of a page.
#define PAGE_END(x) PAGE_START((x) + (PAGE_SIZE-1))
// Magic shared structures that GDB knows about.
struct link_map_t {
uintptr_t l_addr;
char* l_name;
uintptr_t l_ld;
link_map_t* l_next;
link_map_t* l_prev;
};
// Values for r_debug->state
enum {
RT_CONSISTENT,
RT_ADD,
RT_DELETE
};
#if 0
struct r_debug {
int32_t r_version;
link_map_t* r_map;
void (*r_brk)(void);
int32_t r_state;
uintptr_t r_ldbase;
};
#endif
#define FLAG_LINKED 0x00000001
#define FLAG_EXE 0x00000004 // The main executable
#define FLAG_LINKER 0x00000010 // The linker itself
#define SOINFO_NAME_LEN 128
typedef void (*linker_function_t)();
// Android uses REL for 32-bit but only uses RELA for 64-bit.
#if defined(__LP64__)
#define USE_RELA 1
#endif
struct soinfo {
public:
char name[SOINFO_NAME_LEN];
const Elf_Phdr* phdr;
size_t phnum;
Elf_Addr entry;
Elf_Addr base;
unsigned size;
#ifndef __LP64__
uint32_t unused1; // DO NOT USE, maintained for compatibility.
#endif
Elf_Dyn* dynamic;
#ifndef __LP64__
uint32_t unused2; // DO NOT USE, maintained for compatibility
uint32_t unused3; // DO NOT USE, maintained for compatibility
#endif
soinfo* next;
unsigned flags;
const char* strtab;
Elf_Sym* symtab;
size_t nbucket;
size_t nchain;
unsigned* bucket;
unsigned* chain;
#if !defined(__LP64__)
// This is only used by 32-bit MIPS, but needs to be here for
// all 32-bit architectures to preserve binary compatibility.
unsigned* plt_got;
#endif
#if defined(USE_RELA)
Elf_Rela* plt_rela;
size_t plt_rela_count;
Elf_Rela* rela;
size_t rela_count;
#else
Elf_Rel* plt_rel;
size_t plt_rel_count;
Elf_Rel* rel;
size_t rel_count;
#endif
linker_function_t* preinit_array;
size_t preinit_array_count;
linker_function_t* init_array;
size_t init_array_count;
linker_function_t* fini_array;
size_t fini_array_count;
linker_function_t init_func;
linker_function_t fini_func;
#if defined(__arm__)
// ARM EABI section used for stack unwinding.
unsigned* ARM_exidx;
size_t ARM_exidx_count;
#elif defined(__mips__)
unsigned mips_symtabno;
unsigned mips_local_gotno;
unsigned mips_gotsym;
#endif
size_t ref_count;
link_map_t link_map;
bool constructors_called;
// When you read a virtual address from the ELF file, add this
// value to get the corresponding address in the process' address space.
Elf_Addr load_bias;
#if !defined(__LP64__)
bool has_text_relocations;
#endif
bool has_DT_SYMBOLIC;
void CallConstructors();
void CallDestructors();
void CallPreInitConstructors();
private:
void CallArray(const char* array_name, linker_function_t* functions, size_t count, bool reverse);
void CallFunction(const char* function_name, linker_function_t function);
};
extern soinfo libdl_info;
void do_android_update_LD_LIBRARY_PATH(const char* ld_library_path);
soinfo* do_dlopen(const char* name, int flags);
int do_dlclose(soinfo* si);
Elf_Sym* dlsym_linear_lookup(const char* name, soinfo** found, soinfo* start);
soinfo* find_containing_library(const void* addr);
Elf_Sym* dladdr_find_symbol(soinfo* si, const void* addr);
Elf_Sym* dlsym_handle_lookup(soinfo* si, const char* name);
void debuggerd_init();
extern "C" void notify_gdb_of_libraries();
char* linker_get_error_buffer();
size_t linker_get_error_buffer_size();
#endif
#endif
Loading…
Cancel
Save