2e85579c34
Changed it so that when the linker generates error messages, they are scribbled away into a buffer that dlfcn and friends can read from. Since the error messages are generetad with snprintf, and snprintf MAY call malloc during some code paths, we now link against a version of libc that does not contain malloc/free/realloc/calloc. We then define malloc and friends in the dynamic loader, and make them abort() if they are ever called. Signed-off-by: Dima Zavin <dima@android.com>
216 lines
5 KiB
C
216 lines
5 KiB
C
/*
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* Copyright (C) 2008 The Android Open Source Project
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* All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* * Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* * Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in
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* the documentation and/or other materials provided with the
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* distribution.
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*
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* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
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* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
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* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
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* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
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* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
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* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
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* OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
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* AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
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* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
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* OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* SUCH DAMAGE.
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*/
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#ifndef _LINKER_H_
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#define _LINKER_H_
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#include <unistd.h>
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#include <sys/types.h>
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#include <linux/elf.h>
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#undef PAGE_MASK
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#undef PAGE_SIZE
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#define PAGE_SIZE 4096
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#define PAGE_MASK 4095
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void debugger_init();
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const char *addr_to_name(unsigned addr);
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/* magic shared structures that GDB knows about */
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struct link_map
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{
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uintptr_t l_addr;
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char * l_name;
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uintptr_t l_ld;
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struct link_map * l_next;
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struct link_map * l_prev;
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};
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/* needed for dl_iterate_phdr to be passed to the callbacks provided */
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struct dl_phdr_info
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{
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Elf32_Addr dlpi_addr;
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const char *dlpi_name;
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const Elf32_Phdr *dlpi_phdr;
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Elf32_Half dlpi_phnum;
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};
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// Values for r_debug->state
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enum {
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RT_CONSISTENT,
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RT_ADD,
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RT_DELETE
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};
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struct r_debug
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{
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int32_t r_version;
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struct link_map * r_map;
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void (*r_brk)(void);
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int32_t r_state;
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uintptr_t r_ldbase;
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};
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typedef struct soinfo soinfo;
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#define FLAG_LINKED 0x00000001
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#define FLAG_ERROR 0x00000002
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#define FLAG_EXE 0x00000004 // The main executable
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#define FLAG_PRELINKED 0x00000008 // This is a pre-linked lib
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#define SOINFO_NAME_LEN 128
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struct soinfo
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{
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const char name[SOINFO_NAME_LEN];
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Elf32_Phdr *phdr;
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int phnum;
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unsigned entry;
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unsigned base;
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unsigned size;
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// buddy-allocator index, negative for prelinked libraries
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int ba_index;
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unsigned *dynamic;
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unsigned wrprotect_start;
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unsigned wrprotect_end;
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soinfo *next;
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unsigned flags;
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const char *strtab;
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Elf32_Sym *symtab;
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unsigned nbucket;
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unsigned nchain;
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unsigned *bucket;
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unsigned *chain;
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unsigned *plt_got;
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Elf32_Rel *plt_rel;
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unsigned plt_rel_count;
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Elf32_Rel *rel;
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unsigned rel_count;
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unsigned *preinit_array;
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unsigned preinit_array_count;
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unsigned *init_array;
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unsigned init_array_count;
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unsigned *fini_array;
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unsigned fini_array_count;
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void (*init_func)(void);
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void (*fini_func)(void);
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#ifdef ANDROID_ARM_LINKER
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/* ARM EABI section used for stack unwinding. */
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unsigned *ARM_exidx;
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unsigned ARM_exidx_count;
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#endif
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unsigned refcount;
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struct link_map linkmap;
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};
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extern soinfo libdl_info;
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/* these must all be powers of two */
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#define LIBBASE 0x80000000
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#define LIBLAST 0x90000000
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#define LIBINC 0x00100000
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#ifdef ANDROID_ARM_LINKER
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#define R_ARM_COPY 20
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#define R_ARM_GLOB_DAT 21
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#define R_ARM_JUMP_SLOT 22
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#define R_ARM_RELATIVE 23
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#elif defined(ANDROID_X86_LINKER)
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#define R_386_32 1
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#define R_386_PC32 2
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#define R_386_GLOB_DAT 6
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#define R_386_JUMP_SLOT 7
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#define R_386_RELATIVE 8
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#endif /* ANDROID_*_LINKER */
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#ifndef DT_INIT_ARRAY
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#define DT_INIT_ARRAY 25
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#endif
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#ifndef DT_FINI_ARRAY
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#define DT_FINI_ARRAY 26
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#endif
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#ifndef DT_INIT_ARRAYSZ
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#define DT_INIT_ARRAYSZ 27
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#endif
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#ifndef DT_FINI_ARRAYSZ
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#define DT_FINI_ARRAYSZ 28
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#endif
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#ifndef DT_PREINIT_ARRAY
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#define DT_PREINIT_ARRAY 32
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#endif
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#ifndef DT_PREINIT_ARRAYSZ
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#define DT_PREINIT_ARRAYSZ 33
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#endif
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/* in theory we only need the above relative relocations,
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but in practice the following one turns up from time
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to time. fushigi na.
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*/
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#define R_ARM_ABS32 2
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soinfo *find_library(const char *name);
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unsigned unload_library(soinfo *si);
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Elf32_Sym *lookup_in_library(soinfo *si, const char *name);
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Elf32_Sym *lookup(const char *name, unsigned *base);
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const char *linker_get_error(void);
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#ifdef ANDROID_ARM_LINKER
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typedef long unsigned int *_Unwind_Ptr;
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_Unwind_Ptr dl_unwind_find_exidx(_Unwind_Ptr pc, int *pcount);
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#elif defined(ANDROID_X86_LINKER)
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int dl_iterate_phdr(int (*cb)(struct dl_phdr_info *, size_t, void *), void *);
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#endif
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#endif
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