backtrace-x86.c revision b4ef91b97513434a13d6d84a810512315ecf4768
110484a068412613aaf3924f63a0b2f61400c7d1eJeff Brown/* 210484a068412613aaf3924f63a0b2f61400c7d1eJeff Brown * Copyright (C) 2011 The Android Open Source Project 310484a068412613aaf3924f63a0b2f61400c7d1eJeff Brown * 410484a068412613aaf3924f63a0b2f61400c7d1eJeff Brown * Licensed under the Apache License, Version 2.0 (the "License"); 510484a068412613aaf3924f63a0b2f61400c7d1eJeff Brown * you may not use this file except in compliance with the License. 610484a068412613aaf3924f63a0b2f61400c7d1eJeff Brown * You may obtain a copy of the License at 710484a068412613aaf3924f63a0b2f61400c7d1eJeff Brown * 810484a068412613aaf3924f63a0b2f61400c7d1eJeff Brown * http://www.apache.org/licenses/LICENSE-2.0 910484a068412613aaf3924f63a0b2f61400c7d1eJeff Brown * 1010484a068412613aaf3924f63a0b2f61400c7d1eJeff Brown * Unless required by applicable law or agreed to in writing, software 1110484a068412613aaf3924f63a0b2f61400c7d1eJeff Brown * distributed under the License is distributed on an "AS IS" BASIS, 1210484a068412613aaf3924f63a0b2f61400c7d1eJeff Brown * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 1310484a068412613aaf3924f63a0b2f61400c7d1eJeff Brown * See the License for the specific language governing permissions and 1410484a068412613aaf3924f63a0b2f61400c7d1eJeff Brown * limitations under the License. 1510484a068412613aaf3924f63a0b2f61400c7d1eJeff Brown */ 1610484a068412613aaf3924f63a0b2f61400c7d1eJeff Brown 1710484a068412613aaf3924f63a0b2f61400c7d1eJeff Brown/* 1810484a068412613aaf3924f63a0b2f61400c7d1eJeff Brown * Backtracing functions for x86. 1910484a068412613aaf3924f63a0b2f61400c7d1eJeff Brown */ 2010484a068412613aaf3924f63a0b2f61400c7d1eJeff Brown 2110484a068412613aaf3924f63a0b2f61400c7d1eJeff Brown#define LOG_TAG "Corkscrew" 2210484a068412613aaf3924f63a0b2f61400c7d1eJeff Brown//#define LOG_NDEBUG 0 2310484a068412613aaf3924f63a0b2f61400c7d1eJeff Brown 2410484a068412613aaf3924f63a0b2f61400c7d1eJeff Brown#include "../backtrace-arch.h" 2510484a068412613aaf3924f63a0b2f61400c7d1eJeff Brown#include "../backtrace-helper.h" 2610484a068412613aaf3924f63a0b2f61400c7d1eJeff Brown#include <corkscrew/ptrace.h> 2710484a068412613aaf3924f63a0b2f61400c7d1eJeff Brown 2810484a068412613aaf3924f63a0b2f61400c7d1eJeff Brown#include <stdlib.h> 2910484a068412613aaf3924f63a0b2f61400c7d1eJeff Brown#include <signal.h> 3010484a068412613aaf3924f63a0b2f61400c7d1eJeff Brown#include <stdbool.h> 3110484a068412613aaf3924f63a0b2f61400c7d1eJeff Brown#include <limits.h> 3210484a068412613aaf3924f63a0b2f61400c7d1eJeff Brown#include <errno.h> 3310484a068412613aaf3924f63a0b2f61400c7d1eJeff Brown#include <sys/ptrace.h> 3410484a068412613aaf3924f63a0b2f61400c7d1eJeff Brown#include <sys/exec_elf.h> 3510484a068412613aaf3924f63a0b2f61400c7d1eJeff Brown#include <cutils/log.h> 3610484a068412613aaf3924f63a0b2f61400c7d1eJeff Brown 37b4ef91b97513434a13d6d84a810512315ecf4768David 'Digit' Turner#if !defined(__BIONIC_HAVE_UCONTEXT_T) 38b4ef91b97513434a13d6d84a810512315ecf4768David 'Digit' Turner/* Old versions of the Android <signal.h> didn't define ucontext_t. */ 39b4ef91b97513434a13d6d84a810512315ecf4768David 'Digit' Turner 40b4ef91b97513434a13d6d84a810512315ecf4768David 'Digit' Turnertypedef struct { 41b4ef91b97513434a13d6d84a810512315ecf4768David 'Digit' Turner uint32_t gregs[32]; 42b4ef91b97513434a13d6d84a810512315ecf4768David 'Digit' Turner void* fpregs; 43b4ef91b97513434a13d6d84a810512315ecf4768David 'Digit' Turner uint32_t oldmask; 44b4ef91b97513434a13d6d84a810512315ecf4768David 'Digit' Turner uint32_t cr2; 45b4ef91b97513434a13d6d84a810512315ecf4768David 'Digit' Turner} mcontext_t; 46b4ef91b97513434a13d6d84a810512315ecf4768David 'Digit' Turner 47b4ef91b97513434a13d6d84a810512315ecf4768David 'Digit' Turnerenum { 48b4ef91b97513434a13d6d84a810512315ecf4768David 'Digit' Turner REG_GS = 0, REG_FS, REG_ES, REG_DS, 49b4ef91b97513434a13d6d84a810512315ecf4768David 'Digit' Turner REG_EDI, REG_ESI, REG_EBP, REG_ESP, 50b4ef91b97513434a13d6d84a810512315ecf4768David 'Digit' Turner REG_EBX, REG_EDX, REG_ECX, REG_EAX, 51b4ef91b97513434a13d6d84a810512315ecf4768David 'Digit' Turner REG_TRAPNO, REG_ERR, REG_EIP, REG_CS, 52b4ef91b97513434a13d6d84a810512315ecf4768David 'Digit' Turner REG_EFL, REG_UESP, REG_SS 53b4ef91b97513434a13d6d84a810512315ecf4768David 'Digit' Turner}; 54b4ef91b97513434a13d6d84a810512315ecf4768David 'Digit' Turner 5510484a068412613aaf3924f63a0b2f61400c7d1eJeff Brown/* Machine context at the time a signal was raised. */ 5610484a068412613aaf3924f63a0b2f61400c7d1eJeff Browntypedef struct ucontext { 5710484a068412613aaf3924f63a0b2f61400c7d1eJeff Brown uint32_t uc_flags; 5810484a068412613aaf3924f63a0b2f61400c7d1eJeff Brown struct ucontext* uc_link; 5910484a068412613aaf3924f63a0b2f61400c7d1eJeff Brown stack_t uc_stack; 60b4ef91b97513434a13d6d84a810512315ecf4768David 'Digit' Turner mcontext_t uc_mcontext; 6110484a068412613aaf3924f63a0b2f61400c7d1eJeff Brown uint32_t uc_sigmask; 6210484a068412613aaf3924f63a0b2f61400c7d1eJeff Brown} ucontext_t; 63b4ef91b97513434a13d6d84a810512315ecf4768David 'Digit' Turner#endif /* !__BIONIC_HAVE_UCONTEXT_T */ 6410484a068412613aaf3924f63a0b2f61400c7d1eJeff Brown 6510484a068412613aaf3924f63a0b2f61400c7d1eJeff Brown/* Unwind state. */ 6610484a068412613aaf3924f63a0b2f61400c7d1eJeff Browntypedef struct { 6710484a068412613aaf3924f63a0b2f61400c7d1eJeff Brown uint32_t ebp; 6810484a068412613aaf3924f63a0b2f61400c7d1eJeff Brown uint32_t eip; 6910484a068412613aaf3924f63a0b2f61400c7d1eJeff Brown uint32_t esp; 7010484a068412613aaf3924f63a0b2f61400c7d1eJeff Brown} unwind_state_t; 7110484a068412613aaf3924f63a0b2f61400c7d1eJeff Brown 72f0c5872637a63e28e3cd314cfc915c07f76df9c6Jeff Brownuintptr_t rewind_pc_arch(const memory_t* memory, uintptr_t pc) { 73f0c5872637a63e28e3cd314cfc915c07f76df9c6Jeff Brown // TODO: Implement for x86. 74f0c5872637a63e28e3cd314cfc915c07f76df9c6Jeff Brown return pc; 75f0c5872637a63e28e3cd314cfc915c07f76df9c6Jeff Brown} 76f0c5872637a63e28e3cd314cfc915c07f76df9c6Jeff Brown 77f0c5872637a63e28e3cd314cfc915c07f76df9c6Jeff Brownstatic ssize_t unwind_backtrace_common(const memory_t* memory, 78f0c5872637a63e28e3cd314cfc915c07f76df9c6Jeff Brown const map_info_t* map_info_list, 7910484a068412613aaf3924f63a0b2f61400c7d1eJeff Brown unwind_state_t* state, backtrace_frame_t* backtrace, 8010484a068412613aaf3924f63a0b2f61400c7d1eJeff Brown size_t ignore_depth, size_t max_depth) { 8110484a068412613aaf3924f63a0b2f61400c7d1eJeff Brown size_t ignored_frames = 0; 8210484a068412613aaf3924f63a0b2f61400c7d1eJeff Brown size_t returned_frames = 0; 8310484a068412613aaf3924f63a0b2f61400c7d1eJeff Brown 84f0c5872637a63e28e3cd314cfc915c07f76df9c6Jeff Brown for (size_t index = 0; state->ebp && returned_frames < max_depth; index++) { 85f0c5872637a63e28e3cd314cfc915c07f76df9c6Jeff Brown backtrace_frame_t* frame = add_backtrace_entry( 86f0c5872637a63e28e3cd314cfc915c07f76df9c6Jeff Brown index ? rewind_pc_arch(memory, state->eip) : state->eip, 8710484a068412613aaf3924f63a0b2f61400c7d1eJeff Brown backtrace, ignore_depth, max_depth, 8810484a068412613aaf3924f63a0b2f61400c7d1eJeff Brown &ignored_frames, &returned_frames); 8910484a068412613aaf3924f63a0b2f61400c7d1eJeff Brown uint32_t next_esp = state->ebp + 8; 9010484a068412613aaf3924f63a0b2f61400c7d1eJeff Brown if (frame) { 9110484a068412613aaf3924f63a0b2f61400c7d1eJeff Brown frame->stack_top = state->esp; 9210484a068412613aaf3924f63a0b2f61400c7d1eJeff Brown if (state->esp < next_esp) { 9310484a068412613aaf3924f63a0b2f61400c7d1eJeff Brown frame->stack_size = next_esp - state->esp; 9410484a068412613aaf3924f63a0b2f61400c7d1eJeff Brown } 9510484a068412613aaf3924f63a0b2f61400c7d1eJeff Brown } 9610484a068412613aaf3924f63a0b2f61400c7d1eJeff Brown state->esp = next_esp; 97f0c5872637a63e28e3cd314cfc915c07f76df9c6Jeff Brown if (!try_get_word(memory, state->ebp + 4, &state->eip) 98f0c5872637a63e28e3cd314cfc915c07f76df9c6Jeff Brown || !try_get_word(memory, state->ebp, &state->ebp) 9910484a068412613aaf3924f63a0b2f61400c7d1eJeff Brown || !state->eip) { 10010484a068412613aaf3924f63a0b2f61400c7d1eJeff Brown break; 10110484a068412613aaf3924f63a0b2f61400c7d1eJeff Brown } 10210484a068412613aaf3924f63a0b2f61400c7d1eJeff Brown } 10310484a068412613aaf3924f63a0b2f61400c7d1eJeff Brown 10410484a068412613aaf3924f63a0b2f61400c7d1eJeff Brown return returned_frames; 10510484a068412613aaf3924f63a0b2f61400c7d1eJeff Brown} 10610484a068412613aaf3924f63a0b2f61400c7d1eJeff Brown 10710484a068412613aaf3924f63a0b2f61400c7d1eJeff Brownssize_t unwind_backtrace_signal_arch(siginfo_t* siginfo, void* sigcontext, 108f0c5872637a63e28e3cd314cfc915c07f76df9c6Jeff Brown const map_info_t* map_info_list, 10910484a068412613aaf3924f63a0b2f61400c7d1eJeff Brown backtrace_frame_t* backtrace, size_t ignore_depth, size_t max_depth) { 11010484a068412613aaf3924f63a0b2f61400c7d1eJeff Brown const ucontext_t* uc = (const ucontext_t*)sigcontext; 11110484a068412613aaf3924f63a0b2f61400c7d1eJeff Brown 11210484a068412613aaf3924f63a0b2f61400c7d1eJeff Brown unwind_state_t state; 113b4ef91b97513434a13d6d84a810512315ecf4768David 'Digit' Turner state.ebp = uc->uc_mcontext.gregs[REG_EBP]; 114b4ef91b97513434a13d6d84a810512315ecf4768David 'Digit' Turner state.eip = uc->uc_mcontext.gregs[REG_EIP]; 115b4ef91b97513434a13d6d84a810512315ecf4768David 'Digit' Turner state.esp = uc->uc_mcontext.gregs[REG_ESP]; 11610484a068412613aaf3924f63a0b2f61400c7d1eJeff Brown 117f0c5872637a63e28e3cd314cfc915c07f76df9c6Jeff Brown memory_t memory; 118f0c5872637a63e28e3cd314cfc915c07f76df9c6Jeff Brown init_memory(&memory, map_info_list); 119f0c5872637a63e28e3cd314cfc915c07f76df9c6Jeff Brown return unwind_backtrace_common(&memory, map_info_list, 120f0c5872637a63e28e3cd314cfc915c07f76df9c6Jeff Brown &state, backtrace, ignore_depth, max_depth); 12110484a068412613aaf3924f63a0b2f61400c7d1eJeff Brown} 12210484a068412613aaf3924f63a0b2f61400c7d1eJeff Brown 12310484a068412613aaf3924f63a0b2f61400c7d1eJeff Brownssize_t unwind_backtrace_ptrace_arch(pid_t tid, const ptrace_context_t* context, 12410484a068412613aaf3924f63a0b2f61400c7d1eJeff Brown backtrace_frame_t* backtrace, size_t ignore_depth, size_t max_depth) { 12510484a068412613aaf3924f63a0b2f61400c7d1eJeff Brown pt_regs_x86_t regs; 12610484a068412613aaf3924f63a0b2f61400c7d1eJeff Brown if (ptrace(PTRACE_GETREGS, tid, 0, ®s)) { 12710484a068412613aaf3924f63a0b2f61400c7d1eJeff Brown return -1; 12810484a068412613aaf3924f63a0b2f61400c7d1eJeff Brown } 12910484a068412613aaf3924f63a0b2f61400c7d1eJeff Brown 13010484a068412613aaf3924f63a0b2f61400c7d1eJeff Brown unwind_state_t state; 13110484a068412613aaf3924f63a0b2f61400c7d1eJeff Brown state.ebp = regs.ebp; 13210484a068412613aaf3924f63a0b2f61400c7d1eJeff Brown state.eip = regs.eip; 13310484a068412613aaf3924f63a0b2f61400c7d1eJeff Brown state.esp = regs.esp; 13410484a068412613aaf3924f63a0b2f61400c7d1eJeff Brown 135f0c5872637a63e28e3cd314cfc915c07f76df9c6Jeff Brown memory_t memory; 136f0c5872637a63e28e3cd314cfc915c07f76df9c6Jeff Brown init_memory_ptrace(&memory, tid); 137f0c5872637a63e28e3cd314cfc915c07f76df9c6Jeff Brown return unwind_backtrace_common(&memory, context->map_info_list, 138f0c5872637a63e28e3cd314cfc915c07f76df9c6Jeff Brown &state, backtrace, ignore_depth, max_depth); 13910484a068412613aaf3924f63a0b2f61400c7d1eJeff Brown} 140