/* * Copyright (C) 2013 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. */ #define LOG_TAG "libbacktrace" #include #include #include #define UNW_LOCAL_ONLY #include #include "UnwindCurrent.h" // Define the ucontext_t structures needed for each supported arch. #if defined(__arm__) // The current version of the doesn't define ucontext_t. #include // Ensure 'struct sigcontext' is defined. // Machine context at the time a signal was raised. typedef struct ucontext { uint32_t uc_flags; struct ucontext* uc_link; stack_t uc_stack; struct sigcontext uc_mcontext; uint32_t uc_sigmask; } ucontext_t; #elif defined(__mips__) typedef struct ucontext { uint32_t sp; uint32_t ra; uint32_t pc; } ucontext_t; #elif defined(__i386__) #include #include typedef struct ucontext ucontext_t; #else #error Unsupported architecture. #endif //------------------------------------------------------------------------- // UnwindCurrent functions. //------------------------------------------------------------------------- UnwindCurrent::UnwindCurrent() { } UnwindCurrent::~UnwindCurrent() { } bool UnwindCurrent::Unwind(size_t num_ignore_frames) { int ret = unw_getcontext(&context_); if (ret < 0) { BACK_LOGW("unw_getcontext failed %d", ret); return false; } return UnwindFromContext(num_ignore_frames, true); } std::string UnwindCurrent::GetFunctionNameRaw(uintptr_t pc, uintptr_t* offset) { *offset = 0; char buf[512]; unw_word_t value; if (unw_get_proc_name_by_ip(unw_local_addr_space, pc, buf, sizeof(buf), &value, &context_) >= 0 && buf[0] != '\0') { *offset = static_cast(value); return buf; } return ""; } bool UnwindCurrent::UnwindFromContext(size_t num_ignore_frames, bool resolve) { backtrace_t* backtrace = GetBacktraceData(); backtrace->num_frames = 0; // The cursor structure is pretty large, do not put it on the stack. unw_cursor_t* cursor = new unw_cursor_t; int ret = unw_init_local(cursor, &context_); if (ret < 0) { BACK_LOGW("unw_init_local failed %d", ret); return false; } do { unw_word_t pc; ret = unw_get_reg(cursor, UNW_REG_IP, &pc); if (ret < 0) { BACK_LOGW("Failed to read IP %d", ret); break; } unw_word_t sp; ret = unw_get_reg(cursor, UNW_REG_SP, &sp); if (ret < 0) { BACK_LOGW("Failed to read SP %d", ret); break; } if (num_ignore_frames == 0) { size_t num_frames = backtrace->num_frames; backtrace_frame_data_t* frame = &backtrace->frames[num_frames]; frame->pc = static_cast(pc); frame->sp = static_cast(sp); frame->stack_size = 0; frame->map_name = NULL; frame->map_offset = 0; frame->func_name = NULL; frame->func_offset = 0; if (num_frames > 0) { // Set the stack size for the previous frame. backtrace_frame_data_t* prev = &backtrace->frames[num_frames-1]; prev->stack_size = frame->sp - prev->sp; } if (resolve) { std::string func_name = backtrace_obj_->GetFunctionName(frame->pc, &frame->func_offset); if (!func_name.empty()) { frame->func_name = strdup(func_name.c_str()); } uintptr_t map_start; frame->map_name = backtrace_obj_->GetMapName(frame->pc, &map_start); if (frame->map_name) { frame->map_offset = frame->pc - map_start; } } backtrace->num_frames++; } else { num_ignore_frames--; } ret = unw_step (cursor); } while (ret > 0 && backtrace->num_frames < MAX_BACKTRACE_FRAMES); delete cursor; return true; } void UnwindCurrent::ExtractContext(void* sigcontext) { unw_tdep_context_t* context = reinterpret_cast(&context_); const ucontext_t* uc = reinterpret_cast(sigcontext); #if defined(__arm__) context->regs[0] = uc->uc_mcontext.arm_r0; context->regs[1] = uc->uc_mcontext.arm_r1; context->regs[2] = uc->uc_mcontext.arm_r2; context->regs[3] = uc->uc_mcontext.arm_r3; context->regs[4] = uc->uc_mcontext.arm_r4; context->regs[5] = uc->uc_mcontext.arm_r5; context->regs[6] = uc->uc_mcontext.arm_r6; context->regs[7] = uc->uc_mcontext.arm_r7; context->regs[8] = uc->uc_mcontext.arm_r8; context->regs[9] = uc->uc_mcontext.arm_r9; context->regs[10] = uc->uc_mcontext.arm_r10; context->regs[11] = uc->uc_mcontext.arm_fp; context->regs[12] = uc->uc_mcontext.arm_ip; context->regs[13] = uc->uc_mcontext.arm_sp; context->regs[14] = uc->uc_mcontext.arm_lr; context->regs[15] = uc->uc_mcontext.arm_pc; #elif defined(__mips__) context->uc_mcontext.sp = uc->sp; context->uc_mcontext.pc = uc->pc; context->uc_mcontext.ra = uc->ra; #elif defined(__i386__) context->uc_mcontext.gregs[REG_EBP] = uc->uc_mcontext.gregs[REG_EBP]; context->uc_mcontext.gregs[REG_ESP] = uc->uc_mcontext.gregs[REG_ESP]; context->uc_mcontext.gregs[REG_EIP] = uc->uc_mcontext.gregs[REG_EIP]; #endif } //------------------------------------------------------------------------- // UnwindThread functions. //------------------------------------------------------------------------- UnwindThread::UnwindThread() { } UnwindThread::~UnwindThread() { } bool UnwindThread::Init() { return true; } void UnwindThread::ThreadUnwind( siginfo_t* /*siginfo*/, void* sigcontext, size_t num_ignore_frames) { ExtractContext(sigcontext); UnwindFromContext(num_ignore_frames, false); } //------------------------------------------------------------------------- // C++ object creation function. //------------------------------------------------------------------------- Backtrace* CreateCurrentObj() { return new BacktraceCurrent(new UnwindCurrent()); } Backtrace* CreateThreadObj(pid_t tid) { UnwindThread* thread_obj = new UnwindThread(); return new BacktraceThread(thread_obj, thread_obj, tid); }