diff options
Diffstat (limited to 'libcorkscrew/arch-x86/backtrace-x86.c')
| -rw-r--r-- | libcorkscrew/arch-x86/backtrace-x86.c | 143 |
1 files changed, 143 insertions, 0 deletions
diff --git a/libcorkscrew/arch-x86/backtrace-x86.c b/libcorkscrew/arch-x86/backtrace-x86.c new file mode 100644 index 0000000..24fadcb --- /dev/null +++ b/libcorkscrew/arch-x86/backtrace-x86.c @@ -0,0 +1,143 @@ +/* + * Copyright (C) 2011 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. + */ + +/* + * Backtracing functions for x86. + */ + +#define LOG_TAG "Corkscrew" +//#define LOG_NDEBUG 0 + +#include "../backtrace-arch.h" +#include "../backtrace-helper.h" +#include <corkscrew/ptrace.h> + +#include <stdlib.h> +#include <signal.h> +#include <stdbool.h> +#include <limits.h> +#include <errno.h> +#include <sys/ptrace.h> +#include <sys/exec_elf.h> +#include <cutils/log.h> + +/* 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 { + uint32_t gs; + uint32_t fs; + uint32_t es; + uint32_t ds; + uint32_t edi; + uint32_t esi; + uint32_t ebp; + uint32_t esp; + uint32_t ebx; + uint32_t edx; + uint32_t ecx; + uint32_t eax; + uint32_t trapno; + uint32_t err; + uint32_t eip; + uint32_t cs; + uint32_t efl; + uint32_t uesp; + uint32_t ss; + void* fpregs; + uint32_t oldmask; + uint32_t cr2; + } uc_mcontext; + uint32_t uc_sigmask; +} ucontext_t; + +/* Unwind state. */ +typedef struct { + uint32_t ebp; + uint32_t eip; + uint32_t esp; +} unwind_state_t; + +uintptr_t rewind_pc_arch(const memory_t* memory, uintptr_t pc) { + // TODO: Implement for x86. + return pc; +} + +static ssize_t unwind_backtrace_common(const memory_t* memory, + const map_info_t* map_info_list, + unwind_state_t* state, backtrace_frame_t* backtrace, + size_t ignore_depth, size_t max_depth) { + size_t ignored_frames = 0; + size_t returned_frames = 0; + + for (size_t index = 0; state->ebp && returned_frames < max_depth; index++) { + backtrace_frame_t* frame = add_backtrace_entry( + index ? rewind_pc_arch(memory, state->eip) : state->eip, + backtrace, ignore_depth, max_depth, + &ignored_frames, &returned_frames); + uint32_t next_esp = state->ebp + 8; + if (frame) { + frame->stack_top = state->esp; + if (state->esp < next_esp) { + frame->stack_size = next_esp - state->esp; + } + } + state->esp = next_esp; + if (!try_get_word(memory, state->ebp + 4, &state->eip) + || !try_get_word(memory, state->ebp, &state->ebp) + || !state->eip) { + break; + } + } + + return returned_frames; +} + +ssize_t unwind_backtrace_signal_arch(siginfo_t* siginfo, void* sigcontext, + const map_info_t* map_info_list, + backtrace_frame_t* backtrace, size_t ignore_depth, size_t max_depth) { + const ucontext_t* uc = (const ucontext_t*)sigcontext; + + unwind_state_t state; + state.ebp = uc->uc_mcontext.ebp; + state.eip = uc->uc_mcontext.eip; + state.esp = uc->uc_mcontext.esp; + + memory_t memory; + init_memory(&memory, map_info_list); + return unwind_backtrace_common(&memory, map_info_list, + &state, backtrace, ignore_depth, max_depth); +} + +ssize_t unwind_backtrace_ptrace_arch(pid_t tid, const ptrace_context_t* context, + backtrace_frame_t* backtrace, size_t ignore_depth, size_t max_depth) { + pt_regs_x86_t regs; + if (ptrace(PTRACE_GETREGS, tid, 0, ®s)) { + return -1; + } + + unwind_state_t state; + state.ebp = regs.ebp; + state.eip = regs.eip; + state.esp = regs.esp; + + memory_t memory; + init_memory_ptrace(&memory, tid); + return unwind_backtrace_common(&memory, context->map_info_list, + &state, backtrace, ignore_depth, max_depth); +} |