Unwinding implementation via eh_frame sections for x86 (af2cb366) · Commits · e / os / android_system_core

debuggerd/crasher.c

+16 −0

Original line number	Diff line number	Diff line
		@@ -101,6 +101,21 @@ int do_action_on_thread(const char* arg)
		return (int) result;
		}

		__attribute__((noinline)) int crash3(int a) {
		((int) 0xdead) = a;
		return a*4;
		}

		__attribute__((noinline)) int crash2(int a) {
		a = crash3(a) + 2;
		return a*3;
		}

		__attribute__((noinline)) int crash(int a) {
		a = crash2(a) + 1;
		return a*2;
		}

		int do_action(const char* arg)
		{
		if(!strncmp(arg, "thread-", strlen("thread-"))) {
		@@ -111,6 +126,7 @@ int do_action(const char* arg)
		if(!strcmp(arg,"nostack")) crashnostack();
		if(!strcmp(arg,"ctest")) return ctest();
		if(!strcmp(arg,"exit")) exit(1);
		if(!strcmp(arg,"crash")) return crash(42);
		if(!strcmp(arg,"abort")) maybeabort();

		pthread_t thr;

libcorkscrew/arch-x86/backtrace-x86.c

100644 → 100755

+716 −25

File changed.File mode changed from 100644 to 100755.

Preview size limit exceeded, changes collapsed.

libcorkscrew/arch-x86/dwarf.h

0 → 100755

+140 −0

Original line number	Diff line number	Diff line
		/*
		* 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.
		*/

		/*
		* Dwarf2 data encoding flags.
		*/

		#define DW_EH_PE_absptr 0x00
		#define DW_EH_PE_omit 0xff
		#define DW_EH_PE_uleb128 0x01
		#define DW_EH_PE_udata2 0x02
		#define DW_EH_PE_udata4 0x03
		#define DW_EH_PE_udata8 0x04
		#define DW_EH_PE_sleb128 0x09
		#define DW_EH_PE_sdata2 0x0A
		#define DW_EH_PE_sdata4 0x0B
		#define DW_EH_PE_sdata8 0x0C
		#define DW_EH_PE_signed 0x08
		#define DW_EH_PE_pcrel 0x10
		#define DW_EH_PE_textrel 0x20
		#define DW_EH_PE_datarel 0x30
		#define DW_EH_PE_funcrel 0x40
		#define DW_EH_PE_aligned 0x50
		#define DW_EH_PE_indirect 0x80

		/*
		* Dwarf2 call frame instructions.
		*/

		typedef enum {
		DW_CFA_advance_loc = 0x40,
		DW_CFA_offset = 0x80,
		DW_CFA_restore = 0xc0,
		DW_CFA_nop = 0x00,
		DW_CFA_set_loc = 0x01,
		DW_CFA_advance_loc1 = 0x02,
		DW_CFA_advance_loc2 = 0x03,
		DW_CFA_advance_loc4 = 0x04,
		DW_CFA_offset_extended = 0x05,
		DW_CFA_restore_extended = 0x06,
		DW_CFA_undefined = 0x07,
		DW_CFA_same_value = 0x08,
		DW_CFA_register = 0x09,
		DW_CFA_remember_state = 0x0a,
		DW_CFA_restore_state = 0x0b,
		DW_CFA_def_cfa = 0x0c,
		DW_CFA_def_cfa_register = 0x0d,
		DW_CFA_def_cfa_offset = 0x0e
		} dwarf_CFA;

		/*
		* eh_frame_hdr information.
		*/

		typedef struct {
		uint8_t version;
		uint8_t eh_frame_ptr_enc;
		uint8_t fde_count_enc;
		uint8_t fde_table_enc;
		uintptr_t eh_frame_ptr;
		uint32_t fde_count;
		} eh_frame_hdr_info_t;

		/*
		* CIE information.
		*/

		typedef struct {
		uint8_t version;
		uint32_t code_align;
		uint32_t data_align;
		uint32_t reg;
		uint32_t aug_z;
		uint8_t aug_L;
		uint8_t aug_R;
		uint8_t aug_S;
		uint32_t aug_P;
		} cie_info_t;

		/*
		* FDE information.
		*/

		typedef struct {
		uint32_t start;
		uint32_t length; // number of instructions covered by FDE
		uint32_t aug_z;
		uint32_t aug_L;
		} fde_info_t;

		/*
		* Dwarf state.
		*/

		/* Stack of states: required for DW_CFA_remember_state/DW_CFA_restore_state
		30 should be enough */
		#define DWARF_STATES_STACK 30

		typedef struct {
		char rule; // rule: o - offset(value); r - register(value)
		uint32_t value; // value
		} reg_rule_t;

		/* Dwarf preserved number of registers for x86. */

		#define DWARF_REGISTERS 17

		typedef struct {
		uintptr_t loc; // location (ip)
		uint8_t cfa_reg; // index of register where CFA location stored
		intptr_t cfa_off; // offset
		reg_rule_t regs[DWARF_REGISTERS]; // dwarf preserved registers for x86
		} dwarf_state_t;

		/* DWARF registers we are caring about. */

		#define DWARF_EAX 0
		#define DWARF_ECX 1
		#define DWARF_EDX 2
		#define DWARF_EBX 3
		#define DWARF_ESP 4
		#define DWARF_EBP 5
		#define DWARF_ESI 6
		#define DWARF_EDI 7
		#define DWARF_EIP 8

libcorkscrew/arch-x86/ptrace-x86.c

100644 → 100755

+36 −3

Original line number	Diff line number	Diff line
		@@ -19,11 +19,44 @@

		#include "../ptrace-arch.h"

		#include <stddef.h>
		#include <elf.h>
		#include <cutils/log.h>

		void load_ptrace_map_info_data_arch(pid_t pid __attribute__((unused)),
		map_info_t* mi __attribute__((unused)),
		map_info_data_t* data __attribute__((unused))) {
		static void load_eh_frame_hdr(pid_t pid, map_info_t* mi, uintptr_t *eh_frame_hdr) {
		uint32_t elf_phoff;
		uint32_t elf_phentsize_ehsize;
		uint32_t elf_shentsize_phnum;
		if (try_get_word_ptrace(pid, mi->start + offsetof(Elf32_Ehdr, e_phoff), &elf_phoff)
		&& try_get_word_ptrace(pid, mi->start + offsetof(Elf32_Ehdr, e_ehsize),
		&elf_phentsize_ehsize)
		&& try_get_word_ptrace(pid, mi->start + offsetof(Elf32_Ehdr, e_phnum),
		&elf_shentsize_phnum)) {
		uint32_t elf_phentsize = elf_phentsize_ehsize >> 16;
		uint32_t elf_phnum = elf_shentsize_phnum & 0xffff;
		for (uint32_t i = 0; i < elf_phnum; i++) {
		uintptr_t elf_phdr = mi->start + elf_phoff + i * elf_phentsize;
		uint32_t elf_phdr_type;
		if (!try_get_word_ptrace(pid, elf_phdr + offsetof(Elf32_Phdr, p_type), &elf_phdr_type)) {
		break;
		}
		if (elf_phdr_type == PT_GNU_EH_FRAME) {
		uint32_t elf_phdr_offset;
		if (!try_get_word_ptrace(pid, elf_phdr + offsetof(Elf32_Phdr, p_offset),
		&elf_phdr_offset)) {
		break;
		}
		*eh_frame_hdr = mi->start + elf_phdr_offset;
		ALOGV("Parsed .eh_frame_hdr info for %s: start=0x%08x", mi->name, *eh_frame_hdr);
		return;
		}
		}
		}
		*eh_frame_hdr = 0;
		}

		void load_ptrace_map_info_data_arch(pid_t pid, map_info_t* mi, map_info_data_t* data) {
		load_eh_frame_hdr(pid, mi, &data->eh_frame_hdr);
		}

		void free_ptrace_map_info_data_arch(map_info_t* mi __attribute__((unused)),

libcorkscrew/ptrace-arch.h

100644 → 100755

+2 −0

Original line number	Diff line number	Diff line
		@@ -33,6 +33,8 @@ typedef struct {
		#ifdef __arm__
		uintptr_t exidx_start;
		size_t exidx_size;
		#elif __i386__
		uintptr_t eh_frame_hdr;
		#endif
		symbol_table_t* symbol_table;
		} map_info_data_t;