1/* system/debuggerd/debuggerd.c 2** 3** Copyright 2006, The Android Open Source Project 4** 5** Licensed under the Apache License, Version 2.0 (the "License"); 6** you may not use this file except in compliance with the License. 7** You may obtain a copy of the License at 8** 9** http://www.apache.org/licenses/LICENSE-2.0 10** 11** Unless required by applicable law or agreed to in writing, software 12** distributed under the License is distributed on an "AS IS" BASIS, 13** WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 14** See the License for the specific language governing permissions and 15** limitations under the License. 16*/ 17 18#include <stddef.h> 19#include <stdbool.h> 20#include <stdlib.h> 21#include <string.h> 22#include <stdio.h> 23#include <errno.h> 24#include <sys/types.h> 25#include <sys/ptrace.h> 26 27#include <corkscrew/ptrace.h> 28 29#include <linux/user.h> 30 31#include "../utility.h" 32#include "../machine.h" 33 34/* enable to dump memory pointed to by every register */ 35#define DUMP_MEMORY_FOR_ALL_REGISTERS 1 36 37#ifdef WITH_VFP 38#ifdef WITH_VFP_D32 39#define NUM_VFP_REGS 32 40#else 41#define NUM_VFP_REGS 16 42#endif 43#endif 44 45static void dump_memory(log_t* log, pid_t tid, uintptr_t addr, bool at_fault) { 46 char code_buffer[64]; /* actual 8+1+((8+1)*4) + 1 == 45 */ 47 char ascii_buffer[32]; /* actual 16 + 1 == 17 */ 48 uintptr_t p, end; 49 50 p = addr & ~3; 51 p -= 32; 52 if (p > addr) { 53 /* catch underflow */ 54 p = 0; 55 } 56 /* Dump more memory content for the crashing thread. */ 57 end = p + 256; 58 /* catch overflow; 'end - p' has to be multiples of 16 */ 59 while (end < p) 60 end -= 16; 61 62 /* Dump the code around PC as: 63 * addr contents ascii 64 * 00008d34 ef000000 e8bd0090 e1b00000 512fff1e ............../Q 65 * 00008d44 ea00b1f9 e92d0090 e3a070fc ef000000 ......-..p...... 66 */ 67 while (p < end) { 68 char* asc_out = ascii_buffer; 69 70 sprintf(code_buffer, "%08x ", p); 71 72 int i; 73 for (i = 0; i < 4; i++) { 74 /* 75 * If we see (data == -1 && errno != 0), we know that the ptrace 76 * call failed, probably because we're dumping memory in an 77 * unmapped or inaccessible page. I don't know if there's 78 * value in making that explicit in the output -- it likely 79 * just complicates parsing and clarifies nothing for the 80 * enlightened reader. 81 */ 82 long data = ptrace(PTRACE_PEEKTEXT, tid, (void*)p, NULL); 83 sprintf(code_buffer + strlen(code_buffer), "%08lx ", data); 84 85 /* Enable the following code blob to dump ASCII values */ 86#if 0 87 int j; 88 for (j = 0; j < 4; j++) { 89 /* 90 * Our isprint() allows high-ASCII characters that display 91 * differently (often badly) in different viewers, so we 92 * just use a simpler test. 93 */ 94 char val = (data >> (j*8)) & 0xff; 95 if (val >= 0x20 && val < 0x7f) { 96 *asc_out++ = val; 97 } else { 98 *asc_out++ = '.'; 99 } 100 } 101#endif 102 p += 4; 103 } 104 *asc_out = '\0'; 105 _LOG(log, !at_fault, " %s %s\n", code_buffer, ascii_buffer); 106 } 107} 108 109/* 110 * If configured to do so, dump memory around *all* registers 111 * for the crashing thread. 112 */ 113void dump_memory_and_code(const ptrace_context_t* context __attribute((unused)), 114 log_t* log, pid_t tid, bool at_fault) { 115 struct pt_regs regs; 116 if(ptrace(PTRACE_GETREGS, tid, 0, ®s)) { 117 return; 118 } 119 120 if (at_fault && DUMP_MEMORY_FOR_ALL_REGISTERS) { 121 static const char REG_NAMES[] = "r0r1r2r3r4r5r6r7r8r9slfpipsp"; 122 123 for (int reg = 0; reg < 14; reg++) { 124 /* this may not be a valid way to access, but it'll do for now */ 125 uintptr_t addr = regs.uregs[reg]; 126 127 /* 128 * Don't bother if it looks like a small int or ~= null, or if 129 * it's in the kernel area. 130 */ 131 if (addr < 4096 || addr >= 0xc0000000) { 132 continue; 133 } 134 135 _LOG(log, false, "\nmemory near %.2s:\n", ®_NAMES[reg * 2]); 136 dump_memory(log, tid, addr, at_fault); 137 } 138 } 139 140 _LOG(log, !at_fault, "\ncode around pc:\n"); 141 dump_memory(log, tid, (uintptr_t)regs.ARM_pc, at_fault); 142 143 if (regs.ARM_pc != regs.ARM_lr) { 144 _LOG(log, !at_fault, "\ncode around lr:\n"); 145 dump_memory(log, tid, (uintptr_t)regs.ARM_lr, at_fault); 146 } 147} 148 149void dump_registers(const ptrace_context_t* context __attribute((unused)), 150 log_t* log, pid_t tid, bool at_fault) 151{ 152 struct pt_regs r; 153 bool only_in_tombstone = !at_fault; 154 155 if(ptrace(PTRACE_GETREGS, tid, 0, &r)) { 156 _LOG(log, only_in_tombstone, "cannot get registers: %s\n", strerror(errno)); 157 return; 158 } 159 160 _LOG(log, only_in_tombstone, " r0 %08x r1 %08x r2 %08x r3 %08x\n", 161 (uint32_t)r.ARM_r0, (uint32_t)r.ARM_r1, (uint32_t)r.ARM_r2, (uint32_t)r.ARM_r3); 162 _LOG(log, only_in_tombstone, " r4 %08x r5 %08x r6 %08x r7 %08x\n", 163 (uint32_t)r.ARM_r4, (uint32_t)r.ARM_r5, (uint32_t)r.ARM_r6, (uint32_t)r.ARM_r7); 164 _LOG(log, only_in_tombstone, " r8 %08x r9 %08x sl %08x fp %08x\n", 165 (uint32_t)r.ARM_r8, (uint32_t)r.ARM_r9, (uint32_t)r.ARM_r10, (uint32_t)r.ARM_fp); 166 _LOG(log, only_in_tombstone, " ip %08x sp %08x lr %08x pc %08x cpsr %08x\n", 167 (uint32_t)r.ARM_ip, (uint32_t)r.ARM_sp, (uint32_t)r.ARM_lr, 168 (uint32_t)r.ARM_pc, (uint32_t)r.ARM_cpsr); 169 170#ifdef WITH_VFP 171 struct user_vfp vfp_regs; 172 int i; 173 174 if(ptrace(PTRACE_GETVFPREGS, tid, 0, &vfp_regs)) { 175 _LOG(log, only_in_tombstone, "cannot get registers: %s\n", strerror(errno)); 176 return; 177 } 178 179 for (i = 0; i < NUM_VFP_REGS; i += 2) { 180 _LOG(log, only_in_tombstone, " d%-2d %016llx d%-2d %016llx\n", 181 i, vfp_regs.fpregs[i], i+1, vfp_regs.fpregs[i+1]); 182 } 183 _LOG(log, only_in_tombstone, " scr %08lx\n", vfp_regs.fpscr); 184#endif 185} 186