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 45 static 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 end = p + 80; 57 /* catch overflow; 'end - p' has to be multiples of 16 */ 58 while (end < p) 59 end -= 16; 60 61 /* Dump the code around PC as: 62 * addr contents ascii 63 * 00008d34 ef000000 e8bd0090 e1b00000 512fff1e ............../Q 64 * 00008d44 ea00b1f9 e92d0090 e3a070fc ef000000 ......-..p...... 65 */ 66 while (p < end) { 67 char* asc_out = ascii_buffer; 68 69 sprintf(code_buffer, "%08x ", p); 70 71 int i; 72 for (i = 0; i < 4; i++) { 73 /* 74 * If we see (data == -1 && errno != 0), we know that the ptrace 75 * call failed, probably because we're dumping memory in an 76 * unmapped or inaccessible page. I don't know if there's 77 * value in making that explicit in the output -- it likely 78 * just complicates parsing and clarifies nothing for the 79 * enlightened reader. 80 */ 81 long data = ptrace(PTRACE_PEEKTEXT, tid, (void*)p, NULL); 82 sprintf(code_buffer + strlen(code_buffer), "%08lx ", data); 83 84 int j; 85 for (j = 0; j < 4; j++) { 86 /* 87 * Our isprint() allows high-ASCII characters that display 88 * differently (often badly) in different viewers, so we 89 * just use a simpler test. 90 */ 91 char val = (data >> (j*8)) & 0xff; 92 if (val >= 0x20 && val < 0x7f) { 93 *asc_out++ = val; 94 } else { 95 *asc_out++ = '.'; 96 } 97 } 98 p += 4; 99 } 100 *asc_out = '\0'; 101 _LOG(log, !at_fault, " %s %s\n", code_buffer, ascii_buffer); 102 } 103 } 104 105 /* 106 * If configured to do so, dump memory around *all* registers 107 * for the crashing thread. 108 */ 109 void dump_memory_and_code(const ptrace_context_t* context __attribute((unused)), 110 log_t* log, pid_t tid, bool at_fault) { 111 struct pt_regs regs; 112 if(ptrace(PTRACE_GETREGS, tid, 0, ®s)) { 113 return; 114 } 115 116 if (at_fault && DUMP_MEMORY_FOR_ALL_REGISTERS) { 117 static const char REG_NAMES[] = "r0r1r2r3r4r5r6r7r8r9slfpipsp"; 118 119 for (int reg = 0; reg < 14; reg++) { 120 /* this may not be a valid way to access, but it'll do for now */ 121 uintptr_t addr = regs.uregs[reg]; 122 123 /* 124 * Don't bother if it looks like a small int or ~= null, or if 125 * it's in the kernel area. 126 */ 127 if (addr < 4096 || addr >= 0xc0000000) { 128 continue; 129 } 130 131 _LOG(log, false, "\nmemory near %.2s:\n", ®_NAMES[reg * 2]); 132 dump_memory(log, tid, addr, at_fault); 133 } 134 } 135 136 _LOG(log, !at_fault, "\ncode around pc:\n"); 137 dump_memory(log, tid, (uintptr_t)regs.ARM_pc, at_fault); 138 139 if (regs.ARM_pc != regs.ARM_lr) { 140 _LOG(log, !at_fault, "\ncode around lr:\n"); 141 dump_memory(log, tid, (uintptr_t)regs.ARM_lr, at_fault); 142 } 143 } 144 145 void dump_registers(const ptrace_context_t* context __attribute((unused)), 146 log_t* log, pid_t tid, bool at_fault) 147 { 148 struct pt_regs r; 149 bool only_in_tombstone = !at_fault; 150 151 if(ptrace(PTRACE_GETREGS, tid, 0, &r)) { 152 _LOG(log, only_in_tombstone, "cannot get registers: %s\n", strerror(errno)); 153 return; 154 } 155 156 _LOG(log, only_in_tombstone, " r0 %08x r1 %08x r2 %08x r3 %08x\n", 157 (uint32_t)r.ARM_r0, (uint32_t)r.ARM_r1, (uint32_t)r.ARM_r2, (uint32_t)r.ARM_r3); 158 _LOG(log, only_in_tombstone, " r4 %08x r5 %08x r6 %08x r7 %08x\n", 159 (uint32_t)r.ARM_r4, (uint32_t)r.ARM_r5, (uint32_t)r.ARM_r6, (uint32_t)r.ARM_r7); 160 _LOG(log, only_in_tombstone, " r8 %08x r9 %08x sl %08x fp %08x\n", 161 (uint32_t)r.ARM_r8, (uint32_t)r.ARM_r9, (uint32_t)r.ARM_r10, (uint32_t)r.ARM_fp); 162 _LOG(log, only_in_tombstone, " ip %08x sp %08x lr %08x pc %08x cpsr %08x\n", 163 (uint32_t)r.ARM_ip, (uint32_t)r.ARM_sp, (uint32_t)r.ARM_lr, 164 (uint32_t)r.ARM_pc, (uint32_t)r.ARM_cpsr); 165 166 #ifdef WITH_VFP 167 struct user_vfp vfp_regs; 168 int i; 169 170 if(ptrace(PTRACE_GETVFPREGS, tid, 0, &vfp_regs)) { 171 _LOG(log, only_in_tombstone, "cannot get registers: %s\n", strerror(errno)); 172 return; 173 } 174 175 for (i = 0; i < NUM_VFP_REGS; i += 2) { 176 _LOG(log, only_in_tombstone, " d%-2d %016llx d%-2d %016llx\n", 177 i, vfp_regs.fpregs[i], i+1, vfp_regs.fpregs[i+1]); 178 } 179 _LOG(log, only_in_tombstone, " scr %08lx\n", vfp_regs.fpscr); 180 #endif 181 } 182
