| /* system/debuggerd/debuggerd.c |
| ** |
| ** Copyright 2006, 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. |
| */ |
| |
| #include <stdio.h> |
| #include <errno.h> |
| #include <signal.h> |
| #include <pthread.h> |
| #include <fcntl.h> |
| #include <sys/types.h> |
| #include <dirent.h> |
| |
| #include <sys/ptrace.h> |
| #include <sys/wait.h> |
| #include <sys/exec_elf.h> |
| #include <sys/stat.h> |
| |
| #include <cutils/sockets.h> |
| #include <cutils/properties.h> |
| |
| #include <linux/input.h> |
| #include <linux/user.h> |
| |
| #include "utility.h" |
| |
| /* enable to dump memory pointed to by every register */ |
| #define DUMP_MEM_FOR_ALL_REGS 1 |
| |
| #ifdef WITH_VFP |
| #ifdef WITH_VFP_D32 |
| #define NUM_VFP_REGS 32 |
| #else |
| #define NUM_VFP_REGS 16 |
| #endif |
| #endif |
| |
| /* Main entry point to get the backtrace from the crashing process */ |
| extern int unwind_backtrace_with_ptrace(int tfd, pid_t pid, mapinfo *map, |
| unsigned int sp_list[], |
| int *frame0_pc_sane, |
| bool at_fault); |
| |
| /* |
| * If this isn't clearly a null pointer dereference, dump the |
| * /proc/maps entries near the fault address. |
| * |
| * This only makes sense to do on the thread that crashed. |
| */ |
| static void show_nearby_maps(int tfd, int pid, mapinfo *map) |
| { |
| siginfo_t si; |
| |
| memset(&si, 0, sizeof(si)); |
| if (ptrace(PTRACE_GETSIGINFO, pid, 0, &si)) { |
| _LOG(tfd, false, "cannot get siginfo for %d: %s\n", |
| pid, strerror(errno)); |
| return; |
| } |
| if (!signal_has_address(si.si_signo)) |
| return; |
| |
| uintptr_t addr = (uintptr_t) si.si_addr; |
| addr &= ~0xfff; /* round to 4K page boundary */ |
| if (addr == 0) /* null-pointer deref */ |
| return; |
| |
| _LOG(tfd, false, "\nmemory map around addr %08x:\n", si.si_addr); |
| |
| /* |
| * Search for a match, or for a hole where the match would be. The list |
| * is backward from the file content, so it starts at high addresses. |
| */ |
| bool found = false; |
| mapinfo *next = NULL; |
| mapinfo *prev = NULL; |
| while (map != NULL) { |
| if (addr >= map->start && addr < map->end) { |
| found = true; |
| next = map->next; |
| break; |
| } else if (addr >= map->end) { |
| /* map would be between "prev" and this entry */ |
| next = map; |
| map = NULL; |
| break; |
| } |
| |
| prev = map; |
| map = map->next; |
| } |
| |
| /* |
| * Show "next" then "match" then "prev" so that the addresses appear in |
| * ascending order (like /proc/pid/maps). |
| */ |
| if (next != NULL) { |
| _LOG(tfd, false, "%08x-%08x %s\n", next->start, next->end, next->name); |
| } else { |
| _LOG(tfd, false, "(no map below)\n"); |
| } |
| if (map != NULL) { |
| _LOG(tfd, false, "%08x-%08x %s\n", map->start, map->end, map->name); |
| } else { |
| _LOG(tfd, false, "(no map for address)\n"); |
| } |
| if (prev != NULL) { |
| _LOG(tfd, false, "%08x-%08x %s\n", prev->start, prev->end, prev->name); |
| } else { |
| _LOG(tfd, false, "(no map above)\n"); |
| } |
| } |
| |
| /* |
| * Dumps a few bytes of memory, starting a bit before and ending a bit |
| * after the specified address. |
| */ |
| static void dump_memory(int tfd, int pid, uintptr_t addr, |
| bool only_in_tombstone) |
| { |
| char code_buffer[64]; /* actual 8+1+((8+1)*4) + 1 == 45 */ |
| char ascii_buffer[32]; /* actual 16 + 1 == 17 */ |
| uintptr_t p, end; |
| |
| p = addr & ~3; |
| p -= 32; |
| if (p > addr) { |
| /* catch underflow */ |
| p = 0; |
| } |
| end = p + 80; |
| /* catch overflow; 'end - p' has to be multiples of 16 */ |
| while (end < p) |
| end -= 16; |
| |
| /* Dump the code around PC as: |
| * addr contents ascii |
| * 00008d34 ef000000 e8bd0090 e1b00000 512fff1e ............../Q |
| * 00008d44 ea00b1f9 e92d0090 e3a070fc ef000000 ......-..p...... |
| */ |
| while (p < end) { |
| char* asc_out = ascii_buffer; |
| |
| sprintf(code_buffer, "%08x ", p); |
| |
| int i; |
| for (i = 0; i < 4; i++) { |
| /* |
| * If we see (data == -1 && errno != 0), we know that the ptrace |
| * call failed, probably because we're dumping memory in an |
| * unmapped or inaccessible page. I don't know if there's |
| * value in making that explicit in the output -- it likely |
| * just complicates parsing and clarifies nothing for the |
| * enlightened reader. |
| */ |
| long data = ptrace(PTRACE_PEEKTEXT, pid, (void*)p, NULL); |
| sprintf(code_buffer + strlen(code_buffer), "%08lx ", data); |
| |
| int j; |
| for (j = 0; j < 4; j++) { |
| /* |
| * Our isprint() allows high-ASCII characters that display |
| * differently (often badly) in different viewers, so we |
| * just use a simpler test. |
| */ |
| char val = (data >> (j*8)) & 0xff; |
| if (val >= 0x20 && val < 0x7f) { |
| *asc_out++ = val; |
| } else { |
| *asc_out++ = '.'; |
| } |
| } |
| p += 4; |
| } |
| *asc_out = '\0'; |
| _LOG(tfd, only_in_tombstone, "%s %s\n", code_buffer, ascii_buffer); |
| } |
| |
| } |
| |
| void dump_stack_and_code(int tfd, int pid, mapinfo *map, |
| int unwind_depth, unsigned int sp_list[], |
| bool at_fault) |
| { |
| struct pt_regs r; |
| int sp_depth; |
| bool only_in_tombstone = !at_fault; |
| |
| if(ptrace(PTRACE_GETREGS, pid, 0, &r)) return; |
| |
| if (DUMP_MEM_FOR_ALL_REGS && at_fault) { |
| /* |
| * If configured to do so, dump memory around *all* registers |
| * for the crashing thread. |
| * |
| * TODO: remove duplicates. |
| */ |
| static const char REG_NAMES[] = "R0R1R2R3R4R5R6R7R8R9SLFPIPSPLRPC"; |
| |
| int reg; |
| for (reg = 0; reg < 16; reg++) { |
| /* this may not be a valid way to access, but it'll do for now */ |
| uintptr_t addr = r.uregs[reg]; |
| |
| /* |
| * Don't bother if it looks like a small int or ~= null, or if |
| * it's in the kernel area. |
| */ |
| if (addr < 4096 || addr >= 0xc0000000) { |
| continue; |
| } |
| |
| _LOG(tfd, only_in_tombstone, "\nmem near %.2s:\n", |
| ®_NAMES[reg*2]); |
| dump_memory(tfd, pid, addr, false); |
| } |
| } else { |
| unsigned int pc, lr; |
| pc = r.ARM_pc; |
| lr = r.ARM_lr; |
| |
| _LOG(tfd, only_in_tombstone, "\ncode around pc:\n"); |
| dump_memory(tfd, pid, (uintptr_t) pc, only_in_tombstone); |
| |
| if (lr != pc) { |
| _LOG(tfd, only_in_tombstone, "\ncode around lr:\n"); |
| dump_memory(tfd, pid, (uintptr_t) lr, only_in_tombstone); |
| } |
| } |
| |
| if (at_fault) { |
| show_nearby_maps(tfd, pid, map); |
| } |
| |
| unsigned int p, end; |
| unsigned int sp = r.ARM_sp; |
| |
| p = sp - 64; |
| if (p > sp) |
| p = 0; |
| p &= ~3; |
| if (unwind_depth != 0) { |
| if (unwind_depth < STACK_CONTENT_DEPTH) { |
| end = sp_list[unwind_depth-1]; |
| } |
| else { |
| end = sp_list[STACK_CONTENT_DEPTH-1]; |
| } |
| } |
| else { |
| end = p + 256; |
| /* 'end - p' has to be multiples of 4 */ |
| if (end < p) |
| end = ~7; |
| } |
| |
| _LOG(tfd, only_in_tombstone, "\nstack:\n"); |
| |
| /* If the crash is due to PC == 0, there will be two frames that |
| * have identical SP value. |
| */ |
| if (sp_list[0] == sp_list[1]) { |
| sp_depth = 1; |
| } |
| else { |
| sp_depth = 0; |
| } |
| |
| while (p <= end) { |
| char *prompt; |
| char level[16]; |
| long data = ptrace(PTRACE_PEEKTEXT, pid, (void*)p, NULL); |
| if (p == sp_list[sp_depth]) { |
| sprintf(level, "#%02d", sp_depth++); |
| prompt = level; |
| } |
| else { |
| prompt = " "; |
| } |
| |
| /* Print the stack content in the log for the first 3 frames. For the |
| * rest only print them in the tombstone file. |
| */ |
| _LOG(tfd, (sp_depth > 2) || only_in_tombstone, |
| "%s %08x %08x %s\n", prompt, p, data, |
| map_to_name(map, data, "")); |
| p += 4; |
| } |
| /* print another 64-byte of stack data after the last frame */ |
| |
| end = p+64; |
| /* 'end - p' has to be multiples of 4 */ |
| if (end < p) |
| end = ~7; |
| |
| while (p <= end) { |
| long data = ptrace(PTRACE_PEEKTEXT, pid, (void*)p, NULL); |
| _LOG(tfd, (sp_depth > 2) || only_in_tombstone, |
| " %08x %08x %s\n", p, data, |
| map_to_name(map, data, "")); |
| p += 4; |
| } |
| } |
| |
| void dump_pc_and_lr(int tfd, int pid, mapinfo *map, int unwound_level, |
| bool at_fault) |
| { |
| struct pt_regs r; |
| |
| if(ptrace(PTRACE_GETREGS, pid, 0, &r)) { |
| _LOG(tfd, !at_fault, "tid %d not responding!\n", pid); |
| return; |
| } |
| |
| if (unwound_level == 0) { |
| _LOG(tfd, !at_fault, " #%02d pc %08x %s\n", 0, r.ARM_pc, |
| map_to_name(map, r.ARM_pc, "<unknown>")); |
| } |
| _LOG(tfd, !at_fault, " #%02d lr %08x %s\n", 1, r.ARM_lr, |
| map_to_name(map, r.ARM_lr, "<unknown>")); |
| } |
| |
| void dump_registers(int tfd, int pid, bool at_fault) |
| { |
| struct pt_regs r; |
| bool only_in_tombstone = !at_fault; |
| |
| if(ptrace(PTRACE_GETREGS, pid, 0, &r)) { |
| _LOG(tfd, only_in_tombstone, |
| "cannot get registers: %s\n", strerror(errno)); |
| return; |
| } |
| |
| _LOG(tfd, only_in_tombstone, " r0 %08x r1 %08x r2 %08x r3 %08x\n", |
| r.ARM_r0, r.ARM_r1, r.ARM_r2, r.ARM_r3); |
| _LOG(tfd, only_in_tombstone, " r4 %08x r5 %08x r6 %08x r7 %08x\n", |
| r.ARM_r4, r.ARM_r5, r.ARM_r6, r.ARM_r7); |
| _LOG(tfd, only_in_tombstone, " r8 %08x r9 %08x 10 %08x fp %08x\n", |
| r.ARM_r8, r.ARM_r9, r.ARM_r10, r.ARM_fp); |
| _LOG(tfd, only_in_tombstone, |
| " ip %08x sp %08x lr %08x pc %08x cpsr %08x\n", |
| r.ARM_ip, r.ARM_sp, r.ARM_lr, r.ARM_pc, r.ARM_cpsr); |
| |
| #ifdef WITH_VFP |
| struct user_vfp vfp_regs; |
| int i; |
| |
| if(ptrace(PTRACE_GETVFPREGS, pid, 0, &vfp_regs)) { |
| _LOG(tfd, only_in_tombstone, |
| "cannot get registers: %s\n", strerror(errno)); |
| return; |
| } |
| |
| for (i = 0; i < NUM_VFP_REGS; i += 2) { |
| _LOG(tfd, only_in_tombstone, |
| " d%-2d %016llx d%-2d %016llx\n", |
| i, vfp_regs.fpregs[i], i+1, vfp_regs.fpregs[i+1]); |
| } |
| _LOG(tfd, only_in_tombstone, " scr %08lx\n\n", vfp_regs.fpscr); |
| #endif |
| } |