| /* system/debuggerd/utility.c |
| ** |
| ** Copyright 2008, 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 <signal.h> |
| #include <string.h> |
| #include <cutils/logd.h> |
| #include <sys/ptrace.h> |
| #include <errno.h> |
| #include <corkscrew/demangle.h> |
| |
| #include "utility.h" |
| |
| #define STACK_DEPTH 32 |
| #define STACK_WORDS 16 |
| |
| void _LOG(int tfd, bool in_tombstone_only, const char *fmt, ...) { |
| char buf[512]; |
| |
| va_list ap; |
| va_start(ap, fmt); |
| |
| if (tfd >= 0) { |
| int len; |
| vsnprintf(buf, sizeof(buf), fmt, ap); |
| len = strlen(buf); |
| if(tfd >= 0) write(tfd, buf, len); |
| } |
| |
| if (!in_tombstone_only) |
| __android_log_vprint(ANDROID_LOG_INFO, "DEBUG", fmt, ap); |
| va_end(ap); |
| } |
| |
| bool signal_has_address(int sig) { |
| switch (sig) { |
| case SIGILL: |
| case SIGFPE: |
| case SIGSEGV: |
| case SIGBUS: |
| return true; |
| default: |
| return false; |
| } |
| } |
| |
| static void dump_backtrace(const ptrace_context_t* context __attribute((unused)), |
| int tfd, pid_t tid __attribute((unused)), bool at_fault, |
| const backtrace_frame_t* backtrace, size_t frames) { |
| _LOG(tfd, !at_fault, "\nbacktrace:\n"); |
| |
| backtrace_symbol_t backtrace_symbols[STACK_DEPTH]; |
| get_backtrace_symbols_ptrace(context, backtrace, frames, backtrace_symbols); |
| for (size_t i = 0; i < frames; i++) { |
| char line[MAX_BACKTRACE_LINE_LENGTH]; |
| format_backtrace_line(i, &backtrace[i], &backtrace_symbols[i], |
| line, MAX_BACKTRACE_LINE_LENGTH); |
| _LOG(tfd, !at_fault, " %s\n", line); |
| } |
| free_backtrace_symbols(backtrace_symbols, frames); |
| } |
| |
| static void dump_stack_segment(const ptrace_context_t* context, int tfd, pid_t tid, |
| bool only_in_tombstone, uintptr_t* sp, size_t words, int label) { |
| for (size_t i = 0; i < words; i++) { |
| uint32_t stack_content; |
| if (!try_get_word_ptrace(tid, *sp, &stack_content)) { |
| break; |
| } |
| |
| const map_info_t* mi; |
| const symbol_t* symbol; |
| find_symbol_ptrace(context, stack_content, &mi, &symbol); |
| |
| if (symbol) { |
| char* demangled_name = demangle_symbol_name(symbol->name); |
| const char* symbol_name = demangled_name ? demangled_name : symbol->name; |
| uint32_t offset = stack_content - (mi->start + symbol->start); |
| if (!i && label >= 0) { |
| if (offset) { |
| _LOG(tfd, only_in_tombstone, " #%02d %08x %08x %s (%s+%u)\n", |
| label, *sp, stack_content, mi ? mi->name : "", symbol_name, offset); |
| } else { |
| _LOG(tfd, only_in_tombstone, " #%02d %08x %08x %s (%s)\n", |
| label, *sp, stack_content, mi ? mi->name : "", symbol_name); |
| } |
| } else { |
| if (offset) { |
| _LOG(tfd, only_in_tombstone, " %08x %08x %s (%s+%u)\n", |
| *sp, stack_content, mi ? mi->name : "", symbol_name, offset); |
| } else { |
| _LOG(tfd, only_in_tombstone, " %08x %08x %s (%s)\n", |
| *sp, stack_content, mi ? mi->name : "", symbol_name); |
| } |
| } |
| free(demangled_name); |
| } else { |
| if (!i && label >= 0) { |
| _LOG(tfd, only_in_tombstone, " #%02d %08x %08x %s\n", |
| label, *sp, stack_content, mi ? mi->name : ""); |
| } else { |
| _LOG(tfd, only_in_tombstone, " %08x %08x %s\n", |
| *sp, stack_content, mi ? mi->name : ""); |
| } |
| } |
| |
| *sp += sizeof(uint32_t); |
| } |
| } |
| |
| static void dump_stack(const ptrace_context_t* context, int tfd, pid_t tid, bool at_fault, |
| const backtrace_frame_t* backtrace, size_t frames) { |
| bool have_first = false; |
| size_t first, last; |
| for (size_t i = 0; i < frames; i++) { |
| if (backtrace[i].stack_top) { |
| if (!have_first) { |
| have_first = true; |
| first = i; |
| } |
| last = i; |
| } |
| } |
| if (!have_first) { |
| return; |
| } |
| |
| _LOG(tfd, !at_fault, "\nstack:\n"); |
| |
| // Dump a few words before the first frame. |
| bool only_in_tombstone = !at_fault; |
| uintptr_t sp = backtrace[first].stack_top - STACK_WORDS * sizeof(uint32_t); |
| dump_stack_segment(context, tfd, tid, only_in_tombstone, &sp, STACK_WORDS, -1); |
| |
| // Dump a few words from all successive frames. |
| // Only log the first 3 frames, put the rest in the tombstone. |
| for (size_t i = first; i <= last; i++) { |
| const backtrace_frame_t* frame = &backtrace[i]; |
| if (sp != frame->stack_top) { |
| _LOG(tfd, only_in_tombstone, " ........ ........\n"); |
| sp = frame->stack_top; |
| } |
| if (i - first == 3) { |
| only_in_tombstone = true; |
| } |
| if (i == last) { |
| dump_stack_segment(context, tfd, tid, only_in_tombstone, &sp, STACK_WORDS, i); |
| if (sp < frame->stack_top + frame->stack_size) { |
| _LOG(tfd, only_in_tombstone, " ........ ........\n"); |
| } |
| } else { |
| size_t words = frame->stack_size / sizeof(uint32_t); |
| if (words == 0) { |
| words = 1; |
| } else if (words > STACK_WORDS) { |
| words = STACK_WORDS; |
| } |
| dump_stack_segment(context, tfd, tid, only_in_tombstone, &sp, words, i); |
| } |
| } |
| } |
| |
| void dump_backtrace_and_stack(const ptrace_context_t* context, int tfd, pid_t tid, |
| bool at_fault) { |
| backtrace_frame_t backtrace[STACK_DEPTH]; |
| ssize_t frames = unwind_backtrace_ptrace(tid, context, backtrace, 0, STACK_DEPTH); |
| if (frames > 0) { |
| dump_backtrace(context, tfd, tid, at_fault, backtrace, frames); |
| dump_stack(context, tfd, tid, at_fault, backtrace, frames); |
| } |
| } |
| |
| void dump_memory(int tfd, pid_t tid, uintptr_t addr, bool at_fault) { |
| 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, tid, (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, !at_fault, " %s %s\n", code_buffer, ascii_buffer); |
| } |
| } |
| |
| void dump_nearby_maps(const ptrace_context_t* context, int tfd, pid_t tid) { |
| siginfo_t si; |
| memset(&si, 0, sizeof(si)); |
| if (ptrace(PTRACE_GETSIGINFO, tid, 0, &si)) { |
| _LOG(tfd, false, "cannot get siginfo for %d: %s\n", |
| tid, 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 fault addr %08x:\n", (int)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; |
| map_info_t* map = context->map_info_list; |
| map_info_t *next = NULL; |
| map_info_t *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"); |
| } |
| } |
