platform_system_core/debuggerd/tombstone.cpp
Brigid Smith 8606eaa770 Improving maps output.
Maps output now displays fault address location more intelligently.  If
the fault is not in a mapped region, it now shows where that address is
with respect to the other maps.

In addition, the size of the map is now printed as part of the output.

Also, crasher now supports an "mmap" option which mmaps/munmaps a region
of memory and then attempts to access it, causing a fault address in
between mapped regions that can be used to test that new part of the
maps output.

Change-Id: Ia5e1926802bdfcbbdb7857e3631ddf395ae0c5b8
2014-07-08 10:53:49 -07:00

776 lines
24 KiB
C++
Executable file

/*
* Copyright (C) 2012-2014 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.
*/
#define LOG_TAG "DEBUG"
#include <dirent.h>
#include <errno.h>
#include <fcntl.h>
#include <inttypes.h>
#include <signal.h>
#include <stddef.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <time.h>
#include <sys/ptrace.h>
#include <sys/socket.h>
#include <sys/stat.h>
#include <sys/un.h>
#include <private/android_filesystem_config.h>
#include <cutils/properties.h>
#include <log/log.h>
#include <log/logger.h>
#include <log/logprint.h>
#include <backtrace/Backtrace.h>
#include <backtrace/BacktraceMap.h>
#include <selinux/android.h>
#include <UniquePtr.h>
#include "machine.h"
#include "tombstone.h"
#include "backtrace.h"
#define STACK_WORDS 16
#define MAX_TOMBSTONES 10
#define TOMBSTONE_DIR "/data/tombstones"
#define TOMBSTONE_TEMPLATE (TOMBSTONE_DIR"/tombstone_%02d")
// Must match the path defined in NativeCrashListener.java
#define NCRASH_SOCKET_PATH "/data/system/ndebugsocket"
static bool signal_has_si_addr(int sig) {
switch (sig) {
case SIGBUS:
case SIGFPE:
case SIGILL:
case SIGSEGV:
return true;
default:
return false;
}
}
static const char* get_signame(int sig) {
switch(sig) {
case SIGABRT: return "SIGABRT";
case SIGBUS: return "SIGBUS";
case SIGFPE: return "SIGFPE";
case SIGILL: return "SIGILL";
case SIGPIPE: return "SIGPIPE";
case SIGSEGV: return "SIGSEGV";
#if defined(SIGSTKFLT)
case SIGSTKFLT: return "SIGSTKFLT";
#endif
case SIGSTOP: return "SIGSTOP";
case SIGTRAP: return "SIGTRAP";
default: return "?";
}
}
static const char* get_sigcode(int signo, int code) {
// Try the signal-specific codes...
switch (signo) {
case SIGILL:
switch (code) {
case ILL_ILLOPC: return "ILL_ILLOPC";
case ILL_ILLOPN: return "ILL_ILLOPN";
case ILL_ILLADR: return "ILL_ILLADR";
case ILL_ILLTRP: return "ILL_ILLTRP";
case ILL_PRVOPC: return "ILL_PRVOPC";
case ILL_PRVREG: return "ILL_PRVREG";
case ILL_COPROC: return "ILL_COPROC";
case ILL_BADSTK: return "ILL_BADSTK";
}
static_assert(NSIGILL == ILL_BADSTK, "missing ILL_* si_code");
break;
case SIGBUS:
switch (code) {
case BUS_ADRALN: return "BUS_ADRALN";
case BUS_ADRERR: return "BUS_ADRERR";
case BUS_OBJERR: return "BUS_OBJERR";
case BUS_MCEERR_AR: return "BUS_MCEERR_AR";
case BUS_MCEERR_AO: return "BUS_MCEERR_AO";
}
static_assert(NSIGBUS == BUS_MCEERR_AO, "missing BUS_* si_code");
break;
case SIGFPE:
switch (code) {
case FPE_INTDIV: return "FPE_INTDIV";
case FPE_INTOVF: return "FPE_INTOVF";
case FPE_FLTDIV: return "FPE_FLTDIV";
case FPE_FLTOVF: return "FPE_FLTOVF";
case FPE_FLTUND: return "FPE_FLTUND";
case FPE_FLTRES: return "FPE_FLTRES";
case FPE_FLTINV: return "FPE_FLTINV";
case FPE_FLTSUB: return "FPE_FLTSUB";
}
static_assert(NSIGFPE == FPE_FLTSUB, "missing FPE_* si_code");
break;
case SIGSEGV:
switch (code) {
case SEGV_MAPERR: return "SEGV_MAPERR";
case SEGV_ACCERR: return "SEGV_ACCERR";
}
static_assert(NSIGSEGV == SEGV_ACCERR, "missing SEGV_* si_code");
break;
case SIGTRAP:
switch (code) {
case TRAP_BRKPT: return "TRAP_BRKPT";
case TRAP_TRACE: return "TRAP_TRACE";
case TRAP_BRANCH: return "TRAP_BRANCH";
case TRAP_HWBKPT: return "TRAP_HWBKPT";
}
static_assert(NSIGTRAP == TRAP_HWBKPT, "missing TRAP_* si_code");
break;
}
// Then the other codes...
switch (code) {
case SI_USER: return "SI_USER";
case SI_KERNEL: return "SI_KERNEL";
case SI_QUEUE: return "SI_QUEUE";
case SI_TIMER: return "SI_TIMER";
case SI_MESGQ: return "SI_MESGQ";
case SI_ASYNCIO: return "SI_ASYNCIO";
case SI_SIGIO: return "SI_SIGIO";
case SI_TKILL: return "SI_TKILL";
case SI_DETHREAD: return "SI_DETHREAD";
}
// Then give up...
return "?";
}
static void dump_header_info(log_t* log) {
char fingerprint[PROPERTY_VALUE_MAX];
char revision[PROPERTY_VALUE_MAX];
property_get("ro.build.fingerprint", fingerprint, "unknown");
property_get("ro.revision", revision, "unknown");
_LOG(log, logtype::HEADER, "Build fingerprint: '%s'\n", fingerprint);
_LOG(log, logtype::HEADER, "Revision: '%s'\n", revision);
_LOG(log, logtype::HEADER, "ABI: '%s'\n", ABI_STRING);
}
static void dump_signal_info(log_t* log, pid_t tid, int signal, int si_code) {
siginfo_t si;
memset(&si, 0, sizeof(si));
if (ptrace(PTRACE_GETSIGINFO, tid, 0, &si) == -1) {
_LOG(log, logtype::HEADER, "cannot get siginfo: %s\n", strerror(errno));
return;
}
// bionic has to re-raise some signals, which overwrites the si_code with SI_TKILL.
si.si_code = si_code;
char addr_desc[32]; // ", fault addr 0x1234"
if (signal_has_si_addr(signal)) {
snprintf(addr_desc, sizeof(addr_desc), "%p", si.si_addr);
} else {
snprintf(addr_desc, sizeof(addr_desc), "--------");
}
_LOG(log, logtype::HEADER, "signal %d (%s), code %d (%s), fault addr %s\n",
signal, get_signame(signal), si.si_code, get_sigcode(signal, si.si_code), addr_desc);
}
static void dump_thread_info(log_t* log, pid_t pid, pid_t tid) {
char path[64];
char threadnamebuf[1024];
char* threadname = NULL;
FILE *fp;
snprintf(path, sizeof(path), "/proc/%d/comm", tid);
if ((fp = fopen(path, "r"))) {
threadname = fgets(threadnamebuf, sizeof(threadnamebuf), fp);
fclose(fp);
if (threadname) {
size_t len = strlen(threadname);
if (len && threadname[len - 1] == '\n') {
threadname[len - 1] = '\0';
}
}
}
char procnamebuf[1024];
char* procname = NULL;
snprintf(path, sizeof(path), "/proc/%d/cmdline", pid);
if ((fp = fopen(path, "r"))) {
procname = fgets(procnamebuf, sizeof(procnamebuf), fp);
fclose(fp);
}
_LOG(log, logtype::HEADER, "pid: %d, tid: %d, name: %s >>> %s <<<\n", pid, tid,
threadname ? threadname : "UNKNOWN", procname ? procname : "UNKNOWN");
}
static void dump_stack_segment(
Backtrace* backtrace, log_t* log, uintptr_t* sp, size_t words, int label) {
for (size_t i = 0; i < words; i++) {
word_t stack_content;
if (!backtrace->ReadWord(*sp, &stack_content)) {
break;
}
const backtrace_map_t* map = backtrace->FindMap(stack_content);
const char* map_name;
if (!map) {
map_name = "";
} else {
map_name = map->name.c_str();
}
uintptr_t offset = 0;
std::string func_name(backtrace->GetFunctionName(stack_content, &offset));
if (!func_name.empty()) {
if (!i && label >= 0) {
if (offset) {
_LOG(log, logtype::STACK, " #%02d %" PRIPTR " %" PRIPTR " %s (%s+%" PRIuPTR ")\n",
label, *sp, stack_content, map_name, func_name.c_str(), offset);
} else {
_LOG(log, logtype::STACK, " #%02d %" PRIPTR " %" PRIPTR " %s (%s)\n",
label, *sp, stack_content, map_name, func_name.c_str());
}
} else {
if (offset) {
_LOG(log, logtype::STACK, " %" PRIPTR " %" PRIPTR " %s (%s+%" PRIuPTR ")\n",
*sp, stack_content, map_name, func_name.c_str(), offset);
} else {
_LOG(log, logtype::STACK, " %" PRIPTR " %" PRIPTR " %s (%s)\n",
*sp, stack_content, map_name, func_name.c_str());
}
}
} else {
if (!i && label >= 0) {
_LOG(log, logtype::STACK, " #%02d %" PRIPTR " %" PRIPTR " %s\n",
label, *sp, stack_content, map_name);
} else {
_LOG(log, logtype::STACK, " %" PRIPTR " %" PRIPTR " %s\n",
*sp, stack_content, map_name);
}
}
*sp += sizeof(word_t);
}
}
static void dump_stack(Backtrace* backtrace, log_t* log) {
size_t first = 0, last;
for (size_t i = 0; i < backtrace->NumFrames(); i++) {
const backtrace_frame_data_t* frame = backtrace->GetFrame(i);
if (frame->sp) {
if (!first) {
first = i+1;
}
last = i;
}
}
if (!first) {
return;
}
first--;
// Dump a few words before the first frame.
word_t sp = backtrace->GetFrame(first)->sp - STACK_WORDS * sizeof(word_t);
dump_stack_segment(backtrace, log, &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_data_t* frame = backtrace->GetFrame(i);
if (sp != frame->sp) {
_LOG(log, logtype::STACK, " ........ ........\n");
sp = frame->sp;
}
if (i == last) {
dump_stack_segment(backtrace, log, &sp, STACK_WORDS, i);
if (sp < frame->sp + frame->stack_size) {
_LOG(log, logtype::STACK, " ........ ........\n");
}
} else {
size_t words = frame->stack_size / sizeof(word_t);
if (words == 0) {
words = 1;
} else if (words > STACK_WORDS) {
words = STACK_WORDS;
}
dump_stack_segment(backtrace, log, &sp, words, i);
}
}
}
static void dump_backtrace_and_stack(Backtrace* backtrace, log_t* log) {
if (backtrace->NumFrames()) {
_LOG(log, logtype::BACKTRACE, "\nbacktrace:\n");
dump_backtrace_to_log(backtrace, log, " ");
_LOG(log, logtype::STACK, "\nstack:\n");
dump_stack(backtrace, log);
}
}
static void dump_map(log_t* log, const backtrace_map_t* map, bool fault_addr) {
_LOG(log, logtype::MAPS, "%s%" PRIPTR "-%" PRIPTR " %c%c%c %7d %s\n",
(fault_addr? "--->" : " "), map->start, map->end - 1,
(map->flags & PROT_READ) ? 'r' : '-', (map->flags & PROT_WRITE) ? 'w' : '-',
(map->flags & PROT_EXEC) ? 'x' : '-',
(map->end - map->start), map->name.c_str());
}
static void dump_nearby_maps(BacktraceMap* map, log_t* log, pid_t tid) {
siginfo_t si;
memset(&si, 0, sizeof(si));
if (ptrace(PTRACE_GETSIGINFO, tid, 0, &si)) {
_LOG(log, logtype::MAPS, "cannot get siginfo for %d: %s\n", tid, strerror(errno));
return;
}
bool is_running = (si.si_code == SI_USER);
uintptr_t addr = reinterpret_cast<uintptr_t>(si.si_addr);
addr &= ~0xfff; // round to 4K page boundary
if (!is_running && addr == 0) { // null-pointer deref
return;
}
_LOG(log, logtype::MAPS, "\nmemory map: %s\n", is_running? "" : "(fault address prefixed with --->)");
if(!is_running && (addr < map->begin()->start)) {
_LOG(log, logtype::MAPS, "--->Fault address falls at %" PRIPTR " before any mapped regions\n", addr);
}
BacktraceMap::const_iterator prev = map->begin();
for (BacktraceMap::const_iterator it = map->begin(); it != map->end(); ++it) {
if (addr >= (*prev).end && addr < (*it).start) {
_LOG(log, logtype::MAPS, "--->Fault address falls at %" PRIPTR " between mapped regions\n", addr);
}
prev = it;
bool in_map = !is_running && (addr >= (*it).start) && (addr < (*it).end);
dump_map(log, &*it, in_map);
}
if (!is_running && (addr >= (*prev).end)) {
_LOG(log, logtype::MAPS, "--->Fault address falls at %" PRIPTR " after any mapped regions\n", addr);
}
}
static void dump_thread(
Backtrace* backtrace, log_t* log, int* total_sleep_time_usec) {
wait_for_stop(backtrace->Tid(), total_sleep_time_usec);
dump_registers(log, backtrace->Tid());
dump_backtrace_and_stack(backtrace, log);
dump_memory_and_code(log, backtrace->Tid());
dump_nearby_maps(backtrace->GetMap(), log, backtrace->Tid());
}
// Return true if some thread is not detached cleanly
static bool dump_sibling_thread_report(
log_t* log, pid_t pid, pid_t tid, int* total_sleep_time_usec, BacktraceMap* map) {
char task_path[64];
snprintf(task_path, sizeof(task_path), "/proc/%d/task", pid);
DIR* d = opendir(task_path);
// Bail early if the task directory cannot be opened
if (d == NULL) {
ALOGE("Cannot open /proc/%d/task\n", pid);
return false;
}
bool detach_failed = false;
struct dirent* de;
while ((de = readdir(d)) != NULL) {
// Ignore "." and ".."
if (!strcmp(de->d_name, ".") || !strcmp(de->d_name, "..")) {
continue;
}
// The main thread at fault has been handled individually
char* end;
pid_t new_tid = strtoul(de->d_name, &end, 10);
if (*end || new_tid == tid) {
continue;
}
// Skip this thread if cannot ptrace it
if (ptrace(PTRACE_ATTACH, new_tid, 0, 0) < 0) {
_LOG(log, logtype::ERROR, "ptrace attach to %d failed: %s\n", new_tid, strerror(errno));
continue;
}
log->current_tid = new_tid;
_LOG(log, logtype::THREAD, "--- --- --- --- --- --- --- --- --- --- --- --- --- --- --- ---\n");
dump_thread_info(log, pid, new_tid);
UniquePtr<Backtrace> backtrace(Backtrace::Create(pid, new_tid, map));
if (backtrace->Unwind(0)) {
dump_thread(backtrace.get(), log, total_sleep_time_usec);
}
log->current_tid = log->crashed_tid;
if (ptrace(PTRACE_DETACH, new_tid, 0, 0) != 0) {
_LOG(log, logtype::ERROR, "ptrace detach from %d failed: %s\n", new_tid, strerror(errno));
detach_failed = true;
}
}
closedir(d);
return detach_failed;
}
// Reads the contents of the specified log device, filters out the entries
// that don't match the specified pid, and writes them to the tombstone file.
//
// If "tail" is non-zero, log the last "tail" number of lines.
static EventTagMap* g_eventTagMap = NULL;
static void dump_log_file(
log_t* log, pid_t pid, const char* filename, unsigned int tail) {
bool first = true;
struct logger_list* logger_list;
logger_list = android_logger_list_open(
android_name_to_log_id(filename), O_RDONLY | O_NONBLOCK, tail, pid);
if (!logger_list) {
ALOGE("Unable to open %s: %s\n", filename, strerror(errno));
return;
}
struct log_msg log_entry;
while (true) {
ssize_t actual = android_logger_list_read(logger_list, &log_entry);
struct logger_entry* entry;
if (actual < 0) {
if (actual == -EINTR) {
// interrupted by signal, retry
continue;
} else if (actual == -EAGAIN) {
// non-blocking EOF; we're done
break;
} else {
_LOG(log, logtype::ERROR, "Error while reading log: %s\n",
strerror(-actual));
break;
}
} else if (actual == 0) {
_LOG(log, logtype::ERROR, "Got zero bytes while reading log: %s\n",
strerror(errno));
break;
}
// NOTE: if you ALOGV something here, this will spin forever,
// because you will be writing as fast as you're reading. Any
// high-frequency debug diagnostics should just be written to
// the tombstone file.
entry = &log_entry.entry_v1;
if (first) {
_LOG(log, logtype::LOGS, "--------- %slog %s\n",
tail ? "tail end of " : "", filename);
first = false;
}
// Msg format is: <priority:1><tag:N>\0<message:N>\0
//
// We want to display it in the same format as "logcat -v threadtime"
// (although in this case the pid is redundant).
static const char* kPrioChars = "!.VDIWEFS";
unsigned hdr_size = log_entry.entry.hdr_size;
if (!hdr_size) {
hdr_size = sizeof(log_entry.entry_v1);
}
char* msg = reinterpret_cast<char*>(log_entry.buf) + hdr_size;
char timeBuf[32];
time_t sec = static_cast<time_t>(entry->sec);
struct tm tmBuf;
struct tm* ptm;
ptm = localtime_r(&sec, &tmBuf);
strftime(timeBuf, sizeof(timeBuf), "%m-%d %H:%M:%S", ptm);
if (log_entry.id() == LOG_ID_EVENTS) {
if (!g_eventTagMap) {
g_eventTagMap = android_openEventTagMap(EVENT_TAG_MAP_FILE);
}
AndroidLogEntry e;
char buf[512];
android_log_processBinaryLogBuffer(entry, &e, g_eventTagMap, buf, sizeof(buf));
_LOG(log, logtype::LOGS, "%s.%03d %5d %5d %c %-8s: %s\n",
timeBuf, entry->nsec / 1000000, entry->pid, entry->tid,
'I', e.tag, e.message);
continue;
}
unsigned char prio = msg[0];
char* tag = msg + 1;
msg = tag + strlen(tag) + 1;
// consume any trailing newlines
char* nl = msg + strlen(msg) - 1;
while (nl >= msg && *nl == '\n') {
*nl-- = '\0';
}
char prioChar = (prio < strlen(kPrioChars) ? kPrioChars[prio] : '?');
// Look for line breaks ('\n') and display each text line
// on a separate line, prefixed with the header, like logcat does.
do {
nl = strchr(msg, '\n');
if (nl) {
*nl = '\0';
++nl;
}
_LOG(log, logtype::LOGS, "%s.%03d %5d %5d %c %-8s: %s\n",
timeBuf, entry->nsec / 1000000, entry->pid, entry->tid,
prioChar, tag, msg);
} while ((msg = nl));
}
android_logger_list_free(logger_list);
}
// Dumps the logs generated by the specified pid to the tombstone, from both
// "system" and "main" log devices. Ideally we'd interleave the output.
static void dump_logs(log_t* log, pid_t pid, unsigned int tail) {
dump_log_file(log, pid, "system", tail);
dump_log_file(log, pid, "main", tail);
}
static void dump_abort_message(Backtrace* backtrace, log_t* log, uintptr_t address) {
if (address == 0) {
return;
}
address += sizeof(size_t); // Skip the buffer length.
char msg[512];
memset(msg, 0, sizeof(msg));
char* p = &msg[0];
while (p < &msg[sizeof(msg)]) {
word_t data;
size_t len = sizeof(word_t);
if (!backtrace->ReadWord(address, &data)) {
break;
}
address += sizeof(word_t);
while (len > 0 && (*p++ = (data >> (sizeof(word_t) - len) * 8) & 0xff) != 0)
len--;
}
msg[sizeof(msg) - 1] = '\0';
_LOG(log, logtype::HEADER, "Abort message: '%s'\n", msg);
}
// Dumps all information about the specified pid to the tombstone.
static bool dump_crash(log_t* log, pid_t pid, pid_t tid, int signal, int si_code,
uintptr_t abort_msg_address, bool dump_sibling_threads,
int* total_sleep_time_usec) {
// don't copy log messages to tombstone unless this is a dev device
char value[PROPERTY_VALUE_MAX];
property_get("ro.debuggable", value, "0");
bool want_logs = (value[0] == '1');
if (log->amfd >= 0) {
// Activity Manager protocol: binary 32-bit network-byte-order ints for the
// pid and signal number, followed by the raw text of the dump, culminating
// in a zero byte that marks end-of-data.
uint32_t datum = htonl(pid);
TEMP_FAILURE_RETRY( write(log->amfd, &datum, 4) );
datum = htonl(signal);
TEMP_FAILURE_RETRY( write(log->amfd, &datum, 4) );
}
_LOG(log, logtype::HEADER,
"*** *** *** *** *** *** *** *** *** *** *** *** *** *** *** ***\n");
dump_header_info(log);
dump_thread_info(log, pid, tid);
if (signal) {
dump_signal_info(log, tid, signal, si_code);
}
UniquePtr<BacktraceMap> map(BacktraceMap::Create(pid));
UniquePtr<Backtrace> backtrace(Backtrace::Create(pid, tid, map.get()));
if (backtrace->Unwind(0)) {
dump_abort_message(backtrace.get(), log, abort_msg_address);
dump_thread(backtrace.get(), log, total_sleep_time_usec);
}
if (want_logs) {
dump_logs(log, pid, 5);
}
bool detach_failed = false;
if (dump_sibling_threads) {
detach_failed = dump_sibling_thread_report(log, pid, tid, total_sleep_time_usec, map.get());
}
if (want_logs) {
dump_logs(log, pid, 0);
}
// send EOD to the Activity Manager, then wait for its ack to avoid racing ahead
// and killing the target out from under it
if (log->amfd >= 0) {
uint8_t eodMarker = 0;
TEMP_FAILURE_RETRY( write(log->amfd, &eodMarker, 1) );
// 3 sec timeout reading the ack; we're fine if that happens
TEMP_FAILURE_RETRY( read(log->amfd, &eodMarker, 1) );
}
return detach_failed;
}
// find_and_open_tombstone - find an available tombstone slot, if any, of the
// form tombstone_XX where XX is 00 to MAX_TOMBSTONES-1, inclusive. If no
// file is available, we reuse the least-recently-modified file.
//
// Returns the path of the tombstone file, allocated using malloc(). Caller must free() it.
static char* find_and_open_tombstone(int* fd) {
// In a single pass, find an available slot and, in case none
// exist, find and record the least-recently-modified file.
char path[128];
int oldest = -1;
struct stat oldest_sb;
for (int i = 0; i < MAX_TOMBSTONES; i++) {
snprintf(path, sizeof(path), TOMBSTONE_TEMPLATE, i);
struct stat sb;
if (!stat(path, &sb)) {
if (oldest < 0 || sb.st_mtime < oldest_sb.st_mtime) {
oldest = i;
oldest_sb.st_mtime = sb.st_mtime;
}
continue;
}
if (errno != ENOENT)
continue;
*fd = open(path, O_CREAT | O_EXCL | O_WRONLY, 0600);
if (*fd < 0)
continue; // raced ?
fchown(*fd, AID_SYSTEM, AID_SYSTEM);
return strdup(path);
}
if (oldest < 0) {
ALOGE("Failed to find a valid tombstone, default to using tombstone 0.\n");
oldest = 0;
}
// we didn't find an available file, so we clobber the oldest one
snprintf(path, sizeof(path), TOMBSTONE_TEMPLATE, oldest);
*fd = open(path, O_CREAT | O_TRUNC | O_WRONLY, 0600);
if (*fd < 0) {
ALOGE("failed to open tombstone file '%s': %s\n", path, strerror(errno));
return NULL;
}
fchown(*fd, AID_SYSTEM, AID_SYSTEM);
return strdup(path);
}
static int activity_manager_connect() {
int amfd = socket(PF_UNIX, SOCK_STREAM, 0);
if (amfd >= 0) {
struct sockaddr_un address;
int err;
memset(&address, 0, sizeof(address));
address.sun_family = AF_UNIX;
strncpy(address.sun_path, NCRASH_SOCKET_PATH, sizeof(address.sun_path));
err = TEMP_FAILURE_RETRY(connect(
amfd, reinterpret_cast<struct sockaddr*>(&address), sizeof(address)));
if (!err) {
struct timeval tv;
memset(&tv, 0, sizeof(tv));
tv.tv_sec = 1; // tight leash
err = setsockopt(amfd, SOL_SOCKET, SO_SNDTIMEO, &tv, sizeof(tv));
if (!err) {
tv.tv_sec = 3; // 3 seconds on handshake read
err = setsockopt(amfd, SOL_SOCKET, SO_RCVTIMEO, &tv, sizeof(tv));
}
}
if (err) {
close(amfd);
amfd = -1;
}
}
return amfd;
}
char* engrave_tombstone(pid_t pid, pid_t tid, int signal, int original_si_code,
uintptr_t abort_msg_address, bool dump_sibling_threads,
bool* detach_failed, int* total_sleep_time_usec) {
log_t log;
log.current_tid = tid;
log.crashed_tid = tid;
if ((mkdir(TOMBSTONE_DIR, 0755) == -1) && (errno != EEXIST)) {
_LOG(&log, logtype::ERROR, "failed to create %s: %s\n", TOMBSTONE_DIR, strerror(errno));
}
if (chown(TOMBSTONE_DIR, AID_SYSTEM, AID_SYSTEM) == -1) {
_LOG(&log, logtype::ERROR, "failed to change ownership of %s: %s\n", TOMBSTONE_DIR, strerror(errno));
}
int fd = -1;
char* path = NULL;
if (selinux_android_restorecon(TOMBSTONE_DIR, 0) == 0) {
path = find_and_open_tombstone(&fd);
} else {
_LOG(&log, logtype::ERROR, "Failed to restore security context, not writing tombstone.\n");
}
if (fd < 0) {
_LOG(&log, logtype::ERROR, "Skipping tombstone write, nothing to do.\n");
*detach_failed = false;
return NULL;
}
log.tfd = fd;
// Preserve amfd since it can be modified through the calls below without
// being closed.
int amfd = activity_manager_connect();
log.amfd = amfd;
*detach_failed = dump_crash(&log, pid, tid, signal, original_si_code, abort_msg_address,
dump_sibling_threads, total_sleep_time_usec);
ALOGI("\nTombstone written to: %s\n", path);
// Either of these file descriptors can be -1, any error is ignored.
close(amfd);
close(fd);
return path;
}