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-rw-r--r--debuggerd/arm/machine.c9
-rw-r--r--debuggerd/debuggerd.c120
2 files changed, 103 insertions, 26 deletions
diff --git a/debuggerd/arm/machine.c b/debuggerd/arm/machine.c
index fb0d6baa..d5efb79f 100644
--- a/debuggerd/arm/machine.c
+++ b/debuggerd/arm/machine.c
@@ -56,6 +56,8 @@ extern int unwind_backtrace_with_ptrace(int tfd, pid_t pid, mapinfo *map,
/*
* 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)
{
@@ -63,7 +65,8 @@ static void show_nearby_maps(int tfd, int pid, mapinfo *map)
memset(&si, 0, sizeof(si));
if (ptrace(PTRACE_GETSIGINFO, pid, 0, &si)) {
- _LOG(tfd, false, "cannot get siginfo: %s\n", strerror(errno));
+ _LOG(tfd, false, "cannot get siginfo for %d: %s\n",
+ pid, strerror(errno));
return;
}
if (!signal_has_address(si.si_signo))
@@ -237,7 +240,9 @@ void dump_stack_and_code(int tfd, int pid, mapinfo *map,
}
}
- show_nearby_maps(tfd, pid, map);
+ if (at_fault) {
+ show_nearby_maps(tfd, pid, map);
+ }
unsigned int p, end;
unsigned int sp = r.ARM_sp;
diff --git a/debuggerd/debuggerd.c b/debuggerd/debuggerd.c
index 91d9dda3..2acf26d1 100644
--- a/debuggerd/debuggerd.c
+++ b/debuggerd/debuggerd.c
@@ -43,6 +43,9 @@
#define ANDROID_LOG_INFO 4
+void _LOG(int tfd, bool in_tombstone_only, const char *fmt, ...)
+ __attribute__ ((format(printf, 3, 4)));
+
/* Log information onto the tombstone */
void _LOG(int tfd, bool in_tombstone_only, const char *fmt, ...)
{
@@ -60,6 +63,7 @@ void _LOG(int tfd, bool in_tombstone_only, const char *fmt, ...)
if (!in_tombstone_only)
__android_log_vprint(ANDROID_LOG_INFO, "DEBUG", fmt, ap);
+ va_end(ap);
}
// 6f000000-6f01e000 rwxp 00000000 00:0c 16389419 /system/lib/libcomposer.so
@@ -177,7 +181,7 @@ void dump_fault_addr(int tfd, int pid, int sig)
_LOG(tfd, false, "signal %d (%s), code %d (%s), fault addr %08x\n",
sig, get_signame(sig),
si.si_code, get_sigcode(sig, si.si_code),
- si.si_addr);
+ (uintptr_t) si.si_addr);
} else {
_LOG(tfd, false, "signal %d (%s), code %d (%s), fault addr --------\n",
sig, get_signame(sig), si.si_code, get_sigcode(sig, si.si_code));
@@ -408,24 +412,40 @@ static bool dump_sibling_thread_report(int tfd, unsigned pid, unsigned tid)
continue;
dump_crash_report(tfd, pid, new_tid, false);
- need_cleanup |= ptrace(PTRACE_DETACH, new_tid, 0, 0);
+
+ if (ptrace(PTRACE_DETACH, new_tid, 0, 0) != 0) {
+ XLOG("detach of tid %d failed: %s\n", new_tid, strerror(errno));
+ need_cleanup = 1;
+ }
}
closedir(d);
+
return need_cleanup != 0;
}
/*
* 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 "tailOnly" is set, we only print the last few lines.
*/
-static void dump_log_file(int tfd, unsigned pid, const char* filename)
+static void dump_log_file(int tfd, unsigned pid, const char* filename,
+ bool tailOnly)
{
+ bool first = true;
+
+ /* circular buffer, for "tailOnly" mode */
+ const int kShortLogMaxLines = 5;
+ const int kShortLogLineLen = 256;
+ char shortLog[kShortLogMaxLines][kShortLogLineLen];
+ int shortLogCount = 0;
+ int shortLogNext = 0;
+
int logfd = open(filename, O_RDONLY | O_NONBLOCK);
if (logfd < 0) {
XLOG("Unable to open %s: %s\n", filename, strerror(errno));
return;
}
- _LOG(tfd, true, "--------- log %s\n", filename);
union {
unsigned char buf[LOGGER_ENTRY_MAX_LEN + 1];
@@ -466,6 +486,12 @@ static void dump_log_file(int tfd, unsigned pid, const char* filename)
continue;
}
+ if (first) {
+ _LOG(tfd, true, "--------- %slog %s\n",
+ tailOnly ? "tail end of " : "", filename);
+ first = false;
+ }
+
/*
* Msg format is: <priority:1><tag:N>\0<message:N>\0
*
@@ -477,10 +503,16 @@ static void dump_log_file(int tfd, unsigned pid, const char* filename)
*/
static const char* kPrioChars = "!.VDIWEFS";
unsigned char prio = entry->msg[0];
- const char* tag = entry->msg + 1;
- const char* msg = tag + strlen(tag) + 1;
+ char* tag = entry->msg + 1;
+ char* msg = tag + strlen(tag) + 1;
+
+ /* consume any trailing newlines */
+ char* eatnl = msg + strlen(msg) - 1;
+ while (eatnl >= msg && *eatnl == '\n') {
+ *eatnl-- = '\0';
+ }
- log_entry.entry.msg[entry->len] = '\0';
+ char prioChar = (prio < strlen(kPrioChars) ? kPrioChars[prio] : '?');
char timeBuf[32];
time_t sec = (time_t) entry->sec;
@@ -489,11 +521,37 @@ static void dump_log_file(int tfd, unsigned pid, const char* filename)
ptm = localtime_r(&sec, &tmBuf);
strftime(timeBuf, sizeof(timeBuf), "%m-%d %H:%M:%S", ptm);
- _LOG(tfd, true, "%s.%03ld %5d %5d %c %-8s: %s\n",
- timeBuf, entry->nsec / 1000000,
- entry->pid, entry->tid,
- (prio < strlen(kPrioChars) ? kPrioChars[prio] : '?'),
- tag, msg);
+ if (tailOnly) {
+ snprintf(shortLog[shortLogNext], kShortLogLineLen,
+ "%s.%03d %5d %5d %c %-8s: %s",
+ timeBuf, entry->nsec / 1000000, entry->pid, entry->tid,
+ prioChar, tag, msg);
+ shortLogNext = (shortLogNext + 1) % kShortLogMaxLines;
+ shortLogCount++;
+ } else {
+ _LOG(tfd, true, "%s.%03d %5d %5d %c %-8s: %s\n",
+ timeBuf, entry->nsec / 1000000, entry->pid, entry->tid,
+ prioChar, tag, msg);
+ }
+ }
+
+ if (tailOnly) {
+ int i;
+
+ /*
+ * If we filled the buffer, we want to start at "next", which has
+ * the oldest entry. If we didn't, we want to start at zero.
+ */
+ if (shortLogCount < kShortLogMaxLines) {
+ shortLogNext = 0;
+ } else {
+ shortLogCount = kShortLogMaxLines; /* cap at window size */
+ }
+
+ for (i = 0; i < shortLogCount; i++) {
+ _LOG(tfd, true, "%s\n", shortLog[shortLogNext]);
+ shortLogNext = (shortLogNext + 1) % kShortLogMaxLines;
+ }
}
close(logfd);
@@ -503,10 +561,10 @@ static void dump_log_file(int tfd, unsigned pid, const char* filename)
* 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(int tfd, unsigned pid)
+static void dump_logs(int tfd, unsigned pid, bool tailOnly)
{
- dump_log_file(tfd, pid, "/dev/log/system");
- dump_log_file(tfd, pid, "/dev/log/main");
+ dump_log_file(tfd, pid, "/dev/log/system", tailOnly);
+ dump_log_file(tfd, pid, "/dev/log/main", tailOnly);
}
/* Return true if some thread is not detached cleanly */
@@ -516,6 +574,11 @@ static bool engrave_tombstone(unsigned pid, unsigned tid, int debug_uid,
int fd;
bool need_cleanup = false;
+ /* 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 wantLogs = (value[0] == '1');
+
mkdir(TOMBSTONE_DIR, 0755);
chown(TOMBSTONE_DIR, AID_SYSTEM, AID_SYSTEM);
@@ -525,6 +588,11 @@ static bool engrave_tombstone(unsigned pid, unsigned tid, int debug_uid,
dump_crash_banner(fd, pid, tid, signal);
dump_crash_report(fd, pid, tid, true);
+
+ if (wantLogs) {
+ dump_logs(fd, pid, true);
+ }
+
/*
* If the user has requested to attach gdb, don't collect the per-thread
* information as it increases the chance to lose track of the process.
@@ -533,11 +601,8 @@ static bool engrave_tombstone(unsigned pid, unsigned tid, int debug_uid,
need_cleanup = dump_sibling_thread_report(fd, pid, tid);
}
- /* don't copy log to tombstone unless this is a dev device */
- char value[PROPERTY_VALUE_MAX];
- property_get("ro.debuggable", value, "0");
- if (value[0] == '1') {
- dump_logs(fd, pid);
+ if (wantLogs) {
+ dump_logs(fd, pid, false);
}
close(fd);
@@ -703,9 +768,11 @@ static void handle_crashing_process(int fd)
* is blocked in a read() call. This gives us the time to PTRACE_ATTACH
* to it before it has a chance to really fault.
*
- * After the attach, the thread is stopped, and we write to the file
- * descriptor to ensure that it will run as soon as we call PTRACE_CONT
- * below. See details in bionic/libc/linker/debugger.c, in function
+ * The PTRACE_ATTACH sends a SIGSTOP to the target process, but it
+ * won't necessarily have stopped by the time ptrace() returns. (We
+ * currently assume it does.) We write to the file descriptor to
+ * ensure that it can run as soon as we call PTRACE_CONT below.
+ * See details in bionic/libc/linker/debugger.c, in function
* debugger_signal_handler().
*/
tid_attach_status = ptrace(PTRACE_ATTACH, tid, 0, 0);
@@ -813,7 +880,12 @@ done:
wait_for_user_action(tid, &cr);
}
- /* resume stopped process (so it can crash in peace) */
+ /*
+ * Resume stopped process (so it can crash in peace). If we didn't
+ * successfully detach, we're still the parent, and the actual parent
+ * won't receive a death notification via wait(2). At this point
+ * there's not much we can do about that.
+ */
kill(cr.pid, SIGCONT);
if (need_cleanup) {