There is a problem about tombstone, which it will fail to
generate tombstone file in some scenarios due to socket
communication exception.
Reproduce step:
step 1: reboot device
step 2: ps -ef |grep zygote , get the pid of zygote64
(Attention: zygote64 should never been killed or reboot,
otherwise we can get the tombstone file)
step 3: kill -5 pid of zygote64
step 4: cd data/tombstones/, and could not find the tombstone
file of zygote64.
[Cause Analysis]
1. There are following logs by logcat:
11-19 15:38:43.789 569 569 F libc : Fatal signal 5 (SIGTRAP),
code 0 (SI_USER) in tid 569 (main), pid 569 (main)
11-19 15:38:43.829 6115 6115 I crash_dump64: obtaining output
fd from tombstoned, type: kDebuggerdTombstone
11-19 15:38:43.830 569 5836 I Zygote : Process 6114 exited
cleanly (0)
11-19 15:38:43.830 777 777 I /system/bin/tombstoned: received
crash request for pid 569
11-19 15:38:43.831 6115 6115 I crash_dump64: performing dump of
process 569 (target tid = 569)
...
11-19 15:38:43.937 777 777 W /system/bin/tombstoned: crash
socket received short read of length 0 (expected 12)
2. The last log was print by function of crash_request_cb in
file of tombstoned.cpp, following related code:
rc = TEMP_FAILURE_RETRY(read(sockfd, &request, sizeof(request)));
if (rc == -1) {
PLOG(WARNING) << "failed to read from crash socket";
goto fail;
} else if (rc != sizeof(request)) {
LOG(WARNING) << "crash socket received short read of length " << rc << " (expected "
<< sizeof(request) << ")";
goto fail;
}
Tombstoned read message by socket, and now the message length is
zero. Some socket communication exception occurs at that time.
We try to let crash_dump resend the socket message when the
communication is abnormal. Just as this CL.
Test: 1 reboot device
2 ps -ef |grep zygote , get the pid of zygote64
(Attention: zygote64 should never been killed or reboot,
otherwise we can get the tombstone file)
3 kill -5 pid of zygote64
4 cd data/tombstones/, and could find the tombstone file of
zygote64.
Change-Id: Ic152b081024d6c12f757927079fd221b63445b18
8ac2f27cc2