Commit graph

105 commits

Author SHA1 Message Date
Mark Salyzyn
0f92fdc5d6 logd: cap out-of-order entry search
Reduce the period we are willing to look back at for out-of-order
entries.  Cap the number of iterations we are willing to look back
for out-of-order entries to 300.

Test: gTest liblog-unit-tests, logd-unit-tests and logcat-unit-tests
Bug: 36875387
Bug: 36874561
Bug: 36861142
Change-Id: Icee289dfc0a37ccab9912dc8ab40a10ef3967b7a
2017-04-04 11:03:26 -07:00
Mark Salyzyn
ae2abf112c logd: correctly label identical lines
Move lastTid array from local in LogBuffer::flushTo to per-reader
context in LogTimes::mLastTid and pass into LogBuffer::flushTo.

Replace NULL with nullptr in touched files.

Simplify LogTimeEntry::cleanSkip_Locked initialization of skipAhead
to memset, to match mLastTid memset initialization.

Test: gTest liblog-unit-tests, logd-unit-tests & logcat-unit-tests
Test: adb logcat -b all | grep chatty | grep -v identical
Bug: 36488201
Change-Id: I0c3887f220a57f80c0490be4b182657b9563aa3f
2017-03-31 13:56:38 -07:00
Mark Salyzyn
1f46716f1c logd: last iterator initialized incorrectly
last should start with mLogElements.end() and be updated as
we iterate to find a matching time entry in the list. Since
it is impossible(sic) for a newer start time to be supplied
than the list, the incorrect iterator initialization should
be inconsequential, but if it ever happens this change will
behave correctly and dump nothing.

Test: gTest liblog-unit-tests, logd-unit-tests and logcat-unit-tests
Bug: 36536248
Bug: 36608728
Change-Id: I96998c4b713258f29d5db2e24a83ae562ddf3420
2017-03-27 21:26:13 +00:00
Mark Salyzyn
0484b3b575 logd: ASAN cleansing
A mixture of fixes and cleanup for LogKlog.cpp and friends.

- sscanf calls strlen.  Check if the string is missing a nul
  terminator, if it is, do not call sscanf.
- replace NULL with nullptr for stronger typechecking.
- pass by reference for simpler code.
- Use ssize_t where possible to check for negative values.
- fix FastCmp to add some validity checking since ASAN reports that
  callers are not making sure pre-conditions are met.
- add fasticmp templates for completeness.
- if the buffer is too small to contain a meaningful time, do not
  call down to log_time::strptime() because it does not limit its
  accesses to the buffer boundaries, instead stopping at a
  terminating nul or invalid match.
- move strnstr to LogUtils.h, drop size checking of needle and
  clearly report the list of needles used with android::strnstr
- replace 'sizeof(static const char[]) - 1' with strlen.

Test: gTest liblog-unit-test, logd-unit-tests & logcat-unit-tests
Bug: 30792935
Bug: 36536248
Bug: 35468874
Bug: 34949125
Bug: 34606909
Bug: 36075298
Bug: 36608728
Change-Id: I161bf03ba029050e809b31cceef03f729d318866
2017-03-27 13:32:57 -07:00
Mark Salyzyn
09d663229f logd: cap how far back in-place sort will go to 5 seconds
Add some deterministic behavior should the user change the hour
backwards when altering the device time, prevent sort-in-place
and cause the logger to land the new entries at the end.

Do not limit how far kernel logs can be sorted.

Test: gTest liblog-unit-tests logd-unit-tests logcat-unit-tests
Bug: 35373582
Change-Id: Ie897c40b97adf1e3996687a0e28c1199c41e0d0c
2017-03-17 14:17:38 +00:00
Mark Salyzyn
3b941d457b logd: continue search out-of-order entries timestamp tail
Regression from commit 8e8e8db549

For liblogcat reader -t or -T <timestamp> tail requests, continue
search for pertinent out-of-order entries for an additional 30 seconds
back into logging history to find a more inclusive starting point.

For example, if you have an out of order landing like
[..., 3, 6, 1, 8, 2, 5] and ask for 3 you used to get only 5, and now
you get 3, 6, 8, 5 as 'expected'

Test: gTest liblog-unit-tests logd-unit-tests logcat-unit-tests
Bug: 35373582
Change-Id: I2a0732933fa371aed383d49c8d48d01f33db2a79
2017-03-16 16:57:53 +00:00
Mark Salyzyn
5a34d6ea43 logd: drop mSequence from LogBufferElement
Use getRealTime() instead and leverage private liblog log_time
comparison and math functions.  This saves 8 bytes off each
element in the logging database.

Test: gTest liblog-unit-tests logd-unit-tests logcat-unit-tests
Bug: 35373582
Change-Id: Ia55ef8b95cbb2a841ccb1dae9a24f314735b076a
2017-03-16 08:22:00 -07:00
Mark Salyzyn
1d84f0b2af logd: ensure LogBufferElement mSequence is monotonic
- Improves accuracy of -t/-T '<timestamp>' behavior when out of order
  arrival of entries messes with mSequence as the list will now have
  monotonic sequence numbers enforced.
- Out of order time entries still remain because of reader requiring
  the ability to receive newly arrived old entries.
- -t/-T '<timestamp>' can still quit backward search prematurely
  because an old entry lands later in the list.
- Adjust insert in place algorithm from two loops of scan placement
  and then limit against watermark, into one that does all of that
  plus iteratively swap update the sequence numbers to set
  monotonicity.  Side effect will be that the read lock (which is
  actually the LogTimes lock) will be held longer while we search
  for a placement above the youngest LogTimes watermark.  We need
  to hold the read (LogTimes) lock because we may be altering the
  sequence numbers affecting -t/-T '<timestamp>' search.

Test: gTest logd-unit-tests liblog-unit-tests logcat-unit-tests
Bug: 35373582
Change-Id: I79a385fc149bac2179128b53d4c8f71e429181ae
2017-03-16 08:13:43 -07:00
Evgenii Stepanov
03fc2fedd7 Fix heap-buffer-overflow detected by ASAN.
Bug: 34949125
Bug: 34606909
Test: Make sure Android boots when built with SANITIZE_TARGET='address'
Change-Id: I9c004e806f2025098aa72228284b05affd2c2802
2017-03-14 14:47:25 -07:00
Mark Salyzyn
501c373916 logd: specify clang format
Switch _all_ file's coding style to match to ease all future changes.

SideEffects: None
Test: compile
Bug: 35373582
Change-Id: I470cb17f64fa48f14aafc02f574e296bffe3a3f3
2017-03-13 10:31:09 -07:00
Mark Salyzyn
61e9ce6709 logd: add getEventTag command and service
Will register a new event tag by name and format, and return an
event-log-tags format response with the newly allocated tag.
If format is not specified, then nothing will be recorded, but
a pre-existing named entry will be listed. If name and format are
not specified, list all dynamic entries. If name=* list all
event log tag entries.

Stickiness through logd crash will be managed with the tmpfs file
/dev/event-log-tags and through a reboot with add_tag entries in
the pmsg last logcat event log. On debug builds we retain a
/data/misc/logd/event-log-tags file that aids stickiness and that
can be picked up by the bugreport.

If we detect truncation damage to /dev/event-log-tags, or to
/data/misc/logd/event-log-tags, rebuild file with a new first line
signature incorporating the time so mmap'd readers of the file can
detect the possible change in shape and order.

Manual testing:

Make sure nc (netcat) is built for the target platform on the host:
$ m nc

Then the following can be used to issue a request on the platform:
$ echo -n 'getEventTag name=<name> format="<format>"\0EXIT\0' |
> nc -U /dev/socket/logd

Test: gTest logd-unit-test --gtest_filter=getEventTag*
Bug: 31456426
Change-Id: I5dacc5f84a24d52dae09cca5ee1a3a9f9207f06d
2017-02-02 14:24:18 -08:00
Mark Salyzyn
b5b8796785 logd: multiple identical do not report expired
Report multiple identical chatty messages differently than for
regular expire chatty messages.  Multiple identical will
report identical count, while spam filter will report
expire count.

This should reduce the expected flood of people confused
but chatty messages in continuous logcat output.

Test: gTest logd_unit_tests --gtest_filter=logd.multiple*
Change-Id: Iad93d3efc6a3938a4b87ccadddbd86626a015d44
2017-01-24 11:02:18 -08:00
Mark Salyzyn
684bdb576d logd: LogBufferElementKey use uint32_t for uid
Test: gTest liblog-unit-tests, logd-unit-tests & logcat-unit-test
Change-Id: Icae34b1fa0b3df0a45ad175ec81aaf232f322f38
2016-12-21 12:16:46 -08:00
Mark Salyzyn
1dfb4de436 logd: sum liblog tag messages
As an extension to the duplicate multiple message filtering, special
case liblog tagged event messages to be summed.  This solves the
inefficient and confusing duplicate message report from the DOS attack
detection such as:

liblog: 2
liblog: 2
liblog: 2
liblog: 2
liblog: 3

which would result in:

liblog: 2
chatty: ... expire 2 lines
liblog: 2
liblog: 3

And instead sums them and turns them all into:

liblog: 11

liblog messages should never be subject to chatty conversion.

Test: liblog-benchmarks manually check for coalesced liblog messages
      and make sure they do not turn into chatty messages.
      Instrumented code to capture sum intermediates to be sure.
Bug: 33535908
Change-Id: I3bf03c4bfa36071b578bcd6f62234b409a91184b
2016-12-19 14:03:38 -08:00
Mark Salyzyn
8f83a35511 logd: correct duplicate message state machine
Inspection turned up that for the case of three identical messages,
the result would be a stutter of the first message only.  Added
comments to describe the state machine, incoming variables, outcoming
and false condition outputs, for proper maintenance in the future.

Test: gTest liblog-benchmarks BM_log_maximum* and manually check
      for correct midstream chatty messages,
Bug: 33535908
Change-Id: I852260d18a484e6207b80063159f1a74eaa83b55
2016-12-19 14:01:45 -08:00
Mark Salyzyn
a2c022257c logd: record multiple duplicate messages as chatty
If a series of messages arrive from a single source with identical
message content payload, then suppress them and generate a chatty
report.  The checking is done on a per log id basis.

This alters the assumption that chatty messages are always at the
oldest entries, they now show up in the middle too.  To address this
change in behavior we print the first line, a chatty reference
which internally takes little space, then the last line in the series.

This does not conserve processing time in logd, and certainly has no
impact on the long path of formatting and submitting log messages from
from the source, but it may contribute to memory space and signal to
noise savings under heavy spammy loads.

Test: gTest liblog-unit-tests, logd-unit-tests & logcat-unit-tests
Bug: 33535908
Change-Id: I3160c36d4f4e2f8216f528605a1b3993173f4dec
2016-12-15 16:31:51 -08:00
Mark Salyzyn
60636fa872 logd: getTag() functional for chatty entries
getTag() becomes invalid when entry is dropped because mMsg
disappears to save space; but the per-tag spam filter depends on it
still being valid.  Conserve space in LogBufferElement by optimizing
the size of the fields, then add a new mTag field that is set in the
object constructor.  Add an isBinary() method.

SideEffects: save 12 bytes/log message overhead on 64-bit.
Test: define DEBUG_CHECK_FOR_STALE_ENTRIES and look for stale entries
Bug: 32247044
Change-Id: Iaa5f416718a92c9e0e6ffd56bd5260d8b908d5c0
2016-10-25 21:48:33 +00:00
Mark Salyzyn
8fcfd85acc logd: address code fragility in last watermarks
Do not make the assumption that if worstPid is set, that the log
buffer id is not LOG_ID_EVENTS or LOG_ID_SECURITY. Add comments
to prevent future over-optimization based on this assumption.

Make sure we reset mLast[id] = begin() when we mark it unset, but
tell optimizer this is an _impossible_ path.

SideEffects: drop two branches in all erase calls, gain an unordered
             find() on an empty list for events and security buffers.
Test: gTest logd-unit-tests, liblog-unit-test & logcat-unit-tests
Bug: 32247044
Change-Id: Ic156ca2253c050c28021cedf48bedaf7bd692c09
2016-10-24 10:43:52 -07:00
Mark Salyzyn
fa07f9dc4b logd: mLastWorstPidOFSystem crash
mLastWorstPidOfSystem is filled with iterator references
that are not from AID_SYSTEM to aid the performance. But
we only clear entries from the list during erase if they
are from AID_SYSTEM. Remove the filter check in erase so
the stale references will be removed.

The conditions that caused this failure are difficult to
reproduce and are rare.

Test: gTests logd-unit-tests, liblog-unit-tests and logcat-unit-tests
Bug: 32247044
Bug: 31237377
Change-Id: Ie405dd643203b816cac15eef5c97600551cee450
2016-10-21 10:20:55 -07:00
Mark Salyzyn
f10e273790 logd: Use private interfaces for buffer size properties
Test: gTest logd-unit-tests, liblog-unit-tests and logcat-unit-tests
Bug: 31750617
Change-Id: I692577cfdf4bf8c93616f32df4b56786918aef1c
2016-10-18 09:49:51 -07:00
Mark Salyzyn
807e40ecc9 liblog: logd: Add android_lookupEventTag_len()
Allows us to mitigate the impact of MAP_PRIVATE and copy on write by
calling android_lookupEventTag_len instead of android_lookupEventTag,
and delaying the copy on write impact to the later.  We return a
string length in a supplied location along with the string pointer
with android_lookupEventTag_len(const EventTagMap* map, size_t* len,
int tag).  The string is not guaranteed to be nul terminated.  Since
android_lookupEventTag() called even once can cause the memory
impact, we will mark it as deprecated, but we currently have no
timeframe for removal since this is a very old interface.

Add an API for __android_log_is_loggable_len() that accepts the non
null terminated content and fixup callers that would gain because the
length is known prior to the call either in the compiler or at
runtime.  Tackle transition to android_lookupEventTag_len() and
fixup callers.

On any application that performs logging (eg: com.android.phone)

/proc/<pid>/smaps before:

xxxxxxxxxx-xxxxxxxxxx rw-p 00000000 fd:00 463 /system/etc/event-log-tags
Size:                 20 kB
Rss:                  20 kB
Pss:                   1 kB
Shared_Clean:          0 kB
Shared_Dirty:         20 kB
Private_Clean:         0 kB
Private_Dirty:         0 kB
Referenced:            0 kB
Anonymous:            20 kB
AnonHugePages:         0 kB
Swap:                  0 kB
SwapPss:               0 kB
KernelPageSize:        4 kB
MMUPageSize:           4 kB
Locked:                0 kB
VmFlags: rd wr mr mw me ac

/proc/<pid>/smaps after:

xxxxxxxxxx-xxxxxxxxxx rw-p 00000000 fd:00 1773 /system/etc/event-log-tags
Size:                 20 kB
Rss:                  20 kB
Pss:                   1 kB
Shared_Clean:         20 kB  (was 0kB)
Shared_Dirty:          0 kB  (was 20kB)
Private_Clean:         0 kB
Private_Dirty:         0 kB
Referenced:           20 kB  (was 0kB)
Anonymous:             0 kB  (was 20kB)
AnonHugePages:         0 kB
Swap:                  0 kB
SwapPss:               0 kB
KernelPageSize:        4 kB
MMUPageSize:           4 kB
Locked:                0 kB
VmFlags: rd wr mr mw me ac

Added liblog-unit-tests --gtest_filter=liblog.event_log_tags to
check for Shared_Clean: to not be 0 and Anonymous: to be 0 for
all processes referencing event-log-tags.  Which can include multiple
references to /system/etc/event-log-tags and future possible refs to
/data/misc/logd/event-log-tags and /dev/event-log-tags.  We want
failure messages to help point to errant code using the deprecated
interface.

This change saves 1/4MB of memory or more on a typical system.

Test: gTest liblog-unit-tests
Bug: 31456426
Change-Id: I9e08e44d9092bd96fe704b5709242e7195281d33
2016-10-03 11:08:34 -07:00
Mark Salyzyn
43a5f31e94 logd: clear all from non system user status request
pruneRows not necessarily ULONG_MAX when uid not system source,
allow for speed up for status response if pruneRows exhausted.

Change-Id: I38c76bb20215e3d96513a575e2e3bc85a5e5b41c
2016-09-02 07:41:27 -07:00
Mark Salyzyn
1eefca281e logd: crash in prune mLastWorstPidOfSystem
mLastWorstPidOfSystem is supposed to be indexed by element->getPid()

Bug: 31237377
Bug: 30797725
Bug: 30688716
Change-Id: I81a55e92f175ded1c571a0aa8836736d86b36b1d
2016-09-02 07:41:27 -07:00
Mark Salyzyn
6a06694a61 logd: Worst Tag filter enabled for events buffer
- Add drop logistics to TagTable
- replace uid references to a key reference since it
  is an UID for most buffers, but a TAG for the
  events and security buffer
- template the find worst entry mechanics into LogFindWorst class

Bug: 30118730
Change-Id: Ibea4be2c50d6ff4b39039e371365fed2453f17a2
2016-07-15 14:58:17 -07:00
Mark Salyzyn
0f85817985 logd: rename sort() for pids to sortPids()
Bug: 30118730
Change-Id: If992b53b52a7470427fbe82abb93c95c1b2dc57a
2016-07-15 14:37:04 -07:00
Chih-Hung Hsieh
1cc82ce95c Fix google-explicit-constructor warnings.
Bug: 28341362
Change-Id: I2cf746fd07addc6e6c22e98e2a5bb8a8ce47c885
2016-04-25 13:49:46 -07:00
Mark Salyzyn
8fa8896d2e logd: security buffer only AID_SYSTEM reader
- limit AID_SYSTEM uid or gid to read security buffer messages
- adjust liblog tests to reflect the reality of this adjustment

To fully test all security buffer paths and modes

$ su 0,0,0 /data/nativetest/liblog-unit-tests/liblog-unit-tests --gtest_filter=liblog.__security*
$ su 1000,1000,1000 /data/nativetest/liblog-unit-tests/liblog-unit-tests --gtest_filter=liblog.__security*
$ su 2000,2000,2000 /data/nativetest/liblog-unit-tests/liblog-unit-tests --gtest_filter=liblog.__security*

ToDo: Integrate the above individually into the gTest Q/A testing

Bug: 26029733
Change-Id: Idcf5492db78fa6934ef6fb43f3ef861052675651
2016-02-01 13:29:06 -08:00
Mark Salyzyn
7fd6c5c6f5 logd: prune maintain per-id watermark (part deux)
iterator corruption as we allow mLast to slip through the FIFO

Bug: 23685592
Bug: 26646087
Change-Id: Ifcbaecf390ee47b195c3d823d080c66c15db4530
2016-01-19 16:14:39 -08:00
Mark Salyzyn
507eb9fec2 logd: prune maintain per-id watermark
Without this change LogBuffer::prune and LogBuffer::erase
contributes 16.7% and 1.79% respectively. With this change,
they contributes 3.06 and 2.33% respectively. Pruning is
performed roughly 1 in every 255 log entries, a periodic
tamer latency spike.

Bug: 23685592
Change-Id: I6ae1cf9f3559bca4cf448efe8bcb2b96a1914c54
2016-01-11 14:46:51 -08:00
Mark Salyzyn
1a5bac2069 Merge "Revert "logd: liblog: whitelist "snet_event_log""" 2016-01-06 21:22:04 +00:00
Mark Salyzyn
0ee8de3c2d Revert "logd: liblog: whitelist "snet_event_log""
Callers will not guarantee that they can or will ratelimit, we need to
retain the ability to blacklist snet_event_log as a result.

This reverts commit 6aa21b225d.

Bug: 26178938
Change-Id: Ibf47d2e23a84c56f5f72d02312c698df7ff2b601
2016-01-06 21:19:23 +00:00
Mark Salyzyn
66607ebc0e logd: document ro.logd.size
Bad comment advise in LogBuffer.cpp results in partners failing to
considering using ro.logd.size to set the platform buffer size
default.

NB: It is not good practice to increase the log buffer size to deal
with logspam, as increases will result in logd scale issues getting
closer to hitting the background cgroup cpu cap. Once we hit that
cap, logd spirals, pruning old entries slower than the incoming log
entries. logd.writer will take 100% cpu.

Change-Id: If4a7a74f300d078eeaed0ffd3eb3fd77d1f9fe90
2016-01-05 09:09:18 -08:00
Mark Salyzyn
6aa21b225d logd: liblog: whitelist "snet_event_log"
Dangerous bridge to cross to whitelist, who is special, who is not?
Rationalized as these events are used to catch exploits on platform.
As it stands no one should be allowed to block any messages in the
security context, not even for development purposes.

Bug: 26178938
Change-Id: Ibdc76bc0fe29ba05be168b623af1c9f41d7edbd2
2015-12-30 10:07:19 -08:00
Mark Salyzyn
bec3c3def9 logd: Add worst pid of system filter
- Add a new statistic that reports per pid and log_id for AID_SYSTEM
- Add a new pruning filter ~1000/! boolean
- Use this new statistic to prune on worst pid within AID_SYSTEM

Bug: 26029733
Bug: 21615139
Bug: 22855208
Change-Id: Iab5dd28f807dcf03d276372853883f3b6afa8294
2015-12-29 09:32:35 -08:00
Mark Salyzyn
9c66a58f21 logd: Allow flags "eng" and "svelte" in boolean
- enhance property_get_bool, drop property_get_bool_svelte
- enhance base properties with ro and persist variants
- update and fortify README.property
- primarily move auditd and kernel logger into a realm where
  they can be controlled by build properties.
- Move logd.klogd to logd.kernel, and add ro.logd.kernel
  and persist.logd.kernel.
- Add ro.logd.auditd and persist.logd.auditd.
- Document persist.logd.security
- Document log.tag and persist.logd.tag properties.
- Document ro.logd.size, persist.logd.size and logd.size
  properties.

Bug: 26178938
Bug: 26029733
Bug: 17760225
Change-Id: Ibc1a497e45d69db5cf52133937f7ba6fb1d6cd21
2015-12-22 07:44:31 -08:00
Mark Salyzyn
ee3b838e13 logd: statistics per-pid filter
Primarily gives access to the Chattiest TIDs and TAGs
associated with a pid.

Has a secondary effect of allowing us to pull out the
command line, comm and in some cases the associated
PACKAGE for a specific pid while the logs are still
present even if the executable is gone.

Bug: 26029733
Bug: 21615139
Change-Id: I1ea63165a680a9318360579b70b1512078ed5682
2015-12-18 13:17:37 -08:00
Mark Salyzyn
cdda62b2c1 logd: ro.config.low_ram set buffer size to 64K
Bug: 25792367
Change-Id: Icae85a7de70b3a71f89b2bf8c80866649f727177
2015-12-14 14:37:07 -08:00
Mark Salyzyn
86052a5d4f Merge "logd: liblog: logcat: Add LOG_ID_SECURITY" 2015-12-11 17:33:33 +00:00
Mark Salyzyn
7b87365ecf logd: readlog apps get logger_entry_v4
Adds the uid field to outgoing content for readlog applications.
AID_LOG, AID_ROOT and AID_SYSTEM gain access to the information.

Bug: 25996918
Change-Id: I0254303c19d174cbf5e722c38844be5c54410c85
2015-12-09 08:12:07 -08:00
Mark Salyzyn
083b037c07 logd: liblog: logcat: Add LOG_ID_SECURITY
- Largish commit, buffer and access controls done together
- Add LOG_ID_SECURITY binary content log
- Add "default" meta buffer
- allow LOG_ID_SECURITY only from AID_SYSTEM and AID_ROOT UID & GID
- Use __android_log_security() to gate logging
- Add __android_log_security_bwrite() native access to security
  logging.
- Add liblog.__security_buffer end-to-end gTest

Bug: 26029733
Change-Id: Ibcf5b4660c17c1aa6902c0d93f8ffd29c93d9a93
2015-12-08 16:46:29 -08:00
Mark Salyzyn
b75cce0389 logd: wakeup on wrap or timeout
If a timeout is specified for the reader, then go to sleep
with the socket open. If the start time is about to get
pruned in the specified log buffers, then wakeup and dump
the logs; or wakeup on timeout, whichever comes first.

Bug: 25929746
Change-Id: I7d2421c2c5083b33747b84f74d9a560d3ba645df
2015-12-07 14:24:02 -08:00
Mark Salyzyn
ba7a9a016b logd: liblog: logcat: switch to android_log_clockid() (2)
android_log_timestamp returns the property leading letter,
it is better to return a clockid_t with android_log_clockid()

Bug: 23668800
Change-Id: I38dee773bf3844177826b03a26b03215c79a5359
2015-12-07 18:45:31 +00:00
Mark Salyzyn
9e18cdcebd Revert "logd: liblog: logcat: switch to android_log_clockid()"
This reverts commit 77b5696b1d.

Change-Id: I7711bf1a7e3f72ed29a2498d7287b725a0e624bd
2015-12-07 18:30:58 +00:00
Mark Salyzyn
77b5696b1d logd: liblog: logcat: switch to android_log_clockid()
android_log_timestamp returns the property leading letter,
it is better to return a clockid_t with android_log_clockid()

Bug: 23668800
Change-Id: I3c4e3e6b87f6676950797f1f0e203b44c542ed43
2015-12-04 14:49:19 -08:00
Mark Salyzyn
c2e7d4965f Revert "liblog: resolve deadlocks"
This reverts commit 7a2a307192.

Bug: 25693940
Change-Id: I9a7c926289e972f80c03c92e33535e1dedaa7381
2015-11-16 19:00:41 +00:00
Mark Salyzyn
7a2a307192 liblog: resolve deadlocks
Although ever present, an increased regression introduced with
commit b6bee33182 (liblog: logd:
support logd.timestamp = monotonic).

A signal handler can interrupt in locked context, if log is written
in the signal handler, we are in deadlock. Block signals while we
are locked. Separate out timestamp lock from is loggable lock to
reduce contention situations. Provide a best-guess response if
lock would fail in timestamp path.

Bug: 25563384
Change-Id: I6dccd6b99ebace1c473c03a785a35c63ed5c6a8a
2015-11-12 15:39:04 -08:00
Mark Salyzyn
8897a3fffd Merge "liblog: logd: support logd.timestamp = monotonic" 2015-11-04 00:31:53 +00:00
Mark Salyzyn
50122695d2 logd: pruning time horizon
Estimate a time horizon of ten fold for worst UID pruning

Bug: 24782000
Change-Id: I7118deb6d42531c68ed2ac2a59c57b0580b942cc
2015-11-03 15:34:15 -08:00
Mark Salyzyn
b6bee33182 liblog: logd: support logd.timestamp = monotonic
if ro.logd.timestamp or persist.logd.timestamp are set to the value
monotonic then liblog writer, liblog printing and logd all switch to
recording/printing monotonic time rather than realtime. If reinit
detects a change for presist.logd.timestamp, correct the older entry
timestamps in place.

ToDo: A corner case condition where new log entries in monotonic time
      occur before logd reinit detects persist.logd.timestamp, there
      will be a few out-of-order entries, but with accurate
      timestamps. This problem does not happen for ro.logd.timestamp
      as it is set before logd starts.

NB: This offers a nano second time accuracy on all log entries
    that may be more suitable for merging with other system
    activities, such as systrace, that also use monotonic time. This
    feature is for debugging.

Bug: 23668800
Change-Id: Iee6dab7140061b1a6627254921411f61b01aa5c2
2015-11-03 15:15:51 -08:00
Mark Salyzyn
58b8be8906 logd: correct for number of elements in prune
Chatty logs would distort the average log size by elevating the
elements, but not the size. Add statistical collection for the
number of elements that report chatty, and subtract that from
the number of elements to improve the pruning estimate. Pick
minElements as 1% rather than 10% of the total with this more
accurate number of elements, to a minumum of 4.

Bug: 24511000
Change-Id: I3f36558138aa0b2a50e4fac6440c3a8505d95276
2015-10-13 13:43:16 -07:00