--wrap flag in logcat translates directly to the mTimeout inside logd,
the value set is ANDROID_LOG_WRAP_DEFAULT_TIMEOUT defined in
<log/log_read.h> as 7200 or 2 hours. For a non blocking read with
a selected timeout, the logger waits until either the log buffer is
about to 'wrap' and prune the log entry, or at the specified timeout.
Non blocking in the logger context means that when there are no more
log entries, the socket is closed.
clock_gettime(CLOCK_REALTIME) is UTC 1970 epoch *NIX time. Is only
affected for time updates, not timezone or daylight savings time.
If there is a large user initiated time change, both the log entries
and the timeout mentioned above really get called into question, so we
trigger a release of the logs for clarity. This is so that the log
reader can handle the disruptively updated time, and can immediately
check the local time if necessary.
The logger has a 5 second window for entries to land in time sorted
order into the logging list. This should offer the log reader some
differentiation between logging order sequence for monotonically
increasing time, and sequence order in the face of user initiated time
adjustments that break monotonicity.
This change is about major time adjustments that can cause Fear,
Uncertainty or Doubt about log entries. By returning, immediate action
can be taken, rather than having to comb through the logs with less
details about the time disruptions in hand. The least it can do is
record what we have, and restart the call with a new tail time and
timeout.
Test: gTest liblog-unit-tests logcat-unit-test logd-unit-tests
Bug: 35373582
Change-Id: I92cac83be99d68634ffd4ebd2f3a3067cfd0e942
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
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
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
- 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
Better keep the right order, or ASAN will complain when you read
out of bounds.
Bug: 36234128
Test: m
Test: m && m SANITIZE_TARGET=address
Test: Sanitized device boots without ASAN crashes
Change-Id: Ifc09cb0ece6835d2b636a3ad2128e09ca9aa45c9
Bug: 34949125
Bug: 34606909
Test: Make sure Android boots when built with SANITIZE_TARGET='address'
Change-Id: I9c004e806f2025098aa72228284b05affd2c2802
Switch _all_ file's coding style to match to ease all future changes.
SideEffects: None
Test: compile
Bug: 35373582
Change-Id: I470cb17f64fa48f14aafc02f574e296bffe3a3f3
Bug: 34949125
Bug: 34606909
Test: Make sure Android boots when built with SANITIZE_TARGET='address'
Change-Id: I9c004e806f2025098aa72228284b05affd2c2802
This is the precursor for "Plan B" recovery when access to
/dev/event-log-tags is blocked to untrusted zones. Also
deals with mitigating issues with long-lived mappings that
do not update /dev/event-log-tags when dynamically changed.
Test: gTest logd-unit-test --gtest_filter=logd.getEventTag_42
Bug: 31456426
Bug: 35326290
Change-Id: I3db2e73763603727a369da3952c5ab4cf709f901
android_lookupEventTagNum added. Adds support for creating a new
log tag at runtime, registered to the logd service.
Tested on Hikey, all services stopped, shell only access, CPUs not
locked (there is enough repeatability on this platform).
$ /data/nativetest64/liblog-benchmarks/liblog-benchmarks BM_lookupEventTagNum
iterations ns/op
Precharge: start
Precharge: stop 231
NB: only Tag matching, linear lookup (as reference, before unordered_map)
BM_lookupEventTagNum 1000000 1017
NB: unordered_map with full Tag & Format lookup, but with Tag hashing
BM_lookupEventTagNum 2000000 683
NB: with full Tag & Format hash and lookup for matching
BM_lookupEventTagNum 2000000 814
NB: only Tag matching (Hail Mary path)
BM_lookupEventTagNum 5000000 471
Because the database can now be dynamic, we added reader/writer locks
which adds a 65ns (uncontended) premium on lookups, and switch to
check for an allocation adds 25ns (either open code, or using
string_view, no difference) which means our overall speed takes 90%
as long as the requests did before we switched to unordered_map.
Faster than before where we originally utilized binary lookup on
static content, but not by much. Dynamic updates that are not cached
locally take the following times to acquire long path to logd to
generate.
BM_lookupEventTag 20000000 139
BM_lookupEventTag_NOT 20000000 87
BM_lookupEventFormat 20000000 139
BM_lookupEventTagNum_logd_new 5000 335936
BM_lookupEventTagNum_logd_existing 10000 249226
The long path pickups are mitigated by the built-in caching, and
the public mapping in /dev/event-log-tags.
SideEffects: Event tags and signal handlers do not mix
Test: liblog benchmarks
Bug: 31456426
Change-Id: I69e6489d899cf35cdccffcee0d8d7cad469ada0a
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
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
Resolve issues seen on continuous testing frame:
- statistics test, info instead of fail on missing radio log data.
- sepolicy switch from /data/misc/logd/ to /data/backup/ as the
directory we access(2) to inject sepolicy violations. The key here
is we are still root, but we are in u:r:shell:s0, and the directory
does not provide us DAC access (0700 system system) so we trigger
the pair dac_override and dac_read_search on every try to get past
the message de-duper. /data/misc/logd is not always there, until
logpersist is enabled, but /data/backup is always there.
- a stricter signature of '): avc: denied'
- put in a looser threshold for sepolicy_rate_limiter_spam test.
Test: gTest logd-unit-tests --gtest_filter=logd.sepolicy*
Bug: 34454758
Change-Id: I28ce4fdb51dc4869944e3253b593ce222d16ec98
Processing overhead for selinux violation messages is costly. We want
to deal with bursts of violations, but we have no intent of allowing
that sustained burst to go unabated as there is a cost of processing
and battery usage.
Tunables in libaudit.h are:
AUDIT_RATE_LIMIT_DEFAULT 20 /* acceptable burst rate */
AUDIT_RATE_LIMIT_BURST_DURATION 10 /* number of seconds of burst */
AUDIT_RATE_LIMIT_MAX 5 /* acceptable sustained rate */
Since we can only asymptotically handle DEFAULT rate, we set an upper
threshold of half way between the MAX and DEFAULT rate.
Default kernel audit subsystem message rate is set to 20 a second.
If sepolicy exceeds 125 violation messages over up to ten seconds
(>=~12/s), tell kernel audit subsystem to drop the rate to 5 messages
a second. If rate drops below 50 messages over the past ten seconds
(<5/s), tell kernel it is ok to increase the burst rate back to 20
messages a second.
Test: gTest logd-unit-tests --gtest_filter=logd.sepolicy_rate_limiter_*
Bug: 27878170
Change-Id: I843f8dcfbb3ecfbbe94a4865ea332c858e3be7f2
Some kernels have a bug which causes a newline to show up in audit
messages. The embedded newlines cause one message to look like two due
to prefix controls.
Replace any newlines with spaces. Duplicate spaces are further
consolidated in code immediately after this newly added code.
Test: create an audit message with a newline, and watch it be cleaned up.
Bug: 27878170
Change-Id: Id90c29ab9e10d3be96f51403b0293622d782422a
log selinux audit messages boolean (true or false, default true)
selection for logging destinations:
ro.logd.auditd - turn on logd.auditd to pick up violations.
ro.logd.auditd.dmesg - to the kernel log.
ro.logd.auditd.main - to the "main" log buffer.
ro.logd.auditd.events - to the "events" log buffer.
We used to also read logd.auditd.dmesg and persist.logd.auditd.dmesg
which do not get refreshed when /data mounts internally. This is a
confusing state as these properties will be read after a logd crash
and restart, adjusting the behavior of the logger. Same can be said
for logd.auditd as well. Drop reading these other parameters.
Test: manual set r/o parameters, stop/start logd to confirm behavior
Bug: 33969000
Bug: 27878170
Change-Id: I1a6bb4a903074c9aa7b227cf583a0094d49cbefd
Until the socket ages out, it sticks around and gets reused in
subsequent tests affecting the outcome of those tests. We opt
to run logd.timeout in a forked and isolated process to keep
these conditions from interfering.
Adjusted benchmark execute to only run the tests we are
interested in to improve the time it takes to run.
Commented some areas of code to make them easier to maintain.
Test: gTest logd-unit-tests success
Bug: 33962045
Change-Id: Ic1b98bc4a2d7e8927f1a87628e3bcc368c9cf8ce
Caused +/- field data to land under the Pruned column
This reverts commit 0adcc3e3e8.
Test: manual
Bug: 30118730
Change-Id: Ic75ce3a90baded19f3efc0cc77474fe5d9a8accd
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
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
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
To support upcoming disk usage calculation optimizations, this change
creates a new GID for each app that will be used to mark its cached
data. We're allocating these unique GIDs so that we can use
quotactl() to track cached data on a per-app basis.
This change also tightens up the implementation of both the cache
and shared GID calculation to ensure that they stay inside the valid
ranges, and includes tests to verify.
Test: builds, boots, tests pass
Bug: 27948817
Change-Id: Ie4377e5aae267f2da39a165888139228995987cb
Move existing fast<str*cmp> templates for general use, pulled from
the implementation used in logd that dealt with speed through cache
locality and subroutine call mitigation. Rename to fastcmp.
Test: logd-benchmarks and based on manual profiling from the past
Bug: 31456426
Change-Id: Ic62f4a437fc3e06ffdeaae73a6f34e197957a6b0
NULL represents system default. In the future, NULL could represent
static and dynamic tags, which can come from multiple files based on
implementation details in the liblog library.
Test: gTest logd-unit-tests & liblog-unit-tests
Bug: 31456426
Change-Id: I0e3d296de81ca299ae63d7b83781639ee67ec298
Debugging aid. Allows us to run:
$ cat -n '<STUFF>\0EXIT\0' | nc -U /dev/socket/logd
and the pipeline will exit once done. Without the EXIT command
we will have to <CTRL+C> out to terminate the pipeline. This is
necessary since Android's netcat command does not support the -q
feature, and having the EXIT command is faster and cleaner anyways.
Test: manual as noted above.
Bug: 31456426
Change-Id: I65333358188db85e2eb1bb6a14deed1565826ac4
files.[h|cpp] is bound to be abused with junk, replace with
android_get_control_file.[h|cpp]. Plus some sundry cleanup.
Test: gTest libcutils-tests, logd-unit-tests, liblog-unit-tests,
logcat-unit-tests and init_tests
Bug: 32450474
Change-Id: Ibd4a7aa4624ea19a43d1f98a3c71ac37805d36b5
Mark Salyzyn