platform_system_core/logd
Tom Cherry be0f4abfaf logd: Allow setDropped() to be called on already dropped messages
rprichard@ pointed out a bug where LogBufferElement::setDropped()
reallocates mMsg to the size of mMsgLen in the case where getTag() !=
0.  However, mMsgLen is in a union with mDroppedCount and
mDroppedCount is the value used when a message is already dropped.
Therefore, it's possible that logd uses the wrong value and allocates
much more memory than intended.

We do call setDropped() on elements that have already been dropped in
LogBufferElementLast::coalesce(), so this is not a superfluous issue.

To simplify this even more, this code puts an mTag in a union with
mMsg, such that if mDropped is true, there will never be an allocated
message; mTag will be directly referred to instead.  This also reduces
the number of allocations needed very slightly.

Test: logd/liblog/logcat unit tests.
Change-Id: Ia1bfba076439fe31c745a243283d41902bca45ac
2019-08-23 14:58:14 -07:00
..
tests Avoid get same timestamps in log testcase 2019-06-19 16:38:33 +08:00
.clang-format logd: use .clang-format-4 like the rest of system/core 2019-01-16 15:20:15 -08:00
Android.bp Revert "Modularize logd." 2019-06-28 14:16:13 -07:00
auditctl.cpp introduce auditctl and use it to configure SELinux throttling 2019-04-09 13:19:08 -07:00
CommandListener.cpp [logd] Modernize codebase by replacing NULL with nullptr 2018-07-13 17:50:55 -07:00
CommandListener.h
event.logtags
FlushCommand.cpp logd: rework logic for LogTimeEntry 2018-10-12 18:28:59 -07:00
FlushCommand.h logd: rework logic for LogTimeEntry 2018-10-12 18:28:59 -07:00
libaudit.c introduce auditctl and use it to configure SELinux throttling 2019-04-09 13:19:08 -07:00
libaudit.h introduce auditctl and use it to configure SELinux throttling 2019-04-09 13:19:08 -07:00
LogAudit.cpp logd: remove SELinux dup handling 2019-04-24 13:32:58 -07:00
LogAudit.h Logd: include app package name in selinux metadata 2018-05-03 22:40:18 -07:00
LogBuffer.cpp Fix clang-tidy warnings in log_time.h 2019-01-17 14:45:19 +09:00
LogBuffer.h Revert "Modularize logd." 2019-06-28 14:16:13 -07:00
LogBufferElement.cpp logd: Allow setDropped() to be called on already dropped messages 2019-08-23 14:58:14 -07:00
LogBufferElement.h logd: Allow setDropped() to be called on already dropped messages 2019-08-23 14:58:14 -07:00
LogCommand.cpp [logd] Modernize codebase by replacing NULL with nullptr 2018-07-13 17:50:55 -07:00
LogCommand.h
logd.rc logd: don't drop user/groups/capabilities/priority in drop_privs() 2019-06-07 15:52:27 +00:00
LogKlog.cpp Fix clang-tidy warnings in log_time.h 2019-01-17 14:45:19 +09:00
LogKlog.h Fix clang-tidy warnings in log_time.h 2019-01-17 14:45:19 +09:00
LogListener.cpp Revert "Modularize logd." 2019-06-28 14:16:13 -07:00
LogListener.h Revert "Modularize logd." 2019-06-28 14:16:13 -07:00
LogReader.cpp logd: clear timeout if no start time is given 2018-10-19 13:51:35 -07:00
LogReader.h Remove execute bit for source files 2018-07-13 17:45:39 -07:00
LogStatistics.cpp Revert "logd: validate and fill in socket credentials" 2019-06-28 14:16:00 -07:00
LogStatistics.h Revert "logd: validate and fill in socket credentials" 2019-06-28 14:16:00 -07:00
logtagd.rc
LogTags.cpp Remove __android_log_event_list and the reader aspect of android_log_event_list 2019-01-16 15:35:20 -08:00
LogTags.h [logd] Modernize codebase by replacing NULL with nullptr 2018-07-13 17:50:55 -07:00
LogTimes.cpp logd: fix memory leak due to slow reader 2018-11-12 10:24:15 -08:00
LogTimes.h logd: improve logd prune 2018-12-20 23:35:54 +08:00
LogUtils.h Revert "logd: validate and fill in socket credentials" 2019-06-28 14:16:00 -07:00
LogWhiteBlackList.cpp [logd] Modernize codebase by replacing NULL with nullptr 2018-07-13 17:50:55 -07:00
LogWhiteBlackList.h
main.cpp logd: handle uidToName() directly 2019-06-07 11:39:24 -07:00
OWNERS Add OWNERS. 2017-12-07 13:30:03 -08:00
README.auditd
README.property Logcatd: Add new properties control logcat file size and file count. 2019-05-24 07:23:22 +00:00

The properties that logd and friends react to are:

name                       type default  description
ro.logd.auditd             bool   true   Enable selinux audit daemon
ro.logd.auditd.dmesg       bool   true   selinux audit messages sent to dmesg.
ro.logd.auditd.main        bool   true   selinux audit messages sent to main.
ro.logd.auditd.events      bool   true   selinux audit messages sent to events.
persist.logd.security      bool   false  Enable security buffer.
ro.device_owner            bool   false  Override persist.logd.security to false
ro.logd.kernel             bool+ svelte+ Enable klogd daemon
ro.logd.statistics         bool+ svelte+ Enable logcat -S statistics.
ro.debuggable              number        if not "1", logd.statistics &
                                         ro.logd.kernel default false.
logd.logpersistd.enable    bool   auto   Safe to start logpersist daemon service
logd.logpersistd          string persist Enable logpersist daemon, "logcatd"
                                         turns on logcat -f in logd context.
					 Responds to logcatd, clear and stop.
logd.logpersistd.buffer          persist logpersistd buffers to collect
logd.logpersistd.size            persist logpersistd size in MB
logd.logpersistd.rotate_kbytes   	 persist logpersistd outout file size in KB.
persist.logd.logpersistd   string        Enable logpersist daemon, "logcatd"
                                         turns on logcat -f in logd context.
persist.logd.logpersistd.buffer    all   logpersistd buffers to collect
persist.logd.logpersistd.size      256   logpersistd size in MB
persist.logd.logpersistd.count     256   sets max number of rotated logs to <count>.
persist.logd.logpersistd.rotate_kbytes   1024  logpersistd output file size in KB
persist.logd.size          number  ro    Global default size of the buffer for
                                         all log ids at initial startup, at
                                         runtime use: logcat -b all -G <value>
ro.logd.size               number svelte default for persist.logd.size. Larger
                                         platform default sizes than 256KB are
                                         known to not scale well under log spam
                                         pressure. Address the spam first,
                                         resist increasing the log buffer.
persist.logd.size.<buffer> number  ro    Size of the buffer for <buffer> log
ro.logd.size.<buffer>      number svelte default for persist.logd.size.<buffer>
ro.config.low_ram          bool   false  if true, logd.statistics,
                                         ro.logd.kernel default false,
                                         logd.size 64K instead of 256K.
persist.logd.filter        string        Pruning filter to optimize content.
                                         At runtime use: logcat -P "<string>"
ro.logd.filter       string "~! ~1000/!" default for persist.logd.filter.
                                         This default means to prune the
                                         oldest entries of chattiest UID, and
                                         the chattiest PID of system
                                         (1000, or AID_SYSTEM).
persist.logd.timestamp     string  ro    The recording timestamp source.
                                         "m[onotonic]" is the only supported
                                         key character, otherwise realtime.
ro.logd.timestamp        string realtime default for persist.logd.timestamp
log.tag                   string persist The global logging level, VERBOSE,
                                         DEBUG, INFO, WARN, ERROR, ASSERT or
                                         SILENT. Only the first character is
                                         the key character.
persist.log.tag            string build  default for log.tag
log.tag.<tag>             string persist The <tag> specific logging level.
persist.log.tag.<tag>      string build  default for log.tag.<tag>

NB:
- auto - managed by /init
- bool+ - "true", "false" and comma separated list of "eng" (forced false if
  ro.debuggable is not "1") or "svelte" (forced false if ro.config.low_ram is
  true).
- svelte - see ro.config.low_ram for details.
- svelte+ - see ro.config.low_ram and ro.debuggable for details.
- ro - <base property> temporary override, ro.<base property> platform default.
- persist - <base property> override, persist.<base property> platform default.
- build - VERBOSE for native, DEBUG for jvm isLoggable, or developer option.
- number - support multipliers (K or M) for convenience. Range is limited
  to between 64K and 256M for log buffer sizes. Individual log buffer ids
  such as main, system, ... override global default.
- Pruning filter is of form of a space-separated list of [~][UID][/PID]
  references, where '~' prefix means to blacklist otherwise whitelist. For
  blacklisting, UID or PID may be a '!' to instead reference the chattiest
  client, with the restriction that the PID must be in the UID group 1000
  (system or AID_SYSTEM).