Commit graph

11 commits

Author SHA1 Message Date
Mark Salyzyn
d69e801fe8 liblog: Harden log_id check.
Logd currently checks against LOG_ID_MAX and LOG_ID_KERNEL to
determine if a given log_id is available.  liblog uses only
LOG_ID_KERNEL.  While this matches with the comments in log/log_id.h
to always keep LOG_ID_KERNEL at the end it does not match with other
checks that logd makes, causing inconsistent behavior.  This
inconsistency is noticable on devices that errantly rewrite
LOG_ID_MAX to not equal LOG_ID_KERNEL + 1.  For log buffers with
id's greater than LOG_ID_KERNEL, liblog reports that logd is
unavailable while logd would accept the request.

The guideline is to not use buffer ids above LOG_ID_KERNEL.
This hardening change prevents an inconsistency that results if these
guidelines are not followed.  Partners are urged instead to increase
LOG_ID_KERNEL locally to match their LOG_ID_MAX - 1 when they add new
local log buffers in their private builds.

Signed-off-by: Evan Ralston <eralston@amazon.com>
Signed-off-by: Mark Salyzyn <salyzyn@google.com>
Test: compiles. no functional change
Change-Id: Icd4b12ac79c1e5cd1d8a32f67a9795797580aad5
2017-02-21 22:29:19 +00:00
Mark Salyzyn
65e1e6284c liblog: retry -ENOTCONN | -ECONNREFUSED | -ENOENT indefinitely
Deal with recovering after transitory failures surrounding logd
crash or recovery.  Improve the chances that the logging functions
can work in a signal handler, not officially supported, but making
sure logging is not blamed for system lockups when misused.

Reorder gTests so that setuid(AID_SYSTEM) is performed after
liblog.enoent test, and that this occurs after other tests that
like to see buffers with content in them as we stop logd.

Test: gTest liblog-unit-tests --gtest_filter=liblog.enoent
Bug: 33755074
Change-Id: I66f88599534614b7b61da6b2ae5fe099ebaced3a
2017-01-09 15:51:09 +00:00
Mark Salyzyn
cfd5b080af system/core: preparation to pull back interfaces from android/log.h
Point to log/log.h where necessary, define LOG_TAG where necessary.
Accept that private/android_logger.h is suitable replacement for
log/logger.h and android/log.h.

Correct liblog/README

Effectively a cleanup and controlled select revert of
'system/core: drop or replace log/logger.h' and
'system/core: Replace log/log.h with android/log.h'.

Test: compile
Bug: 30465923
Change-Id: Ic2ad157bad6f5efe2c6af293a73bb753300b17a2
2016-10-20 08:11:39 -07:00
Mark Salyzyn
db8a266aea liblog: __android_log_pmsg_file_write() cleanup
__android_log_pmsg_file_write() will open /dev/pmsg0 if not
already, and will close it if we opened it.

Added atomic access to the android_log_context as insurance.

Fortify and correct pmsg tests.

Test: gTest liblog-unit-tests --gtest_filter=liblog.__android_log_pmsg_file_*
Bug: 31958686
Change-Id: I2cf6f971b6968938f471fda67367efe20dae3004
2016-10-13 21:43:42 +00:00
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
6584d0a35a liblog: Replace log/log.h with android/log.h
Move all liblog related content into android/log.h, and make
log/log.h points to android/log.h.

Test: Compile
Bug: 26552300
Bug: 31289077
Change-Id: I858e0ebe047b86f2a8530a99bc9c380d3d58edbb
2016-09-30 12:47:05 -07:00
Mark Salyzyn
a166708d15 liblog: logcat: Replace log/logd.h with log/log.h
Should use log/log.h and in some cases android/log.h instead. Can
not remove file because still in use by partners, so log/logd.h
points to log/log.h.

Test: Compile
Bug: 26552300
Bug: 31289077
Change-Id: I3580d46154617abb7231027a44f4ab9ee023febf
2016-09-30 12:47:05 -07:00
Mark Salyzyn
004cd3c55d liblog: logd: logcat: deprecate log/log_read.h
Always used in combination with log/logger.h except in log_time.cpp,
and not used externally.  As a result liblog has to support stl, a
small price to pay since goal is to convert liblog to C++ internally.

Test: compile
Bug: 31456426
Bug: 26552300
Bug: 31289077
Change-Id: I72828ec807d0a2c8e40bbdebd7a69f147a7ca5a9
2016-09-30 12:47:05 -07:00
Elliott Hughes
5ba3003467 liblog: use SOCK_NONBLOCK directly.
No need to have a race, even if it doesn't matter.

Change-Id: Ia79f2633643bc63618de0fd85953b3226415484f
2016-08-22 16:19:58 -07:00
Mark Salyzyn
c33103c440 liblog: gate write on log id available
- Secure LOG_ID_KERNEL in writer
- Secure LOG_ID_SECURITY in reader and writer
- if writer transport says not available, do not write to that log id

Bug: 27566046
Bug: 27896341
Change-Id: If63a78a56fb94adfbf9979454c4cadb81af45c19
2016-03-29 12:29:04 -07:00
Mark Salyzyn
018a96d03f liblog: split out transports into separate files
Create config_logger, logger and logger_read to house the log
interfaces. Add fake_logger, logd_logger and pmsg_logger to
house the write and read transports. Allows for an easier and
direct path to add new transports to the library.

SideEffects: None, logger benchmark performance unaffected

Bug: 27176738
Bug: 27405083
Change-Id: I01b38637334a5242905c8c89f6ab0a92e2540008
2016-03-22 13:01:15 -07:00