Commit Graph

163 Commits

Author SHA1 Message Date
Suren Baghdasaryan a93503e3d7 lmkd: Support process types when registering a process
Add an optional process type field into lmkd registration protocol so that
applications can be distinguished from services.

Bug: 129011369
Test: boot and verify native service registration
Change-Id: Ie610b5d07cbe247a55ab31bc079ee5c5923bea11
Signed-off-by: Suren Baghdasaryan <surenb@google.com>
2019-11-07 18:19:15 +00:00
Suren Baghdasaryan f2cbefd298 lmkd: Prepare lmkd to support connection from init process
In order to register native services init needs ability to communicate with
lmkd. Make liblmkd_utils library available in recovery mode so that init
can link to it and add a data socket in lmkd to support additional
connection from init. Ensure SOCK_CLOEXEC type for lmkd socket to prevent
init children from inheriting it.

Bug: 129011369
Test: boot and verify native service registration
Change-Id: Iaa4f59282fb10f838f6811571e97d55754b1bd41
Signed-off-by: Suren Baghdasaryan <surenb@google.com>
2019-11-07 18:18:46 +00:00
Suren Baghdasaryan 945658abc4 lmkd: Restrict process record modifications to the client that created it
Associate each registered process with the PID of the lmkd client that
registered it to prevent one client from updating records of another
client.

Bug: 129011369
Test: boot and verify native service registration
Change-Id: Id8ca7bb6314df225d04da6469b523d2cdc237eaa
Signed-off-by: Suren Baghdasaryan <surenb@google.com>
2019-11-07 18:15:04 +00:00
Greg Kaiser 5e80ed5ff6 lmkd: Remove unnecessary conditional
We want poll_handler to be handler_info, so it's more efficient
to just unconditionally assign it.

Test: TreeHugger
Change-Id: I55b5164da1817ef77b5d455eb618f9a2471afc5c
2019-10-10 06:52:23 -07:00
Suren Baghdasaryan a10157c0d3 lmkd: Track processes using pidfds
lmkd uses PIDs to track processes, however occasionally a PID of a process
might be reused without lmkd detecting that. This can happen if originally
registered process crashes, PID numbers wrap around and the same PID gets
reused for a different process. In this situation lmkd might kill a wrong
process. To prevent this issue from occurring lmkd will track processes
using their pidfd. During process registration lmkd calls sys_pidfd_open
and stores returned pidfd with the process record. Returned pidfd will not
be reused until lmkd closes it which happens only after the process is
unregistered. This way lmkd ensures that process identification is unique
and can't be reused.

Bug: 135608568
Test: lmkd_unit_test with and without pidfd kernel support
Change-Id: Ida10ea13905c250e47f792cdd6bd2e65aeaa3709
Signed-off-by: Suren Baghdasaryan <surenb@google.com>
2019-10-08 18:15:34 -07:00
Suren Baghdasaryan bc99e1b702 lmkd: Add support for process death notifications
With pidfd polling support lmkd can detect process death without periodic
polling. Implement mechanism to detect kernel pidfd support using
pidfd_open syscall existence as an indicator. Implement the logic to use
pidfd to wait for process death.

Bug: 135608568
Test: lmkd_unit_test with and without pidfd kernel support
Change-Id: Ic6db7e50893534467f5130a7f998b66fb4451272
Signed-off-by: Suren Baghdasaryan <surenb@google.com>
2019-10-08 18:15:12 -07:00
Suren Baghdasaryan 632f1c5365 lmkd: Fix string null termination in proc_get_size and proc_get_name
Fix string null termination and cleanup proc_get_size and proc_get_name
functions.

Bug: 74119935
Test: lmkd_unit_test
Change-Id: Ied176b8d347b672b91866ac59a813d4ff349930a
Signed-off-by: Suren Baghdasaryan <surenb@google.com>
2019-10-07 12:50:38 -07:00
George Burgess IV 3b36b904d6 lmkd: fix an uninit value bug
Caught by clang's static analyzer:
system/core/lmkd/lmkd.c:930:9: warning: 1st function call argument is an
uninitialized value [clang-analyzer-core.CallAndMessage]

Bug: None
Test: TreeHugger
Change-Id: I9dc8e97d6aa22ea977fa06553d957a31a9df8819
2019-10-02 19:55:41 +00:00
Treehugger Robot 3f5cb4c0d8 Merge "lmkd: Avoid potential out of buffer write" 2019-10-02 16:29:27 +00:00
Greg Kaiser 259984f730 lmkd: Avoid potential out of buffer write
Our buffer needs enough space for the '\0' terminator character
as well.

Test: TreeHugger
Change-Id: Ib85d08dacf87b93d5f8b35b033ca0ec478868e66
2019-10-02 07:07:32 -07:00
Suren Baghdasaryan 12cacaedc0 lmkd: Change meminfo_log into killinfo_log and log additional fields
meminfo_log is used to log the state of the memory at the time of a kill.
Instead of reporting kill information and meminfo separately let's combine
them into one killinfo_log report. While normal logs can be trimmed by
chatty, meminfo_log uses a separate log context which gives it a better
chance of survival. As a result we will have all the information relevant
to a kill in one report which has higher chance of surviving chatty.

Bug: 74119935
Test: lmkd_unit_test
Change-Id: I83a9c12d538e1fb107721b04fdafc3c6c0d83b60
Signed-off-by: Suren Baghdasaryan <surenb@google.com>
2019-10-01 23:26:56 +00:00
Suren Baghdasaryan 8b016be930 lmkd: Isolate statslog related code from lmkd code
Move statsd related code out of lmkd.c to minimize ifdefs sprinkled around
the code and make it more maintainable.

Bug: 74119935
Test: lmkd_unit_test
Change-Id: Ib22f90fd380b9a31e09ab18ef16787bc07415ddf
Signed-off-by: Suren Baghdasaryan <surenb@google.com>
2019-10-01 16:36:08 +00:00
Suren Baghdasaryan c2e05b6ffa lmkd: Fix kill failure handling
When lmkd fails to kill it should log the error, remove the process record
and exit immediately.

Bug: 74119935
Test: lmkd_unit_test
Change-Id: I26b0fd873eeed325f7dd56097ec31abc0d63f3a1
Signed-off-by: Suren Baghdasaryan <surenb@google.com>
2019-10-01 16:35:49 +00:00
Suren Baghdasaryan 970a26aeb7 lmkd: Prevent killing foreground processes due to thrashing
Page cache thrashing affects device performance and by killing a process
we try to stop it. However if the thrashing application is the one which
user is interacting with then lmkd should not kill it even though it might
affect device performance.

Bug: 141286980
Test: SequentialRWTest CTS test
Change-Id: If86c0e7e8ad9adf1816659562151ca083eaa65c4
Signed-off-by: Suren Baghdasaryan <surenb@google.com>
2019-09-30 16:54:55 +00:00
Suren Baghdasaryan 89454e620c lmkd: Add optional kill reason description into kill reports
Allow kill report to be appended with the explanation of the reasons
killing has been done. This would help identify kill reasons while
troubleshooting lmkd kills.

Change-Id: Ie5dd7a44e51d04c43c2492be8c1bc964d1b03555
Signed-off-by: Suren Baghdasaryan <surenb@google.com>
2019-09-30 16:54:39 +00:00
Suren Baghdasaryan 2f88e15c3a lmkd: Enable new kill strategy, add and adjust required system properties
Enable new kill strategy when PSI mode is used in combination with
ro.lmk.use_minfree_levels=false. Adjust ro.lmk.swap_free_low_percentage,
introduce ro.lmk.psi_partial_stall_ms and ro.lmk.psi_complete_stall_ms
system properties to support two levels of PSI events measuring partial
and complete stalls. Add ro.lmk.use_new_strategy system property to switch
to the old strategy if necessary.

Bug: 132642304
Test: lmkd_unit_test, ACT memory pressure tests
Change-Id: I6f1b65e19dbe9b58c862e5e4255270c82f0afb9a
Signed-off-by: Suren Baghdasaryan <surenb@google.com>
2019-09-30 16:54:27 +00:00
Suren Baghdasaryan 81c75b2a33 lmkd: Use aggregate zone watermarks as low memory threshold
Parsing /proc/zoneinfo is expensive and zone watermarks normally do no
change often. Instead of checking free memory per each zone we aggregate
zone watermarks and compare them with MemFree from meminfo as an
approximation of memory being under a given watermark.
zoneinfo parsing is rate limited to once per minute to detect a possible
change of the memory margins from userspace.

Bug: 132642304
Test: lmkd_unit_test, ACT memory pressure tests
Change-Id: If4a8154c004e24324e6de44359de416766139df6
Signed-off-by: Suren Baghdasaryan <surenb@google.com>
2019-09-30 16:54:16 +00:00
Suren Baghdasaryan af2be4c55d lmkd: Introduce kill strategy based on zone watermarks, swap and thrashing
Add new kill strategy which makes kill decisions based on which zone
watermark is breached, how much free swap space is still available and
what percentage of the file-backed page cache has been refaulted. This mode
is designed to be used only with PSI signals. It kills unconditionally when
a critical pressure event is received, therefore PSI stall for that event
should be set to a value representing a truly non-responding system
(currently set to 700ms out of 1sec spent in complete stall). New event
handler also controls polling interval based on current memory conditions.

Bug: 132642304
Test: lmkd_unit_test, ACT memory pressure tests
Change-Id: Ia213ef2bb06b245d651ebf2d813e944b4ae7565f
Signed-off-by: Suren Baghdasaryan <surenb@google.com>
2019-09-30 16:54:05 +00:00
Suren Baghdasaryan e12a067ee0 lmkd: Support variable polling intervals set by event handlers
After a memory event happens event handler can assess current memory
condition and decide if and when lmkd should re-check memory metrics in
order to respond to changing memory conditions. Change the event handler
interface to allow control over polling period and ability to start/extend
polling session.

Bug: 132642304
Test: lmkd_unit_test
Change-Id: Ia74011e943140b6cffbf452ff8e1744b7336eacf
Signed-off-by: Suren Baghdasaryan <surenb@google.com>
2019-09-30 16:53:46 +00:00
Suren Baghdasaryan 92d0eec2d2 lmkd: Change zoneinfo parsing to retrieve zone watermarks
/proc/zoneinfo contains per-node data and each node contains per-zone
section for each zone. Current parser does not recognize this hierarchy
and useful per-zone information like zone watermarks cannot be retrieved.
Change the parser to parse zoneinfo into a hierarchical structure. New
parser also handles up to 2 nodes and can be easily extended to handle
more if needed by changing MAX_NR_NODES.

Bug: 132642304
Test: lmkd_unit_test
Change-Id: I9306289ea6d30d78a261c5d5c29f4f6ea167807d
Signed-off-by: Suren Baghdasaryan <surenb@google.com>
2019-09-30 16:53:34 +00:00
Suren Baghdasaryan 03cb836735 lmkd: Change procfs read routine to handle files larger than 1 page in size
Files like /proc/zoneinfo or /proc/<pid>/status can be larger than 4KB
page size. Change reread_file routine to resize read buffer whenever
it is not big enough to read the entire file. Start with 1-page buffer
and double its size until it's big enough to read the entire file.
Read /proc/zoneinfo during initialization to initialize the buffer
to a big enough size and avoid re-allocations when under memory pressure.

Bug: 137010962
Test: lmkd_unit_test
Change-Id: If9a5b0d27c2f4de9063f0fd0f36f908ece87dcce
Signed-off-by: Suren Baghdasaryan <surenb@google.com>
2019-09-30 16:53:18 +00:00
Suren Baghdasaryan 6dce58d561 lmkd: Fix killed process name reporting
Fix termination of killed process name in proc_get_name function. While at
it also fix the coding style in the function.

Test: lmkd_unit_test
Bug: 141780598
Change-Id: I3f99b3e37b9a9d0750ece94f08f0b50ac839dacb
Signed-off-by: Suren Baghdasaryan <surenb@google.com>
2019-09-30 16:02:35 +00:00
Jim Blackler 90853b6203 lmkd: Maintain pid to taskname mapping to amend kill reports.
Required because the kernel cannot always get the taskname safely at
the time the process is killed (due to competition for mm->mmap_sem).

Test: manually
Bug: 130017100
Signed-off-by: Jim Blackler <jimblackler@google.com>
Change-Id: I27a2c3340da321570f0832d58fe9e79ca031620b
2019-09-26 16:27:03 -07:00
Suren Baghdasaryan fe8419215a Merge "lmkd: Prevent non-main threads being registered or killed by lmkd"
am: e0b729d214

Change-Id: I11738b8c2c7acfa4947976e8b12ac9b94e7fc8ac
2019-07-12 13:39:47 -07:00
Suren Baghdasaryan 3ee11d4392 lmkd: Prevent non-main threads being registered or killed by lmkd
Only thread group leaders should be registered with lmkd. Add a check to
ignore any non-leader TIDs and generate an error if such condition is
detected. Run the same check before killing a process to detect cases of
non-leader TIDs being used to kill a process. This might happen if PIDs
overflow and previously registered PID gets reused for a non-leader
thread in the following scenario:

1. pid X is a thread group leader and is registered with lmkd
2. pid X dies without lmkd knowing it and pid gets recycled
3. process Y creates a thread with tid X
4. lmkd kills pid X which results in process Y being killed

Bug: 136408020
Test: lmkd_unit_test
Change-Id: I46c5a0b273f2b72cefc20ec59b80b4393f2a1a37
Signed-off-by: Suren Baghdasaryan <surenb@google.com>
2019-07-12 15:11:54 +00:00
Tim Murray b99e0df08b Merge "lmkd: use ALOGE for logging kills" into qt-dev
am: cc18faf4d6

Change-Id: I51e496d8e5ffa102585dbfaabf8878e9d6bd6c71
2019-05-30 15:31:52 -07:00
Tim Murray 406a184c22 lmkd: use ALOGE for logging kills
Test: boots, works
Bug: 133761317
Signed-off-by: Tim Murray <timmurray@google.com>
Exempt-From-Owner-Approval: trivial change

Change-Id: I1a4a3741694078eec124f1f560ea68e78754bca6
2019-05-30 22:10:36 +00:00
Jim Blackler 700b7191e1 Allow memory metrics on devices that use kernel LMK
Bug: 130017100
Test: Tested manually
Change-Id: I37f6edb71decc1260bd521595842508926fa86aa
2019-04-29 11:02:51 +00:00
Suren Baghdasaryan 881a544aec lmkd: set PSI_POLL_PERIOD to 10ms
Occasionally we see cases when 40ms polling is still too conservative.
Change to 10ms polling period. Since the polling happens only after PSI
signal and continues for 1sec this should not affect system performance.

Test: lmkd_unit_test
Bug: 129358844

Change-Id: Ib759b865b2104be23741fc0eacaa541e22d50dde
Signed-off-by: Suren Baghdasaryan <surenb@google.com>
2019-03-27 02:10:10 +00:00
Tim Murray 0fca3629ca lmkd: set PSI_POLL_PERIOD to 40ms
200ms was too lenient when under severe memory pressure.

Test: boots, works
Bug: 127765309

Change-Id: I8e047de6318574a107720c56473ed0f25582e182
Signed-off-by: Tim Murray <timmurray@google.com>
2019-03-13 10:13:19 -07:00
Suren Baghdasaryan e1228bd545 Add min_score_adj into LmkKillOccurred event
Log min_score_adj when lmkd kills a process to determine the oom_score
levels that lmkd considers during the kill.

Bug: 123024834
Change-Id: I986ae8f2808199b1654bc8d2a32dd88046c79aa3
Signed-off-by: Suren Baghdasaryan <surenb@google.com>
2019-03-05 09:51:06 +00:00
Juju Sung 94cd15bf22 lmkd: Remove redundant free swap and free memory check
lmkd can't kill processes because it has compare the size between free swap and free memory. Free swap is often larger than the free memory when system is under low memory with less swap-backed or swappable pages and finally leads to I/O thrashing.

Test: TreeHugger
Bug: 124727769
Change-Id: Ia2848859aa97a24bd13c704acee4b86cd2d3f647
2019-02-19 17:04:07 +00:00
Greg Kaiser 584f3fd35f lmdk: Remove redundant 'if' check
We already know that "polling" must be non-zero at this point,
because it hasn't been modified since our check on line 1960.
So we remove this check for code clarity.

Test: TreeHugger
Change-Id: I069d9fd0eef70748a5333733dd0518d1ac8021b7
2019-02-04 08:50:10 -08:00
Suren Baghdasaryan 55e3150842 lmkd: Add support for psi monitors
With new psi monitor support in the kernel lmkd can use it to register
custom pressure levels. Add lmkd support for psi monitors when they are
provided by the kernel and use them by default. When kernel does not
support psi lmkd will fall back to vmpressure usage.
Add ability to poll memory status after the initial psi event is triggered
because kernel throttles psi memory pressure events to one per PSI tracking
window (currently set to 1sec). Current implementation polls every 200ms
for 1sec duration after the initial event is triggered.
If ro.lmk.use_psi is set to false psi logic will be disabled even when psi
is supported in kernel.

Bug: 111308141
Test: lmkd_unit_test
Change-Id: I685774b176f393bab7412161773f5c9af51e0163
Signed-off-by: Suren Baghdasaryan <surenb@google.com>
2019-02-01 18:40:32 +00:00
Wei Wang f1ee2e1505 lmkd: bump process priority and set to FOREGROUND group before kill
This should help speed up reclaim memory.

Bug: 118468011
Test: run mem-pressure with lmkd
Change-Id: Iae7aa35483eb0e8bbeccaa425559c6021c845ee1
2019-01-15 14:50:19 -08:00
Jim Blackler f52bcb9c8f Add start time to LmkKillOccurred
This is to measure an application's behavior with respect to being LMKed
(the longer an app lives before being LMKed, the better).

Bug: 119854389
Test: Manual
Change-Id: I4ef6433391c8758626334731d2b5de038e4468ae
Merged-In: I4ef6433391c8758626334731d2b5de038e4468ae
(cherry picked from I4ef6433391c8758626334731d2b5de038e4468ae)
2019-01-04 11:36:54 +00:00
Suren Baghdasaryan 85c31b57c4 lmkd: Cleanup unused code for killing processes in bulk
find_and_kill_processes() does not kill multiple processes at a time
anymore. Remove support for bulk process killing.

Change-Id: Id09132a9cebe44589a1a3ebcbff800a16fa56557
Signed-off-by: Suren Baghdasaryan <surenb@google.com>
2018-10-29 16:20:50 +00:00
Tim Murray a79ec0f5bf lmkd: retune rate at which processes are killed
Kill a single process at a time and try to wait up to 100ms for
that process to reclaim memory before triggering another kill.

Test: boots, works
bug: 116877958
Change-Id: I6775d0534b3e3728c04389d3eae1a00e3cbf9f27
2018-10-29 16:20:29 +00:00
Suren Baghdasaryan a7394ea37f lmkd: Add command to get number of kills
Intrduce LMK_GETKILLCNT command for ActivityManager to get the number of
kills from lmkd.

Bug: 117126077
Test: used lmkd_unit_test to verify correct reporting
Change-Id: I09c720a7176b4df95efc544177cd2694f8d791be
Signed-off-by: Suren Baghdasaryan <surenb@google.com>
2018-10-24 17:18:32 +00:00
Srinivas Paladugu a453f0b9ee lmkd: increase the soft limit for keyboard
lmkd sets the soft limit parameters for Go devices.
The limit for apps in the perceptible group is set to 16M.
However this limit is not sufficient for the keyboard app to
prevent pages from being re-claimed quickly. The mem usage of
the keyboard app is around 55M most cases with some occasional
spikes to 70-80M. Increasing the limit to 64M improves the warm
startup latency for keyboard. It is still lower than the limits
set for foreground and visible apps.

Test: Go device (1G)
Bug: 117517805
Merged-In: Id50e49327cfd76126e41ef6503971845f29196af
Change-Id: Id50e49327cfd76126e41ef6503971845f29196af
2018-10-16 18:58:01 +00:00
Suren Baghdasaryan 83df0088a3 lmkd: Implement pid purge command to clear old pids when zygote restarts
lmkd keeps a list of pids registered by ActivityManager, however on rare
occasions when framework restarts and lmkd survives that list has to be
purged. Implement a command that can be used to clear the pid list.

Bug: 116801366
Test: locally by killing zygote process
Change-Id: I71d6012f86bb83a73edd5b687e05a0848e0569b1
Signed-off-by: Suren Baghdasaryan <surenb@google.com>
2018-10-15 16:22:17 +00:00
Suren Baghdasaryan 8b00c6d79a lmkd: Fix an invalid access to a pointer after it's freed
pid_remove() frees a structure representing registered process and the
pointer can't be used anymore. This change fixes an instance when pointer
was used after it was freed. pid_remove() is moved to the end of the
function and comments are added to prevent similar situation in the future.

Bug: 117625315

Change-Id: I6a922952a31232497b3f9caf87d5a21bd402db94
Signed-off-by: Suren Baghdasaryan <surenb@google.com>
2018-10-12 11:28:33 -07:00
Rajeev Kumar 2534d2e54d Read memory stats from /proc/pid/stat file.
(cherry pick from commit 0301683e49ab255769b15469487feaab3466167a)
Bug: 117333340
Test: Manual testing using alloc-stress tool
Merged-In: Ie555933aafa6a6b7aa1dbf5518ebe804376e0afd
Change-Id: Ie555933aafa6a6b7aa1dbf5518ebe804376e0afd
2018-10-10 22:23:25 +00:00
Suren Baghdasaryan 53be36e6d8 lmkd: rate-limit and cleanup failed kill reports
Excessive number of failed kill reports when lmkd can't find an eligible
process to kill or frees not enough memory pollutes logs and bugreports.
Cleanup kill reports to remove duplicate information and rate limit failed
kill attempts at 1 report per sec. The number of suppressed failed kills
will be reported in the next lmkd report.

Bug: 113864581
Test: Verified using lmkd_unit_test
Change-Id: I67fa1fec97613f136c7582115edcbc56b1503c9c
Signed-off-by: Suren Baghdasaryan <surenb@google.com>
2018-09-06 01:59:49 +00:00
Suren Baghdasaryan 1ed0db1a19 lmkd: Introduce system property to get minfree and oom_adj levels
Introduce sys.lmk.minfree_levels system property to allow minfree level
reporting. The format for this property is:

<minfree 1>:<oom_adj 1>, <minfree 2>:<oom_adj 2>, ...

Max number of minfree levels is 6 and they are specified in the
increasing order. For example:

sys.lmk.minfree_levels=18432:0,23040:100,27648:200,32256:300,55296:900,80640:906

sys.lmk.minfree_levels updates are ratelimited to once per second in order
to prevent DoS attacks.

Bug: 111521182
Test: getprop sys.lmk.minfree_levels returns expected value
Change-Id: I80d75d6836650b12457d6a99ca88898535837a97
Signed-off-by: Suren Baghdasaryan <surenb@google.com>
2018-09-05 10:54:22 -07:00
Treehugger Robot ac26903b12 Merge "lmkd: Do not downgrade/ignore events when swap is full" 2018-08-14 21:31:56 +00:00
Suren Baghdasaryan 08bfa985d1 lmkd: Add meminfo logging after each kill for easy troubleshooting
While troubleshooting memory pressure related issues it's hard to get a
good view of the memory state when lmkd kill happens. Logging relevant
information from /proc/meminfo file that was used to make a kill decision
is very helpful for further analysis. To do this efficiently we are using
Android Logger event library functions and log the data used for kill
decision after the kill signal was issued.

Test: Run lmkd_unit_test and logcat -b events -v descriptive
Change-Id: Id5de41b9d91a04dd5d3eb9b85d4e1babe9755628
Signed-off-by: Suren Baghdasaryan <surenb@google.com>
2018-08-10 14:21:31 -07:00
Vic Yang 65680690d7 lmkd: Do not downgrade/ignore events when swap is full
When the swap space is full, a pressure event is unlikely to resolve by
itself.  In this case, do not downgrade or ignore the events.

Bug: 112056451
Test: Fill up swap on a 1GB device and check critical vmpressure events
      are not downgraded.
Change-Id: If154dc364711bf7c86f32e24ddcd10be359386de
2018-08-08 10:00:06 -07:00
Suren Baghdasaryan 2f81a77326 lmkd: Skip memory.stat usage when per-app memcgs are not used
Initial change to remove memory.stat usage when per-application memcgs
are disabled was partially merged into AOSP under the following id:
Ib6dd7586d3ef1c64cb04d16e2d2b21fa9c8e6a3a
This change adds the missing parts.

Bug: 110384555
Change-Id: I1265021b1ede0e68efbf80d6430a959eaf46a69a
Merged-In: Ib6dd7586d3ef1c64cb04d16e2d2b21fa9c8e6a3a
Signed-off-by: Suren Baghdasaryan <surenb@google.com>
2018-08-08 01:18:38 +00:00
Greg Kaiser f5b1d14fa8 lmkd: Protect against buffer overflow
We're passing a 'line' whose backing buffer is PAGE_MAX in size
into memory_stat_parse_line().  We protect overflowing the smaller
LINE_MAX 'key' buffer via some C preprocessing macros to assure
we limit the size.

Test: Local build with LMKD_LOG_STATS set for this file.
Bug: 76220622
Change-Id: I9e50d4270f7099e37a9bfc7fb9b9b95cc7adb086
2018-08-07 15:42:19 -07:00