llkd: bootstat: propagate detailed livelock canonical boot reason
Report kernel_panic,sysrq,livelock,<state> reboot reason via last
dmesg (pstore console). Add ro.llk.killtest property, which will
allow reliable ABA platforms to drop kill test and go directly
to kernel panic. This should also allow some manual unit testing
of the canonical boot reason report.
New canonical boot reasons from llkd are:
- kernel_panic,sysrq,livelock,alarm llkd itself locked up (Hail Mary)
- kernel_panic,sysrq,livelock,driver uninterrruptible D state
- kernel_panic,sysrq,livelock,zombie uninterrruptible Z state
Manual test assumptions:
- llkd is built by the platform and landed on system partition
- unit test is built and landed in /data/nativetest (could
land in /data/nativetest64, adjust test correspondingly)
- llkd not enabled, ro.llk.enable and ro.llk.killtest
are not set by platform allowing test to adjust all the
configuration properties and start llkd.
- or, llkd is enabled, ro.llk.enable is true, and killtest is
disabled, ro.llk.killtest is false, setup by the platform.
This breaks the go/apct generic operations of the unit test
for llk.zombie and llk.driver as kernel panic results
requiring manual intervention otherwise. If test moves to
go/apct, then we will be forced to bypass these tests under
this condition (but allow them to run if ro.llk.killtest
is "off" so specific testing above/below can be run).
for i in driver zombie; do
adb shell su root setprop ro.llk.killtest off
adb shell /data/nativetest/llkd_unit_test/llkd_unit_test --gtest_filter=llkd.${i}
adb wait-for-device
adb shell su root setprop ro.llk.killtest off
sleep 60
adb shell getprop sys.boot.reason
adb shell /data/nativetest/llkd_unit_test/llkd_unit_test --gtest_filter=llkd.${i}
done
Test: llkd_unit_test (see test assumptions)
Bug: 33808187
Bug: 72838192
Change-Id: I2b24875376ddfdbc282ba3da5c5b3567de85dbc0
diff --git a/bootstat/bootstat.cpp b/bootstat/bootstat.cpp
index c2688e9..8ce9dfc 100644
--- a/bootstat/bootstat.cpp
+++ b/bootstat/bootstat.cpp
@@ -303,6 +303,9 @@
{"kernel_panic,init", 158},
{"kernel_panic,oom", 159},
{"kernel_panic,stack", 160},
+ {"kernel_panic,sysrq,livelock,alarm", 161}, // llkd
+ {"kernel_panic,sysrq,livelock,driver", 162}, // llkd
+ {"kernel_panic,sysrq,livelock,zombie", 163}, // llkd
};
// Converts a string value representing the reason the system booted to an
diff --git a/llkd/README.md b/llkd/README.md
index 71319c8..b2ba2a2 100644
--- a/llkd/README.md
+++ b/llkd/README.md
@@ -53,7 +53,9 @@
conditions. If the test can, it will reconfigure llkd to expedite the test
duration by adjusting the ro.llk.* Android properties. Tests run the D state
with some scheduling progress to ensure that ABA checking prevents false
-triggers.
+triggers. If 100% reliable ABA on platform, then ro.llk.killtest can be
+set to false; however this will result in some of the unit tests to panic
+kernel instead of deal with more graceful kill operation.
Android Properties
------------------
@@ -108,13 +110,6 @@
Architectural Concerns
----------------------
-- Figure out how to communicate the kernel panic better to bootstat canonical
- boot reason determination. This may require an alteration to bootstat, or
- some logging from llkd. Would like to see boot reason to be
- watchdog,livelock as a minimum requirement. Or more specifically would want
- watchdog,livelock,device or watchdog,livelock,zombie be reported.
- Currently reports panic,sysrq (user requested panic) or panic depending on
- system support of pstore.
- Create kernel module and associated gTest to actually test panic.
- Create gTest to test out blacklist (ro.llk.blacklist.<properties> generally
not be inputs). Could require more test-only interfaces to libllkd.
diff --git a/llkd/include/llkd.h b/llkd/include/llkd.h
index bd0739b..e3ae4bb 100644
--- a/llkd/include/llkd.h
+++ b/llkd/include/llkd.h
@@ -37,6 +37,8 @@
#define KHT_ENABLE_PROPERTY "ro." KHT_ENABLE_WRITEABLE_PROPERTY
#define LLK_MLOCKALL_PROPERTY "ro.llk.mlockall"
#define LLK_MLOCKALL_DEFAULT true
+#define LLK_KILLTEST_PROPERTY "ro.llk.killtest"
+#define LLK_KILLTEST_DEFAULT true
#define LLK_TIMEOUT_MS_PROPERTY "ro.llk.timeout_ms"
#define KHT_TIMEOUT_PROPERTY "ro.khungtask.timeout"
#define LLK_D_TIMEOUT_MS_PROPERTY "ro.llk.D.timeout_ms"
diff --git a/llkd/libllkd.cpp b/llkd/libllkd.cpp
index d828105..f357cc2 100644
--- a/llkd/libllkd.cpp
+++ b/llkd/libllkd.cpp
@@ -70,6 +70,7 @@
bool llkEnable = LLK_ENABLE_DEFAULT; // llk daemon enabled
bool llkRunning = false; // thread is running
bool llkMlockall = LLK_MLOCKALL_DEFAULT; // run mlocked
+bool llkTestWithKill = LLK_KILLTEST_DEFAULT; // issue test kills
milliseconds llkTimeoutMs = LLK_TIMEOUT_MS_DEFAULT; // default timeout
enum { llkStateD, llkStateZ, llkNumStates }; // state indexes
milliseconds llkStateTimeoutMs[llkNumStates]; // timeout override for each detection state
@@ -292,7 +293,7 @@
exeMissingValid(false),
cmdlineValid(false),
updated(true),
- killed(false) {
+ killed(!llkTestWithKill) {
memset(comm, '\0', sizeof(comm));
setComm(_comm);
}
@@ -475,8 +476,8 @@
return android::base::Trim(content) == string;
}
-void llkPanicKernel(bool dump, pid_t tid) __noreturn;
-void llkPanicKernel(bool dump, pid_t tid) {
+void llkPanicKernel(bool dump, pid_t tid, const char* state) __noreturn;
+void llkPanicKernel(bool dump, pid_t tid, const char* state) {
auto sysrqTriggerFd = llkFileToWriteFd("/proc/sysrq-trigger");
if (sysrqTriggerFd < 0) {
// DYB
@@ -496,6 +497,8 @@
}
::usleep(200000); // let everything settle
}
+ llkWriteStringToFile(std::string("SysRq : Trigger a crash : 'livelock,") + state + "'\n",
+ "/dev/kmsg");
android::base::WriteStringToFd("c", sysrqTriggerFd);
// NOTREACHED
// DYB
@@ -507,7 +510,7 @@
}
void llkAlarmHandler(int) {
- llkPanicKernel(false, ::getpid());
+ llkPanicKernel(false, ::getpid(), "alarm");
}
milliseconds GetUintProperty(const std::string& key, milliseconds def) {
@@ -686,7 +689,7 @@
(val != procp->nrSwitches)) {
procp->nrSwitches = val;
procp->count = 0ms;
- procp->killed = false;
+ procp->killed = !llkTestWithKill;
}
return;
}
@@ -700,7 +703,7 @@
if (schedUpdate != procp->schedUpdate) {
procp->schedUpdate = schedUpdate;
procp->count = 0ms;
- procp->killed = false;
+ procp->killed = !llkTestWithKill;
}
}
@@ -709,7 +712,7 @@
if (static_cast<uint64_t>(val) != procp->nrSwitches) {
procp->nrSwitches = val;
procp->count = 0ms;
- procp->killed = false;
+ procp->killed = !llkTestWithKill;
}
}
}
@@ -719,6 +722,7 @@
<< LLK_ENABLE_PROPERTY "=" << llkFormat(llkEnable) << "\n"
<< KHT_ENABLE_PROPERTY "=" << llkFormat(khtEnable) << "\n"
<< LLK_MLOCKALL_PROPERTY "=" << llkFormat(llkMlockall) << "\n"
+ << LLK_KILLTEST_PROPERTY "=" << llkFormat(llkTestWithKill) << "\n"
<< KHT_TIMEOUT_PROPERTY "=" << llkFormat(khtTimeout) << "\n"
<< LLK_TIMEOUT_MS_PROPERTY "=" << llkFormat(llkTimeoutMs) << "\n"
<< LLK_D_TIMEOUT_MS_PROPERTY "=" << llkFormat(llkStateTimeoutMs[llkStateD]) << "\n"
@@ -869,7 +873,7 @@
procp->time = utime + stime;
if (procp->state != state) {
procp->count = 0ms;
- procp->killed = false;
+ procp->killed = !llkTestWithKill;
procp->state = state;
} else {
procp->count += llkCycle;
@@ -973,7 +977,7 @@
// We are here because we have confirmed kernel live-lock
LOG(ERROR) << state << ' ' << llkFormat(procp->count) << ' ' << ppid << "->" << pid
<< "->" << tid << ' ' << procp->getComm() << " [panic]";
- llkPanicKernel(true, tid);
+ llkPanicKernel(true, tid, (state == 'Z') ? "zombie" : "driver");
}
LOG(VERBOSE) << "+closedir()";
}
@@ -1045,6 +1049,7 @@
}
khtEnable = android::base::GetBoolProperty(KHT_ENABLE_PROPERTY, khtEnable);
llkMlockall = android::base::GetBoolProperty(LLK_MLOCKALL_PROPERTY, llkMlockall);
+ llkTestWithKill = android::base::GetBoolProperty(LLK_KILLTEST_PROPERTY, llkTestWithKill);
// if LLK_TIMOUT_MS_PROPERTY was not set, we will use a set
// KHT_TIMEOUT_PROPERTY as co-operative guidance for the default value.
khtTimeout = GetUintProperty(KHT_TIMEOUT_PROPERTY, khtTimeout);
diff --git a/llkd/llkd.rc b/llkd/llkd.rc
index f762a5c..e538cdb 100644
--- a/llkd/llkd.rc
+++ b/llkd/llkd.rc
@@ -44,5 +44,6 @@
user llkd
group llkd readproc
capabilities KILL IPC_LOCK
+ file /dev/kmsg w
file /proc/sysrq-trigger w
writepid /dev/cpuset/system-background/tasks
diff --git a/llkd/tests/llkd_test.cpp b/llkd/tests/llkd_test.cpp
index 2de1820..3a15ff1 100644
--- a/llkd/tests/llkd_test.cpp
+++ b/llkd/tests/llkd_test.cpp
@@ -154,6 +154,27 @@
ASSERT_EQ(WTERMSIG(wstatus), SIGKILL);
}
+bool checkKill(const char* reason) {
+ if (android::base::GetBoolProperty(LLK_KILLTEST_PROPERTY, LLK_KILLTEST_DEFAULT)) {
+ return false;
+ }
+ auto bootreason = android::base::GetProperty("sys.boot.reason", "nothing");
+ if (bootreason == reason) {
+ GTEST_LOG_INFO << "Expected test result confirmed " << reason << "\n";
+ return true;
+ }
+ GTEST_LOG_WARNING << "Expected test result is " << reason << "\n";
+
+ // apct adjustment if needed (set LLK_KILLTEST_PROPERTY to "off" to allow test)
+ //
+ // if (android::base::GetProperty(LLK_KILLTEST_PROPERTY, "") == "false") {
+ // GTEST_LOG_WARNING << "Bypassing test\n";
+ // return true;
+ // }
+
+ return false;
+}
+
} // namespace
// The tests that use this helper are to simulate processes stuck in 'D'
@@ -221,6 +242,10 @@
// is that llkd will perform kill mitigation and not progress to kernel_panic.
TEST(llkd, zombie) {
+ if (checkKill("kernel_panic,sysrq,livelock,zombie")) {
+ return;
+ }
+
const auto period = llkdSleepPeriod('Z');
/* Create a Persistent Zombie Process */
@@ -241,6 +266,10 @@
}
TEST(llkd, driver) {
+ if (checkKill("kernel_panic,sysrq,livelock,driver")) {
+ return;
+ }
+
const auto period = llkdSleepPeriod('D');
/* Create a Persistent Device Process */