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/*
* Copyright (C) 2018 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#include <sstream>
#include <stdio.h>
#include <string.h>
#include <string>
#include <sys/mman.h>
#include <sys/types.h>
#include <unistd.h>
#include <android-base/file.h>
#include <android-base/logging.h>
#include <android-base/properties.h>
#include <android-base/stringprintf.h>
#include <android-base/strings.h>
#include <gtest/gtest.h>
#include <lmkd.h>
#include <liblmkd_utils.h>
#include <log/log_properties.h>
#include <private/android_filesystem_config.h>
using namespace android::base;
#define INKERNEL_MINFREE_PATH "/sys/module/lowmemorykiller/parameters/minfree"
#define LMKDTEST_RESPAWN_FLAG "LMKDTEST_RESPAWN"
#define LMKD_LOGCAT_MARKER "lowmemorykiller"
#define LMKD_KILL_MARKER_TEMPLATE LMKD_LOGCAT_MARKER ": Kill '%s'"
#define OOM_MARKER "Out of memory"
#define OOM_KILL_MARKER "Killed process"
#define MIN_LOG_SIZE 100
#define ONE_MB (1 << 20)
/* Test constant parameters */
#define OOM_ADJ_MAX 1000
#define OOM_ADJ_MIN 0
#define OOM_ADJ_STEP 100
#define STEP_COUNT ((OOM_ADJ_MAX - OOM_ADJ_MIN) / OOM_ADJ_STEP + 1)
#define ALLOC_STEP (ONE_MB)
#define ALLOC_DELAY 1000
/* Utility functions */
std::string readCommand(const std::string& command) {
FILE* fp = popen(command.c_str(), "r");
std::string content;
ReadFdToString(fileno(fp), &content);
pclose(fp);
return content;
}
std::string readLogcat(const std::string& marker) {
std::string content = readCommand("logcat -d -b all");
size_t pos = content.find(marker);
if (pos == std::string::npos) return "";
content.erase(0, pos);
return content;
}
bool writeFile(const std::string& file, const std::string& string) {
if (getuid() == static_cast<unsigned>(AID_ROOT)) {
return WriteStringToFile(string, file);
}
return string == readCommand(
"echo -n '" + string + "' | su root tee " + file + " 2>&1");
}
bool writeKmsg(const std::string& marker) {
return writeFile("/dev/kmsg", marker);
}
std::string getTextAround(const std::string& text, size_t pos,
size_t lines_before, size_t lines_after) {
size_t start_pos = pos;
// find start position
// move up lines_before number of lines
while (lines_before > 0 &&
(start_pos = text.rfind('\n', start_pos)) != std::string::npos) {
lines_before--;
}
// move to the beginning of the line
start_pos = text.rfind('\n', start_pos);
start_pos = (start_pos == std::string::npos) ? 0 : start_pos + 1;
// find end position
// move down lines_after number of lines
while (lines_after > 0 &&
(pos = text.find('\n', pos)) != std::string::npos) {
pos++;
lines_after--;
}
return text.substr(start_pos, (pos == std::string::npos) ?
std::string::npos : pos - start_pos);
}
bool getExecPath(std::string &path) {
char buf[PATH_MAX + 1];
int ret = readlink("/proc/self/exe", buf, sizeof(buf) - 1);
if (ret < 0) {
return false;
}
buf[ret] = '\0';
path = buf;
return true;
}
/* Child synchronization primitives */
#define STATE_INIT 0
#define STATE_CHILD_READY 1
#define STATE_PARENT_READY 2
struct state_sync {
pthread_mutex_t mutex;
pthread_cond_t condition;
int state;
};
struct state_sync * init_state_sync_obj() {
struct state_sync *ssync;
ssync = (struct state_sync*)mmap(NULL, sizeof(struct state_sync),
PROT_READ | PROT_WRITE, MAP_ANONYMOUS | MAP_SHARED, -1, 0);
if (ssync == MAP_FAILED) {
return NULL;
}
pthread_mutexattr_t mattr;
pthread_mutexattr_init(&mattr);
pthread_mutexattr_setpshared(&mattr, PTHREAD_PROCESS_SHARED);
pthread_mutex_init(&ssync->mutex, &mattr);
pthread_condattr_t cattr;
pthread_condattr_init(&cattr);
pthread_condattr_setpshared(&cattr, PTHREAD_PROCESS_SHARED);
pthread_cond_init(&ssync->condition, &cattr);
ssync->state = STATE_INIT;
return ssync;
}
void destroy_state_sync_obj(struct state_sync *ssync) {
pthread_cond_destroy(&ssync->condition);
pthread_mutex_destroy(&ssync->mutex);
munmap(ssync, sizeof(struct state_sync));
}
void signal_state(struct state_sync *ssync, int state) {
pthread_mutex_lock(&ssync->mutex);
ssync->state = state;
pthread_cond_signal(&ssync->condition);
pthread_mutex_unlock(&ssync->mutex);
}
void wait_for_state(struct state_sync *ssync, int state) {
pthread_mutex_lock(&ssync->mutex);
while (ssync->state != state) {
pthread_cond_wait(&ssync->condition, &ssync->mutex);
}
pthread_mutex_unlock(&ssync->mutex);
}
/* Memory allocation and data sharing */
struct shared_data {
size_t allocated;
bool finished;
size_t total_size;
size_t step_size;
size_t step_delay;
int oomadj;
};
volatile void *gptr;
void add_pressure(struct shared_data *data) {
volatile void *ptr;
size_t allocated_size = 0;
data->finished = false;
while (allocated_size < data->total_size) {
ptr = mmap(NULL, data->step_size, PROT_READ | PROT_WRITE,
MAP_ANONYMOUS | MAP_PRIVATE, 0, 0);
if (ptr != MAP_FAILED) {
/* create ptr aliasing to prevent compiler optimizing the access */
gptr = ptr;
/* make data non-zero */
memset((void*)ptr, (int)(allocated_size + 1), data->step_size);
allocated_size += data->step_size;
data->allocated = allocated_size;
}
usleep(data->step_delay);
}
data->finished = (allocated_size >= data->total_size);
}
/* Memory stress test main body */
void runMemStressTest() {
struct shared_data *data;
struct state_sync *ssync;
int sock;
pid_t pid;
uid_t uid = getuid();
// check if in-kernel LMK driver is present
if (!access(INKERNEL_MINFREE_PATH, W_OK)) {
GTEST_LOG_(INFO) << "Must not have kernel lowmemorykiller driver,"
<< " terminating test";
return;
}
ASSERT_FALSE((sock = lmkd_connect()) < 0)
<< "Failed to connect to lmkd process, err=" << strerror(errno);
/* allocate shared memory to communicate params with a child */
data = (struct shared_data*)mmap(NULL, sizeof(struct shared_data),
PROT_READ | PROT_WRITE, MAP_ANONYMOUS | MAP_SHARED, -1, 0);
ASSERT_FALSE(data == MAP_FAILED) << "Memory allocation failure";
data->total_size = (size_t)-1; /* allocate until killed */
data->step_size = ALLOC_STEP;
data->step_delay = ALLOC_DELAY;
/* allocate state sync object */
ASSERT_FALSE((ssync = init_state_sync_obj()) == NULL)
<< "Memory allocation failure";
/* run the test gradually decreasing oomadj */
data->oomadj = OOM_ADJ_MAX;
while (data->oomadj >= OOM_ADJ_MIN) {
ASSERT_FALSE((pid = fork()) < 0)
<< "Failed to spawn a child process, err=" << strerror(errno);
if (pid != 0) {
/* Parent */
struct lmk_procprio params;
/* wait for child to start and get ready */
wait_for_state(ssync, STATE_CHILD_READY);
params.pid = pid;
params.uid = uid;
params.oomadj = data->oomadj;
ASSERT_FALSE(lmkd_register_proc(sock, &params) < 0)
<< "Failed to communicate with lmkd, err=" << strerror(errno);
// signal the child it can proceed
signal_state(ssync, STATE_PARENT_READY);
waitpid(pid, NULL, 0);
if (data->finished) {
GTEST_LOG_(INFO) << "Child [pid=" << pid << "] allocated "
<< data->allocated / ONE_MB << "MB";
} else {
GTEST_LOG_(INFO) << "Child [pid=" << pid << "] allocated "
<< data->allocated / ONE_MB
<< "MB before being killed";
}
data->oomadj -= OOM_ADJ_STEP;
} else {
/* Child */
pid = getpid();
GTEST_LOG_(INFO) << "Child [pid=" << pid
<< "] is running at oomadj="
<< data->oomadj;
data->allocated = 0;
data->finished = false;
ASSERT_FALSE(create_memcg(uid, pid) != 0)
<< "Child [pid=" << pid << "] failed to create a cgroup";
signal_state(ssync, STATE_CHILD_READY);
wait_for_state(ssync, STATE_PARENT_READY);
add_pressure(data);
/* should not reach here, child should be killed by OOM/LMK */
FAIL() << "Child [pid=" << pid << "] was not killed";
break;
}
}
destroy_state_sync_obj(ssync);
munmap(data, sizeof(struct shared_data));
close(sock);
}
TEST(lmkd, check_for_oom) {
// test requirements
// userdebug build
if (!__android_log_is_debuggable()) {
GTEST_LOG_(INFO) << "Must be userdebug build, terminating test";
return;
}
// if respawned test process then run the test and exit (no analysis)
if (getenv(LMKDTEST_RESPAWN_FLAG) != NULL) {
runMemStressTest();
return;
}
// Main test process
// mark the beginning of the test
std::string marker = StringPrintf(
"LMKD test start %lu\n", static_cast<unsigned long>(time(nullptr)));
ASSERT_TRUE(writeKmsg(marker));
// get executable complete path
std::string test_path;
ASSERT_TRUE(getExecPath(test_path));
std::string test_output;
if (getuid() != static_cast<unsigned>(AID_ROOT)) {
// if not root respawn itself as root and capture output
std::string command = StringPrintf(
"%s=true su root %s 2>&1", LMKDTEST_RESPAWN_FLAG,
test_path.c_str());
std::string test_output = readCommand(command);
GTEST_LOG_(INFO) << test_output;
} else {
// main test process is root, run the test
runMemStressTest();
}
// Analyze results
// capture logcat containind kernel logs
std::string logcat_out = readLogcat(marker);
// 1. extract LMKD kills from logcat output, count kills
std::stringstream kill_logs;
int hit_count = 0;
size_t pos = 0;
marker = StringPrintf(LMKD_KILL_MARKER_TEMPLATE, test_path.c_str());
while (true) {
if ((pos = logcat_out.find(marker, pos)) != std::string::npos) {
kill_logs << getTextAround(logcat_out, pos, 0, 1);
pos += marker.length();
hit_count++;
} else {
break;
}
}
GTEST_LOG_(INFO) << "====Logged kills====" << std::endl
<< kill_logs.str();
EXPECT_TRUE(hit_count == STEP_COUNT) << "Number of kills " << hit_count
<< " is less than expected "
<< STEP_COUNT;
// 2. check kernel logs for OOM kills
pos = logcat_out.find(OOM_MARKER);
bool oom_detected = (pos != std::string::npos);
bool oom_kill_detected = (oom_detected &&
logcat_out.find(OOM_KILL_MARKER, pos) != std::string::npos);
EXPECT_FALSE(oom_kill_detected) << "OOM kill is detected!";
if (oom_detected || oom_kill_detected) {
// capture logcat with logs around all OOMs
pos = 0;
while ((pos = logcat_out.find(OOM_MARKER, pos)) != std::string::npos) {
GTEST_LOG_(INFO) << "====Logs around OOM====" << std::endl
<< getTextAround(logcat_out, pos,
MIN_LOG_SIZE / 2, MIN_LOG_SIZE / 2);
pos += strlen(OOM_MARKER);
}
}
// output complete logcat with kernel (might get truncated)
GTEST_LOG_(INFO) << "====Complete logcat output====" << std::endl
<< logcat_out;
}