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Merge "Kill services even when cgroups is disabled" am: 5c3e24816d

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Original change: https://android-review.googlesource.com/c/platform/system/core/+/2305473

Change-Id: I8226678ccc8352a4ed255a7efebf472e507bc3bd
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>
This commit is contained in:
Treehugger Robot 2022-12-12 02:04:33 +00:00 • committed by Automerger Merge Worker
commit 18a41fbf65
2 changed files with 64 additions and 46 deletions
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2
init/service.cpp
View file

@ -712,8 +712,6 @@ Result<void> Service::Start() {
if (use_memcg) {
ConfigureMemcg();
}
} else {
process_cgroup_empty_ = true;
}
if (oom_score_adjust_ != DEFAULT_OOM_SCORE_ADJUST) {

108
libprocessgroup/processgroup.cpp
View file

@ -367,59 +367,70 @@ err:
// Returns 0 if there are no processes in the process cgroup left to kill
// Returns -1 on error
static int DoKillProcessGroupOnce(const char* cgroup, uid_t uid, int initialPid, int signal) {
auto path = ConvertUidPidToPath(cgroup, uid, initialPid) + PROCESSGROUP_CGROUP_PROCS_FILE;
std::unique_ptr<FILE, decltype(&fclose)> fd(fopen(path.c_str(), "re"), fclose);
if (!fd) {
if (errno == ENOENT) {
// This happens when process is already dead
return 0;
}
PLOG(WARNING) << __func__ << " failed to open process cgroup uid " << uid << " pid "
<< initialPid;
return -1;
}
// We separate all of the pids in the cgroup into those pids that are also the leaders of
// process groups (stored in the pgids set) and those that are not (stored in the pids set).
std::set<pid_t> pgids;
pgids.emplace(initialPid);
std::set<pid_t> pids;
pid_t pid;
std::unique_ptr<FILE, decltype(&fclose)> fd(nullptr, fclose);
if (CgroupsAvailable()) {
auto path = ConvertUidPidToPath(cgroup, uid, initialPid) + PROCESSGROUP_CGROUP_PROCS_FILE;
fd.reset(fopen(path.c_str(), "re"));
if (!fd) {
if (errno == ENOENT) {
// This happens when process is already dead
return 0;
}
PLOG(WARNING) << __func__ << " failed to open process cgroup uid " << uid << " pid "
<< initialPid;
return -1;
}
pid_t pid;
bool file_is_empty = true;
while (fscanf(fd.get(), "%d\n", &pid) == 1 && pid >= 0) {
file_is_empty = false;
if (pid == 0) {
// Should never happen... but if it does, trying to kill this
// will boomerang right back and kill us! Let's not let that happen.
LOG(WARNING)
<< "Yikes, we've been told to kill pid 0! How about we don't do that?";
continue;
}
pid_t pgid = getpgid(pid);
if (pgid == -1) PLOG(ERROR) << "getpgid(" << pid << ") failed";
if (pgid == pid) {
pgids.emplace(pid);
} else {
pids.emplace(pid);
}
}
if (file_is_empty) {
// This happens when process is already dead
return 0;
}
// Erase all pids that will be killed when we kill the process groups.
for (auto it = pids.begin(); it != pids.end();) {
pid_t pgid = getpgid(*it);
if (pgids.count(pgid) == 1) {
it = pids.erase(it);
} else {
++it;
}
}
}
int processes = 0;
while (fscanf(fd.get(), "%d\n", &pid) == 1 && pid >= 0) {
processes++;
if (pid == 0) {
// Should never happen... but if it does, trying to kill this
// will boomerang right back and kill us! Let's not let that happen.
LOG(WARNING) << "Yikes, we've been told to kill pid 0! How about we don't do that?";
continue;
}
pid_t pgid = getpgid(pid);
if (pgid == -1) PLOG(ERROR) << "getpgid(" << pid << ") failed";
if (pgid == pid) {
pgids.emplace(pid);
} else {
pids.emplace(pid);
}
}
// Erase all pids that will be killed when we kill the process groups.
for (auto it = pids.begin(); it != pids.end();) {
pid_t pgid = getpgid(*it);
if (pgids.count(pgid) == 1) {
it = pids.erase(it);
} else {
++it;
}
}
// Kill all process groups.
for (const auto pgid : pgids) {
LOG(VERBOSE) << "Killing process group " << -pgid << " in uid " << uid
<< " as part of process cgroup " << initialPid;
if (kill(-pgid, signal) == -1 && errno != ESRCH) {
if (kill(-pgid, signal) == 0) {
processes++;
} else if (errno != ESRCH) {
PLOG(WARNING) << "kill(" << -pgid << ", " << signal << ") failed";
}
}
@ -429,18 +440,22 @@ static int DoKillProcessGroupOnce(const char* cgroup, uid_t uid, int initialPid,
LOG(VERBOSE) << "Killing pid " << pid << " in uid " << uid << " as part of process cgroup "
<< initialPid;
if (kill(pid, signal) == -1 && errno != ESRCH) {
if (kill(pid, signal) == 0) {
processes++;
} else if (errno != ESRCH) {
PLOG(WARNING) << "kill(" << pid << ", " << signal << ") failed";
}
}
return feof(fd.get()) ? processes : -1;
return (!fd || feof(fd.get())) ? processes : -1;
}
static int KillProcessGroup(uid_t uid, int initialPid, int signal, int retries,
int* max_processes) {
std::string hierarchy_root_path;
CgroupGetControllerPath(CGROUPV2_CONTROLLER_NAME, &hierarchy_root_path);
if (CgroupsAvailable()) {
CgroupGetControllerPath(CGROUPV2_CONTROLLER_NAME, &hierarchy_root_path);
}
const char* cgroup = hierarchy_root_path.c_str();
std::chrono::steady_clock::time_point start = std::chrono::steady_clock::now();
@ -485,6 +500,11 @@ static int KillProcessGroup(uid_t uid, int initialPid, int signal, int retries,
<< " in " << static_cast<int>(ms) << "ms";
}
if (!CgroupsAvailable()) {
// nothing to do here, if cgroups isn't available
return 0;
}
// 400 retries correspond to 2 secs max timeout
int err = RemoveProcessGroup(cgroup, uid, initialPid, 400);