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Merge "libprocessgroup: make sure SetupCgroups is called once and only by init"

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am: 7b2187c372

Change-Id: I1b1562f7042de6268bcd238adfdad1e8ffe6629e
This commit is contained in:
Suren Baghdasaryan 2019-03-25 13:40:13 -07:00 • committed by android-build-merger
commit 7bb7f6ef28
1 changed files with 19 additions and 3 deletions
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22
libprocessgroup/cgroup_map.cpp
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@ -229,9 +229,11 @@ static bool SetupCgroup(const CgroupDescriptor&) {
static bool WriteRcFile(const std::map<std::string, CgroupDescriptor>& descriptors) { static bool WriteRcFile(const std::map<std::string, CgroupDescriptor>& descriptors) {
std::string cgroup_rc_path = StringPrintf("%s/%s", CGROUPS_RC_DIR, CgroupMap::CGROUPS_RC_FILE); std::string cgroup_rc_path = StringPrintf("%s/%s", CGROUPS_RC_DIR, CgroupMap::CGROUPS_RC_FILE);
unique_fd fd(TEMP_FAILURE_RETRY(open(cgroup_rc_path.c_str(), // Let init keep the FD open to prevent file mappings from becoming invalid
O_CREAT | O_WRONLY | O_TRUNC | O_CLOEXEC, // in case the file gets deleted somehow
S_IRUSR | S_IRGRP | S_IROTH))); static unique_fd fd(TEMP_FAILURE_RETRY(open(cgroup_rc_path.c_str(),
O_CREAT | O_WRONLY | O_TRUNC | O_CLOEXEC,
S_IRUSR | S_IRGRP | S_IROTH)));
if (fd < 0) { if (fd < 0) {
PLOG(ERROR) << "open() failed for " << cgroup_rc_path; PLOG(ERROR) << "open() failed for " << cgroup_rc_path;
return false; return false;
@ -412,6 +414,19 @@ void CgroupMap::Print() const {
bool CgroupMap::SetupCgroups() { bool CgroupMap::SetupCgroups() {
std::map<std::string, CgroupDescriptor> descriptors; std::map<std::string, CgroupDescriptor> descriptors;
if (getpid() != 1) {
LOG(ERROR) << "Cgroup setup can be done only by init process";
return false;
}
// Make sure we do this only one time. No need for std::call_once because
// init is a single-threaded process
static bool setup_done = false;
if (setup_done) {
LOG(WARNING) << "Attempt to call SetupCgroups more than once";
return true;
}
// load cgroups.json file // load cgroups.json file
if (!ReadDescriptors(&descriptors)) { if (!ReadDescriptors(&descriptors)) {
LOG(ERROR) << "Failed to load cgroup description file"; LOG(ERROR) << "Failed to load cgroup description file";
@ -449,6 +464,7 @@ bool CgroupMap::SetupCgroups() {
return false; return false;
} }
setup_done = true;
return true; return true;
} }