Atmosphere/exosphere2/program/source/smc/secmon_smc_se_lock.cpp
2020-06-14 22:07:45 -07:00

78 lines
2.4 KiB
C++

/*
* Copyright (c) 2018-2020 Atmosphère-NX
*
* This program is free software; you can redistribute it and/or modify it
* under the terms and conditions of the GNU General Public License,
* version 2, as published by the Free Software Foundation.
*
* This program is distributed in the hope it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
* more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#include <exosphere.hpp>
#include "../secmon_error.hpp"
#include "secmon_smc_se_lock.hpp"
namespace ams::secmon::smc {
namespace {
constinit std::atomic_bool g_is_locked = false;
}
bool TryLockSecurityEngine() {
bool value = false;
return g_is_locked.compare_exchange_strong(value, true);
}
void UnlockSecurityEngine() {
g_is_locked = false;
}
bool IsSecurityEngineLocked() {
return g_is_locked;
}
SmcResult LockSecurityEngineAndInvoke(SmcArguments &args, SmcHandler impl) {
/* Try to lock the SE. */
if (!TryLockSecurityEngine()) {
return SmcResult::Busy;
}
ON_SCOPE_EXIT { UnlockSecurityEngine(); };
return impl(args);
}
SmcResult LockSecurityEngineAndInvokeAsync(SmcArguments &args, SmcHandler impl, GetResultHandler result_handler) {
SmcResult result = SmcResult::Busy;
/* Try to lock the security engine. */
if (TryLockSecurityEngine()) {
/* Try to start an async operation. */
if (const u64 async_key = BeginAsyncOperation(result_handler); async_key != InvalidAsyncKey) {
/* Invoke the operation. */
result = impl(args);
/* If the operation was successful, return the key. */
if (result == SmcResult::Success) {
args.r[1] = async_key;
return SmcResult::Success;
}
/* Otherwise, cancel the async operation. */
CancelAsyncOperation(async_key);
}
/* We failed to invoke the async op, so unlock the security engine. */
UnlockSecurityEngine();
}
return result;
}
}