Atmosphere/exosphere/program/source/smc/secmon_smc_se_lock.cpp
2021-10-20 11:02:17 -07:00

83 lines
2.5 KiB
C++

/*
* Copyright (c) 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 util::Atomic<bool> g_is_locked = false;
ALWAYS_INLINE bool TryLockSecurityEngineImpl() {
bool value = false;
return g_is_locked.CompareExchangeStrong(value, true);
}
ALWAYS_INLINE void UnlockSecurityEngineImpl() {
g_is_locked = false;
}
ALWAYS_INLINE bool IsSecurityEngineLockedImpl() {
return g_is_locked.Load();
}
}
bool TryLockSecurityEngine() {
return TryLockSecurityEngineImpl();
}
void UnlockSecurityEngine() {
return UnlockSecurityEngineImpl();
}
bool IsSecurityEngineLocked() {
return IsSecurityEngineLockedImpl();
}
SmcResult LockSecurityEngineAndInvoke(SmcArguments &args, SmcHandler impl) {
/* Try to lock the security engine. */
SMC_R_UNLESS(TryLockSecurityEngineImpl(), Busy);
ON_SCOPE_EXIT { UnlockSecurityEngineImpl(); };
return impl(args);
}
SmcResult LockSecurityEngineAndInvokeAsync(SmcArguments &args, SmcHandler impl, GetResultHandler result_handler) {
/* Try to lock the security engine. */
SMC_R_UNLESS(TryLockSecurityEngineImpl(), Busy);
auto se_guard = SCOPE_GUARD { UnlockSecurityEngineImpl(); };
/* Try to start an async operation. */
const u64 async_key = BeginAsyncOperation(result_handler);
SMC_R_UNLESS(async_key != InvalidAsyncKey, Busy);
auto async_guard = SCOPE_GUARD { CancelAsyncOperation(async_key); };
/* Try to invoke the operation. */
SMC_R_TRY(impl(args));
/* We succeeded! Cancel our guards, and return the async key to our caller. */
async_guard.Cancel();
se_guard.Cancel();
args.r[1] = async_key;
return SmcResult::Success;
}
}