Atmosphere/thermosphere/src/traps/hvisor_traps_single_step.cpp
2021-02-19 21:52:29 +00:00

88 lines
3.0 KiB
C++

/*
* Copyright (c) 2019-2020 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 "hvisor_traps_single_step.hpp"
#include "../hvisor_core_context.hpp"
#include "../cpu/hvisor_cpu_sysreg_general.hpp"
#include "../cpu/hvisor_cpu_instructions.hpp"
#include "../debug_manager.h"
namespace ams::hvisor::traps {
SingleStepState GetNextSingleStepState(ExceptionStackFrame *frame)
{
u64 mdscr = THERMOSPHERE_GET_SYSREG(mdscr_el1);
bool mdscrSS = (mdscr & cpu::MDSCR_SS) != 0;
bool pstateSS = (frame->spsr_el2 & cpu::PSR_SS) != 0;
if (!mdscrSS) {
return SingleStepState::Inactive;
} else {
return pstateSS ? SingleStepState::ActiveNotPending : SingleStepState::ActivePending;
}
}
void SetNextSingleStepState(ExceptionStackFrame *frame, SingleStepState state)
{
u64 mdscr = THERMOSPHERE_GET_SYSREG(mdscr_el1);
switch (state) {
case SingleStepState::Inactive:
// Unset mdscr_el1.ss
mdscr &= ~cpu::MDSCR_SS;
break;
case SingleStepState::ActiveNotPending:
// Set mdscr_el1.ss and pstate.ss
mdscr |= cpu::MDSCR_SS;
frame->spsr_el2 |= cpu::PSR_SS;
break;
case SingleStepState::ActivePending:
// We never use this because pstate.ss is 0 by default...
// Set mdscr_el1.ss and unset pstate.ss
mdscr |= cpu::MDSCR_SS;
frame->spsr_el2 &= cpu::PSR_SS;
break;
default:
break;
}
THERMOSPHERE_SET_SYSREG(mdscr_el1, mdscr);
cpu::isb(); // TRM-mandated
}
void HandleSingleStep(ExceptionStackFrame *frame, cpu::ExceptionSyndromeRegister esr)
{
uintptr_t addr = frame->elr_el2;
// Stepping range support;
auto [startAddr, endAddr] = currentCoreCtx->GetSteppingRange();
if (addr >= startAddr && addr < endAddr) {
// Reactivate single-step
SetNextSingleStepState(frame, SingleStepState::ActiveNotPending);
} else {
// Disable single-step
SetNextSingleStepState(frame, SingleStepState::Inactive);
debugManagerReportEvent(DBGEVENT_EXCEPTION);
}
DEBUG("Single-step exeception ELR = 0x%016llx, ISV = %u, EX = %u\n", frame->elr_el2, (esr.iss >> 24) & 1, (esr.iss >> 6) & 1);
}
}