/*
* 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 <mesosphere.hpp>
namespace ams::kern::arch::arm64 {
namespace {
constexpr inline u64 ForbiddenBreakPointFlagsMask = (((1ul << 40) - 1) << 24) | /* Reserved upper bits. */
(((1ul << 1) - 1) << 23) | /* Match VMID BreakPoint Type. */
(((1ul << 2) - 1) << 14) | /* Security State Control. */
(((1ul << 1) - 1) << 13) | /* Hyp Mode Control. */
(((1ul << 4) - 1) << 9) | /* Reserved middle bits. */
(((1ul << 2) - 1) << 3) | /* Reserved lower bits. */
(((1ul << 2) - 1) << 1); /* Privileged Mode Control. */
static_assert(ForbiddenBreakPointFlagsMask == 0xFFFFFFFFFF80FE1Eul);
constexpr inline u64 ForbiddenWatchPointFlagsMask = (((1ul << 32) - 1) << 32) | /* Reserved upper bits. */
(((1ul << 4) - 1) << 20) | /* WatchPoint Type. */
(((1ul << 2) - 1) << 14) | /* Security State Control. */
(((1ul << 1) - 1) << 13) | /* Hyp Mode Control. */
(((1ul << 2) - 1) << 1); /* Privileged Access Control. */
static_assert(ForbiddenWatchPointFlagsMask == 0xFFFFFFFF00F0E006ul);
}
uintptr_t KDebug::GetProgramCounter(const KThread &thread) {
return GetExceptionContext(std::addressof(thread))->pc;
}
void KDebug::SetPreviousProgramCounter() {
/* Get the current thread. */
KThread *thread = GetCurrentThreadPointer();
MESOSPHERE_ASSERT(thread->IsCallingSvc());
/* Get the exception context. */
KExceptionContext *e_ctx = GetExceptionContext(thread);
/* Set the previous pc. */
if (e_ctx->write == 0) {
/* Subtract from the program counter. */
if (thread->GetOwnerProcess()->Is64Bit()) {
e_ctx->pc -= sizeof(u32);
} else {
e_ctx->pc -= (e_ctx->psr & 0x20) ? sizeof(u16) : sizeof(u32);
}
/* Mark that we've set. */
e_ctx->write = 1;
}
}
Result KDebug::BreakIfAttached(ams::svc::BreakReason break_reason, uintptr_t address, size_t size) {
return KDebugBase::OnDebugEvent(ams::svc::DebugEvent_Exception, ams::svc::DebugException_UserBreak, GetProgramCounter(GetCurrentThread()), break_reason, address, size);
}
#define MESOSPHERE_SET_HW_BREAK_POINT(ID, FLAGS, VALUE) \
({ \
cpu::SetDbgBcr##ID##El1(0); \
cpu::EnsureInstructionConsistency(); \
cpu::SetDbgBvr##ID##El1(VALUE); \
cpu::EnsureInstructionConsistency(); \
cpu::SetDbgBcr##ID##El1(FLAGS); \
cpu::EnsureInstructionConsistency(); \
})
#define MESOSPHERE_SET_HW_WATCH_POINT(ID, FLAGS, VALUE) \
({ \
cpu::SetDbgWcr##ID##El1(0); \
cpu::EnsureInstructionConsistency(); \
cpu::SetDbgWvr##ID##El1(VALUE); \
cpu::EnsureInstructionConsistency(); \
cpu::SetDbgWcr##ID##El1(FLAGS); \
cpu::EnsureInstructionConsistency(); \
})
Result KDebug::SetHardwareBreakPoint(ams::svc::HardwareBreakPointRegisterName name, u64 flags, u64 value) {
/* Get the debug feature register. */
cpu::DebugFeatureRegisterAccessor dfr0;
/* Extract interesting info from the debug feature register. */
const auto num_bp = dfr0.GetNumBreakpoints();
const auto num_wp = dfr0.GetNumWatchpoints();
const auto num_ctx = dfr0.GetNumContextAwareBreakpoints();
if (ams::svc::HardwareBreakPointRegisterName_I0 <= name && name <= ams::svc::HardwareBreakPointRegisterName_I15) {
/* Check that the name is a valid instruction breakpoint. */
R_UNLESS((name - ams::svc::HardwareBreakPointRegisterName_I0) <= num_bp, svc::ResultNotSupported());
/* We may be getting the process, so prepare a scoped reference holder. */
KScopedAutoObject<KProcess> process;
/* Configure flags/value. */
if ((flags & 1) != 0) {
/* We're enabling the breakpoint. Check that the flags are allowable. */
R_UNLESS((flags & ForbiddenBreakPointFlagsMask) == 0, svc::ResultInvalidCombination());
/* Require that the breakpoint be linked or match context id. */
R_UNLESS((flags & ((1ul << 21) | (1ul << 20))) != 0, svc::ResultInvalidCombination());
/* If the breakpoint matches context id, we need to get the context id. */
if ((flags & (1ul << 21)) != 0) {
/* Ensure that the breakpoint is context-aware. */
R_UNLESS((name - ams::svc::HardwareBreakPointRegisterName_I0) <= (num_bp - num_ctx), svc::ResultNotSupported());
/* Check that the breakpoint does not have the mismatch bit. */
R_UNLESS((flags & (1ul << 22)) == 0, svc::ResultInvalidCombination());
/* Get the debug object from the current handle table. */
KScopedAutoObject debug = GetCurrentProcess().GetHandleTable().GetObject<KDebug>(static_cast<ams::svc::Handle>(value));
R_UNLESS(debug.IsNotNull(), svc::ResultInvalidHandle());
/* Get the process from the debug object. */
process = debug->GetProcess();
R_UNLESS(process.IsNotNull(), svc::ResultProcessTerminated());
/* Set the value to be the context id. */
value = process->GetId() & 0xFFFFFFFF;
}
/* Set the breakpoint as non-secure EL0-only. */
flags |= (1ul << 14) | (2ul << 1);
} else {
/* We're disabling the breakpoint. */
flags = 0;
value = 0;
}
/* Set the breakpoint. */
switch (name) {
case ams::svc::HardwareBreakPointRegisterName_I0: MESOSPHERE_SET_HW_BREAK_POINT( 0, flags, value); break;
case ams::svc::HardwareBreakPointRegisterName_I1: MESOSPHERE_SET_HW_BREAK_POINT( 1, flags, value); break;
case ams::svc::HardwareBreakPointRegisterName_I2: MESOSPHERE_SET_HW_BREAK_POINT( 2, flags, value); break;
case ams::svc::HardwareBreakPointRegisterName_I3: MESOSPHERE_SET_HW_BREAK_POINT( 3, flags, value); break;
case ams::svc::HardwareBreakPointRegisterName_I4: MESOSPHERE_SET_HW_BREAK_POINT( 4, flags, value); break;
case ams::svc::HardwareBreakPointRegisterName_I5: MESOSPHERE_SET_HW_BREAK_POINT( 5, flags, value); break;
case ams::svc::HardwareBreakPointRegisterName_I6: MESOSPHERE_SET_HW_BREAK_POINT( 6, flags, value); break;
case ams::svc::HardwareBreakPointRegisterName_I7: MESOSPHERE_SET_HW_BREAK_POINT( 7, flags, value); break;
case ams::svc::HardwareBreakPointRegisterName_I8: MESOSPHERE_SET_HW_BREAK_POINT( 8, flags, value); break;
case ams::svc::HardwareBreakPointRegisterName_I9: MESOSPHERE_SET_HW_BREAK_POINT( 9, flags, value); break;
case ams::svc::HardwareBreakPointRegisterName_I10: MESOSPHERE_SET_HW_BREAK_POINT(10, flags, value); break;
case ams::svc::HardwareBreakPointRegisterName_I11: MESOSPHERE_SET_HW_BREAK_POINT(11, flags, value); break;
case ams::svc::HardwareBreakPointRegisterName_I12: MESOSPHERE_SET_HW_BREAK_POINT(12, flags, value); break;
case ams::svc::HardwareBreakPointRegisterName_I13: MESOSPHERE_SET_HW_BREAK_POINT(13, flags, value); break;
case ams::svc::HardwareBreakPointRegisterName_I14: MESOSPHERE_SET_HW_BREAK_POINT(14, flags, value); break;
case ams::svc::HardwareBreakPointRegisterName_I15: MESOSPHERE_SET_HW_BREAK_POINT(15, flags, value); break;
default: break;
}
} else if (ams::svc::HardwareBreakPointRegisterName_D0 <= name && name <= ams::svc::HardwareBreakPointRegisterName_D15) {
/* Check that the name is a valid data breakpoint. */
R_UNLESS((name - ams::svc::HardwareBreakPointRegisterName_D0) <= num_wp, svc::ResultNotSupported());
/* Configure flags/value. */
if ((flags & 1) != 0) {
/* We're enabling the watchpoint. Check that the flags are allowable. */
R_UNLESS((flags & ForbiddenWatchPointFlagsMask) == 0, svc::ResultInvalidCombination());
/* Set the breakpoint as linked non-secure EL0-only. */
flags |= (1ul << 20) | (1ul << 14) | (2ul << 1);
} else {
/* We're disabling the watchpoint. */
flags = 0;
value = 0;
}
/* Set the watchkpoint. */
switch (name) {
case ams::svc::HardwareBreakPointRegisterName_D0: MESOSPHERE_SET_HW_WATCH_POINT( 0, flags, value); break;
case ams::svc::HardwareBreakPointRegisterName_D1: MESOSPHERE_SET_HW_WATCH_POINT( 1, flags, value); break;
case ams::svc::HardwareBreakPointRegisterName_D2: MESOSPHERE_SET_HW_WATCH_POINT( 2, flags, value); break;
case ams::svc::HardwareBreakPointRegisterName_D3: MESOSPHERE_SET_HW_WATCH_POINT( 3, flags, value); break;
case ams::svc::HardwareBreakPointRegisterName_D4: MESOSPHERE_SET_HW_WATCH_POINT( 4, flags, value); break;
case ams::svc::HardwareBreakPointRegisterName_D5: MESOSPHERE_SET_HW_WATCH_POINT( 5, flags, value); break;
case ams::svc::HardwareBreakPointRegisterName_D6: MESOSPHERE_SET_HW_WATCH_POINT( 6, flags, value); break;
case ams::svc::HardwareBreakPointRegisterName_D7: MESOSPHERE_SET_HW_WATCH_POINT( 7, flags, value); break;
case ams::svc::HardwareBreakPointRegisterName_D8: MESOSPHERE_SET_HW_WATCH_POINT( 8, flags, value); break;
case ams::svc::HardwareBreakPointRegisterName_D9: MESOSPHERE_SET_HW_WATCH_POINT( 9, flags, value); break;
case ams::svc::HardwareBreakPointRegisterName_D10: MESOSPHERE_SET_HW_WATCH_POINT(10, flags, value); break;
case ams::svc::HardwareBreakPointRegisterName_D11: MESOSPHERE_SET_HW_WATCH_POINT(11, flags, value); break;
case ams::svc::HardwareBreakPointRegisterName_D12: MESOSPHERE_SET_HW_WATCH_POINT(12, flags, value); break;
case ams::svc::HardwareBreakPointRegisterName_D13: MESOSPHERE_SET_HW_WATCH_POINT(13, flags, value); break;
case ams::svc::HardwareBreakPointRegisterName_D14: MESOSPHERE_SET_HW_WATCH_POINT(14, flags, value); break;
case ams::svc::HardwareBreakPointRegisterName_D15: MESOSPHERE_SET_HW_WATCH_POINT(15, flags, value); break;
default: break;
}
} else {
/* Invalid name. */
return svc::ResultInvalidEnumValue();
}
return ResultSuccess();
}
#undef MESOSPHERE_SET_HW_WATCH_POINT
#undef MESOSPHERE_SET_HW_BREAK_POINT
}