sanchayanmaity/gem5
1
0
Fork 0
Code Issues Pull requests Projects Releases Packages Wiki Activity

arm: Correctly check FP/SIMD access permission in aarch32

Browse source 
The current implementation of aarch32 FP/SIMD in gem5 assumes that EL1
and higher are all 32-bit. This breaks interprocessing since an
aarch64 EL1 uses different enable/disable bits. This change updates
the permission checks to according to what is prescribed by the ARM
ARM.

Change-Id: Icdcef31b00644cfeebec00216b3993aa1de12b88
Signed-off-by: Andreas Sandberg <andreas.sandberg@arm.com>
Reviewed-by: Mitch Hayenga <mitch.hayenga@arm.com>
Reviewed-by: Nathanael Premillieu <nathanael.premillieu@arm.com>
This commit is contained in:
Andreas Sandberg 2016-06-02 13:38:30 +01:00
parent 53ae19bb5d
commit f48ad5b29d
7 changed files with 227 additions and 232 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

134
src/arch/arm/insts/static_inst.cc
View file

@ -1,5 +1,5 @@
/*
* Copyright (c) 2010-2014 ARM Limited
* Copyright (c) 2010-2014, 2016 ARM Limited
* Copyright (c) 2013 Advanced Micro Devices, Inc.
* All rights reserved
*
@ -595,4 +595,136 @@ ArmStaticInst::generateDisassembly(Addr pc,
printMnemonic(ss);
return ss.str();
}
Fault
ArmStaticInst::advSIMDFPAccessTrap64(ExceptionLevel el) const
{
switch (el) {
case EL1:
return std::make_shared<SupervisorTrap>(machInst, 0x1E00000,
EC_TRAPPED_SIMD_FP);
case EL2:
return std::make_shared<HypervisorTrap>(machInst, 0x1E00000,
EC_TRAPPED_SIMD_FP);
case EL3:
return std::make_shared<SecureMonitorTrap>(machInst, 0x1E00000,
EC_TRAPPED_SIMD_FP);
default:
panic("Illegal EL in advSIMDFPAccessTrap64\n");
}
}
Fault
ArmStaticInst::checkFPAdvSIMDTrap64(ThreadContext *tc, CPSR cpsr) const
{
const ExceptionLevel el = (ExceptionLevel) (uint8_t)cpsr.el;
if (ArmSystem::haveVirtualization(tc) && el <= EL2) {
HCPTR cptrEnCheck = tc->readMiscReg(MISCREG_CPTR_EL2);
if (cptrEnCheck.tfp)
return advSIMDFPAccessTrap64(EL2);
}
if (ArmSystem::haveSecurity(tc)) {
HCPTR cptrEnCheck = tc->readMiscReg(MISCREG_CPTR_EL3);
if (cptrEnCheck.tfp)
return advSIMDFPAccessTrap64(EL3);
}
return NoFault;
}
Fault
ArmStaticInst::checkFPAdvSIMDEnabled64(ThreadContext *tc,
CPSR cpsr, CPACR cpacr) const
{
const ExceptionLevel el = (ExceptionLevel) (uint8_t)cpsr.el;
if ((el == EL0 && cpacr.fpen != 0x3) ||
(el == EL1 && !(cpacr.fpen & 0x1)))
return advSIMDFPAccessTrap64(EL1);
return checkFPAdvSIMDTrap64(tc, cpsr);
}
Fault
ArmStaticInst::checkAdvSIMDOrFPEnabled32(ThreadContext *tc,
CPSR cpsr, CPACR cpacr,
NSACR nsacr, FPEXC fpexc,
bool fpexc_check, bool advsimd) const
{
const bool have_virtualization = ArmSystem::haveVirtualization(tc);
const bool have_security = ArmSystem::haveSecurity(tc);
const bool is_secure = inSecureState(tc);
const ExceptionLevel cur_el = opModeToEL(currOpMode(tc));
if (cur_el == EL0 && ELIs64(tc, EL1))
return checkFPAdvSIMDEnabled64(tc, cpsr, cpacr);
uint8_t cpacr_cp10 = cpacr.cp10;
bool cpacr_asedis = cpacr.asedis;
if (have_security && !ELIs64(tc, EL3) && !is_secure) {
if (nsacr.nsasedis)
cpacr_asedis = true;
if (nsacr.cp10 == 0)
cpacr_cp10 = 0;
}
if (cur_el != EL2) {
if (advsimd && cpacr_asedis)
return disabledFault();
if ((cur_el == EL0 && cpacr_cp10 != 0x3) ||
(cur_el != EL0 && !(cpacr_cp10 & 0x1)))
return disabledFault();
}
if (fpexc_check && !fpexc.en)
return disabledFault();
// -- aarch32/exceptions/traps/AArch32.CheckFPAdvSIMDTrap --
if (have_virtualization && !is_secure && ELIs64(tc, EL2))
return checkFPAdvSIMDTrap64(tc, cpsr);
if (have_virtualization && !is_secure) {
HCPTR hcptr = tc->readMiscReg(MISCREG_HCPTR);
bool hcptr_cp10 = hcptr.tcp10;
bool hcptr_tase = hcptr.tase;
if (have_security && !ELIs64(tc, EL3) && !is_secure) {
if (nsacr.nsasedis)
hcptr_tase = true;
if (nsacr.cp10)
hcptr_cp10 = true;
}
if ((advsimd && hcptr_tase) || hcptr_cp10) {
const uint32_t iss = advsimd ? (1 << 5) : 0xA;
if (cur_el == EL2) {
return std::make_shared<UndefinedInstruction>(
machInst, iss,
EC_TRAPPED_HCPTR, mnemonic);
} else {
return std::make_shared<HypervisorTrap>(
machInst, iss,
EC_TRAPPED_HCPTR);
}
}
}
if (have_security && ELIs64(tc, EL3)) {
HCPTR cptrEnCheck = tc->readMiscReg(MISCREG_CPTR_EL3);
if (cptrEnCheck.tfp)
return advSIMDFPAccessTrap64(EL3);
}
return NoFault;
}
}

43
src/arch/arm/insts/static_inst.hh
View file

@ -1,5 +1,5 @@
/*
* Copyright (c) 2010-2013 ARM Limited
* Copyright (c) 2010-2013, 2016 ARM Limited
* All rights reserved
*
* The license below extends only to copyright in the software and shall
@ -363,6 +363,47 @@ class ArmStaticInst : public StaticInst
mnemonic, true);
}
/**
* Trap an access to Advanced SIMD or FP registers due to access
* control bits.
*
* See aarch64/exceptions/traps/AArch64.AdvSIMDFPAccessTrap in the
* ARM ARM psueodcode library.
*
* @param el Target EL for the trap
*/
Fault advSIMDFPAccessTrap64(ExceptionLevel el) const;
/**
* Check an Advaned SIMD access against CPTR_EL2 and CPTR_EL3.
*
* See aarch64/exceptions/traps/AArch64.CheckFPAdvSIMDTrap in the
* ARM ARM psueodcode library.
*/
Fault checkFPAdvSIMDTrap64(ThreadContext *tc, CPSR cpsr) const;
/**
* Check an Advaned SIMD access against CPACR_EL1, CPTR_EL2, and
* CPTR_EL3.
*
* See aarch64/exceptions/traps/AArch64.CheckFPAdvSIMDEnabled in the
* ARM ARM psueodcode library.
*/
Fault checkFPAdvSIMDEnabled64(ThreadContext *tc,
CPSR cpsr, CPACR cpacr) const;
/**
* Check if a VFP/SIMD access from aarch32 should be allowed.
*
* See aarch32/exceptions/traps/AArch32.CheckAdvSIMDOrFPEnabled in the
* ARM ARM psueodcode library.
*/
Fault checkAdvSIMDOrFPEnabled32(ThreadContext *tc,
CPSR cpsr, CPACR cpacr,
NSACR nsacr, FPEXC fpexc,
bool fpexc_check, bool advsimd) const;
public:
virtual void
annotateFault(ArmFault *fault) {}

2
src/arch/arm/isa/insts/fp.isa
View file

@ -260,7 +260,7 @@ let {{
decoder_output += FpRegRegOpConstructor.subst(vmrsFpscrIop);
exec_output += PredOpExecute.subst(vmrsFpscrIop);
vmrsApsrFpscrCode = vmrsApsrEnabledCheckCode + '''
vmrsApsrFpscrCode = vfpEnabledCheckCode + '''
FPSCR fpscr = FpCondCodes;
CondCodesNZ = (fpscr.n << 1) | fpscr.z;
CondCodesC = fpscr.c;

27
src/arch/arm/isa/templates/neon.isa
View file

@ -1,6 +1,6 @@
// -*- mode:c++ -*-
// Copyright (c) 2010-2012 ARM Limited
// Copyright (c) 2010-2012, 2016 ARM Limited
// All rights reserved
//
// The license below extends only to copyright in the software and shall
@ -40,26 +40,11 @@
let {{
simdEnabledCheckCode = '''
{
uint32_t issEnCheck;
bool trapEnCheck;
uint32_t seq;
if (!vfpNeonEnabled(seq, Hcptr, Nsacr, Cpacr, Cpsr, issEnCheck,
trapEnCheck, xc->tcBase(), Fpexc, true))
{return disabledFault();}
if (trapEnCheck) {
CPSR cpsrEnCheck = Cpsr;
if (cpsrEnCheck.mode == MODE_HYP) {
return std::make_shared<UndefinedInstruction>(
machInst, issEnCheck,
EC_TRAPPED_HCPTR);
} else {
if (!inSecureState(Scr, Cpsr)) {
return std::make_shared<HypervisorTrap>(
machInst, issEnCheck,
EC_TRAPPED_HCPTR);
}
}
}
Fault fault = checkAdvSIMDOrFPEnabled32(xc->tcBase(),
Cpsr, Cpacr, Nsacr, Fpexc,
true, true);
if (fault != NoFault)
return fault;
}
'''
}};

142
src/arch/arm/isa/templates/vfp.isa
View file

@ -1,6 +1,6 @@
// -*- mode:c++ -*-
// Copyright (c) 2010-2013 ARM Limited
// Copyright (c) 2010-2013, 2016 ARM Limited
// All rights reserved
//
// The license below extends only to copyright in the software and shall
@ -39,124 +39,60 @@
let {{
vfpEnabledCheckCode = '''
uint32_t issEnCheck;
bool trapEnCheck;
uint32_t seq;
if (!vfpNeonEnabled(seq,Hcptr, Nsacr, Cpacr, Cpsr, issEnCheck,
trapEnCheck, xc->tcBase(), Fpexc))
{return disabledFault();}
if (trapEnCheck) {
CPSR cpsrEnCheck = Cpsr;
if (cpsrEnCheck.mode == MODE_HYP) {
return std::make_shared<UndefinedInstruction>(
machInst, issEnCheck,
EC_TRAPPED_HCPTR, mnemonic);
} else {
if (!inSecureState(Scr, Cpsr)) {
return std::make_shared<HypervisorTrap>(
machInst, issEnCheck,
EC_TRAPPED_HCPTR);
}
}
{
Fault fault = checkAdvSIMDOrFPEnabled32(xc->tcBase(),
Cpsr, Cpacr, Nsacr, Fpexc,
true, false);
if (fault != NoFault)
return fault;
}
'''
vfp64EnabledCheckCode = '''
CPSR cpsrEnCheck = Cpsr;
ExceptionLevel el = (ExceptionLevel) (uint8_t) cpsrEnCheck.el;
if (!vfpNeon64Enabled(Cpacr64, el))
return std::make_shared<SupervisorTrap>(machInst, 0x1E00000,
EC_TRAPPED_SIMD_FP);
if (ArmSystem::haveVirtualization(xc->tcBase()) && el <= EL2) {
HCPTR cptrEnCheck = xc->tcBase()->readMiscReg(MISCREG_CPTR_EL2);
if (cptrEnCheck.tfp)
return std::make_shared<HypervisorTrap>(machInst, 0x1E00000,
EC_TRAPPED_SIMD_FP);
}
if (ArmSystem::haveSecurity(xc->tcBase())) {
HCPTR cptrEnCheck = xc->tcBase()->readMiscReg(MISCREG_CPTR_EL3);
if (cptrEnCheck.tfp)
return std::make_shared<SecureMonitorTrap>(machInst, 0x1E00000,
EC_TRAPPED_SIMD_FP);
{
Fault fault = checkFPAdvSIMDEnabled64(xc->tcBase(), Cpsr, Cpacr64);
if (fault != NoFault)
return fault;
}
'''
vmsrEnabledCheckCode = '''
uint32_t issEnCheck;
bool trapEnCheck;
uint32_t seq;
if (!vfpNeonEnabled(seq,Hcptr, Nsacr, Cpacr, Cpsr, issEnCheck,
trapEnCheck, xc->tcBase()))
if (dest != (int)MISCREG_FPEXC && dest != (int)MISCREG_FPSID)
{return disabledFault();}
if (!inPrivilegedMode(Cpsr))
if (dest != (int)MISCREG_FPSCR)
return disabledFault();
if (trapEnCheck) {
CPSR cpsrEnCheck = Cpsr;
if (cpsrEnCheck.mode == MODE_HYP) {
return std::make_shared<UndefinedInstruction>(
machInst, issEnCheck,
EC_TRAPPED_HCPTR, mnemonic);
{
Fault fault = NoFault;
if (dest == (int)MISCREG_FPSCR) {
fault = checkAdvSIMDOrFPEnabled32(xc->tcBase(),
Cpsr, Cpacr, Nsacr, Fpexc,
true, false);
} else if (!inPrivilegedMode(Cpsr)) {
fault = disabledFault();
} else {
if (!inSecureState(Scr, Cpsr)) {
return std::make_shared<HypervisorTrap>(
machInst, issEnCheck,
EC_TRAPPED_HCPTR);
}
fault = checkAdvSIMDOrFPEnabled32(xc->tcBase(),
Cpsr, Cpacr, Nsacr, Fpexc,
false, false);
}
if (fault != NoFault)
return fault;
}
'''
vmrsEnabledCheckCode = '''
uint32_t issEnCheck;
bool trapEnCheck;
uint32_t seq;
if (!vfpNeonEnabled(seq,Hcptr, Nsacr, Cpacr, Cpsr, issEnCheck,
trapEnCheck, xc->tcBase()))
if (op1 != (int)MISCREG_FPEXC && op1 != (int)MISCREG_FPSID &&
op1 != (int)MISCREG_MVFR0 && op1 != (int)MISCREG_MVFR1)
{return disabledFault();}
if (!inPrivilegedMode(Cpsr))
if (op1 != (int)MISCREG_FPSCR)
return disabledFault();
if (trapEnCheck) {
CPSR cpsrEnCheck = Cpsr;
if (cpsrEnCheck.mode == MODE_HYP) {
return std::make_shared<UndefinedInstruction>(
machInst, issEnCheck,
EC_TRAPPED_HCPTR, mnemonic);
{
Fault fault = NoFault;
if (op1 == (int)MISCREG_FPSCR) {
fault = checkAdvSIMDOrFPEnabled32(xc->tcBase(),
Cpsr, Cpacr, Nsacr, Fpexc,
true, false);
} else if (!inPrivilegedMode(Cpsr)) {
fault = disabledFault();
} else {
if (!inSecureState(Scr, Cpsr)) {
return std::make_shared<HypervisorTrap>(
machInst, issEnCheck,
EC_TRAPPED_HCPTR);
}
}
}
'''
vmrsApsrEnabledCheckCode = '''
uint32_t issEnCheck;
bool trapEnCheck;
uint32_t seq;
if (!vfpNeonEnabled(seq,Hcptr, Nsacr, Cpacr, Cpsr, issEnCheck,
trapEnCheck, xc->tcBase()))
{return disabledFault();}
if (trapEnCheck) {
CPSR cpsrEnCheck = Cpsr;
if (cpsrEnCheck.mode == MODE_HYP) {
return std::make_shared<UndefinedInstruction>(
machInst, issEnCheck,
EC_TRAPPED_HCPTR, mnemonic);
} else {
if (!inSecureState(Scr, Cpsr)) {
return std::make_shared<HypervisorTrap>(
machInst, issEnCheck,
EC_TRAPPED_HCPTR);
}
fault = checkAdvSIMDOrFPEnabled32(xc->tcBase(),
Cpsr, Cpacr, Nsacr, Fpexc,
false, false);
}
if (fault != NoFault)
return fault;
}
'''
}};

85
src/arch/arm/utility.cc
View file

@ -869,91 +869,6 @@ decodeMrsMsrBankedReg(uint8_t sysM, bool r, bool &isIntReg, int &regIdx,
return (ok);
}
bool
vfpNeonEnabled(uint32_t &seq, HCPTR hcptr, NSACR nsacr, CPACR cpacr, CPSR cpsr,
uint32_t &iss, bool &trap, ThreadContext *tc, FPEXC fpexc,
bool isSIMD)
{
iss = 0;
trap = false;
bool undefined = false;
bool haveSecurity = ArmSystem::haveSecurity(tc);
bool haveVirtualization = ArmSystem::haveVirtualization(tc);
bool isSecure = inSecureState(tc);
// Non-secure view of CPACR and HCPTR determines behavior
// Copy register values
uint8_t cpacr_cp10 = cpacr.cp10;
bool cpacr_asedis = cpacr.asedis;
bool hcptr_cp10 = false;
bool hcptr_tase = false;
bool cp10_enabled = cpacr.cp10 == 0x3
|| (cpacr.cp10 == 0x1 && inPrivilegedMode(cpsr));
bool cp11_enabled = cpacr.cp11 == 0x3
|| (cpacr.cp11 == 0x1 && inPrivilegedMode(cpsr));
if (cp11_enabled) {
undefined |= !(fpexc.en && cp10_enabled);
} else {
undefined |= !(fpexc.en && cp10_enabled && (cpacr.cp11 == cpacr.cp10));
}
if (haveVirtualization) {
hcptr_cp10 = hcptr.tcp10;
undefined |= hcptr.tcp10 != hcptr.tcp11;
hcptr_tase = hcptr.tase;
}
if (haveSecurity) {
undefined |= nsacr.cp10 != nsacr.cp11;
if (!isSecure) {
// Modify register values to the Non-secure view
if (!nsacr.cp10) {
cpacr_cp10 = 0;
if (haveVirtualization) {
hcptr_cp10 = true;
}
}
if (nsacr.nsasedis) {
cpacr_asedis = true;
if (haveVirtualization) {
hcptr_tase = true;
}
}
}
}
// Check Coprocessor Access Control Register for permission to use CP10/11.
if (!haveVirtualization || (cpsr.mode != MODE_HYP)) {
switch (cpacr_cp10)
{
case 0:
undefined = true;
break;
case 1:
undefined |= inUserMode(cpsr);
break;
}
// Check if SIMD operations are disabled
if (isSIMD && cpacr_asedis) undefined = true;
}
// If required, check FPEXC enabled bit.
undefined |= !fpexc.en;
if (haveSecurity && haveVirtualization && !isSecure) {
if (hcptr_cp10 || (isSIMD && hcptr_tase)) {
iss = isSIMD ? (1 << 5) : 0xA;
trap = true;
}
}
return (!undefined);
}
bool
SPAlignmentCheckEnabled(ThreadContext* tc)
{

14
src/arch/arm/utility.hh
View file

@ -260,20 +260,6 @@ bool msrMrs64TrapToHyp(const MiscRegIndex miscReg, bool isRead, CPTR cptr,
bool msrMrs64TrapToMon(const MiscRegIndex miscReg, CPTR cptr,
ExceptionLevel el, bool * isVfpNeon);
bool
vfpNeonEnabled(uint32_t &seq, HCPTR hcptr, NSACR nsacr, CPACR cpacr, CPSR cpsr,
uint32_t &iss, bool &trap, ThreadContext *tc,
FPEXC fpexc = (1<<30), bool isSIMD = false);
static inline bool
vfpNeon64Enabled(CPACR cpacr, ExceptionLevel el)
{
if ((el == EL0 && cpacr.fpen != 0x3) ||
(el == EL1 && !(cpacr.fpen & 0x1)))
return false;
return true;
}
bool SPAlignmentCheckEnabled(ThreadContext* tc);
uint64_t getArgument(ThreadContext *tc, int &number, uint16_t size, bool fp);