src/cpu/checker/cpu.cc - public/gem5 - Git at Google

 /*
  * Copyright (c) 2011,2013,2017-2018, 2020 ARM Limited
  * All rights reserved
  *
  * The license below extends only to copyright in the software and shall
  * not be construed as granting a license to any other intellectual
  * property including but not limited to intellectual property relating
  * to a hardware implementation of the functionality of the software
  * licensed hereunder.  You may use the software subject to the license
  * terms below provided that you ensure that this notice is replicated
  * unmodified and in its entirety in all distributions of the software,
  * modified or unmodified, in source code or in binary form.
  *
  * Copyright (c) 2006 The Regents of The University of Michigan
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met: redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer;
  * redistributions in binary form must reproduce the above copyright
  * notice, this list of conditions and the following disclaimer in the
  * documentation and/or other materials provided with the distribution;
  * neither the name of the copyright holders nor the names of its
  * contributors may be used to endorse or promote products derived from
  * this software without specific prior written permission.
  *
  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */

 #include "cpu/checker/cpu.hh"

 #include <list>
 #include <string>

 #include "arch/generic/tlb.hh"
 #include "cpu/base.hh"
 #include "cpu/simple_thread.hh"
 #include "cpu/static_inst.hh"
 #include "cpu/thread_context.hh"
 #include "cpu/utils.hh"
 #include "params/CheckerCPU.hh"
 #include "sim/full_system.hh"

 namespace gem5
 {

 void
 CheckerCPU::init()
 {
     requestorId = systemPtr->getRequestorId(this);
     tc->getIsaPtr()->setThreadContext(tc);
 }

 CheckerCPU::CheckerCPU(const Params &p)
     : BaseCPU(p, true),
       zeroReg(params().isa[0]->regClasses().at(IntRegClass).zeroReg()),
       systemPtr(NULL), icachePort(NULL), dcachePort(NULL),
       tc(NULL), thread(NULL),
       unverifiedReq(nullptr),
       unverifiedMemData(nullptr)
 {
     curStaticInst = NULL;
     curMacroStaticInst = NULL;

     numInst = 0;
     startNumInst = 0;
     numLoad = 0;
     startNumLoad = 0;
     youngestSN = 0;

     changedPC = willChangePC = false;

     exitOnError = p.exitOnError;
     warnOnlyOnLoadError = p.warnOnlyOnLoadError;
     mmu = p.mmu;
     workload = p.workload;

     updateOnError = true;
 }

 CheckerCPU::~CheckerCPU()
 {
 }

 void
 CheckerCPU::setSystem(System *system)
 {
     const Params &p = params();

     systemPtr = system;

     if (FullSystem) {
         thread = new SimpleThread(this, 0, systemPtr, mmu, p.isa[0]);
     } else {
         thread = new SimpleThread(this, 0, systemPtr,
                                   workload.size() ? workload[0] : NULL,
                                   mmu, p.isa[0]);
     }

     tc = thread->getTC();
     threadContexts.push_back(tc);
     // Thread should never be null after this
     assert(thread != NULL);
 }

 void
 CheckerCPU::setIcachePort(RequestPort *icache_port)
 {
     icachePort = icache_port;
 }

 void
 CheckerCPU::setDcachePort(RequestPort *dcache_port)
 {
     dcachePort = dcache_port;
 }

 void
 CheckerCPU::serialize(std::ostream &os) const
 {
 }

 void
 CheckerCPU::unserialize(CheckpointIn &cp)
 {
 }

 RequestPtr
 CheckerCPU::genMemFragmentRequest(Addr frag_addr, int size,
                                   Request::Flags flags,
                                   const std::vector<bool>& byte_enable,
                                   int& frag_size, int& size_left) const
 {
     frag_size = std::min(
         cacheLineSize() - addrBlockOffset(frag_addr, cacheLineSize()),
         (Addr) size_left);
     size_left -= frag_size;

     RequestPtr mem_req;

     // Set up byte-enable mask for the current fragment
     auto it_start = byte_enable.cbegin() + (size - (frag_size +
                                                     size_left));
     auto it_end = byte_enable.cbegin() + (size - size_left);
     if (isAnyActiveElement(it_start, it_end)) {
         mem_req = std::make_shared<Request>(frag_addr, frag_size,
                 flags, requestorId, thread->pcState().instAddr(),
                 tc->contextId());
         mem_req->setByteEnable(std::vector<bool>(it_start, it_end));
     }

     return mem_req;
 }

 Fault
 CheckerCPU::readMem(Addr addr, uint8_t *data, unsigned size,
                     Request::Flags flags,
                     const std::vector<bool>& byte_enable)
 {
     assert(byte_enable.size() == size);

     Fault fault = NoFault;
     bool checked_flags = false;
     bool flags_match = true;
     Addr pAddr = 0x0;

     Addr frag_addr = addr;
     int frag_size = 0;
     int size_left = size;
     bool predicate;

     // Need to account for multiple accesses like the Atomic and TimingSimple
     while (1) {
         RequestPtr mem_req = genMemFragmentRequest(frag_addr, size, flags,
                                                    byte_enable, frag_size,
                                                    size_left);

         predicate = (mem_req != nullptr);

         // translate to physical address
         if (predicate) {
             fault = mmu->translateFunctional(mem_req, tc, BaseMMU::Read);
         }

         if (predicate && !checked_flags && fault == NoFault && unverifiedReq) {
             flags_match = checkFlags(unverifiedReq, mem_req->getVaddr(),
                                      mem_req->getPaddr(), mem_req->getFlags());
             pAddr = mem_req->getPaddr();
             checked_flags = true;
         }

         // Now do the access
         if (predicate && fault == NoFault &&
             !mem_req->getFlags().isSet(Request::NO_ACCESS)) {
             PacketPtr pkt = Packet::createRead(mem_req);

             pkt->dataStatic(data);

             if (!(mem_req->isUncacheable() || mem_req->isLocalAccess())) {
                 // Access memory to see if we have the same data
                 dcachePort->sendFunctional(pkt);
             } else {
                 // Assume the data is correct if it's an uncached access
                 memcpy(data, unverifiedMemData, frag_size);
             }

             delete pkt;
         }

         if (fault != NoFault) {
             if (mem_req->isPrefetch()) {
                 fault = NoFault;
             }
             break;
         }

         //If we don't need to access a second cache line, stop now.
         if (size_left == 0)
         {
             break;
         }

         // Setup for accessing next cache line
         frag_addr += frag_size;
         data += frag_size;
         unverifiedMemData += frag_size;
     }

     if (!flags_match) {
         warn("%lli: Flags do not match CPU:%#x %#x %#x Checker:%#x %#x %#x\n",
              curTick(), unverifiedReq->getVaddr(), unverifiedReq->getPaddr(),
              unverifiedReq->getFlags(), frag_addr, pAddr, flags);
         handleError();
     }

     return fault;
 }

 Fault
 CheckerCPU::writeMem(uint8_t *data, unsigned size,
                      Addr addr, Request::Flags flags, uint64_t *res,
                      const std::vector<bool>& byte_enable)
 {
     assert(byte_enable.size() == size);

     Fault fault = NoFault;
     bool checked_flags = false;
     bool flags_match = true;
     Addr pAddr = 0x0;
     static uint8_t zero_data[64] = {};

     Addr frag_addr = addr;
     int frag_size = 0;
     int size_left = size;
     bool predicate;

     // Need to account for a multiple access like Atomic and Timing CPUs
     while (1) {
         RequestPtr mem_req = genMemFragmentRequest(frag_addr, size, flags,
                                                    byte_enable, frag_size,
                                                    size_left);

         predicate = (mem_req != nullptr);

         if (predicate) {
             fault = mmu->translateFunctional(mem_req, tc, BaseMMU::Write);
         }

         if (predicate && !checked_flags && fault == NoFault && unverifiedReq) {
            flags_match = checkFlags(unverifiedReq, mem_req->getVaddr(),
                                     mem_req->getPaddr(), mem_req->getFlags());
            pAddr = mem_req->getPaddr();
            checked_flags = true;
         }

         /*
          * We don't actually check memory for the store because there
          * is no guarantee it has left the lsq yet, and therefore we
          * can't verify the memory on stores without lsq snooping
          * enabled.  This is left as future work for the Checker: LSQ snooping
          * and memory validation after stores have committed.
          */
         bool was_prefetch = mem_req->isPrefetch();

         //If we don't need to access a second cache line, stop now.
         if (fault != NoFault || size_left == 0)
         {
             if (fault != NoFault && was_prefetch) {
               fault = NoFault;
             }
             break;
         }

         frag_addr += frag_size;
    }

    if (!flags_match) {
        warn("%lli: Flags do not match CPU:%#x %#x Checker:%#x %#x %#x\n",
             curTick(), unverifiedReq->getVaddr(), unverifiedReq->getPaddr(),
             unverifiedReq->getFlags(), frag_addr, pAddr, flags);
        handleError();
    }

    // Assume the result was the same as the one passed in.  This checker
    // doesn't check if the SC should succeed or fail, it just checks the
    // value.
    if (unverifiedReq && res && unverifiedReq->extraDataValid())
        *res = unverifiedReq->getExtraData();

    // Entire purpose here is to make sure we are getting the
    // same data to send to the mem system as the CPU did.
    // Cannot check this is actually what went to memory because
    // there stores can be in ld/st queue or coherent operations
    // overwriting values.
    bool extraData = false;
    if (unverifiedReq) {
        extraData = unverifiedReq->extraDataValid() ?
                         unverifiedReq->getExtraData() : true;
    }

    // If the request is to ZERO a cache block, there is no data to check
    // against, but it's all zero. We need something to compare to, so use a
    // const set of zeros.
    if (flags & Request::STORE_NO_DATA) {
        assert(!data);
        assert(sizeof(zero_data) <= size);
        data = zero_data;
    }

    if (unverifiedReq && unverifiedMemData &&
        memcmp(data, unverifiedMemData, size) && extraData) {
            warn("%lli: Store value does not match value sent to memory! "
                   "data: %#x inst_data: %#x", curTick(), data,
                   unverifiedMemData);
        handleError();
    }

    return fault;
 }

 /**
  * Checks if the flags set by the Checker and Checkee match.
  */
 bool
 CheckerCPU::checkFlags(const RequestPtr &unverified_req, Addr vAddr,
                        Addr pAddr, int flags)
 {
     Addr unverifiedVAddr = unverified_req->getVaddr();
     Addr unverifiedPAddr = unverified_req->getPaddr();
     int unverifiedFlags = unverified_req->getFlags();

     if (unverifiedVAddr != vAddr ||
         unverifiedPAddr != pAddr ||
         unverifiedFlags != flags) {
         return false;
     }

     return true;
 }

 void
 CheckerCPU::dumpAndExit()
 {
     warn("%lli: Checker PC:%s",
          curTick(), thread->pcState());
     panic("Checker found an error!");
 }

 } // namespace gem5
	/*
	* Copyright (c) 2011,2013,2017-2018, 2020 ARM Limited
	* All rights reserved
	*
	* The license below extends only to copyright in the software and shall
	* not be construed as granting a license to any other intellectual
	* property including but not limited to intellectual property relating
	* to a hardware implementation of the functionality of the software
	* licensed hereunder. You may use the software subject to the license
	* terms below provided that you ensure that this notice is replicated
	* unmodified and in its entirety in all distributions of the software,
	* modified or unmodified, in source code or in binary form.
	*
	* Copyright (c) 2006 The Regents of The University of Michigan
	* All rights reserved.
	*
	* Redistribution and use in source and binary forms, with or without
	* modification, are permitted provided that the following conditions are
	* met: redistributions of source code must retain the above copyright
	* notice, this list of conditions and the following disclaimer;
	* redistributions in binary form must reproduce the above copyright
	* notice, this list of conditions and the following disclaimer in the
	* documentation and/or other materials provided with the distribution;
	* neither the name of the copyright holders nor the names of its
	* contributors may be used to endorse or promote products derived from
	* this software without specific prior written permission.
	*
	* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
	* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
	* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
	* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
	* OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
	* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
	* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
	* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
	* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
	* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
	* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
	*/

	#include "cpu/checker/cpu.hh"

	#include <list>
	#include <string>

	#include "arch/generic/tlb.hh"
	#include "cpu/base.hh"
	#include "cpu/simple_thread.hh"
	#include "cpu/static_inst.hh"
	#include "cpu/thread_context.hh"
	#include "cpu/utils.hh"
	#include "params/CheckerCPU.hh"
	#include "sim/full_system.hh"

	namespace gem5
	{

	void
	CheckerCPU::init()
	{
	requestorId = systemPtr->getRequestorId(this);
	tc->getIsaPtr()->setThreadContext(tc);
	}

	CheckerCPU::CheckerCPU(const Params &p)
	: BaseCPU(p, true),
	zeroReg(params().isa[0]->regClasses().at(IntRegClass).zeroReg()),
	systemPtr(NULL), icachePort(NULL), dcachePort(NULL),
	tc(NULL), thread(NULL),
	unverifiedReq(nullptr),
	unverifiedMemData(nullptr)
	{
	curStaticInst = NULL;
	curMacroStaticInst = NULL;

	numInst = 0;
	startNumInst = 0;
	numLoad = 0;
	startNumLoad = 0;
	youngestSN = 0;

	changedPC = willChangePC = false;

	exitOnError = p.exitOnError;
	warnOnlyOnLoadError = p.warnOnlyOnLoadError;
	mmu = p.mmu;
	workload = p.workload;

	updateOnError = true;
	}

	CheckerCPU::~CheckerCPU()
	{
	}

	void
	CheckerCPU::setSystem(System *system)
	{
	const Params &p = params();

	systemPtr = system;

	if (FullSystem) {
	thread = new SimpleThread(this, 0, systemPtr, mmu, p.isa[0]);
	} else {
	thread = new SimpleThread(this, 0, systemPtr,
	workload.size() ? workload[0] : NULL,
	mmu, p.isa[0]);
	}

	tc = thread->getTC();
	threadContexts.push_back(tc);
	// Thread should never be null after this
	assert(thread != NULL);
	}

	void
	CheckerCPU::setIcachePort(RequestPort *icache_port)
	{
	icachePort = icache_port;
	}

	void
	CheckerCPU::setDcachePort(RequestPort *dcache_port)
	{
	dcachePort = dcache_port;
	}

	void
	CheckerCPU::serialize(std::ostream &os) const
	{
	}

	void
	CheckerCPU::unserialize(CheckpointIn &cp)
	{
	}

	RequestPtr
	CheckerCPU::genMemFragmentRequest(Addr frag_addr, int size,
	Request::Flags flags,
	const std::vector<bool>& byte_enable,
	int& frag_size, int& size_left) const
	{
	frag_size = std::min(
	cacheLineSize() - addrBlockOffset(frag_addr, cacheLineSize()),
	(Addr) size_left);
	size_left -= frag_size;

	RequestPtr mem_req;

	// Set up byte-enable mask for the current fragment
	auto it_start = byte_enable.cbegin() + (size - (frag_size +
	size_left));
	auto it_end = byte_enable.cbegin() + (size - size_left);
	if (isAnyActiveElement(it_start, it_end)) {
	mem_req = std::make_shared<Request>(frag_addr, frag_size,
	flags, requestorId, thread->pcState().instAddr(),
	tc->contextId());
	mem_req->setByteEnable(std::vector<bool>(it_start, it_end));
	}

	return mem_req;
	}

	Fault
	CheckerCPU::readMem(Addr addr, uint8_t *data, unsigned size,
	Request::Flags flags,
	const std::vector<bool>& byte_enable)
	{
	assert(byte_enable.size() == size);

	Fault fault = NoFault;
	bool checked_flags = false;
	bool flags_match = true;
	Addr pAddr = 0x0;

	Addr frag_addr = addr;
	int frag_size = 0;
	int size_left = size;
	bool predicate;

	// Need to account for multiple accesses like the Atomic and TimingSimple
	while (1) {
	RequestPtr mem_req = genMemFragmentRequest(frag_addr, size, flags,
	byte_enable, frag_size,
	size_left);

	predicate = (mem_req != nullptr);

	// translate to physical address
	if (predicate) {
	fault = mmu->translateFunctional(mem_req, tc, BaseMMU::Read);
	}

	if (predicate && !checked_flags && fault == NoFault && unverifiedReq) {
	flags_match = checkFlags(unverifiedReq, mem_req->getVaddr(),
	mem_req->getPaddr(), mem_req->getFlags());
	pAddr = mem_req->getPaddr();
	checked_flags = true;
	}

	// Now do the access
	if (predicate && fault == NoFault &&
	!mem_req->getFlags().isSet(Request::NO_ACCESS)) {
	PacketPtr pkt = Packet::createRead(mem_req);

	pkt->dataStatic(data);

	if (!(mem_req->isUncacheable() \|\| mem_req->isLocalAccess())) {
	// Access memory to see if we have the same data
	dcachePort->sendFunctional(pkt);
	} else {
	// Assume the data is correct if it's an uncached access
	memcpy(data, unverifiedMemData, frag_size);
	}

	delete pkt;
	}

	if (fault != NoFault) {
	if (mem_req->isPrefetch()) {
	fault = NoFault;
	}
	break;
	}

	//If we don't need to access a second cache line, stop now.
	if (size_left == 0)
	{
	break;
	}

	// Setup for accessing next cache line
	frag_addr += frag_size;
	data += frag_size;
	unverifiedMemData += frag_size;
	}

	if (!flags_match) {
	warn("%lli: Flags do not match CPU:%#x %#x %#x Checker:%#x %#x %#x\n",
	curTick(), unverifiedReq->getVaddr(), unverifiedReq->getPaddr(),
	unverifiedReq->getFlags(), frag_addr, pAddr, flags);
	handleError();
	}

	return fault;
	}

	Fault
	CheckerCPU::writeMem(uint8_t *data, unsigned size,
	Addr addr, Request::Flags flags, uint64_t *res,
	const std::vector<bool>& byte_enable)
	{
	assert(byte_enable.size() == size);

	Fault fault = NoFault;
	bool checked_flags = false;
	bool flags_match = true;
	Addr pAddr = 0x0;
	static uint8_t zero_data[64] = {};

	Addr frag_addr = addr;
	int frag_size = 0;
	int size_left = size;
	bool predicate;

	// Need to account for a multiple access like Atomic and Timing CPUs
	while (1) {
	RequestPtr mem_req = genMemFragmentRequest(frag_addr, size, flags,
	byte_enable, frag_size,
	size_left);

	predicate = (mem_req != nullptr);

	if (predicate) {
	fault = mmu->translateFunctional(mem_req, tc, BaseMMU::Write);
	}

	if (predicate && !checked_flags && fault == NoFault && unverifiedReq) {
	flags_match = checkFlags(unverifiedReq, mem_req->getVaddr(),
	mem_req->getPaddr(), mem_req->getFlags());
	pAddr = mem_req->getPaddr();
	checked_flags = true;
	}

	/*
	* We don't actually check memory for the store because there
	* is no guarantee it has left the lsq yet, and therefore we
	* can't verify the memory on stores without lsq snooping
	* enabled. This is left as future work for the Checker: LSQ snooping
	* and memory validation after stores have committed.
	*/
	bool was_prefetch = mem_req->isPrefetch();

	//If we don't need to access a second cache line, stop now.
	if (fault != NoFault \|\| size_left == 0)
	{
	if (fault != NoFault && was_prefetch) {
	fault = NoFault;
	}
	break;
	}

	frag_addr += frag_size;
	}

	if (!flags_match) {
	warn("%lli: Flags do not match CPU:%#x %#x Checker:%#x %#x %#x\n",
	curTick(), unverifiedReq->getVaddr(), unverifiedReq->getPaddr(),
	unverifiedReq->getFlags(), frag_addr, pAddr, flags);
	handleError();
	}

	// Assume the result was the same as the one passed in. This checker
	// doesn't check if the SC should succeed or fail, it just checks the
	// value.
	if (unverifiedReq && res && unverifiedReq->extraDataValid())
	*res = unverifiedReq->getExtraData();

	// Entire purpose here is to make sure we are getting the
	// same data to send to the mem system as the CPU did.
	// Cannot check this is actually what went to memory because
	// there stores can be in ld/st queue or coherent operations
	// overwriting values.
	bool extraData = false;
	if (unverifiedReq) {
	extraData = unverifiedReq->extraDataValid() ?
	unverifiedReq->getExtraData() : true;
	}

	// If the request is to ZERO a cache block, there is no data to check
	// against, but it's all zero. We need something to compare to, so use a
	// const set of zeros.
	if (flags & Request::STORE_NO_DATA) {
	assert(!data);
	assert(sizeof(zero_data) <= size);
	data = zero_data;
	}

	if (unverifiedReq && unverifiedMemData &&
	memcmp(data, unverifiedMemData, size) && extraData) {
	warn("%lli: Store value does not match value sent to memory! "
	"data: %#x inst_data: %#x", curTick(), data,
	unverifiedMemData);
	handleError();
	}

	return fault;
	}

	/**
	* Checks if the flags set by the Checker and Checkee match.
	*/
	bool
	CheckerCPU::checkFlags(const RequestPtr &unverified_req, Addr vAddr,
	Addr pAddr, int flags)
	{
	Addr unverifiedVAddr = unverified_req->getVaddr();
	Addr unverifiedPAddr = unverified_req->getPaddr();
	int unverifiedFlags = unverified_req->getFlags();

	if (unverifiedVAddr != vAddr \|\|
	unverifiedPAddr != pAddr \|\|
	unverifiedFlags != flags) {
	return false;
	}

	return true;
	}

	void
	CheckerCPU::dumpAndExit()
	{
	warn("%lli: Checker PC:%s",
	curTick(), thread->pcState());
	panic("Checker found an error!");
	}

	} // namespace gem5