src/arch/riscv/process.cc - public/gem5 - Git at Google

 /*
  * Copyright (c) 2004-2005 The Regents of The University of Michigan
  * Copyright (c) 2016 The University of Virginia
  * 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.
  *
  * Authors: Gabe Black
  *          Ali Saidi
  *          Korey Sewell
  *          Alec Roelke
  */
 #include "arch/riscv/process.hh"

 #include <algorithm>
 #include <cstddef>
 #include <iostream>
 #include <map>
 #include <string>
 #include <vector>

 #include "arch/riscv/isa_traits.hh"
 #include "base/loader/elf_object.hh"
 #include "base/loader/object_file.hh"
 #include "base/misc.hh"
 #include "cpu/thread_context.hh"
 #include "debug/Stack.hh"
 #include "mem/page_table.hh"
 #include "params/Process.hh"
 #include "sim/aux_vector.hh"
 #include "sim/process.hh"
 #include "sim/process_impl.hh"
 #include "sim/syscall_return.hh"
 #include "sim/system.hh"

 using namespace std;
 using namespace RiscvISA;

 RiscvProcess::RiscvProcess(ProcessParams * params,
     ObjectFile *objFile) : Process(params, objFile)
 {
     const Addr stack_base = 0x7FFFFFFFFFFFFFFFL;
     const Addr max_stack_size = PageBytes * 64;
     const Addr next_thread_stack_base = stack_base - max_stack_size;
     const Addr brk_point = roundUp(objFile->bssBase() + objFile->bssSize(),
             PageBytes);
     const Addr mmap_end = 0x4000000000000000L;
     memState = make_shared<MemState>(brk_point, stack_base, max_stack_size,
             next_thread_stack_base, mmap_end);
 }

 void
 RiscvProcess::initState()
 {
     Process::initState();

     argsInit<uint64_t>(PageBytes);
 }

 template<class IntType> void
 RiscvProcess::argsInit(int pageSize)
 {
     updateBias();
     objFile->loadSections(initVirtMem);
     ElfObject* elfObject = dynamic_cast<ElfObject*>(objFile);
     memState->setStackMin(memState->getStackBase());

     // Determine stack size and populate auxv
     Addr stack_top = memState->getStackMin();
     stack_top -= elfObject->programHeaderSize();
     for (const string& arg: argv)
         stack_top -= arg.size() + 1;
     for (const string& env: envp)
         stack_top -= env.size() + 1;
     stack_top &= -sizeof(Addr);

     vector<AuxVector<IntType>> auxv;
     if (elfObject != nullptr) {
         auxv.push_back({M5_AT_ENTRY, objFile->entryPoint()});
         auxv.push_back({M5_AT_PHNUM, elfObject->programHeaderCount()});
         auxv.push_back({M5_AT_PHENT, elfObject->programHeaderSize()});
         auxv.push_back({M5_AT_PHDR, elfObject->programHeaderTable()});
         auxv.push_back({M5_AT_PAGESZ, PageBytes});
         auxv.push_back({M5_AT_SECURE, 0});
         auxv.push_back({M5_AT_RANDOM, stack_top});
         auxv.push_back({M5_AT_NULL, 0});
     }
     stack_top -= (1 + argv.size()) * sizeof(Addr) +
                    (1 + envp.size()) * sizeof(Addr) +
                    sizeof(Addr) + 2 * sizeof(IntType) * auxv.size();
     stack_top &= -2*sizeof(Addr);
     memState->setStackSize(memState->getStackBase() - stack_top);
     allocateMem(roundDown(stack_top, pageSize),
             roundUp(memState->getStackSize(), pageSize));

     // Copy program headers to stack
     memState->setStackMin(memState->getStackMin() -
             elfObject->programHeaderSize());
     uint8_t* phdr = new uint8_t[elfObject->programHeaderSize()];
     initVirtMem.readBlob(elfObject->programHeaderTable(), phdr,
             elfObject->programHeaderSize());
     initVirtMem.writeBlob(memState->getStackMin(), phdr,
             elfObject->programHeaderSize());
     delete phdr;

     // Copy argv to stack
     vector<Addr> argPointers;
     for (const string& arg: argv) {
         memState->setStackMin(memState->getStackMin() - (arg.size() + 1));
         initVirtMem.writeString(memState->getStackMin(), arg.c_str());
         argPointers.push_back(memState->getStackMin());
         if (DTRACE(Stack)) {
             string wrote;
             initVirtMem.readString(wrote, argPointers.back());
             DPRINTFN("Wrote arg \"%s\" to address %p\n",
                     wrote, (void*)memState->getStackMin());
         }
     }
     argPointers.push_back(0);

     // Copy envp to stack
     vector<Addr> envPointers;
     for (const string& env: envp) {
         memState->setStackMin(memState->getStackMin() - (env.size() + 1));
         initVirtMem.writeString(memState->getStackMin(), env.c_str());
         envPointers.push_back(memState->getStackMin());
         DPRINTF(Stack, "Wrote env \"%s\" to address %p\n",
                 env, (void*)memState->getStackMin());
     }
     envPointers.push_back(0);

     // Align stack
     memState->setStackMin(memState->getStackMin() & -sizeof(Addr));

     // Calculate bottom of stack
     memState->setStackMin(memState->getStackMin() -
             ((1 + argv.size()) * sizeof(Addr) +
              (1 + envp.size()) * sizeof(Addr) +
              sizeof(Addr) + 2 * sizeof(IntType) * auxv.size()));
     memState->setStackMin(memState->getStackMin() & -2*sizeof(Addr));
     Addr sp = memState->getStackMin();
     const auto pushOntoStack =
         [this, &sp](const uint8_t* data, const size_t size) {
             initVirtMem.writeBlob(sp, data, size);
             sp += size;
         };

     // Push argc and argv pointers onto stack
     IntType argc = htog((IntType)argv.size());
     DPRINTF(Stack, "Wrote argc %d to address %p\n",
             argv.size(), (void*)sp);
     pushOntoStack((uint8_t*)&argc, sizeof(IntType));
     for (const Addr& argPointer: argPointers) {
         DPRINTF(Stack, "Wrote argv pointer %p to address %p\n",
                 (void*)argPointer, (void*)sp);
         pushOntoStack((uint8_t*)&argPointer, sizeof(Addr));
     }

     // Push env pointers onto stack
     for (const Addr& envPointer: envPointers) {
         DPRINTF(Stack, "Wrote envp pointer %p to address %p\n",
                 (void*)envPointer, (void*)sp);
         pushOntoStack((uint8_t*)&envPointer, sizeof(Addr));
     }

     // Push aux vector onto stack
     std::map<IntType, string> aux_keys = {
         {M5_AT_ENTRY, "M5_AT_ENTRY"},
         {M5_AT_PHNUM, "M5_AT_PHNUM"},
         {M5_AT_PHENT, "M5_AT_PHENT"},
         {M5_AT_PHDR, "M5_AT_PHDR"},
         {M5_AT_PAGESZ, "M5_AT_PAGESZ"},
         {M5_AT_SECURE, "M5_AT_SECURE"},
         {M5_AT_RANDOM, "M5_AT_RANDOM"},
         {M5_AT_NULL, "M5_AT_NULL"}
     };
     for (const AuxVector<IntType>& aux: auxv) {
         DPRINTF(Stack, "Wrote aux key %s to address %p\n",
                 aux_keys[aux.a_type], (void*)sp);
         pushOntoStack((uint8_t*)&aux.a_type, sizeof(IntType));
         DPRINTF(Stack, "Wrote aux value %x to address %p\n",
                 aux.a_val, (void*)sp);
         pushOntoStack((uint8_t*)&aux.a_val, sizeof(IntType));
     }

     ThreadContext *tc = system->getThreadContext(contextIds[0]);
     tc->setIntReg(StackPointerReg, memState->getStackMin());
     tc->pcState(getStartPC());

     memState->setStackMin(roundDown(memState->getStackMin(), pageSize));
 }

 RiscvISA::IntReg
 RiscvProcess::getSyscallArg(ThreadContext *tc, int &i)
 {
     // RISC-V only has four system call argument registers by convention, so
     // if a larger index is requested return 0
     RiscvISA::IntReg retval = 0;
     if (i < 4)
         retval = tc->readIntReg(SyscallArgumentRegs[i]);
     i++;
     return retval;
 }

 void
 RiscvProcess::setSyscallArg(ThreadContext *tc, int i, RiscvISA::IntReg val)
 {
     tc->setIntReg(SyscallArgumentRegs[i], val);
 }

 void
 RiscvProcess::setSyscallReturn(ThreadContext *tc, SyscallReturn sysret)
 {
     if (sysret.successful()) {
         // no error
         tc->setIntReg(SyscallPseudoReturnReg, sysret.returnValue());
     } else {
         // got an error, return details
         tc->setIntReg(SyscallPseudoReturnReg, sysret.errnoValue());
     }
 }
	/*
	* Copyright (c) 2004-2005 The Regents of The University of Michigan
	* Copyright (c) 2016 The University of Virginia
	* 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.
	*
	* Authors: Gabe Black
	* Ali Saidi
	* Korey Sewell
	* Alec Roelke
	*/
	#include "arch/riscv/process.hh"

	#include <algorithm>
	#include <cstddef>
	#include <iostream>
	#include <map>
	#include <string>
	#include <vector>

	#include "arch/riscv/isa_traits.hh"
	#include "base/loader/elf_object.hh"
	#include "base/loader/object_file.hh"
	#include "base/misc.hh"
	#include "cpu/thread_context.hh"
	#include "debug/Stack.hh"
	#include "mem/page_table.hh"
	#include "params/Process.hh"
	#include "sim/aux_vector.hh"
	#include "sim/process.hh"
	#include "sim/process_impl.hh"
	#include "sim/syscall_return.hh"
	#include "sim/system.hh"

	using namespace std;
	using namespace RiscvISA;

	RiscvProcess::RiscvProcess(ProcessParams * params,
	ObjectFile *objFile) : Process(params, objFile)
	{
	const Addr stack_base = 0x7FFFFFFFFFFFFFFFL;
	const Addr max_stack_size = PageBytes * 64;
	const Addr next_thread_stack_base = stack_base - max_stack_size;
	const Addr brk_point = roundUp(objFile->bssBase() + objFile->bssSize(),
	PageBytes);
	const Addr mmap_end = 0x4000000000000000L;
	memState = make_shared<MemState>(brk_point, stack_base, max_stack_size,
	next_thread_stack_base, mmap_end);
	}

	void
	RiscvProcess::initState()
	{
	Process::initState();

	argsInit<uint64_t>(PageBytes);
	}

	template<class IntType> void
	RiscvProcess::argsInit(int pageSize)
	{
	updateBias();
	objFile->loadSections(initVirtMem);
	ElfObject* elfObject = dynamic_cast<ElfObject*>(objFile);
	memState->setStackMin(memState->getStackBase());

	// Determine stack size and populate auxv
	Addr stack_top = memState->getStackMin();
	stack_top -= elfObject->programHeaderSize();
	for (const string& arg: argv)
	stack_top -= arg.size() + 1;
	for (const string& env: envp)
	stack_top -= env.size() + 1;
	stack_top &= -sizeof(Addr);

	vector<AuxVector<IntType>> auxv;
	if (elfObject != nullptr) {
	auxv.push_back({M5_AT_ENTRY, objFile->entryPoint()});
	auxv.push_back({M5_AT_PHNUM, elfObject->programHeaderCount()});
	auxv.push_back({M5_AT_PHENT, elfObject->programHeaderSize()});
	auxv.push_back({M5_AT_PHDR, elfObject->programHeaderTable()});
	auxv.push_back({M5_AT_PAGESZ, PageBytes});
	auxv.push_back({M5_AT_SECURE, 0});
	auxv.push_back({M5_AT_RANDOM, stack_top});
	auxv.push_back({M5_AT_NULL, 0});
	}
	stack_top -= (1 + argv.size()) * sizeof(Addr) +
	(1 + envp.size()) * sizeof(Addr) +
	sizeof(Addr) + 2 * sizeof(IntType) * auxv.size();
	stack_top &= -2*sizeof(Addr);
	memState->setStackSize(memState->getStackBase() - stack_top);
	allocateMem(roundDown(stack_top, pageSize),
	roundUp(memState->getStackSize(), pageSize));

	// Copy program headers to stack
	memState->setStackMin(memState->getStackMin() -
	elfObject->programHeaderSize());
	uint8_t* phdr = new uint8_t[elfObject->programHeaderSize()];
	initVirtMem.readBlob(elfObject->programHeaderTable(), phdr,
	elfObject->programHeaderSize());
	initVirtMem.writeBlob(memState->getStackMin(), phdr,
	elfObject->programHeaderSize());
	delete phdr;

	// Copy argv to stack
	vector<Addr> argPointers;
	for (const string& arg: argv) {
	memState->setStackMin(memState->getStackMin() - (arg.size() + 1));
	initVirtMem.writeString(memState->getStackMin(), arg.c_str());
	argPointers.push_back(memState->getStackMin());
	if (DTRACE(Stack)) {
	string wrote;
	initVirtMem.readString(wrote, argPointers.back());
	DPRINTFN("Wrote arg \"%s\" to address %p\n",
	wrote, (void*)memState->getStackMin());
	}
	}
	argPointers.push_back(0);

	// Copy envp to stack
	vector<Addr> envPointers;
	for (const string& env: envp) {
	memState->setStackMin(memState->getStackMin() - (env.size() + 1));
	initVirtMem.writeString(memState->getStackMin(), env.c_str());
	envPointers.push_back(memState->getStackMin());
	DPRINTF(Stack, "Wrote env \"%s\" to address %p\n",
	env, (void*)memState->getStackMin());
	}
	envPointers.push_back(0);

	// Align stack
	memState->setStackMin(memState->getStackMin() & -sizeof(Addr));

	// Calculate bottom of stack
	memState->setStackMin(memState->getStackMin() -
	((1 + argv.size()) * sizeof(Addr) +
	(1 + envp.size()) * sizeof(Addr) +
	sizeof(Addr) + 2 * sizeof(IntType) * auxv.size()));
	memState->setStackMin(memState->getStackMin() & -2*sizeof(Addr));
	Addr sp = memState->getStackMin();
	const auto pushOntoStack =
	[this, &sp](const uint8_t* data, const size_t size) {
	initVirtMem.writeBlob(sp, data, size);
	sp += size;
	};

	// Push argc and argv pointers onto stack
	IntType argc = htog((IntType)argv.size());
	DPRINTF(Stack, "Wrote argc %d to address %p\n",
	argv.size(), (void*)sp);
	pushOntoStack((uint8_t*)&argc, sizeof(IntType));
	for (const Addr& argPointer: argPointers) {
	DPRINTF(Stack, "Wrote argv pointer %p to address %p\n",
	(void)argPointer, (void)sp);
	pushOntoStack((uint8_t*)&argPointer, sizeof(Addr));
	}

	// Push env pointers onto stack
	for (const Addr& envPointer: envPointers) {
	DPRINTF(Stack, "Wrote envp pointer %p to address %p\n",
	(void)envPointer, (void)sp);
	pushOntoStack((uint8_t*)&envPointer, sizeof(Addr));
	}

	// Push aux vector onto stack
	std::map<IntType, string> aux_keys = {
	{M5_AT_ENTRY, "M5_AT_ENTRY"},
	{M5_AT_PHNUM, "M5_AT_PHNUM"},
	{M5_AT_PHENT, "M5_AT_PHENT"},
	{M5_AT_PHDR, "M5_AT_PHDR"},
	{M5_AT_PAGESZ, "M5_AT_PAGESZ"},
	{M5_AT_SECURE, "M5_AT_SECURE"},
	{M5_AT_RANDOM, "M5_AT_RANDOM"},
	{M5_AT_NULL, "M5_AT_NULL"}
	};
	for (const AuxVector<IntType>& aux: auxv) {
	DPRINTF(Stack, "Wrote aux key %s to address %p\n",
	aux_keys[aux.a_type], (void*)sp);
	pushOntoStack((uint8_t*)&aux.a_type, sizeof(IntType));
	DPRINTF(Stack, "Wrote aux value %x to address %p\n",
	aux.a_val, (void*)sp);
	pushOntoStack((uint8_t*)&aux.a_val, sizeof(IntType));
	}

	ThreadContext *tc = system->getThreadContext(contextIds[0]);
	tc->setIntReg(StackPointerReg, memState->getStackMin());
	tc->pcState(getStartPC());

	memState->setStackMin(roundDown(memState->getStackMin(), pageSize));
	}

	RiscvISA::IntReg
	RiscvProcess::getSyscallArg(ThreadContext *tc, int &i)
	{
	// RISC-V only has four system call argument registers by convention, so
	// if a larger index is requested return 0
	RiscvISA::IntReg retval = 0;
	if (i < 4)
	retval = tc->readIntReg(SyscallArgumentRegs[i]);
	i++;
	return retval;
	}

	void
	RiscvProcess::setSyscallArg(ThreadContext *tc, int i, RiscvISA::IntReg val)
	{
	tc->setIntReg(SyscallArgumentRegs[i], val);
	}

	void
	RiscvProcess::setSyscallReturn(ThreadContext *tc, SyscallReturn sysret)
	{
	if (sysret.successful()) {
	// no error
	tc->setIntReg(SyscallPseudoReturnReg, sysret.returnValue());
	} else {
	// got an error, return details
	tc->setIntReg(SyscallPseudoReturnReg, sysret.errnoValue());
	}
	}