src/sim/process.cc - public/gem5 - Git at Google

 /*
  * Copyright (c) 2001-2005 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.
  *
  * Authors: Nathan Binkert
  *          Steve Reinhardt
  *          Ali Saidi
  */

 #include <unistd.h>
 #include <fcntl.h>
 #include <string>

 #include "arch/remote_gdb.hh"
 #include "base/intmath.hh"
 #include "base/loader/object_file.hh"
 #include "base/loader/symtab.hh"
 #include "base/statistics.hh"
 #include "config/full_system.hh"
 #include "cpu/thread_context.hh"
 #include "mem/page_table.hh"
 #include "mem/physical.hh"
 #include "mem/translating_port.hh"
 #include "params/Process.hh"
 #include "params/LiveProcess.hh"
 #include "sim/process.hh"
 #include "sim/process_impl.hh"
 #include "sim/stats.hh"
 #include "sim/syscall_emul.hh"
 #include "sim/system.hh"

 #include "arch/isa_specific.hh"
 #if THE_ISA == ALPHA_ISA
 #include "arch/alpha/linux/process.hh"
 #include "arch/alpha/tru64/process.hh"
 #elif THE_ISA == SPARC_ISA
 #include "arch/sparc/linux/process.hh"
 #include "arch/sparc/solaris/process.hh"
 #elif THE_ISA == MIPS_ISA
 #include "arch/mips/linux/process.hh"
 #elif THE_ISA == ARM_ISA
 #include "arch/arm/linux/process.hh"
 #elif THE_ISA == X86_ISA
 #include "arch/x86/linux/process.hh"
 #else
 #error "THE_ISA not set"
 #endif


 using namespace std;
 using namespace TheISA;

 //
 // The purpose of this code is to fake the loader & syscall mechanism
 // when there's no OS: thus there's no resone to use it in FULL_SYSTEM
 // mode when we do have an OS
 //
 #if FULL_SYSTEM
 #error "process.cc not compatible with FULL_SYSTEM"
 #endif

 // current number of allocated processes
 int num_processes = 0;

 Process::Process(ProcessParams * params)
     : SimObject(params), system(params->system), checkpointRestored(false),
     max_stack_size(params->max_stack_size)
 {
     string in = params->input;
     string out = params->output;

     // initialize file descriptors to default: same as simulator
     int stdin_fd, stdout_fd, stderr_fd;

     if (in == "stdin" || in == "cin")
         stdin_fd = STDIN_FILENO;
     else if (in == "None")
         stdin_fd = -1;
     else
         stdin_fd = Process::openInputFile(in);

     if (out == "stdout" || out == "cout")
         stdout_fd = STDOUT_FILENO;
     else if (out == "stderr" || out == "cerr")
         stdout_fd = STDERR_FILENO;
     else if (out == "None")
         stdout_fd = -1;
     else
         stdout_fd = Process::openOutputFile(out);

     stderr_fd = (stdout_fd != STDOUT_FILENO) ? stdout_fd : STDERR_FILENO;

     M5_pid = system->allocatePID();
     // initialize first 3 fds (stdin, stdout, stderr)
     Process::FdMap *fdo = &fd_map[STDIN_FILENO];
     fdo->fd = stdin_fd;
     fdo->filename = in;
     fdo->flags = O_RDONLY;
     fdo->mode = -1;
     fdo->fileOffset = 0;

     fdo =  &fd_map[STDOUT_FILENO];
     fdo->fd = stdout_fd;
     fdo->filename = out;
     fdo->flags =  O_WRONLY | O_CREAT | O_TRUNC;
     fdo->mode = 0774;
     fdo->fileOffset = 0;

     fdo = &fd_map[STDERR_FILENO];
     fdo->fd = stderr_fd;
     fdo->filename = "STDERR";
     fdo->flags = O_WRONLY;
     fdo->mode = -1;
     fdo->fileOffset = 0;


     // mark remaining fds as free
     for (int i = 3; i <= MAX_FD; ++i) {
         Process::FdMap *fdo = &fd_map[i];
         fdo->fd = -1;
     }

     mmap_start = mmap_end = 0;
     nxm_start = nxm_end = 0;
     pTable = new PageTable(this);
     // other parameters will be initialized when the program is loaded
 }


 void
 Process::regStats()
 {
     using namespace Stats;

     num_syscalls
         .name(name() + ".PROG:num_syscalls")
         .desc("Number of system calls")
         ;
 }

 //
 // static helper functions
 //
 int
 Process::openInputFile(const string &filename)
 {
     int fd = open(filename.c_str(), O_RDONLY);

     if (fd == -1) {
         perror(NULL);
         cerr << "unable to open \"" << filename << "\" for reading\n";
         fatal("can't open input file");
     }

     return fd;
 }


 int
 Process::openOutputFile(const string &filename)
 {
     int fd = open(filename.c_str(), O_WRONLY | O_CREAT | O_TRUNC, 0774);

     if (fd == -1) {
         perror(NULL);
         cerr << "unable to open \"" << filename << "\" for writing\n";
         fatal("can't open output file");
     }

     return fd;
 }


 int
 Process::registerThreadContext(ThreadContext *tc)
 {
     // add to list
     int myIndex = threadContexts.size();
     threadContexts.push_back(tc);

     RemoteGDB *rgdb = new RemoteGDB(system, tc);
     GDBListener *gdbl = new GDBListener(rgdb, 7000 + myIndex);
     gdbl->listen();
     //gdbl->accept();

     remoteGDB.push_back(rgdb);

     // return CPU number to caller
     return myIndex;
 }

 void
 Process::startup()
 {
     if (threadContexts.empty())
         fatal("Process %s is not associated with any CPUs!\n", name());

     // first thread context for this process... initialize & enable
     ThreadContext *tc = threadContexts[0];

     // mark this context as active so it will start ticking.
     tc->activate(0);

     Port *mem_port;
     mem_port = system->physmem->getPort("functional");
     initVirtMem = new TranslatingPort("process init port", this,
             TranslatingPort::Always);
     mem_port->setPeer(initVirtMem);
     initVirtMem->setPeer(mem_port);
 }

 void
 Process::replaceThreadContext(ThreadContext *tc, int tcIndex)
 {
     if (tcIndex >= threadContexts.size()) {
         panic("replaceThreadContext: bad tcIndex, %d >= %d\n",
               tcIndex, threadContexts.size());
     }

     threadContexts[tcIndex] = tc;
 }

 // map simulator fd sim_fd to target fd tgt_fd
 void
 Process::dup_fd(int sim_fd, int tgt_fd)
 {
     if (tgt_fd < 0 || tgt_fd > MAX_FD)
         panic("Process::dup_fd tried to dup past MAX_FD (%d)", tgt_fd);

     Process::FdMap *fdo = &fd_map[tgt_fd];
     fdo->fd = sim_fd;
 }


 // generate new target fd for sim_fd
 int
 Process::alloc_fd(int sim_fd, string filename, int flags, int mode, bool pipe)
 {
     // in case open() returns an error, don't allocate a new fd
     if (sim_fd == -1)
         return -1;

     // find first free target fd
     for (int free_fd = 0; free_fd <= MAX_FD; ++free_fd) {
         Process::FdMap *fdo = &fd_map[free_fd];
         if (fdo->fd == -1) {
             fdo->fd = sim_fd;
             fdo->filename = filename;
             fdo->mode = mode;
             fdo->fileOffset = 0;
             fdo->flags = flags;
             fdo->isPipe = pipe;
             fdo->readPipeSource = 0;
             return free_fd;
         }
     }

     panic("Process::alloc_fd: out of file descriptors!");
 }


 // free target fd (e.g., after close)
 void
 Process::free_fd(int tgt_fd)
 {
     Process::FdMap *fdo = &fd_map[tgt_fd];
     if (fdo->fd == -1)
         warn("Process::free_fd: request to free unused fd %d", tgt_fd);

     fdo->fd = -1;
     fdo->filename = "NULL";
     fdo->mode = 0;
     fdo->fileOffset = 0;
     fdo->flags = 0;
     fdo->isPipe = false;
     fdo->readPipeSource = 0;
 }


 // look up simulator fd for given target fd
 int
 Process::sim_fd(int tgt_fd)
 {
     if (tgt_fd > MAX_FD)
         return -1;

     return fd_map[tgt_fd].fd;
 }

 Process::FdMap *
 Process::sim_fd_obj(int tgt_fd)
 {
     if (tgt_fd > MAX_FD)
         panic("sim_fd_obj called in fd out of range.");

     return &fd_map[tgt_fd];
 }
 bool
 Process::checkAndAllocNextPage(Addr vaddr)
 {
     // if this is an initial write we might not have
     if (vaddr >= stack_min && vaddr < stack_base) {
         pTable->allocate(roundDown(vaddr, VMPageSize), VMPageSize);
         return true;
     }

     // We've accessed the next page of the stack, so extend the stack
     // to cover it.
     if (vaddr < stack_min && vaddr >= stack_base - max_stack_size) {
         while (vaddr < stack_min) {
             stack_min -= TheISA::PageBytes;
             if(stack_base - stack_min > max_stack_size)
                 fatal("Maximum stack size exceeded\n");
             if(stack_base - stack_min > 8*1024*1024)
                 fatal("Over max stack size for one thread\n");
             pTable->allocate(stack_min, TheISA::PageBytes);
             warn("Increasing stack size by one page.");
         };
         return true;
     }
     return false;
 }

  // find all offsets for currently open files and save them
 void
 Process::fix_file_offsets() {
     Process::FdMap *fdo_stdin = &fd_map[STDIN_FILENO];
     Process::FdMap *fdo_stdout = &fd_map[STDOUT_FILENO];
     Process::FdMap *fdo_stderr = &fd_map[STDERR_FILENO];
     string in = fdo_stdin->filename;
     string out = fdo_stdout->filename;

     // initialize file descriptors to default: same as simulator
     int stdin_fd, stdout_fd, stderr_fd;

     if (in == "stdin" || in == "cin")
         stdin_fd = STDIN_FILENO;
     else if (in == "None")
         stdin_fd = -1;
     else{
         //OPEN standard in and seek to the right location
         stdin_fd = Process::openInputFile(in);
         if (lseek(stdin_fd, fdo_stdin->fileOffset, SEEK_SET) < 0)
             panic("Unable to seek to correct location in file: %s", in);
     }

     if (out == "stdout" || out == "cout")
         stdout_fd = STDOUT_FILENO;
     else if (out == "stderr" || out == "cerr")
         stdout_fd = STDERR_FILENO;
     else if (out == "None")
         stdout_fd = -1;
     else{
         stdout_fd = Process::openOutputFile(out);
         if (lseek(stdin_fd, fdo_stdout->fileOffset, SEEK_SET) < 0)
             panic("Unable to seek to correct in file: %s", out);
     }

     stderr_fd = (stdout_fd != STDOUT_FILENO) ? stdout_fd : STDERR_FILENO;

     fdo_stdin->fd = stdin_fd;
     fdo_stdout->fd = stdout_fd;
     fdo_stderr->fd = stderr_fd;


     for (int free_fd = 3; free_fd <= MAX_FD; ++free_fd) {
         Process::FdMap *fdo = &fd_map[free_fd];
         if (fdo->fd != -1) {
             if (fdo->isPipe){
                 if (fdo->filename == "PIPE-WRITE")
                     continue;
                 else {
                     assert (fdo->filename == "PIPE-READ");
                     //create a new pipe
                     int fds[2];
                     int pipe_retval = pipe(fds);

                     if (pipe_retval < 0) {
                         // error
                         panic("Unable to create new pipe.");
                     }
                     fdo->fd = fds[0]; //set read pipe
                     Process::FdMap *fdo_write = &fd_map[fdo->readPipeSource];
                     if (fdo_write->filename != "PIPE-WRITE")
                         panic ("Couldn't find write end of the pipe");

                     fdo_write->fd = fds[1];//set write pipe
                }
             } else {
                 //Open file
                 int fd = open(fdo->filename.c_str(), fdo->flags, fdo->mode);

                 if (fd == -1)
                     panic("Unable to open file: %s", fdo->filename);
                 fdo->fd = fd;

                 //Seek to correct location before checkpoint
                 if (lseek(fd,fdo->fileOffset, SEEK_SET) < 0)
                     panic("Unable to seek to correct location in file: %s", fdo->filename);
             }
         }
     }
 }
 void
 Process::find_file_offsets(){
     for (int free_fd = 0; free_fd <= MAX_FD; ++free_fd) {
         Process::FdMap *fdo = &fd_map[free_fd];
         if (fdo->fd != -1) {
             fdo->fileOffset = lseek(fdo->fd, 0, SEEK_CUR);
         }  else {
                 fdo->filename = "NULL";
                 fdo->fileOffset = 0;
         }
     }
 }

 void
 Process::setReadPipeSource(int read_pipe_fd, int source_fd){
     Process::FdMap *fdo = &fd_map[read_pipe_fd];
     fdo->readPipeSource = source_fd;
 }

 void
 Process::FdMap::serialize(std::ostream &os)
 {
     SERIALIZE_SCALAR(fd);
     SERIALIZE_SCALAR(isPipe);
     SERIALIZE_SCALAR(filename);
     SERIALIZE_SCALAR(flags);
     SERIALIZE_SCALAR(readPipeSource);
     SERIALIZE_SCALAR(fileOffset);
 }

 void
 Process::FdMap::unserialize(Checkpoint *cp, const std::string &section)
 {
     UNSERIALIZE_SCALAR(fd);
     UNSERIALIZE_SCALAR(isPipe);
     UNSERIALIZE_SCALAR(filename);
     UNSERIALIZE_SCALAR(flags);
     UNSERIALIZE_SCALAR(readPipeSource);
     UNSERIALIZE_SCALAR(fileOffset);
 }

 void
 Process::serialize(std::ostream &os)
 {
     SERIALIZE_SCALAR(initialContextLoaded);
     SERIALIZE_SCALAR(brk_point);
     SERIALIZE_SCALAR(stack_base);
     SERIALIZE_SCALAR(stack_size);
     SERIALIZE_SCALAR(stack_min);
     SERIALIZE_SCALAR(next_thread_stack_base);
     SERIALIZE_SCALAR(mmap_start);
     SERIALIZE_SCALAR(mmap_end);
     SERIALIZE_SCALAR(nxm_start);
     SERIALIZE_SCALAR(nxm_end);
     find_file_offsets();
     pTable->serialize(os);
     for (int x = 0; x <= MAX_FD; x++) {
         nameOut(os, csprintf("%s.FdMap%d", name(), x));
         fd_map[x].serialize(os);
     }

 }

 void
 Process::unserialize(Checkpoint *cp, const std::string &section)
 {
     UNSERIALIZE_SCALAR(initialContextLoaded);
     UNSERIALIZE_SCALAR(brk_point);
     UNSERIALIZE_SCALAR(stack_base);
     UNSERIALIZE_SCALAR(stack_size);
     UNSERIALIZE_SCALAR(stack_min);
     UNSERIALIZE_SCALAR(next_thread_stack_base);
     UNSERIALIZE_SCALAR(mmap_start);
     UNSERIALIZE_SCALAR(mmap_end);
     UNSERIALIZE_SCALAR(nxm_start);
     UNSERIALIZE_SCALAR(nxm_end);
     pTable->unserialize(cp, section);
     for (int x = 0; x <= MAX_FD; x++) {
         fd_map[x].unserialize(cp, csprintf("%s.FdMap%d", section, x));
      }
     fix_file_offsets();

     checkpointRestored = true;

 }


 ////////////////////////////////////////////////////////////////////////
 //
 // LiveProcess member definitions
 //
 ////////////////////////////////////////////////////////////////////////


 LiveProcess::LiveProcess(LiveProcessParams * params, ObjectFile *_objFile)
     : Process(params), objFile(_objFile),
       argv(params->cmd), envp(params->env), cwd(params->cwd)
 {
     __uid = params->uid;
     __euid = params->euid;
     __gid = params->gid;
     __egid = params->egid;
     __pid = params->pid;
     __ppid = params->ppid;

     prog_fname = params->cmd[0];

     // load up symbols, if any... these may be used for debugging or
     // profiling.
     if (!debugSymbolTable) {
         debugSymbolTable = new SymbolTable();
         if (!objFile->loadGlobalSymbols(debugSymbolTable) ||
             !objFile->loadLocalSymbols(debugSymbolTable)) {
             // didn't load any symbols
             delete debugSymbolTable;
             debugSymbolTable = NULL;
         }
     }
 }

 void
 LiveProcess::argsInit(int intSize, int pageSize)
 {
     Process::startup();

     // load object file into target memory
     objFile->loadSections(initVirtMem);

     // Calculate how much space we need for arg & env arrays.
     int argv_array_size = intSize * (argv.size() + 1);
     int envp_array_size = intSize * (envp.size() + 1);
     int arg_data_size = 0;
     for (int i = 0; i < argv.size(); ++i) {
         arg_data_size += argv[i].size() + 1;
     }
     int env_data_size = 0;
     for (int i = 0; i < envp.size(); ++i) {
         env_data_size += envp[i].size() + 1;
     }

     int space_needed =
         argv_array_size + envp_array_size + arg_data_size + env_data_size;
     if (space_needed < 32*1024)
         space_needed = 32*1024;

     // set bottom of stack
     stack_min = stack_base - space_needed;
     // align it
     stack_min = roundDown(stack_min, pageSize);
     stack_size = stack_base - stack_min;
     // map memory
     pTable->allocate(stack_min, roundUp(stack_size, pageSize));

     // map out initial stack contents
     Addr argv_array_base = stack_min + intSize; // room for argc
     Addr envp_array_base = argv_array_base + argv_array_size;
     Addr arg_data_base = envp_array_base + envp_array_size;
     Addr env_data_base = arg_data_base + arg_data_size;

     // write contents to stack
     uint64_t argc = argv.size();
     if (intSize == 8)
         argc = htog((uint64_t)argc);
     else if (intSize == 4)
         argc = htog((uint32_t)argc);
     else
         panic("Unknown int size");

     initVirtMem->writeBlob(stack_min, (uint8_t*)&argc, intSize);

     copyStringArray(argv, argv_array_base, arg_data_base, initVirtMem);
     copyStringArray(envp, envp_array_base, env_data_base, initVirtMem);

     assert(NumArgumentRegs >= 2);
     threadContexts[0]->setIntReg(ArgumentReg[0], argc);
     threadContexts[0]->setIntReg(ArgumentReg[1], argv_array_base);
     threadContexts[0]->setIntReg(StackPointerReg, stack_min);

     Addr prog_entry = objFile->entryPoint();
     threadContexts[0]->setPC(prog_entry);
     threadContexts[0]->setNextPC(prog_entry + sizeof(MachInst));

 #if THE_ISA != ALPHA_ISA //e.g. MIPS or Sparc
     threadContexts[0]->setNextNPC(prog_entry + (2 * sizeof(MachInst)));
 #endif

     num_processes++;
 }

 void
 LiveProcess::syscall(int64_t callnum, ThreadContext *tc)
 {
     num_syscalls++;

     SyscallDesc *desc = getDesc(callnum);
     if (desc == NULL)
         fatal("Syscall %d out of range", callnum);

     desc->doSyscall(callnum, this, tc);
 }

 LiveProcess *
 LiveProcess::create(LiveProcessParams * params)
 {
     LiveProcess *process = NULL;

     string executable =
         params->executable == "" ? params->cmd[0] : params->executable;
     ObjectFile *objFile = createObjectFile(executable);
     if (objFile == NULL) {
         fatal("Can't load object file %s", executable);
     }

     if (objFile->isDynamic())
        fatal("Object file is a dynamic executable however only static "
              "executables are supported!\n       Please recompile your "
              "executable as a static binary and try again.\n");

 #if THE_ISA == ALPHA_ISA
     if (objFile->hasTLS())
         fatal("Object file has a TLS section and single threaded TLS is not\n"
               "       currently supported for Alpha! Please recompile your "
               "executable with \n       a non-TLS toolchain.\n");

     if (objFile->getArch() != ObjectFile::Alpha)
         fatal("Object file architecture does not match compiled ISA (Alpha).");
     switch (objFile->getOpSys()) {
       case ObjectFile::Tru64:
         process = new AlphaTru64Process(params, objFile);
         break;

       case ObjectFile::Linux:
         process = new AlphaLinuxProcess(params, objFile);
         break;

       default:
         fatal("Unknown/unsupported operating system.");
     }
 #elif THE_ISA == SPARC_ISA
     if (objFile->getArch() != ObjectFile::SPARC64 && objFile->getArch() != ObjectFile::SPARC32)
         fatal("Object file architecture does not match compiled ISA (SPARC).");
     switch (objFile->getOpSys()) {
       case ObjectFile::Linux:
         if (objFile->getArch() == ObjectFile::SPARC64) {
             process = new Sparc64LinuxProcess(params, objFile);
         } else {
             process = new Sparc32LinuxProcess(params, objFile);
         }
         break;


       case ObjectFile::Solaris:
         process = new SparcSolarisProcess(params, objFile);
         break;
       default:
         fatal("Unknown/unsupported operating system.");
     }
 #elif THE_ISA == X86_ISA
     if (objFile->getArch() != ObjectFile::X86)
         fatal("Object file architecture does not match compiled ISA (x86).");
     switch (objFile->getOpSys()) {
       case ObjectFile::Linux:
         process = new X86LinuxProcess(params, objFile);
         break;
       default:
         fatal("Unknown/unsupported operating system.");
     }
 #elif THE_ISA == MIPS_ISA
     if (objFile->getArch() != ObjectFile::Mips)
         fatal("Object file architecture does not match compiled ISA (MIPS).");
     switch (objFile->getOpSys()) {
       case ObjectFile::Linux:
         process = new MipsLinuxProcess(params, objFile);
         break;

       default:
         fatal("Unknown/unsupported operating system.");
     }
 #elif THE_ISA == ARM_ISA
     if (objFile->getArch() != ObjectFile::Arm)
         fatal("Object file architecture does not match compiled ISA (ARM).");
     switch (objFile->getOpSys()) {
       case ObjectFile::Linux:
         process = new ArmLinuxProcess(params, objFile);
         break;

       default:
         fatal("Unknown/unsupported operating system.");
     }
 #else
 #error "THE_ISA not set"
 #endif


     if (process == NULL)
         fatal("Unknown error creating process object.");
     return process;
 }

 LiveProcess *
 LiveProcessParams::create()
 {
     return LiveProcess::create(this);
 }
	/*
	* Copyright (c) 2001-2005 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.
	*
	* Authors: Nathan Binkert
	* Steve Reinhardt
	* Ali Saidi
	*/

	#include <unistd.h>
	#include <fcntl.h>
	#include <string>

	#include "arch/remote_gdb.hh"
	#include "base/intmath.hh"
	#include "base/loader/object_file.hh"
	#include "base/loader/symtab.hh"
	#include "base/statistics.hh"
	#include "config/full_system.hh"
	#include "cpu/thread_context.hh"
	#include "mem/page_table.hh"
	#include "mem/physical.hh"
	#include "mem/translating_port.hh"
	#include "params/Process.hh"
	#include "params/LiveProcess.hh"
	#include "sim/process.hh"
	#include "sim/process_impl.hh"
	#include "sim/stats.hh"
	#include "sim/syscall_emul.hh"
	#include "sim/system.hh"

	#include "arch/isa_specific.hh"
	#if THE_ISA == ALPHA_ISA
	#include "arch/alpha/linux/process.hh"
	#include "arch/alpha/tru64/process.hh"
	#elif THE_ISA == SPARC_ISA
	#include "arch/sparc/linux/process.hh"
	#include "arch/sparc/solaris/process.hh"
	#elif THE_ISA == MIPS_ISA
	#include "arch/mips/linux/process.hh"
	#elif THE_ISA == ARM_ISA
	#include "arch/arm/linux/process.hh"
	#elif THE_ISA == X86_ISA
	#include "arch/x86/linux/process.hh"
	#else
	#error "THE_ISA not set"
	#endif


	using namespace std;
	using namespace TheISA;

	//
	// The purpose of this code is to fake the loader & syscall mechanism
	// when there's no OS: thus there's no resone to use it in FULL_SYSTEM
	// mode when we do have an OS
	//
	#if FULL_SYSTEM
	#error "process.cc not compatible with FULL_SYSTEM"
	#endif

	// current number of allocated processes
	int num_processes = 0;

	Process::Process(ProcessParams * params)
	: SimObject(params), system(params->system), checkpointRestored(false),
	max_stack_size(params->max_stack_size)
	{
	string in = params->input;
	string out = params->output;

	// initialize file descriptors to default: same as simulator
	int stdin_fd, stdout_fd, stderr_fd;

	if (in == "stdin" \|\| in == "cin")
	stdin_fd = STDIN_FILENO;
	else if (in == "None")
	stdin_fd = -1;
	else
	stdin_fd = Process::openInputFile(in);

	if (out == "stdout" \|\| out == "cout")
	stdout_fd = STDOUT_FILENO;
	else if (out == "stderr" \|\| out == "cerr")
	stdout_fd = STDERR_FILENO;
	else if (out == "None")
	stdout_fd = -1;
	else
	stdout_fd = Process::openOutputFile(out);

	stderr_fd = (stdout_fd != STDOUT_FILENO) ? stdout_fd : STDERR_FILENO;

	M5_pid = system->allocatePID();
	// initialize first 3 fds (stdin, stdout, stderr)
	Process::FdMap *fdo = &fd_map[STDIN_FILENO];
	fdo->fd = stdin_fd;
	fdo->filename = in;
	fdo->flags = O_RDONLY;
	fdo->mode = -1;
	fdo->fileOffset = 0;

	fdo = &fd_map[STDOUT_FILENO];
	fdo->fd = stdout_fd;
	fdo->filename = out;
	fdo->flags = O_WRONLY \| O_CREAT \| O_TRUNC;
	fdo->mode = 0774;
	fdo->fileOffset = 0;

	fdo = &fd_map[STDERR_FILENO];
	fdo->fd = stderr_fd;
	fdo->filename = "STDERR";
	fdo->flags = O_WRONLY;
	fdo->mode = -1;
	fdo->fileOffset = 0;


	// mark remaining fds as free
	for (int i = 3; i <= MAX_FD; ++i) {
	Process::FdMap *fdo = &fd_map[i];
	fdo->fd = -1;
	}

	mmap_start = mmap_end = 0;
	nxm_start = nxm_end = 0;
	pTable = new PageTable(this);
	// other parameters will be initialized when the program is loaded
	}


	void
	Process::regStats()
	{
	using namespace Stats;

	num_syscalls
	.name(name() + ".PROG:num_syscalls")
	.desc("Number of system calls")
	;
	}

	//
	// static helper functions
	//
	int
	Process::openInputFile(const string &filename)
	{
	int fd = open(filename.c_str(), O_RDONLY);

	if (fd == -1) {
	perror(NULL);
	cerr << "unable to open \"" << filename << "\" for reading\n";
	fatal("can't open input file");
	}

	return fd;
	}


	int
	Process::openOutputFile(const string &filename)
	{
	int fd = open(filename.c_str(), O_WRONLY \| O_CREAT \| O_TRUNC, 0774);

	if (fd == -1) {
	perror(NULL);
	cerr << "unable to open \"" << filename << "\" for writing\n";
	fatal("can't open output file");
	}

	return fd;
	}


	int
	Process::registerThreadContext(ThreadContext *tc)
	{
	// add to list
	int myIndex = threadContexts.size();
	threadContexts.push_back(tc);

	RemoteGDB *rgdb = new RemoteGDB(system, tc);
	GDBListener *gdbl = new GDBListener(rgdb, 7000 + myIndex);
	gdbl->listen();
	//gdbl->accept();

	remoteGDB.push_back(rgdb);

	// return CPU number to caller
	return myIndex;
	}

	void
	Process::startup()
	{
	if (threadContexts.empty())
	fatal("Process %s is not associated with any CPUs!\n", name());

	// first thread context for this process... initialize & enable
	ThreadContext *tc = threadContexts[0];

	// mark this context as active so it will start ticking.
	tc->activate(0);

	Port *mem_port;
	mem_port = system->physmem->getPort("functional");
	initVirtMem = new TranslatingPort("process init port", this,
	TranslatingPort::Always);
	mem_port->setPeer(initVirtMem);
	initVirtMem->setPeer(mem_port);
	}

	void
	Process::replaceThreadContext(ThreadContext *tc, int tcIndex)
	{
	if (tcIndex >= threadContexts.size()) {
	panic("replaceThreadContext: bad tcIndex, %d >= %d\n",
	tcIndex, threadContexts.size());
	}

	threadContexts[tcIndex] = tc;
	}

	// map simulator fd sim_fd to target fd tgt_fd
	void
	Process::dup_fd(int sim_fd, int tgt_fd)
	{
	if (tgt_fd < 0 \|\| tgt_fd > MAX_FD)
	panic("Process::dup_fd tried to dup past MAX_FD (%d)", tgt_fd);

	Process::FdMap *fdo = &fd_map[tgt_fd];
	fdo->fd = sim_fd;
	}


	// generate new target fd for sim_fd
	int
	Process::alloc_fd(int sim_fd, string filename, int flags, int mode, bool pipe)
	{
	// in case open() returns an error, don't allocate a new fd
	if (sim_fd == -1)
	return -1;

	// find first free target fd
	for (int free_fd = 0; free_fd <= MAX_FD; ++free_fd) {
	Process::FdMap *fdo = &fd_map[free_fd];
	if (fdo->fd == -1) {
	fdo->fd = sim_fd;
	fdo->filename = filename;
	fdo->mode = mode;
	fdo->fileOffset = 0;
	fdo->flags = flags;
	fdo->isPipe = pipe;
	fdo->readPipeSource = 0;
	return free_fd;
	}
	}

	panic("Process::alloc_fd: out of file descriptors!");
	}


	// free target fd (e.g., after close)
	void
	Process::free_fd(int tgt_fd)
	{
	Process::FdMap *fdo = &fd_map[tgt_fd];
	if (fdo->fd == -1)
	warn("Process::free_fd: request to free unused fd %d", tgt_fd);

	fdo->fd = -1;
	fdo->filename = "NULL";
	fdo->mode = 0;
	fdo->fileOffset = 0;
	fdo->flags = 0;
	fdo->isPipe = false;
	fdo->readPipeSource = 0;
	}


	// look up simulator fd for given target fd
	int
	Process::sim_fd(int tgt_fd)
	{
	if (tgt_fd > MAX_FD)
	return -1;

	return fd_map[tgt_fd].fd;
	}

	Process::FdMap *
	Process::sim_fd_obj(int tgt_fd)
	{
	if (tgt_fd > MAX_FD)
	panic("sim_fd_obj called in fd out of range.");

	return &fd_map[tgt_fd];
	}
	bool
	Process::checkAndAllocNextPage(Addr vaddr)
	{
	// if this is an initial write we might not have
	if (vaddr >= stack_min && vaddr < stack_base) {
	pTable->allocate(roundDown(vaddr, VMPageSize), VMPageSize);
	return true;
	}

	// We've accessed the next page of the stack, so extend the stack
	// to cover it.
	if (vaddr < stack_min && vaddr >= stack_base - max_stack_size) {
	while (vaddr < stack_min) {
	stack_min -= TheISA::PageBytes;
	if(stack_base - stack_min > max_stack_size)
	fatal("Maximum stack size exceeded\n");
	if(stack_base - stack_min > 810241024)
	fatal("Over max stack size for one thread\n");
	pTable->allocate(stack_min, TheISA::PageBytes);
	warn("Increasing stack size by one page.");
	};
	return true;
	}
	return false;
	}

	// find all offsets for currently open files and save them
	void
	Process::fix_file_offsets() {
	Process::FdMap *fdo_stdin = &fd_map[STDIN_FILENO];
	Process::FdMap *fdo_stdout = &fd_map[STDOUT_FILENO];
	Process::FdMap *fdo_stderr = &fd_map[STDERR_FILENO];
	string in = fdo_stdin->filename;
	string out = fdo_stdout->filename;

	// initialize file descriptors to default: same as simulator
	int stdin_fd, stdout_fd, stderr_fd;

	if (in == "stdin" \|\| in == "cin")
	stdin_fd = STDIN_FILENO;
	else if (in == "None")
	stdin_fd = -1;
	else{
	//OPEN standard in and seek to the right location
	stdin_fd = Process::openInputFile(in);
	if (lseek(stdin_fd, fdo_stdin->fileOffset, SEEK_SET) < 0)
	panic("Unable to seek to correct location in file: %s", in);
	}

	if (out == "stdout" \|\| out == "cout")
	stdout_fd = STDOUT_FILENO;
	else if (out == "stderr" \|\| out == "cerr")
	stdout_fd = STDERR_FILENO;
	else if (out == "None")
	stdout_fd = -1;
	else{
	stdout_fd = Process::openOutputFile(out);
	if (lseek(stdin_fd, fdo_stdout->fileOffset, SEEK_SET) < 0)
	panic("Unable to seek to correct in file: %s", out);
	}

	stderr_fd = (stdout_fd != STDOUT_FILENO) ? stdout_fd : STDERR_FILENO;

	fdo_stdin->fd = stdin_fd;
	fdo_stdout->fd = stdout_fd;
	fdo_stderr->fd = stderr_fd;


	for (int free_fd = 3; free_fd <= MAX_FD; ++free_fd) {
	Process::FdMap *fdo = &fd_map[free_fd];
	if (fdo->fd != -1) {
	if (fdo->isPipe){
	if (fdo->filename == "PIPE-WRITE")
	continue;
	else {
	assert (fdo->filename == "PIPE-READ");
	//create a new pipe
	int fds[2];
	int pipe_retval = pipe(fds);

	if (pipe_retval < 0) {
	// error
	panic("Unable to create new pipe.");
	}
	fdo->fd = fds[0]; //set read pipe
	Process::FdMap *fdo_write = &fd_map[fdo->readPipeSource];
	if (fdo_write->filename != "PIPE-WRITE")
	panic ("Couldn't find write end of the pipe");

	fdo_write->fd = fds[1];//set write pipe
	}
	} else {
	//Open file
	int fd = open(fdo->filename.c_str(), fdo->flags, fdo->mode);

	if (fd == -1)
	panic("Unable to open file: %s", fdo->filename);
	fdo->fd = fd;

	//Seek to correct location before checkpoint
	if (lseek(fd,fdo->fileOffset, SEEK_SET) < 0)
	panic("Unable to seek to correct location in file: %s", fdo->filename);
	}
	}
	}
	}
	void
	Process::find_file_offsets(){
	for (int free_fd = 0; free_fd <= MAX_FD; ++free_fd) {
	Process::FdMap *fdo = &fd_map[free_fd];
	if (fdo->fd != -1) {
	fdo->fileOffset = lseek(fdo->fd, 0, SEEK_CUR);
	} else {
	fdo->filename = "NULL";
	fdo->fileOffset = 0;
	}
	}
	}

	void
	Process::setReadPipeSource(int read_pipe_fd, int source_fd){
	Process::FdMap *fdo = &fd_map[read_pipe_fd];
	fdo->readPipeSource = source_fd;
	}

	void
	Process::FdMap::serialize(std::ostream &os)
	{
	SERIALIZE_SCALAR(fd);
	SERIALIZE_SCALAR(isPipe);
	SERIALIZE_SCALAR(filename);
	SERIALIZE_SCALAR(flags);
	SERIALIZE_SCALAR(readPipeSource);
	SERIALIZE_SCALAR(fileOffset);
	}

	void
	Process::FdMap::unserialize(Checkpoint *cp, const std::string &section)
	{
	UNSERIALIZE_SCALAR(fd);
	UNSERIALIZE_SCALAR(isPipe);
	UNSERIALIZE_SCALAR(filename);
	UNSERIALIZE_SCALAR(flags);
	UNSERIALIZE_SCALAR(readPipeSource);
	UNSERIALIZE_SCALAR(fileOffset);
	}

	void
	Process::serialize(std::ostream &os)
	{
	SERIALIZE_SCALAR(initialContextLoaded);
	SERIALIZE_SCALAR(brk_point);
	SERIALIZE_SCALAR(stack_base);
	SERIALIZE_SCALAR(stack_size);
	SERIALIZE_SCALAR(stack_min);
	SERIALIZE_SCALAR(next_thread_stack_base);
	SERIALIZE_SCALAR(mmap_start);
	SERIALIZE_SCALAR(mmap_end);
	SERIALIZE_SCALAR(nxm_start);
	SERIALIZE_SCALAR(nxm_end);
	find_file_offsets();
	pTable->serialize(os);
	for (int x = 0; x <= MAX_FD; x++) {
	nameOut(os, csprintf("%s.FdMap%d", name(), x));
	fd_map[x].serialize(os);
	}

	}

	void
	Process::unserialize(Checkpoint *cp, const std::string &section)
	{
	UNSERIALIZE_SCALAR(initialContextLoaded);
	UNSERIALIZE_SCALAR(brk_point);
	UNSERIALIZE_SCALAR(stack_base);
	UNSERIALIZE_SCALAR(stack_size);
	UNSERIALIZE_SCALAR(stack_min);
	UNSERIALIZE_SCALAR(next_thread_stack_base);
	UNSERIALIZE_SCALAR(mmap_start);
	UNSERIALIZE_SCALAR(mmap_end);
	UNSERIALIZE_SCALAR(nxm_start);
	UNSERIALIZE_SCALAR(nxm_end);
	pTable->unserialize(cp, section);
	for (int x = 0; x <= MAX_FD; x++) {
	fd_map[x].unserialize(cp, csprintf("%s.FdMap%d", section, x));
	}
	fix_file_offsets();

	checkpointRestored = true;

	}


	////////////////////////////////////////////////////////////////////////
	//
	// LiveProcess member definitions
	//
	////////////////////////////////////////////////////////////////////////


	LiveProcess::LiveProcess(LiveProcessParams * params, ObjectFile *_objFile)
	: Process(params), objFile(_objFile),
	argv(params->cmd), envp(params->env), cwd(params->cwd)
	{
	__uid = params->uid;
	__euid = params->euid;
	__gid = params->gid;
	__egid = params->egid;
	__pid = params->pid;
	__ppid = params->ppid;

	prog_fname = params->cmd[0];

	// load up symbols, if any... these may be used for debugging or
	// profiling.
	if (!debugSymbolTable) {
	debugSymbolTable = new SymbolTable();
	if (!objFile->loadGlobalSymbols(debugSymbolTable) \|\|
	!objFile->loadLocalSymbols(debugSymbolTable)) {
	// didn't load any symbols
	delete debugSymbolTable;
	debugSymbolTable = NULL;
	}
	}
	}

	void
	LiveProcess::argsInit(int intSize, int pageSize)
	{
	Process::startup();

	// load object file into target memory
	objFile->loadSections(initVirtMem);

	// Calculate how much space we need for arg & env arrays.
	int argv_array_size = intSize * (argv.size() + 1);
	int envp_array_size = intSize * (envp.size() + 1);
	int arg_data_size = 0;
	for (int i = 0; i < argv.size(); ++i) {
	arg_data_size += argv[i].size() + 1;
	}
	int env_data_size = 0;
	for (int i = 0; i < envp.size(); ++i) {
	env_data_size += envp[i].size() + 1;
	}

	int space_needed =
	argv_array_size + envp_array_size + arg_data_size + env_data_size;
	if (space_needed < 32*1024)
	space_needed = 32*1024;

	// set bottom of stack
	stack_min = stack_base - space_needed;
	// align it
	stack_min = roundDown(stack_min, pageSize);
	stack_size = stack_base - stack_min;
	// map memory
	pTable->allocate(stack_min, roundUp(stack_size, pageSize));

	// map out initial stack contents
	Addr argv_array_base = stack_min + intSize; // room for argc
	Addr envp_array_base = argv_array_base + argv_array_size;
	Addr arg_data_base = envp_array_base + envp_array_size;
	Addr env_data_base = arg_data_base + arg_data_size;

	// write contents to stack
	uint64_t argc = argv.size();
	if (intSize == 8)
	argc = htog((uint64_t)argc);
	else if (intSize == 4)
	argc = htog((uint32_t)argc);
	else
	panic("Unknown int size");

	initVirtMem->writeBlob(stack_min, (uint8_t*)&argc, intSize);

	copyStringArray(argv, argv_array_base, arg_data_base, initVirtMem);
	copyStringArray(envp, envp_array_base, env_data_base, initVirtMem);

	assert(NumArgumentRegs >= 2);
	threadContexts[0]->setIntReg(ArgumentReg[0], argc);
	threadContexts[0]->setIntReg(ArgumentReg[1], argv_array_base);
	threadContexts[0]->setIntReg(StackPointerReg, stack_min);

	Addr prog_entry = objFile->entryPoint();
	threadContexts[0]->setPC(prog_entry);
	threadContexts[0]->setNextPC(prog_entry + sizeof(MachInst));

	#if THE_ISA != ALPHA_ISA //e.g. MIPS or Sparc
	threadContexts[0]->setNextNPC(prog_entry + (2 * sizeof(MachInst)));
	#endif

	num_processes++;
	}

	void
	LiveProcess::syscall(int64_t callnum, ThreadContext *tc)
	{
	num_syscalls++;

	SyscallDesc *desc = getDesc(callnum);
	if (desc == NULL)
	fatal("Syscall %d out of range", callnum);

	desc->doSyscall(callnum, this, tc);
	}

	LiveProcess *
	LiveProcess::create(LiveProcessParams * params)
	{
	LiveProcess *process = NULL;

	string executable =
	params->executable == "" ? params->cmd[0] : params->executable;
	ObjectFile *objFile = createObjectFile(executable);
	if (objFile == NULL) {
	fatal("Can't load object file %s", executable);
	}

	if (objFile->isDynamic())
	fatal("Object file is a dynamic executable however only static "
	"executables are supported!\n Please recompile your "
	"executable as a static binary and try again.\n");

	#if THE_ISA == ALPHA_ISA
	if (objFile->hasTLS())
	fatal("Object file has a TLS section and single threaded TLS is not\n"
	" currently supported for Alpha! Please recompile your "
	"executable with \n a non-TLS toolchain.\n");

	if (objFile->getArch() != ObjectFile::Alpha)
	fatal("Object file architecture does not match compiled ISA (Alpha).");
	switch (objFile->getOpSys()) {
	case ObjectFile::Tru64:
	process = new AlphaTru64Process(params, objFile);
	break;

	case ObjectFile::Linux:
	process = new AlphaLinuxProcess(params, objFile);
	break;

	default:
	fatal("Unknown/unsupported operating system.");
	}
	#elif THE_ISA == SPARC_ISA
	if (objFile->getArch() != ObjectFile::SPARC64 && objFile->getArch() != ObjectFile::SPARC32)
	fatal("Object file architecture does not match compiled ISA (SPARC).");
	switch (objFile->getOpSys()) {
	case ObjectFile::Linux:
	if (objFile->getArch() == ObjectFile::SPARC64) {
	process = new Sparc64LinuxProcess(params, objFile);
	} else {
	process = new Sparc32LinuxProcess(params, objFile);
	}
	break;


	case ObjectFile::Solaris:
	process = new SparcSolarisProcess(params, objFile);
	break;
	default:
	fatal("Unknown/unsupported operating system.");
	}
	#elif THE_ISA == X86_ISA
	if (objFile->getArch() != ObjectFile::X86)
	fatal("Object file architecture does not match compiled ISA (x86).");
	switch (objFile->getOpSys()) {
	case ObjectFile::Linux:
	process = new X86LinuxProcess(params, objFile);
	break;
	default:
	fatal("Unknown/unsupported operating system.");
	}
	#elif THE_ISA == MIPS_ISA
	if (objFile->getArch() != ObjectFile::Mips)
	fatal("Object file architecture does not match compiled ISA (MIPS).");
	switch (objFile->getOpSys()) {
	case ObjectFile::Linux:
	process = new MipsLinuxProcess(params, objFile);
	break;

	default:
	fatal("Unknown/unsupported operating system.");
	}
	#elif THE_ISA == ARM_ISA
	if (objFile->getArch() != ObjectFile::Arm)
	fatal("Object file architecture does not match compiled ISA (ARM).");
	switch (objFile->getOpSys()) {
	case ObjectFile::Linux:
	process = new ArmLinuxProcess(params, objFile);
	break;

	default:
	fatal("Unknown/unsupported operating system.");
	}
	#else
	#error "THE_ISA not set"
	#endif


	if (process == NULL)
	fatal("Unknown error creating process object.");
	return process;
	}

	LiveProcess *
	LiveProcessParams::create()
	{
	return LiveProcess::create(this);
	}