process.hh

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/*
 * Copyright (c) 2014-2016 Advanced Micro Devices, Inc.
 * Copyright (c) 2001-2005 The Regents of The University of Michigan
 * All rights reserved.
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 * 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
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#ifndef __PROCESS_HH__
#define __PROCESS_HH__
 
#include <inttypes.h>
 
#include <map>
#include <memory>
#include <string>
#include <vector>
 
#include "base/loader/memory_image.hh"
#include "base/statistics.hh"
#include "base/types.hh"
#include "sim/fd_array.hh"
#include "sim/fd_entry.hh"
#include "sim/mem_state.hh"
#include "sim/sim_object.hh"
 
namespace gem5
{
 
namespace loader
{
class ObjectFile;
} // namespace loader
 
struct ProcessParams;
 
class EmulatedDriver;
class EmulationPageTable;
class SEWorkload;
class SyscallDesc;
class SyscallReturn;
class System;
class ThreadContext;
 
class Process : public SimObject
{
  public:
    Process(const ProcessParams &params, EmulationPageTable *pTable,
            loader::ObjectFile *obj_file);
 
    void serialize(CheckpointOut &cp) const override;
    void unserialize(CheckpointIn &cp) override;
 
    void init() override;
    void initState() override;
    DrainState drain() override;
 
    virtual void syscall(ThreadContext *tc) { numSyscalls++; }
 
    inline uint64_t uid() { return _uid; }
    inline uint64_t euid() { return _euid; }
    inline uint64_t gid() { return _gid; }
    inline uint64_t egid() { return _egid; }
    inline uint64_t pid() { return _pid; }
    inline uint64_t ppid() { return _ppid; }
    inline uint64_t pgid() { return _pgid; }
    inline void pgid(uint64_t pgid) { _pgid = pgid; }
    inline uint64_t tgid() { return _tgid; }
 
    const char *progName() const { return executable.c_str(); }

    EmulatedDriver *findDriver(std::string filename);
 
    // This function acts as a callback to update the bias value in
    // the object file because the parameters needed to calculate the
    // bias are not available when the object file is created.
    void updateBias();
    Addr getBias();
    Addr getStartPC();
    loader::ObjectFile *getInterpreter();
 
    // This function allocates physical memory as backing store, and then maps
    // it into the virtual address space of the process. The range of virtual
    // addresses being configured starts at the address "vaddr" and is of size
    // "size" bytes. If some part of this range of virtual addresses is already
    // configured, this function will error out unless "clobber" is set. If
    // clobber is set, then those existing mappings will be replaced.
    //
    // If the beginning or end of the virtual address range does not perfectly
    // align to page boundaries, it will be expanded in either direction until
    // it does. This function will therefore set up *at least* the range
    // requested, and may configure more if necessary.
    void allocateMem(Addr vaddr, int64_t size, bool clobber=false);

    void deallocateMem(Addr vaddr, int64_t size);

    bool fixupFault(Addr vaddr);
 
    // After getting registered with system object, tell process which
    // system-wide context id it is assigned.
    void
    assignThreadContext(ContextID context_id)
    {
        contextIds.push_back(context_id);
    }

    void revokeThreadContext(int context_id);

    virtual bool mmapGrowsDown() const { return true; }

    bool map(Addr vaddr, Addr paddr, int64_t size, bool cacheable = true);
 
    void replicatePage(Addr vaddr, Addr new_paddr, ThreadContext *old_tc,
                       ThreadContext *new_tc, bool alloc_page);
 
    virtual void clone(ThreadContext *old_tc, ThreadContext *new_tc,
                       Process *new_p, RegVal flags);
 
    // thread contexts associated with this process
    std::vector<ContextID> contextIds;
 
    // system object which owns this process
    System *system;
 
    SEWorkload *seWorkload;
 
    // flag for using architecture specific page table
    bool useArchPT;
    // running KVM requires special initialization
    bool kvmInSE;
    // flag for using the process as a thread which shares page tables
    bool useForClone;

    bool zeroPages;
 
    EmulationPageTable *pTable;
 
    // Memory proxy for initial image load.
    std::unique_ptr<SETranslatingPortProxy> initVirtMem;

    class Loader
    {
      public:
        Loader();
 
        /* Loader instances are singletons. */
        Loader(const Loader &) = delete;
        void operator=(const Loader &) = delete;
 
        virtual ~Loader() {}

        virtual Process *load(const ProcessParams &params,
                              loader::ObjectFile *obj_file) = 0;
    };
 
    // Try all the Loader instance's "load" methods one by one until one is
    // successful. If none are, complain and fail.
    static Process *tryLoaders(const ProcessParams &params,
                               loader::ObjectFile *obj_file);
 
    loader::ObjectFile *objFile;
    loader::MemoryImage image;
    loader::MemoryImage interpImage;
    std::vector<std::string> argv;
    std::vector<std::string> envp;
    std::string executable;

    std::string absolutePath(const std::string &path, bool host_fs);

    std::string checkPathRedirect(const std::string &filename);

    std::string tgtCwd;
    std::string hostCwd;
 
    // Syscall emulation uname release.
    std::string release;
 
    // Id of the owner of the process
    uint64_t _uid;
    uint64_t _euid;
    uint64_t _gid;
    uint64_t _egid;
 
    // pid of the process and it's parent
    uint64_t _pid;
    uint64_t _ppid;
    uint64_t _pgid;
    uint64_t _tgid;
 
    // Emulated drivers available to this process
    std::vector<EmulatedDriver *> drivers;
 
    std::shared_ptr<FDArray> fds;
 
    bool *exitGroup;
    std::shared_ptr<MemState> memState;

    uint64_t childClearTID;
 
    // Process was forked with SIGCHLD set.
    bool *sigchld;
 
    // Contexts to wake up when this thread exits or calls execve
    std::vector<ContextID> vforkContexts;
 
    // Track how many system calls are executed
    statistics::Scalar numSyscalls;
};
 
} // namespace gem5
 
#endif // __PROCESS_HH__