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

 /*
  * Copyright (c) 2014-2016 Advanced Micro Devices, Inc.
  * 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.
  */

 #ifndef __PROCESS_HH__
 #define __PROCESS_HH__

 #include <inttypes.h>

 #include <map>
 #include <memory>
 #include <string>
 #include <vector>

 #include "arch/registers.hh"
 #include "base/loader/memory_image.hh"
 #include "base/statistics.hh"
 #include "base/types.hh"
 #include "config/the_isa.hh"
 #include "mem/se_translating_port_proxy.hh"
 #include "sim/fd_array.hh"
 #include "sim/fd_entry.hh"
 #include "sim/mem_state.hh"
 #include "sim/sim_object.hh"

 namespace Loader
 {
 class ObjectFile;
 } // namespace Loader

 struct ProcessParams;

 class EmulatedDriver;
 class EmulationPageTable;
 class SyscallDesc;
 class SyscallReturn;
 class System;
 class ThreadContext;

 class Process : public SimObject
 {
   public:
     Process(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(); }

     /**
      * Find an emulated device driver.
      *
      * @param filename Name of the device (under /dev)
      * @return Pointer to driver object if found, else nullptr
      */
     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();

     // override of virtual SimObject method: register statistics
     void regStats() override;

     void allocateMem(Addr vaddr, int64_t size, bool clobber = false);

     /// Attempt to fix up a fault at vaddr by allocating a page on the stack.
     /// @return Whether the fault has been fixed.
     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);
     }

     /**
      * After delegating a thread context to a child process
      * no longer should relate to the ThreadContext
      */
     void revokeThreadContext(int context_id);

     /**
      * Does mmap region grow upward or downward from mmapEnd?  Most
      * platforms grow downward, but a few (such as Alpha) grow upward
      * instead, so they can override this method to return false.
      */
     virtual bool mmapGrowsDown() const { return true; }

     /**
      * Maps a contiguous range of virtual addresses in this process's
      * address space to a contiguous range of physical addresses.
      * This function exists primarily to expose the map operation to
      * python, so that configuration scripts can set up mappings in SE mode.
      *
      * @param vaddr The starting virtual address of the range.
      * @param paddr The starting physical address of the range.
      * @param size The length of the range in bytes.
      * @param cacheable Specifies whether accesses are cacheable.
      * @return True if the map operation was successful.  (At this
      *           point in time, the map operation always succeeds.)
      */
     bool map(Addr vaddr, Addr paddr, int 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;

     Stats::Scalar numSyscalls;  // track how many system calls are executed

     // 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;

     EmulationPageTable *pTable;

     // Memory proxy for initial image load.
     std::unique_ptr<SETranslatingPortProxy> initVirtMem;

     /**
      * Each instance of a Loader subclass will have a chance to try to load
      * an object file when tryLoaders is called. If they can't because they
      * aren't compatible with it (wrong arch, wrong OS, etc), then they
      * silently fail by returning nullptr so other loaders can try.
      */
     class Loader
     {
       public:
         Loader();

         /* Loader instances are singletons. */
         Loader(const Loader &) = delete;
         void operator=(const Loader &) = delete;

         virtual ~Loader() {}

         /**
          * Each subclass needs to implement this method. If the loader is
          * compatible with the passed in object file, it should return the
          * created Process object corresponding to it. If not, it should fail
          * silently and return nullptr. If there's a non-compatibliity related
          * error like file IO errors, etc., those should fail non-silently
          * with a panic or fail as normal.
          */
         virtual Process *load(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(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;

     /**
      * Return an absolute path given a relative path paired with the current
      * working directory of the process running under simulation.
      *
      * @param path The relative path (generally a filename) that needs the
      * current working directory prepended.
      * @param host_fs A flag which determines whether to return a
      * path for the host filesystem or the filesystem of the process running
      * under simulation. Only matters if filesysem redirection is used to
      * replace files (or directories) that would normally appear via the
      * host filesystem.
      * @return String containing an absolute path.
      */
     std::string absolutePath(const std::string &path, bool host_fs);

     /**
      * Redirect file path if it matches any keys initialized by system object.
      * @param filename An input parameter containing either a relative path
      * or an absolute path. If given a relative path, the path will be
      * prepended to the current working directory of the simulation with
      * respect to the host filesystem.
      * @return String containing an absolute path.
      */
     std::string checkPathRedirect(const std::string &filename);

     /**
      * The cwd members are used to track changes to the current working
      * directory for the purpose of executing system calls which depend on
      * relative paths (i.e. open, chdir).
      *
      * The tgt member and host member may differ if the path for the current
      * working directory is redirected to point to a different location
      * (i.e. `cd /proc` should point to '$(gem5_repo)/m5out/fs/proc'
      * instead of '/proc').
      */
     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;

     /**
      * Calls a futex wakeup at the address specified by this pointer when
      * this process exits.
      */
     uint64_t childClearTID;

     // Process was forked with SIGCHLD set.
     bool *sigchld;
 };

 #endif // __PROCESS_HH__
	/*
	* Copyright (c) 2014-2016 Advanced Micro Devices, Inc.
	* 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.
	*/

	#ifndef __PROCESS_HH__
	#define __PROCESS_HH__

	#include <inttypes.h>

	#include <map>
	#include <memory>
	#include <string>
	#include <vector>

	#include "arch/registers.hh"
	#include "base/loader/memory_image.hh"
	#include "base/statistics.hh"
	#include "base/types.hh"
	#include "config/the_isa.hh"
	#include "mem/se_translating_port_proxy.hh"
	#include "sim/fd_array.hh"
	#include "sim/fd_entry.hh"
	#include "sim/mem_state.hh"
	#include "sim/sim_object.hh"

	namespace Loader
	{
	class ObjectFile;
	} // namespace Loader

	struct ProcessParams;

	class EmulatedDriver;
	class EmulationPageTable;
	class SyscallDesc;
	class SyscallReturn;
	class System;
	class ThreadContext;

	class Process : public SimObject
	{
	public:
	Process(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(); }

	/**
	* Find an emulated device driver.
	*
	* @param filename Name of the device (under /dev)
	* @return Pointer to driver object if found, else nullptr
	*/
	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();

	// override of virtual SimObject method: register statistics
	void regStats() override;

	void allocateMem(Addr vaddr, int64_t size, bool clobber = false);

	/// Attempt to fix up a fault at vaddr by allocating a page on the stack.
	/// @return Whether the fault has been fixed.
	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);
	}

	/**
	* After delegating a thread context to a child process
	* no longer should relate to the ThreadContext
	*/
	void revokeThreadContext(int context_id);

	/**
	* Does mmap region grow upward or downward from mmapEnd? Most
	* platforms grow downward, but a few (such as Alpha) grow upward
	* instead, so they can override this method to return false.
	*/
	virtual bool mmapGrowsDown() const { return true; }

	/**
	* Maps a contiguous range of virtual addresses in this process's
	* address space to a contiguous range of physical addresses.
	* This function exists primarily to expose the map operation to
	* python, so that configuration scripts can set up mappings in SE mode.
	*
	* @param vaddr The starting virtual address of the range.
	* @param paddr The starting physical address of the range.
	* @param size The length of the range in bytes.
	* @param cacheable Specifies whether accesses are cacheable.
	* @return True if the map operation was successful. (At this
	* point in time, the map operation always succeeds.)
	*/
	bool map(Addr vaddr, Addr paddr, int 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;

	Stats::Scalar numSyscalls; // track how many system calls are executed

	// 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;

	EmulationPageTable *pTable;

	// Memory proxy for initial image load.
	std::unique_ptr<SETranslatingPortProxy> initVirtMem;

	/**
	* Each instance of a Loader subclass will have a chance to try to load
	* an object file when tryLoaders is called. If they can't because they
	* aren't compatible with it (wrong arch, wrong OS, etc), then they
	* silently fail by returning nullptr so other loaders can try.
	*/
	class Loader
	{
	public:
	Loader();

	/* Loader instances are singletons. */
	Loader(const Loader &) = delete;
	void operator=(const Loader &) = delete;

	virtual ~Loader() {}

	/**
	* Each subclass needs to implement this method. If the loader is
	* compatible with the passed in object file, it should return the
	* created Process object corresponding to it. If not, it should fail
	* silently and return nullptr. If there's a non-compatibliity related
	* error like file IO errors, etc., those should fail non-silently
	* with a panic or fail as normal.
	*/
	virtual Process load(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(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;

	/**
	* Return an absolute path given a relative path paired with the current
	* working directory of the process running under simulation.
	*
	* @param path The relative path (generally a filename) that needs the
	* current working directory prepended.
	* @param host_fs A flag which determines whether to return a
	* path for the host filesystem or the filesystem of the process running
	* under simulation. Only matters if filesysem redirection is used to
	* replace files (or directories) that would normally appear via the
	* host filesystem.
	* @return String containing an absolute path.
	*/
	std::string absolutePath(const std::string &path, bool host_fs);

	/**
	* Redirect file path if it matches any keys initialized by system object.
	* @param filename An input parameter containing either a relative path
	* or an absolute path. If given a relative path, the path will be
	* prepended to the current working directory of the simulation with
	* respect to the host filesystem.
	* @return String containing an absolute path.
	*/
	std::string checkPathRedirect(const std::string &filename);

	/**
	* The cwd members are used to track changes to the current working
	* directory for the purpose of executing system calls which depend on
	* relative paths (i.e. open, chdir).
	*
	* The tgt member and host member may differ if the path for the current
	* working directory is redirected to point to a different location
	* (i.e. `cd /proc` should point to '$(gem5_repo)/m5out/fs/proc'
	* instead of '/proc').
	*/
	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;

	/**
	* Calls a futex wakeup at the address specified by this pointer when
	* this process exits.
	*/
	uint64_t childClearTID;

	// Process was forked with SIGCHLD set.
	bool *sigchld;
	};

	#endif // __PROCESS_HH__