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syscall_emul: Put BufferArg classes in a separate header.

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Move the BufferArg classes that support syscall buffer args
(i.e., pointers into simulated user space) out of syscall_emul.hh
and into a new header syscall_emul_buf.hh so they are accessible
to emulated driver implementations.

Take the opportunity to add some comments as well.
This commit is contained in:
Steve Reinhardt
2014-10-22 15:53:34 -07:00
parent 44ec1d2124
commit 44af2c6a69
2 changed files with 169 additions and 68 deletions
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69
src/sim/syscall_emul.hh
View File

@@ -75,10 +75,10 @@
#include "cpu/thread_context.hh"
#include "debug/SyscallVerbose.hh"
#include "mem/page_table.hh"
#include "mem/se_translating_port_proxy.hh"
#include "sim/byteswap.hh"
#include "sim/emul_driver.hh"
#include "sim/process.hh"
#include "sim/syscall_emul_buf.hh"
#include "sim/syscallreturn.hh"
#include "sim/system.hh"
@@ -117,73 +117,6 @@ class SyscallDesc {
};
class BaseBufferArg {
public:
BaseBufferArg(Addr _addr, int _size) : addr(_addr), size(_size)
{
bufPtr = new uint8_t[size];
// clear out buffer: in case we only partially populate this,
// and then do a copyOut(), we want to make sure we don't
// introduce any random junk into the simulated address space
memset(bufPtr, 0, size);
}
virtual ~BaseBufferArg() { delete [] bufPtr; }
//
// copy data into simulator space (read from target memory)
//
virtual bool copyIn(SETranslatingPortProxy &memproxy)
{
memproxy.readBlob(addr, bufPtr, size);
return true; // no EFAULT detection for now
}
//
// copy data out of simulator space (write to target memory)
//
virtual bool copyOut(SETranslatingPortProxy &memproxy)
{
memproxy.writeBlob(addr, bufPtr, size);
return true; // no EFAULT detection for now
}
protected:
Addr addr;
int size;
uint8_t *bufPtr;
};
class BufferArg : public BaseBufferArg
{
public:
BufferArg(Addr _addr, int _size) : BaseBufferArg(_addr, _size) { }
void *bufferPtr() { return bufPtr; }
};
template <class T>
class TypedBufferArg : public BaseBufferArg
{
public:
// user can optionally specify a specific number of bytes to
// allocate to deal with those structs that have variable-size
// arrays at the end
TypedBufferArg(Addr _addr, int _size = sizeof(T))
: BaseBufferArg(_addr, _size)
{ }
// type case
operator T*() { return (T *)bufPtr; }
// dereference operators
T &operator*() { return *((T *)bufPtr); }
T* operator->() { return (T *)bufPtr; }
T &operator[](int i) { return ((T *)bufPtr)[i]; }
};
//////////////////////////////////////////////////////////////////////
//
// The following emulation functions are generic enough that they

168
src/sim/syscall_emul_buf.hh Normal file
View File

@@ -0,0 +1,168 @@
/*
* Copyright (c) 2003-2005 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: Steve Reinhardt
*/
#ifndef __SIM_SYSCALL_EMUL_BUF_HH__
#define __SIM_SYSCALL_EMUL_BUF_HH__
///
/// @file syscall_emul_buf.hh
///
/// This file defines buffer classes used to handle pointer arguments
/// in emulated syscalls.
#include <cstring>
#include "base/types.hh"
#include "mem/se_translating_port_proxy.hh"
/**
* Base class for BufferArg and TypedBufferArg, Not intended to be
* used directly.
*
* The BufferArg classes represent buffers in target user space that
* are passed by reference to an (emulated) system call. Each
* instance provides an internal (simulator-space) buffer of the
* appropriate size and tracks the user-space address. The copyIn()
* and copyOut() methods copy the user-space buffer to and from the
* simulator-space buffer, respectively.
*/
class BaseBufferArg {
public:
/**
* Allocate a buffer of size 'size' representing the memory at
* target address 'addr'.
*/
BaseBufferArg(Addr _addr, int _size)
: addr(_addr), size(_size), bufPtr(new uint8_t[size])
{
// clear out buffer: in case we only partially populate this,
// and then do a copyOut(), we want to make sure we don't
// introduce any random junk into the simulated address space
memset(bufPtr, 0, size);
}
virtual ~BaseBufferArg() { delete [] bufPtr; }
/**
* copy data into simulator space (read from target memory)
*/
virtual bool copyIn(SETranslatingPortProxy &memproxy)
{
memproxy.readBlob(addr, bufPtr, size);
return true; // no EFAULT detection for now
}
/**
* copy data out of simulator space (write to target memory)
*/
virtual bool copyOut(SETranslatingPortProxy &memproxy)
{
memproxy.writeBlob(addr, bufPtr, size);
return true; // no EFAULT detection for now
}
protected:
const Addr addr; ///< address of buffer in target address space
const int size; ///< buffer size
uint8_t * const bufPtr; ///< pointer to buffer in simulator space
};
/**
* BufferArg represents an untyped buffer in target user space that is
* passed by reference to an (emulated) system call.
*/
class BufferArg : public BaseBufferArg
{
public:
/**
* Allocate a buffer of size 'size' representing the memory at
* target address 'addr'.
*/
BufferArg(Addr _addr, int _size) : BaseBufferArg(_addr, _size) { }
/**
* Return a pointer to the internal simulator-space buffer.
*/
void *bufferPtr() { return bufPtr; }
};
/**
* TypedBufferArg is a class template; instances of this template
* represent typed buffers in target user space that are passed by
* reference to an (emulated) system call.
*
* This template provides operator overloads for convenience, allowing
* for example the use of '->' to reference fields within a struct
* type.
*/
template <class T>
class TypedBufferArg : public BaseBufferArg
{
public:
/**
* Allocate a buffer of type T representing the memory at target
* address 'addr'. The user can optionally specify a specific
* number of bytes to allocate to deal with structs that have
* variable-size arrays at the end.
*/
TypedBufferArg(Addr _addr, int _size = sizeof(T))
: BaseBufferArg(_addr, _size)
{ }
/**
* Convert TypedBufferArg<T> to a pointer to T that points to the
* internal buffer.
*/
operator T*() { return (T *)bufPtr; }
/**
* Convert TypedBufferArg<T> to a reference to T that references the
* internal buffer value.
*/
T &operator*() { return *((T *)bufPtr); }
/**
* Enable the use of '->' to reference fields where T is a struct
* type.
*/
T* operator->() { return (T *)bufPtr; }
/**
* Enable the use of '[]' to reference fields where T is an array
* type.
*/
T &operator[](int i) { return ((T *)bufPtr)[i]; }
};
#endif // __SIM_SYSCALL_EMUL_BUF_HH__