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authorSteve Reinhardt <steve.reinhardt@amd.com>2014-10-22 15:53:34 -0700
committerSteve Reinhardt <steve.reinhardt@amd.com>2014-10-22 15:53:34 -0700
commit44af2c6a6913d35a2c34bd928dbfdef3c16dcaf9 (patch)
tree89217c9e07be0227d76b3930d90ba63648a2c9e6
parent44ec1d212499246be3cef40ce7c96a3f65286153 (diff)
downloadgem5-44af2c6a6913d35a2c34bd928dbfdef3c16dcaf9.tar.xz
syscall_emul: Put BufferArg classes in a separate header.
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.
-rw-r--r--src/sim/syscall_emul.hh69
-rw-r--r--src/sim/syscall_emul_buf.hh168
2 files changed, 169 insertions, 68 deletions
diff --git a/src/sim/syscall_emul.hh b/src/sim/syscall_emul.hh
index 1c84e9f48..a4f9b238e 100644
--- a/src/sim/syscall_emul.hh
+++ b/src/sim/syscall_emul.hh
@@ -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
diff --git a/src/sim/syscall_emul_buf.hh b/src/sim/syscall_emul_buf.hh
new file mode 100644
index 000000000..cbd10f2f6
--- /dev/null
+++ b/src/sim/syscall_emul_buf.hh
@@ -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__