src/sim/syscall_desc.hh

   1 /*
   2  * Copyright (c) 2012-2013, 2015 ARM Limited
   3  * Copyright (c) 2015-2016 Advanced Micro Devices, Inc.
   4  * All rights reserved
   5  *
   6  * The license below extends only to copyright in the software and shall
   7  * not be construed as granting a license to any other intellectual
   8  * property including but not limited to intellectual property relating
   9  * to a hardware implementation of the functionality of the software
  10  * licensed hereunder.  You may use the software subject to the license
  11  * terms below provided that you ensure that this notice is replicated
  12  * unmodified and in its entirety in all distributions of the software,
  13  * modified or unmodified, in source code or in binary form.
  14  *
  15  * Copyright (c) 2003-2005 The Regents of The University of Michigan
  16  * All rights reserved.
  17  *
  18  * Redistribution and use in source and binary forms, with or without
  19  * modification, are permitted provided that the following conditions are
  20  * met: redistributions of source code must retain the above copyright
  21  * notice, this list of conditions and the following disclaimer;
  22  * redistributions in binary form must reproduce the above copyright
  23  * notice, this list of conditions and the following disclaimer in the
  24  * documentation and/or other materials provided with the distribution;
  25  * neither the name of the copyright holders nor the names of its
  26  * contributors may be used to endorse or promote products derived from
  27  * this software without specific prior written permission.
  28  *
  29  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  30  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  31  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
  32  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  33  * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  34  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  35  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  36  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  37  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  38  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  39  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  40  *
  41  * Authors: Steve Reinhardt
  42  *          Kevin Lim
  43  *          Brandon Potter
  44  */
  45
  46 #ifndef __SIM_SYSCALL_DESC_HH__
  47 #define __SIM_SYSCALL_DESC_HH__
  48
  49 #include <string>
  50
  51 class Process;
  52 class SyscallReturn;
  53 class ThreadContext;
  54
  55 /**
  56  * This class provides the wrapper interface for the system call
  57  * implementations which are defined in the sim/syscall_emul files and
  58  * bound to the ISAs in the architecture specific code
  59  * (i.e. arch/X86/linux/process.cc).
  60  */
  61 class SyscallDesc {
  62   public:
  63     /** Typedef the function pointer here to clean up code below */
  64     typedef SyscallReturn (*SyscallExecutor)(SyscallDesc*, int num,
  65                                              Process*, ThreadContext*);
  66
  67     SyscallDesc(const char *name, SyscallExecutor sys_exec, int flags = 0)
  68         : _name(name), executor(sys_exec), _flags(flags), _warned(false)
  69     {
  70     }
  71
  72     /** Provide a mechanism to specify behavior for abnormal system calls */
  73     enum Flags {
  74         /**
  75          * Do not set return registers according to executor return value.
  76          * Used for system calls with non-standard return conventions that
  77          * explicitly set the thread context regs (e.g., sigreturn, clone)
  78          */
  79         SuppressReturnValue = 1,
  80         /** Warn only once for unimplemented system calls */
  81         WarnOnce = 2
  82         /* X2 = 4, // Remove these comments when the next field is added; */
  83         /* X3 = 8, // point is to make it obvious that this defines vector */
  84     };
  85
  86     /**
  87      * Interface for invoking the system call funcion pointer. Note that
  88      * this acts as a gateway for all system calls and serves a good point
  89      * to add filters for behaviors or apply checks for all system calls.
  90      * @param callnum Number associated with call (by operating system)
  91      * @param proc Handle for the owning Process to pass information
  92      * @param tc Handle for owning ThreadContext to pass information
  93      */
  94     void doSyscall(int callnum, Process *proc, ThreadContext *tc);
  95
  96     /**
  97      * Return false if WarnOnce is set and a warning has already been issued.
  98      * Otherwise, return true. Updates state as a side effect to help
  99      * keep track of issued warnings.
 100      */
 101     bool needWarning();
 102
 103     bool warnOnce() const { return (_flags & WarnOnce); }
 104
 105     std::string name() { return _name; }
 106
 107   private:
 108     /** System call name (e.g., open, mmap, clone, socket, etc.) */
 109     std::string _name;
 110
 111     /** Mechanism for ISAs to connect to the emul function definitions */
 112     SyscallExecutor executor;
 113
 114     /**
 115      * Holds values set with the preceding enum; note that this has been
 116      * used primarily for features that are mutually exclusive, but there's
 117      * no reason that this needs to be true going forward.
 118      */
 119     int _flags;
 120
 121     /** Set if WarnOnce is specified in flags AFTER first call */
 122     bool _warned;
 123 };
 124
 125 #endif // __SIM_SYSCALL_DESC_HH__