syscall_desc.hh revision 11886 
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#include "base/types.hh"
52
53class Process;
54class SyscallReturn;
55class ThreadContext;
56
57/**
58 * This class provides the wrapper interface for the system call
59 * implementations which are defined in the sim/syscall_emul files and
60 * bound to the ISAs in the architecture specific code
61 * (i.e. arch/X86/linux/process.cc).
62 */
63class SyscallDesc {
64  public:
65    /** Typedef the function pointer here to clean up code below */
66    typedef SyscallReturn (*SyscallExecutor)(SyscallDesc*, int num,
67                                             Process*, ThreadContext*);
68
69    SyscallDesc(const char *name, SyscallExecutor sys_exec, int flags = 0)
70        : _name(name), executor(sys_exec), _flags(flags), _warned(false)
71    {
72    }
73
74    /** Provide a mechanism to specify behavior for abnormal system calls */
75    enum Flags {
76        /**
77         * Do not set return registers according to executor return value.
78         * Used for system calls with non-standard return conventions that
79         * explicitly set the thread context regs (e.g., sigreturn, clone)
80         */
81        SuppressReturnValue = 1,
82        /** Warn only once for unimplemented system calls */
83        WarnOnce = 2
84        /* X2 = 4, // Remove these comments when the next field is added; */
85        /* X3 = 8, // point is to make it obvious that this defines vector */
86    };
87
88    /**
89     * Interface for invoking the system call funcion pointer. Note that
90     * this acts as a gateway for all system calls and serves a good point
91     * to add filters for behaviors or apply checks for all system calls.
92     * @param callnum Number associated with call (by operating system)
93     * @param proc Handle for the owning Process to pass information
94     * @param tc Handle for owning ThreadContext to pass information
95     */
96    void doSyscall(int callnum, Process *proc, ThreadContext *tc,
97                   Fault *fault);
98
99    /**
100     * Return false if WarnOnce is set and a warning has already been issued.
101     * Otherwise, return true. Updates state as a side effect to help
102     * keep track of issued warnings.
103     */
104    bool needWarning();
105
106    bool warnOnce() const { return (_flags & WarnOnce); }
107
108    std::string name() { return _name; }
109
110    int getFlags() const { return _flags; }
111
112    void setFlags(int flags) { _flags = flags; }
113
114  private:
115    /** System call name (e.g., open, mmap, clone, socket, etc.) */
116    std::string _name;
117
118    /** Mechanism for ISAs to connect to the emul function definitions */
119    SyscallExecutor executor;
120
121    /**
122     * Holds values set with the preceding enum; note that this has been
123     * used primarily for features that are mutually exclusive, but there's
124     * no reason that this needs to be true going forward.
125     */
126    int _flags;
127
128    /** Set if WarnOnce is specified in flags AFTER first call */
129    bool _warned;
130};
131
132#endif // __SIM_SYSCALL_DESC_HH__
133