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 <functional>
  50 #include <string>
  51
  52 #include "base/types.hh"
  53 #include "cpu/thread_context.hh"
  54 #include "sim/guest_abi.hh"
  55 #include "sim/process.hh"
  56 #include "sim/syscall_return.hh"
  57
  58 class SyscallDesc;
  59
  60 SyscallReturn unimplementedFunc(SyscallDesc *desc, int num,
  61                                 ThreadContext *tc);
  62
  63 /**
  64  * This class provides the wrapper interface for the system call
  65  * implementations which are defined in the sim/syscall_emul files and
  66  * bound to the ISAs in the architecture specific code
  67  * (i.e. arch/X86/linux/process.cc).
  68  */
  69 class SyscallDesc {
  70   public:
  71     using SyscallExecutor =
  72         std::function<SyscallReturn(SyscallDesc *, int num, ThreadContext *)>;
  73
  74     SyscallDesc(const char *name, SyscallExecutor sys_exec=unimplementedFunc)
  75         : _name(name), executor(sys_exec)
  76     {}
  77
  78     /**
  79      * Interface for invoking the system call funcion pointer. Note that
  80      * this acts as a gateway for all system calls and serves a good point
  81      * to add filters for behaviors or apply checks for all system calls.
  82      * @param callnum Number associated with call (by operating system)
  83      * @param proc Handle for the owning Process to pass information
  84      * @param tc Handle for owning ThreadContext to pass information
  85      */
  86     void doSyscall(int callnum, ThreadContext *tc, Fault *fault);
  87
  88     std::string name() { return _name; }
  89
  90   private:
  91     /** System call name (e.g., open, mmap, clone, socket, etc.) */
  92     std::string _name;
  93
  94     /** Mechanism for ISAs to connect to the emul function definitions */
  95     SyscallExecutor executor;
  96 };
  97
  98 /*
  99  * This SyscallDesc subclass template adapts a given syscall implementation so
 100  * that some arguments can come from the simulator (desc, num and tc) while the
 101  * rest can come from the guest using the GuestABI mechanism.
 102  */
 103 template <typename ABI>
 104 class SyscallDescABI : public SyscallDesc
 105 {
 106   private:
 107     // Aliases to make the code below a little more concise.
 108     template <typename ...Args>
 109     using SyscallABIExecutor =
 110         std::function<SyscallReturn(SyscallDesc *, int,
 111                                     ThreadContext *, Args...)>;
 112
 113     template <typename ...Args>
 114     using SyscallABIExecutorPtr =
 115         SyscallReturn (*)(SyscallDesc *, int, ThreadContext *, Args...);
 116
 117
 118     // Wrap an executor with guest arguments with a normal executor that gets
 119     // those additional arguments from the guest context.
 120     template <typename ...Args>
 121     static inline SyscallExecutor
 122     buildExecutor(SyscallABIExecutor<Args...> target)
 123     {
 124         return [target](SyscallDesc *desc, int num,
 125                         ThreadContext *tc) -> SyscallReturn {
 126             // Create a partial function which will stick desc and num to the
 127             // front of the parameter list.
 128             auto partial = [target,desc,num](
 129                     ThreadContext *tc, Args... args) -> SyscallReturn {
 130                 return target(desc, num, tc, args...);
 131             };
 132
 133             // Use invokeSimcall to gather the other arguments based on the
 134             // given ABI and pass them to the syscall implementation.
 135             return invokeSimcall<ABI, SyscallReturn, Args...>(tc,
 136                     std::function<SyscallReturn(ThreadContext *, Args...)>(
 137                         partial));
 138         };
 139     }
 140
 141
 142   public:
 143     // Constructors which plumb in buildExecutor.
 144     template <typename ...Args>
 145     SyscallDescABI(const char *name, SyscallABIExecutor<Args...> target) :
 146         SyscallDesc(name, buildExecutor<Args...>(target))
 147     {}
 148
 149     template <typename ...Args>
 150     SyscallDescABI(const char *name, SyscallABIExecutorPtr<Args...> target) :
 151         SyscallDescABI(name, SyscallABIExecutor<Args...>(target))
 152     {}
 153
 154     using SyscallDesc::SyscallDesc;
 155 };
 156
 157 struct DefaultSyscallABI
 158 {
 159     using Position = int;
 160 };
 161
 162 namespace GuestABI
 163 {
 164
 165 template <>
 166 struct Result<DefaultSyscallABI, SyscallReturn>
 167 {
 168     static void
 169     store(ThreadContext *tc, const SyscallReturn &ret)
 170     {
 171         auto *process = tc->getProcessPtr();
 172         process->setSyscallReturn(tc, ret);
 173     }
 174 };
 175
 176 template <typename Arg>
 177 struct Argument<DefaultSyscallABI, Arg,
 178     typename std::enable_if<std::is_integral<Arg>::value>::type>
 179 {
 180     static Arg
 181     get(ThreadContext *tc, DefaultSyscallABI::Position &position)
 182     {
 183         auto *process = tc->getProcessPtr();
 184         return process->getSyscallArg(tc, position);
 185     }
 186 };
 187
 188 template <typename Arg>
 189 struct Argument<DefaultSyscallABI, Arg,
 190     typename std::enable_if<std::is_pointer<Arg>::value>::type>
 191 {
 192     static Arg
 193     get(ThreadContext *tc, DefaultSyscallABI::Position &position)
 194     {
 195         auto *process = tc->getProcessPtr();
 196         RegVal reg = process->getSyscallArg(tc, position);
 197         return (Arg)(uintptr_t)(reg);
 198     }
 199 };
 200
 201 } // namespace GuestABI
 202
 203 #endif // __SIM_SYSCALL_DESC_HH__