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
  42 #ifndef __SIM_SYSCALL_DESC_HH__
  43 #define __SIM_SYSCALL_DESC_HH__
  44
  45 #include <functional>
  46 #include <map>
  47 #include <string>
  48
  49 #include "base/logging.hh"
  50 #include "base/types.hh"
  51 #include "cpu/thread_context.hh"
  52 #include "sim/guest_abi.hh"
  53 #include "sim/process.hh"
  54 #include "sim/syscall_return.hh"
  55
  56 class SyscallDesc;
  57
  58 SyscallReturn unimplementedFunc(SyscallDesc *desc, ThreadContext *tc);
  59
  60 /**
  61  * This class provides the wrapper interface for the system call
  62  * implementations which are defined in the sim/syscall_emul files and
  63  * bound to the ISAs in the architecture specific code
  64  * (i.e. arch/X86/linux/process.cc).
  65  */
  66 class SyscallDesc {
  67   public:
  68     /**
  69      * Interface for invoking the system call funcion pointer. Note that
  70      * this acts as a gateway for all system calls and serves a good point
  71      * to add filters for behaviors or apply checks for all system calls.
  72      * @param tc Handle for owning ThreadContext to pass information
  73      */
  74     void doSyscall(ThreadContext *tc, Fault *fault);
  75
  76     std::string name() const { return _name; }
  77     int num() const { return _num; }
  78
  79     /**
  80      * For use within the system call executor if new threads are created and
  81      * need something returned into them.
  82      */
  83     virtual void returnInto(ThreadContext *tc, const SyscallReturn &ret) = 0;
  84
  85   protected:
  86     using Executor =
  87         std::function<SyscallReturn(SyscallDesc *, ThreadContext *)>;
  88     using Dumper = std::function<std::string(std::string, ThreadContext *)>;
  89
  90     SyscallDesc(int num, const char *name, Executor exec, Dumper dump) :
  91         _name(name), _num(num), executor(exec), dumper(dump)
  92     {}
  93
  94   private:
  95     /** System call name (e.g., open, mmap, clone, socket, etc.) */
  96     std::string _name;
  97     int _num;
  98
  99     /** Mechanism for ISAs to connect to the emul function definitions */
 100     Executor executor;
 101     Dumper dumper;
 102 };
 103
 104 /*
 105  * This SyscallDesc subclass template adapts a given syscall implementation so
 106  * that some arguments can come from the simulator (desc, num and tc) while the
 107  * rest can come from the guest using the GuestABI mechanism.
 108  */
 109 template <typename ABI>
 110 class SyscallDescABI : public SyscallDesc
 111 {
 112   private:
 113     // Aliases to make the code below a little more concise.
 114     template <typename ...Args>
 115     using ABIExecutor =
 116         std::function<SyscallReturn(SyscallDesc *, ThreadContext *, Args...)>;
 117
 118     template <typename ...Args>
 119     using ABIExecutorPtr =
 120         SyscallReturn (*)(SyscallDesc *, ThreadContext *, Args...);
 121
 122
 123     // Wrap an executor with guest arguments with a normal executor that gets
 124     // those additional arguments from the guest context.
 125     template <typename ...Args>
 126     static inline Executor
 127     buildExecutor(ABIExecutor<Args...> target)
 128     {
 129         return [target](SyscallDesc *desc,
 130                         ThreadContext *tc) -> SyscallReturn {
 131             // Create a partial function which will stick desc to the front of
 132             // the parameter list.
 133             auto partial = [target,desc](
 134                     ThreadContext *tc, Args... args) -> SyscallReturn {
 135                 return target(desc, tc, args...);
 136             };
 137
 138             // Use invokeSimcall to gather the other arguments based on the
 139             // given ABI and pass them to the syscall implementation.
 140             return invokeSimcall<ABI, SyscallReturn, Args...>(tc,
 141                     std::function<SyscallReturn(ThreadContext *, Args...)>(
 142                         partial));
 143         };
 144     }
 145
 146     template <typename ...Args>
 147     static inline Dumper
 148     buildDumper()
 149     {
 150         return [](std::string name, ThreadContext *tc) -> std::string {
 151             return dumpSimcall<ABI, SyscallReturn, Args...>(name, tc);
 152         };
 153     }
 154
 155   public:
 156     // Constructors which plumb in buildExecutor.
 157     template <typename ...Args>
 158     SyscallDescABI(int num, const char *name, ABIExecutor<Args...> target) :
 159         SyscallDesc(num, name, buildExecutor<Args...>(target),
 160                                buildDumper<Args...>())
 161     {}
 162
 163     template <typename ...Args>
 164     SyscallDescABI(int num, const char *name, ABIExecutorPtr<Args...> target) :
 165         SyscallDescABI(num, name, ABIExecutor<Args...>(target))
 166     {}
 167
 168     SyscallDescABI(int num, const char *name) :
 169         SyscallDescABI(num, name, ABIExecutor<>(unimplementedFunc))
 170     {}
 171
 172     void
 173     returnInto(ThreadContext *tc, const SyscallReturn &ret) override
 174     {
 175         GuestABI::Result<ABI, SyscallReturn>::store(tc, ret);
 176     }
 177 };
 178
 179 template <typename ABI>
 180 class SyscallDescTable
 181 {
 182   private:
 183     std::map<int, SyscallDescABI<ABI>> _descs;
 184
 185   public:
 186     SyscallDescTable(std::initializer_list<SyscallDescABI<ABI>> descs)
 187     {
 188         for (auto &desc: descs) {
 189             auto res = _descs.insert({desc.num(), desc});
 190             panic_if(!res.second, "Failed to insert desc %s", desc.name());
 191         }
 192     }
 193
 194     SyscallDesc
 195     *get(int num, bool fatal_if_missing=true)
 196     {
 197         auto it = _descs.find(num);
 198         if (it == _descs.end()) {
 199             if (fatal_if_missing)
 200                 fatal("Syscall %d out of range", num);
 201             else
 202                 return nullptr;
 203         }
 204         return &it->second;
 205     }
 206 };
 207
 208 #endif // __SIM_SYSCALL_DESC_HH__