src/sim/syscall_desc.cc

   1 /*
   2  * Copyright (c) 2016 Advanced Micro Devices, Inc.
   3  * Copyright (c) 2003-2005 The Regents of The University of Michigan
   4  * All rights reserved.
   5  *
   6  * Redistribution and use in source and binary forms, with or without
   7  * modification, are permitted provided that the following conditions are
   8  * met: redistributions of source code must retain the above copyright
   9  * notice, this list of conditions and the following disclaimer;
  10  * redistributions in binary form must reproduce the above copyright
  11  * notice, this list of conditions and the following disclaimer in the
  12  * documentation and/or other materials provided with the distribution;
  13  * neither the name of the copyright holders nor the names of its
  14  * contributors may be used to endorse or promote products derived from
  15  * this software without specific prior written permission.
  16  *
  17  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  18  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  19  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
  20  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  21  * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  22  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  23  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  24  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  25  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  26  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  27  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  28  *
  29  * Authors: Steve Reinhardt
  30  *          Ali Saidi
  31  *          Brandon Potter
  32  */
  33
  34 #include "sim/syscall_desc.hh"
  35
  36 #include <memory>
  37
  38 #include "base/trace.hh"
  39 #include "base/types.hh"
  40 #include "config/the_isa.hh"
  41 #include "cpu/base.hh"
  42 #include "cpu/thread_context.hh"
  43 #include "sim/faults.hh"
  44 #include "sim/process.hh"
  45 #include "sim/syscall_debug_macros.hh"
  46 #include "sim/syscall_return.hh"
  47
  48 void
  49 SyscallDesc::doSyscall(int callnum, Process *process, ThreadContext *tc,
  50                        Fault *fault)
  51 {
  52     TheISA::IntReg arg[6] M5_VAR_USED;
  53
  54     /**
  55      * Step through the first six parameters for the system call and
  56      * retrieve their values. Note that index is incremented as a
  57      * side-effect of the getSyscallArg method which is why the LHS
  58      * needs the "-1".
  59      */
  60     for (int index = 0; index < 6; )
  61         arg[index - 1] = process->getSyscallArg(tc, index);
  62
  63     /**
  64      * Linux supports up to six system call arguments through registers
  65      * so we want to print all six. Check to the relevant man page to
  66      * verify how many are actually used by a given system call.
  67      */
  68     DPRINTF_SYSCALL(Base, "%s called w/arguments %d, %d, %d, %d, %d, %d\n",
  69                     _name, arg[0], arg[1], arg[2], arg[3], arg[4], arg[5]);
  70
  71     /** Invoke the system call */
  72     SyscallReturn retval = (*executor)(this, callnum, process, tc);
  73
  74     /**
  75      * If the system call needs to be restarted, most likely due to
  76      * blocking behavior, warn that the system call will retry;
  77      * alternatively, print the return value.
  78      */
  79     if (retval.needsRetry()) {
  80         *fault = std::make_shared<SyscallRetryFault>();
  81         DPRINTF_SYSCALL(Base, "%s needs retry\n", _name);
  82     } else
  83         DPRINTF_SYSCALL(Base, "%s returns %d\n", _name, retval.encodedValue());
  84
  85     if (!(_flags & SyscallDesc::SuppressReturnValue) && !retval.needsRetry())
  86         process->setSyscallReturn(tc, retval);
  87 }
  88
  89 bool
  90 SyscallDesc::needWarning()
  91 {
  92     bool suppress_warning = warnOnce() && _warned;
  93     _warned = true;
  94     return !suppress_warning;
  95 }