src/arch/riscv/process.cc

   1 /*
   2  * Copyright (c) 2004-2005 The Regents of The University of Michigan
   3  * Copyright (c) 2016 The University of Virginia
   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: Gabe Black
  30  *          Ali Saidi
  31  *          Korey Sewell
  32  *          Alec Roelke
  33  */
  34 #include "arch/riscv/process.hh"
  35
  36 #include <algorithm>
  37 #include <cstddef>
  38 #include <iostream>
  39 #include <iterator>
  40 #include <map>
  41 #include <string>
  42 #include <vector>
  43
  44 #include "arch/riscv/isa_traits.hh"
  45 #include "base/loader/elf_object.hh"
  46 #include "base/loader/object_file.hh"
  47 #include "base/logging.hh"
  48 #include "base/random.hh"
  49 #include "cpu/thread_context.hh"
  50 #include "debug/Stack.hh"
  51 #include "mem/page_table.hh"
  52 #include "params/Process.hh"
  53 #include "sim/aux_vector.hh"
  54 #include "sim/process.hh"
  55 #include "sim/process_impl.hh"
  56 #include "sim/syscall_return.hh"
  57 #include "sim/system.hh"
  58
  59 using namespace std;
  60 using namespace RiscvISA;
  61
  62 RiscvProcess::RiscvProcess(ProcessParams * params,
  63     ObjectFile *objFile) : Process(params, objFile)
  64 {
  65     const Addr stack_base = 0x7FFFFFFFFFFFFFFFL;
  66     const Addr max_stack_size = 8 * 1024 * 1024;
  67     const Addr next_thread_stack_base = stack_base - max_stack_size;
  68     const Addr brk_point = roundUp(objFile->bssBase() + objFile->bssSize(),
  69             PageBytes);
  70     const Addr mmap_end = 0x4000000000000000L;
  71     memState = make_shared<MemState>(brk_point, stack_base, max_stack_size,
  72             next_thread_stack_base, mmap_end);
  73 }
  74
  75 void
  76 RiscvProcess::initState()
  77 {
  78     Process::initState();
  79
  80     argsInit<uint64_t>(PageBytes);
  81 }
  82
  83 template<class IntType> void
  84 RiscvProcess::argsInit(int pageSize)
  85 {
  86     const int RandomBytes = 16;
  87
  88     updateBias();
  89     objFile->loadSections(initVirtMem);
  90     ElfObject* elfObject = dynamic_cast<ElfObject*>(objFile);
  91     memState->setStackMin(memState->getStackBase());
  92
  93     // Determine stack size and populate auxv
  94     Addr stack_top = memState->getStackMin();
  95     stack_top -= RandomBytes;
  96     for (const string& arg: argv)
  97         stack_top -= arg.size() + 1;
  98     for (const string& env: envp)
  99         stack_top -= env.size() + 1;
 100     stack_top &= -sizeof(Addr);
 101
 102     vector<AuxVector<IntType>> auxv;
 103     if (elfObject != nullptr) {
 104         auxv.push_back({M5_AT_ENTRY, objFile->entryPoint()});
 105         auxv.push_back({M5_AT_PHNUM, elfObject->programHeaderCount()});
 106         auxv.push_back({M5_AT_PHENT, elfObject->programHeaderSize()});
 107         auxv.push_back({M5_AT_PHDR, elfObject->programHeaderTable()});
 108         auxv.push_back({M5_AT_PAGESZ, PageBytes});
 109         auxv.push_back({M5_AT_SECURE, 0});
 110         auxv.push_back({M5_AT_RANDOM, stack_top});
 111         auxv.push_back({M5_AT_NULL, 0});
 112     }
 113     stack_top -= (1 + argv.size()) * sizeof(Addr) +
 114                    (1 + envp.size()) * sizeof(Addr) +
 115                    sizeof(Addr) + 2 * sizeof(IntType) * auxv.size();
 116     stack_top &= -2*sizeof(Addr);
 117     memState->setStackSize(memState->getStackBase() - stack_top);
 118     allocateMem(roundDown(stack_top, pageSize),
 119             roundUp(memState->getStackSize(), pageSize));
 120
 121     // Copy random bytes (for AT_RANDOM) to stack
 122     memState->setStackMin(memState->getStackMin() - RandomBytes);
 123     uint8_t at_random[RandomBytes];
 124     generate(begin(at_random), end(at_random),
 125              [&]{ return random_mt.random(0, 0xFF); });
 126     initVirtMem.writeBlob(memState->getStackMin(), at_random, RandomBytes);
 127
 128     // Copy argv to stack
 129     vector<Addr> argPointers;
 130     for (const string& arg: argv) {
 131         memState->setStackMin(memState->getStackMin() - (arg.size() + 1));
 132         initVirtMem.writeString(memState->getStackMin(), arg.c_str());
 133         argPointers.push_back(memState->getStackMin());
 134         if (DTRACE(Stack)) {
 135             string wrote;
 136             initVirtMem.readString(wrote, argPointers.back());
 137             DPRINTFN("Wrote arg \"%s\" to address %p\n",
 138                     wrote, (void*)memState->getStackMin());
 139         }
 140     }
 141     argPointers.push_back(0);
 142
 143     // Copy envp to stack
 144     vector<Addr> envPointers;
 145     for (const string& env: envp) {
 146         memState->setStackMin(memState->getStackMin() - (env.size() + 1));
 147         initVirtMem.writeString(memState->getStackMin(), env.c_str());
 148         envPointers.push_back(memState->getStackMin());
 149         DPRINTF(Stack, "Wrote env \"%s\" to address %p\n",
 150                 env, (void*)memState->getStackMin());
 151     }
 152     envPointers.push_back(0);
 153
 154     // Align stack
 155     memState->setStackMin(memState->getStackMin() & -sizeof(Addr));
 156
 157     // Calculate bottom of stack
 158     memState->setStackMin(memState->getStackMin() -
 159             ((1 + argv.size()) * sizeof(Addr) +
 160              (1 + envp.size()) * sizeof(Addr) +
 161              sizeof(Addr) + 2 * sizeof(IntType) * auxv.size()));
 162     memState->setStackMin(memState->getStackMin() & -2*sizeof(Addr));
 163     Addr sp = memState->getStackMin();
 164     const auto pushOntoStack =
 165         [this, &sp](const uint8_t* data, const size_t size) {
 166             initVirtMem.writeBlob(sp, data, size);
 167             sp += size;
 168         };
 169
 170     // Push argc and argv pointers onto stack
 171     IntType argc = htog((IntType)argv.size());
 172     DPRINTF(Stack, "Wrote argc %d to address %p\n",
 173             argv.size(), (void*)sp);
 174     pushOntoStack((uint8_t*)&argc, sizeof(IntType));
 175     for (const Addr& argPointer: argPointers) {
 176         DPRINTF(Stack, "Wrote argv pointer %p to address %p\n",
 177                 (void*)argPointer, (void*)sp);
 178         pushOntoStack((uint8_t*)&argPointer, sizeof(Addr));
 179     }
 180
 181     // Push env pointers onto stack
 182     for (const Addr& envPointer: envPointers) {
 183         DPRINTF(Stack, "Wrote envp pointer %p to address %p\n",
 184                 (void*)envPointer, (void*)sp);
 185         pushOntoStack((uint8_t*)&envPointer, sizeof(Addr));
 186     }
 187
 188     // Push aux vector onto stack
 189     std::map<IntType, string> aux_keys = {
 190         {M5_AT_ENTRY, "M5_AT_ENTRY"},
 191         {M5_AT_PHNUM, "M5_AT_PHNUM"},
 192         {M5_AT_PHENT, "M5_AT_PHENT"},
 193         {M5_AT_PHDR, "M5_AT_PHDR"},
 194         {M5_AT_PAGESZ, "M5_AT_PAGESZ"},
 195         {M5_AT_SECURE, "M5_AT_SECURE"},
 196         {M5_AT_RANDOM, "M5_AT_RANDOM"},
 197         {M5_AT_NULL, "M5_AT_NULL"}
 198     };
 199     for (const AuxVector<IntType>& aux: auxv) {
 200         DPRINTF(Stack, "Wrote aux key %s to address %p\n",
 201                 aux_keys[aux.a_type], (void*)sp);
 202         pushOntoStack((uint8_t*)&aux.a_type, sizeof(IntType));
 203         DPRINTF(Stack, "Wrote aux value %x to address %p\n",
 204                 aux.a_val, (void*)sp);
 205         pushOntoStack((uint8_t*)&aux.a_val, sizeof(IntType));
 206     }
 207
 208     ThreadContext *tc = system->getThreadContext(contextIds[0]);
 209     tc->setIntReg(StackPointerReg, memState->getStackMin());
 210     tc->pcState(getStartPC());
 211
 212     memState->setStackMin(roundDown(memState->getStackMin(), pageSize));
 213 }
 214
 215 RiscvISA::IntReg
 216 RiscvProcess::getSyscallArg(ThreadContext *tc, int &i)
 217 {
 218     // If a larger index is requested than there are syscall argument
 219     // registers, return 0
 220     RiscvISA::IntReg retval = 0;
 221     if (i < SyscallArgumentRegs.size())
 222         retval = tc->readIntReg(SyscallArgumentRegs[i]);
 223     i++;
 224     return retval;
 225 }
 226
 227 void
 228 RiscvProcess::setSyscallArg(ThreadContext *tc, int i, RiscvISA::IntReg val)
 229 {
 230     tc->setIntReg(SyscallArgumentRegs[i], val);
 231 }
 232
 233 void
 234 RiscvProcess::setSyscallReturn(ThreadContext *tc, SyscallReturn sysret)
 235 {
 236     if (sysret.successful()) {
 237         // no error
 238         tc->setIntReg(SyscallPseudoReturnReg, sysret.returnValue());
 239     } else {
 240         // got an error, return details
 241         tc->setIntReg(SyscallPseudoReturnReg, sysret.errnoValue());
 242     }
 243 }