process.cc revision 12412 
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
59using namespace std;
60using namespace RiscvISA;
61
62RiscvProcess::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
75void
76RiscvProcess::initState()
77{
78    Process::initState();
79
80    argsInit<uint64_t>(PageBytes);
81}
82
83template<class IntType> void
84RiscvProcess::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
215RiscvISA::IntReg
216RiscvProcess::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
227void
228RiscvProcess::setSyscallArg(ThreadContext *tc, int i, RiscvISA::IntReg val)
229{
230    tc->setIntReg(SyscallArgumentRegs[i], val);
231}
232
233void
234RiscvProcess::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}
244