process.cc revision 11905 
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 <vector>
37
38#include "arch/riscv/isa_traits.hh"
39#include "base/loader/elf_object.hh"
40#include "base/loader/object_file.hh"
41#include "base/misc.hh"
42#include "cpu/thread_context.hh"
43#include "debug/Loader.hh"
44#include "mem/page_table.hh"
45#include "sim/aux_vector.hh"
46#include "sim/process.hh"
47#include "sim/process_impl.hh"
48#include "sim/syscall_return.hh"
49#include "sim/system.hh"
50
51using namespace std;
52using namespace RiscvISA;
53
54RiscvProcess::RiscvProcess(ProcessParams * params,
55    ObjectFile *objFile) : Process(params, objFile)
56{
57    // Set up stack. On RISC-V, stack starts at the top of kuseg
58    // user address space. RISC-V stack grows down from here
59    Addr stack_base = 0x7FFFFFFF;
60
61    Addr max_stack_size = 8 * 1024 * 1024;
62
63    // Set pointer for next thread stack.  Reserve 8M for main stack.
64    Addr next_thread_stack_base = stack_base - max_stack_size;
65
66    // Set up break point (Top of Heap)
67    Addr brk_point = objFile->bssBase() + objFile->bssSize();
68
69    // Set up region for mmaps.  Start it 1GB above the top of the heap.
70    Addr mmap_end = brk_point + 0x40000000L;
71
72    memState = make_shared<MemState>(brk_point, stack_base, max_stack_size,
73                                     next_thread_stack_base, mmap_end);
74}
75
76void
77RiscvProcess::initState()
78{
79    Process::initState();
80
81    argsInit<uint64_t>(PageBytes);
82}
83
84template<class IntType> void
85RiscvProcess::argsInit(int pageSize)
86{
87    updateBias();
88
89    // load object file into target memory
90    objFile->loadSections(initVirtMem);
91
92    typedef AuxVector<IntType> auxv_t;
93    vector<auxv_t> auxv;
94    ElfObject * elfObject = dynamic_cast<ElfObject *>(objFile);
95    if (elfObject) {
96        // Set the system page size
97        auxv.push_back(auxv_t(M5_AT_PAGESZ, RiscvISA::PageBytes));
98        // Set the frequency at which time() increments
99        auxv.push_back(auxv_t(M5_AT_CLKTCK, 100));
100        // For statically linked executables, this is the virtual
101        // address of the program header tables if they appear in the
102        // executable image.
103        auxv.push_back(auxv_t(M5_AT_PHDR, elfObject->programHeaderTable()));
104        DPRINTF(Loader, "auxv at PHDR %08p\n",
105            elfObject->programHeaderTable());
106        // This is the size of a program header entry from the elf file.
107        auxv.push_back(auxv_t(M5_AT_PHENT, elfObject->programHeaderSize()));
108        // This is the number of program headers from the original elf file.
109        auxv.push_back(auxv_t(M5_AT_PHNUM, elfObject->programHeaderCount()));
110        auxv.push_back(auxv_t(M5_AT_BASE, getBias()));
111        //The entry point to the program
112        auxv.push_back(auxv_t(M5_AT_ENTRY, objFile->entryPoint()));
113        //Different user and group IDs
114        auxv.push_back(auxv_t(M5_AT_UID, uid()));
115        auxv.push_back(auxv_t(M5_AT_EUID, euid()));
116        auxv.push_back(auxv_t(M5_AT_GID, gid()));
117        auxv.push_back(auxv_t(M5_AT_EGID, egid()));
118    }
119
120    const IntType zero = 0;
121    IntType argc = htog((IntType)argv.size());
122    int argv_array_size = sizeof(Addr) * argv.size();
123    int arg_data_size = 0;
124    for (string arg: argv)
125        arg_data_size += arg.size() + 1;
126    int envp_array_size = sizeof(Addr) * envp.size();
127    int env_data_size = 0;
128    for (string env: envp)
129        env_data_size += env.size() + 1;
130    int auxv_array_size = 2 * sizeof(IntType)*auxv.size();
131
132    Addr stack_size = sizeof(IntType) + argv_array_size + 2 * sizeof(Addr) +
133        sizeof(Addr) + arg_data_size + 2 * sizeof(Addr);
134    if (!envp.empty()) {
135        stack_size += 2 * sizeof(Addr) + envp_array_size + 2 *
136            sizeof(Addr) + env_data_size;
137    }
138    if (!auxv.empty())
139        stack_size += 2 * sizeof(Addr) + auxv_array_size;
140
141    memState->setStackSize(stack_size);
142
143    Addr stack_min = roundDown(memState->getStackBase() -
144                               stack_size, pageSize);
145    allocateMem(stack_min, roundUp(memState->getStackSize(), pageSize));
146
147    memState->setStackMin(stack_min);
148
149    Addr argv_array_base = memState->getStackMin() + sizeof(IntType);
150    Addr arg_data_base = argv_array_base + argv_array_size + 2 * sizeof(Addr);
151    Addr envp_array_base = arg_data_base + arg_data_size;
152    if (!envp.empty())
153        envp_array_base += 2 * sizeof(Addr);
154    Addr env_data_base = envp_array_base + envp_array_size;
155    if (!envp.empty())
156        env_data_base += 2 * sizeof(Addr);
157
158    vector<Addr> arg_pointers;
159    if (!argv.empty()) {
160        arg_pointers.push_back(arg_data_base);
161        for (int i = 0; i < argv.size() - 1; i++) {
162            arg_pointers.push_back(arg_pointers[i] + argv[i].size() + 1);
163        }
164    }
165
166    vector<Addr> env_pointers;
167    if (!envp.empty()) {
168        env_pointers.push_back(env_data_base);
169        for (int i = 0; i < envp.size() - 1; i++) {
170            env_pointers.push_back(env_pointers[i] + envp[i].size() + 1);
171        }
172    }
173
174    Addr sp = memState->getStackMin();
175    initVirtMem.writeBlob(sp, (uint8_t *)&argc, sizeof(IntType));
176    sp += sizeof(IntType);
177    for (Addr arg_pointer: arg_pointers) {
178        initVirtMem.writeBlob(sp, (uint8_t *)&arg_pointer, sizeof(Addr));
179        sp += sizeof(Addr);
180    }
181    for (int i = 0; i < 2; i++) {
182        initVirtMem.writeBlob(sp, (uint8_t *)&zero, sizeof(Addr));
183        sp += sizeof(Addr);
184    }
185    for (int i = 0; i < argv.size(); i++) {
186        initVirtMem.writeString(sp, argv[i].c_str());
187        sp += argv[i].size() + 1;
188    }
189    if (!envp.empty()) {
190        for (int i = 0; i < 2; i++) {
191            initVirtMem.writeBlob(sp, (uint8_t *)&zero, sizeof(Addr));
192            sp += sizeof(Addr);
193        }
194    }
195    for (Addr env_pointer: env_pointers)
196        initVirtMem.writeBlob(sp, (uint8_t *)&env_pointer, sizeof(Addr));
197    if (!envp.empty()) {
198        for (int i = 0; i < 2; i++) {
199            initVirtMem.writeBlob(sp, (uint8_t *)&zero, sizeof(Addr));
200            sp += sizeof(Addr);
201        }
202    }
203    for (int i = 0; i < envp.size(); i++) {
204        initVirtMem.writeString(sp, envp[i].c_str());
205        sp += envp[i].size() + 1;
206    }
207    if (!auxv.empty()) {
208        for (int i = 0; i < 2; i++) {
209            initVirtMem.writeBlob(sp, (uint8_t *)&zero, sizeof(Addr));
210            sp += sizeof(Addr);
211        }
212    }
213    for (auxv_t aux: auxv) {
214        initVirtMem.writeBlob(sp, (uint8_t *)&aux.a_type, sizeof(IntType));
215        initVirtMem.writeBlob(sp + sizeof(IntType), (uint8_t *)&aux.a_val,
216            sizeof(IntType));
217        sp += 2 * sizeof(IntType);
218    }
219    for (int i = 0; i < 2; i++) {
220        initVirtMem.writeBlob(sp, (uint8_t *)&zero, sizeof(Addr));
221        sp += sizeof(Addr);
222    }
223
224    ThreadContext *tc = system->getThreadContext(contextIds[0]);
225    tc->setIntReg(StackPointerReg, memState->getStackMin());
226    tc->pcState(getStartPC());
227}
228
229RiscvISA::IntReg
230RiscvProcess::getSyscallArg(ThreadContext *tc, int &i)
231{
232    // RISC-V only has four system call argument registers by convention, so
233    // if a larger index is requested return 0
234    RiscvISA::IntReg retval = 0;
235    if (i < 4)
236        retval = tc->readIntReg(SyscallArgumentRegs[i]);
237    i++;
238    return retval;
239}
240
241void
242RiscvProcess::setSyscallArg(ThreadContext *tc, int i, RiscvISA::IntReg val)
243{
244    tc->setIntReg(SyscallArgumentRegs[i], val);
245}
246
247void
248RiscvProcess::setSyscallReturn(ThreadContext *tc, SyscallReturn sysret)
249{
250    if (sysret.successful()) {
251        // no error
252        tc->setIntReg(SyscallPseudoReturnReg, sysret.returnValue());
253    } else {
254        // got an error, return details
255        tc->setIntReg(SyscallPseudoReturnReg, sysret.errnoValue());
256    }
257}
258