process.cc revision 11970
1/*
2 * Copyright (c) 2014-2016 Advanced Micro Devices, Inc.
3 * Copyright (c) 2012 ARM Limited
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) 2001-2005 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 * Authors: Nathan Binkert
42 *          Steve Reinhardt
43 *          Ali Saidi
44 *          Brandon Potter
45 */
46
47#include "sim/process.hh"
48
49#include <fcntl.h>
50#include <unistd.h>
51
52#include <array>
53#include <csignal>
54#include <map>
55#include <string>
56#include <vector>
57
58#include "base/intmath.hh"
59#include "base/loader/object_file.hh"
60#include "base/loader/symtab.hh"
61#include "base/statistics.hh"
62#include "config/the_isa.hh"
63#include "cpu/thread_context.hh"
64#include "mem/page_table.hh"
65#include "mem/se_translating_port_proxy.hh"
66#include "params/Process.hh"
67#include "sim/emul_driver.hh"
68#include "sim/fd_array.hh"
69#include "sim/fd_entry.hh"
70#include "sim/syscall_desc.hh"
71#include "sim/system.hh"
72
73#if THE_ISA == ALPHA_ISA
74#include "arch/alpha/linux/process.hh"
75
76#elif THE_ISA == SPARC_ISA
77#include "arch/sparc/linux/process.hh"
78#include "arch/sparc/solaris/process.hh"
79
80#elif THE_ISA == MIPS_ISA
81#include "arch/mips/linux/process.hh"
82
83#elif THE_ISA == ARM_ISA
84#include "arch/arm/freebsd/process.hh"
85#include "arch/arm/linux/process.hh"
86
87#elif THE_ISA == X86_ISA
88#include "arch/x86/linux/process.hh"
89
90#elif THE_ISA == POWER_ISA
91#include "arch/power/linux/process.hh"
92
93#elif THE_ISA == RISCV_ISA
94#include "arch/riscv/linux/process.hh"
95
96#else
97#error "THE_ISA not set"
98#endif
99
100
101using namespace std;
102using namespace TheISA;
103
104Process::Process(ProcessParams * params, ObjectFile * obj_file)
105    : SimObject(params), system(params->system),
106      useArchPT(params->useArchPT),
107      kvmInSE(params->kvmInSE),
108      pTable(useArchPT ?
109        static_cast<PageTableBase *>(new ArchPageTable(name(), params->pid,
110            system)) :
111        static_cast<PageTableBase *>(new FuncPageTable(name(), params->pid))),
112      initVirtMem(system->getSystemPort(), this,
113                  SETranslatingPortProxy::Always),
114      objFile(obj_file),
115      argv(params->cmd), envp(params->env), cwd(params->cwd),
116      executable(params->executable),
117      _uid(params->uid), _euid(params->euid),
118      _gid(params->gid), _egid(params->egid),
119      _pid(params->pid), _ppid(params->ppid),
120      _pgid(params->pgid), drivers(params->drivers),
121      fds(make_shared<FDArray>(params->input, params->output, params->errout)),
122      childClearTID(0)
123{
124    if (_pid >= System::maxPID)
125        fatal("_pid is too large: %d", _pid);
126
127    auto ret_pair = system->PIDs.emplace(_pid);
128    if (!ret_pair.second)
129        fatal("_pid %d is already used", _pid);
130
131    /**
132     * Linux bundles together processes into this concept called a thread
133     * group. The thread group is responsible for recording which processes
134     * behave as threads within a process context. The thread group leader
135     * is the process who's tgid is equal to its pid. Other processes which
136     * belong to the thread group, but do not lead the thread group, are
137     * treated as child threads. These threads are created by the clone system
138     * call with options specified to create threads (differing from the
139     * options used to implement a fork). By default, set up the tgid/pid
140     * with a new, equivalent value. If CLONE_THREAD is specified, patch
141     * the tgid value with the old process' value.
142     */
143    _tgid = params->pid;
144
145    exitGroup = new bool();
146    sigchld = new bool();
147
148    if (!debugSymbolTable) {
149        debugSymbolTable = new SymbolTable();
150        if (!objFile->loadGlobalSymbols(debugSymbolTable) ||
151            !objFile->loadLocalSymbols(debugSymbolTable) ||
152            !objFile->loadWeakSymbols(debugSymbolTable)) {
153            delete debugSymbolTable;
154            debugSymbolTable = nullptr;
155        }
156    }
157}
158
159void
160Process::clone(ThreadContext *otc, ThreadContext *ntc,
161               Process *np, TheISA::IntReg flags)
162{
163#ifndef CLONE_VM
164#define CLONE_VM 0
165#endif
166#ifndef CLONE_FILES
167#define CLONE_FILES 0
168#endif
169#ifndef CLONE_THREAD
170#define CLONE_THREAD 0
171#endif
172    if (CLONE_VM & flags) {
173        /**
174         * Share the process memory address space between the new process
175         * and the old process. Changes in one will be visible in the other
176         * due to the pointer use.
177         */
178        delete np->pTable;
179        np->pTable = pTable;
180        ntc->getMemProxy().setPageTable(np->pTable);
181
182        np->memState = memState;
183    } else {
184        /**
185         * Duplicate the process memory address space. The state needs to be
186         * copied over (rather than using pointers to share everything).
187         */
188        typedef std::vector<pair<Addr,Addr>> MapVec;
189        MapVec mappings;
190        pTable->getMappings(&mappings);
191
192        for (auto map : mappings) {
193            Addr paddr, vaddr = map.first;
194            bool alloc_page = !(np->pTable->translate(vaddr, paddr));
195            np->replicatePage(vaddr, paddr, otc, ntc, alloc_page);
196        }
197
198        *np->memState = *memState;
199    }
200
201    if (CLONE_FILES & flags) {
202        /**
203         * The parent and child file descriptors are shared because the
204         * two FDArray pointers are pointing to the same FDArray. Opening
205         * and closing file descriptors will be visible to both processes.
206         */
207        np->fds = fds;
208    } else {
209        /**
210         * Copy the file descriptors from the old process into the new
211         * child process. The file descriptors entry can be opened and
212         * closed independently of the other process being considered. The
213         * host file descriptors are also dup'd so that the flags for the
214         * host file descriptor is independent of the other process.
215         */
216        for (int tgt_fd = 0; tgt_fd < fds->getSize(); tgt_fd++) {
217            std::shared_ptr<FDArray> nfds = np->fds;
218            std::shared_ptr<FDEntry> this_fde = (*fds)[tgt_fd];
219            if (!this_fde) {
220                nfds->setFDEntry(tgt_fd, nullptr);
221                continue;
222            }
223            nfds->setFDEntry(tgt_fd, this_fde->clone());
224
225            auto this_hbfd = std::dynamic_pointer_cast<HBFDEntry>(this_fde);
226            if (!this_hbfd)
227                continue;
228
229            int this_sim_fd = this_hbfd->getSimFD();
230            if (this_sim_fd <= 2)
231                continue;
232
233            int np_sim_fd = dup(this_sim_fd);
234            assert(np_sim_fd != -1);
235
236            auto nhbfd = std::dynamic_pointer_cast<HBFDEntry>((*nfds)[tgt_fd]);
237            nhbfd->setSimFD(np_sim_fd);
238        }
239    }
240
241    if (CLONE_THREAD & flags) {
242        np->_tgid = _tgid;
243        delete np->exitGroup;
244        np->exitGroup = exitGroup;
245    }
246
247    np->argv.insert(np->argv.end(), argv.begin(), argv.end());
248    np->envp.insert(np->envp.end(), envp.begin(), envp.end());
249}
250
251void
252Process::regStats()
253{
254    SimObject::regStats();
255
256    using namespace Stats;
257
258    numSyscalls
259        .name(name() + ".numSyscalls")
260        .desc("Number of system calls")
261        ;
262}
263
264ThreadContext *
265Process::findFreeContext()
266{
267    for (auto &it : system->threadContexts) {
268        if (ThreadContext::Halted == it->status())
269            return it;
270    }
271    return nullptr;
272}
273
274void
275Process::revokeThreadContext(int context_id)
276{
277    std::vector<ContextID>::iterator it;
278    for (it = contextIds.begin(); it != contextIds.end(); it++) {
279        if (*it == context_id) {
280            contextIds.erase(it);
281            return;
282        }
283    }
284    warn("Unable to find thread context to revoke");
285}
286
287void
288Process::initState()
289{
290    if (contextIds.empty())
291        fatal("Process %s is not associated with any HW contexts!\n", name());
292
293    // first thread context for this process... initialize & enable
294    ThreadContext *tc = system->getThreadContext(contextIds[0]);
295
296    // mark this context as active so it will start ticking.
297    tc->activate();
298
299    pTable->initState(tc);
300}
301
302DrainState
303Process::drain()
304{
305    fds->updateFileOffsets();
306    return DrainState::Drained;
307}
308
309void
310Process::allocateMem(Addr vaddr, int64_t size, bool clobber)
311{
312    int npages = divCeil(size, (int64_t)PageBytes);
313    Addr paddr = system->allocPhysPages(npages);
314    pTable->map(vaddr, paddr, size,
315                clobber ? PageTableBase::Clobber : PageTableBase::Zero);
316}
317
318void
319Process::replicatePage(Addr vaddr, Addr new_paddr, ThreadContext *old_tc,
320                       ThreadContext *new_tc, bool allocate_page)
321{
322    if (allocate_page)
323        new_paddr = system->allocPhysPages(1);
324
325    // Read from old physical page.
326    uint8_t *buf_p = new uint8_t[PageBytes];
327    old_tc->getMemProxy().readBlob(vaddr, buf_p, PageBytes);
328
329    // Create new mapping in process address space by clobbering existing
330    // mapping (if any existed) and then write to the new physical page.
331    bool clobber = true;
332    pTable->map(vaddr, new_paddr, PageBytes, clobber);
333    new_tc->getMemProxy().writeBlob(vaddr, buf_p, PageBytes);
334    delete[] buf_p;
335}
336
337bool
338Process::fixupStackFault(Addr vaddr)
339{
340    Addr stack_min = memState->getStackMin();
341    Addr stack_base = memState->getStackBase();
342    Addr max_stack_size = memState->getMaxStackSize();
343
344    // Check if this is already on the stack and there's just no page there
345    // yet.
346    if (vaddr >= stack_min && vaddr < stack_base) {
347        allocateMem(roundDown(vaddr, PageBytes), PageBytes);
348        return true;
349    }
350
351    // We've accessed the next page of the stack, so extend it to include
352    // this address.
353    if (vaddr < stack_min && vaddr >= stack_base - max_stack_size) {
354        while (vaddr < stack_min) {
355            stack_min -= TheISA::PageBytes;
356            if (stack_base - stack_min > max_stack_size)
357                fatal("Maximum stack size exceeded\n");
358            allocateMem(stack_min, TheISA::PageBytes);
359            inform("Increasing stack size by one page.");
360        }
361        memState->setStackMin(stack_min);
362        return true;
363    }
364    return false;
365}
366
367void
368Process::serialize(CheckpointOut &cp) const
369{
370    pTable->serialize(cp);
371    /**
372     * Checkpoints for file descriptors currently do not work. Need to
373     * come back and fix them at a later date.
374     */
375
376    warn("Checkpoints for file descriptors currently do not work.");
377#if 0
378    for (int x = 0; x < fds->getSize(); x++)
379        (*fds)[x].serializeSection(cp, csprintf("FDEntry%d", x));
380#endif
381
382}
383
384void
385Process::unserialize(CheckpointIn &cp)
386{
387    pTable->unserialize(cp);
388    /**
389     * Checkpoints for file descriptors currently do not work. Need to
390     * come back and fix them at a later date.
391     */
392    warn("Checkpoints for file descriptors currently do not work.");
393#if 0
394    for (int x = 0; x < fds->getSize(); x++)
395        (*fds)[x]->unserializeSection(cp, csprintf("FDEntry%d", x));
396    fds->restoreFileOffsets();
397#endif
398    // The above returns a bool so that you could do something if you don't
399    // find the param in the checkpoint if you wanted to, like set a default
400    // but in this case we'll just stick with the instantiated value if not
401    // found.
402}
403
404bool
405Process::map(Addr vaddr, Addr paddr, int size, bool cacheable)
406{
407    pTable->map(vaddr, paddr, size,
408                cacheable ? PageTableBase::Zero : PageTableBase::Uncacheable);
409    return true;
410}
411
412void
413Process::syscall(int64_t callnum, ThreadContext *tc, Fault *fault)
414{
415    numSyscalls++;
416
417    SyscallDesc *desc = getDesc(callnum);
418    if (desc == nullptr)
419        fatal("Syscall %d out of range", callnum);
420
421    desc->doSyscall(callnum, this, tc, fault);
422}
423
424IntReg
425Process::getSyscallArg(ThreadContext *tc, int &i, int width)
426{
427    return getSyscallArg(tc, i);
428}
429
430EmulatedDriver *
431Process::findDriver(std::string filename)
432{
433    for (EmulatedDriver *d : drivers) {
434        if (d->match(filename))
435            return d;
436    }
437
438    return nullptr;
439}
440
441void
442Process::updateBias()
443{
444    ObjectFile *interp = objFile->getInterpreter();
445
446    if (!interp || !interp->relocatable())
447        return;
448
449    // Determine how large the interpreters footprint will be in the process
450    // address space.
451    Addr interp_mapsize = roundUp(interp->mapSize(), TheISA::PageBytes);
452
453    // We are allocating the memory area; set the bias to the lowest address
454    // in the allocated memory region.
455    Addr mmap_end = memState->getMmapEnd();
456    Addr ld_bias = mmapGrowsDown() ? mmap_end - interp_mapsize : mmap_end;
457
458    // Adjust the process mmap area to give the interpreter room; the real
459    // execve system call would just invoke the kernel's internal mmap
460    // functions to make these adjustments.
461    mmap_end = mmapGrowsDown() ? ld_bias : mmap_end + interp_mapsize;
462    memState->setMmapEnd(mmap_end);
463
464    interp->updateBias(ld_bias);
465}
466
467ObjectFile *
468Process::getInterpreter()
469{
470    return objFile->getInterpreter();
471}
472
473Addr
474Process::getBias()
475{
476    ObjectFile *interp = getInterpreter();
477
478    return interp ? interp->bias() : objFile->bias();
479}
480
481Addr
482Process::getStartPC()
483{
484    ObjectFile *interp = getInterpreter();
485
486    return interp ? interp->entryPoint() : objFile->entryPoint();
487}
488
489Process *
490ProcessParams::create()
491{
492    Process *process = nullptr;
493
494    // If not specified, set the executable parameter equal to the
495    // simulated system's zeroth command line parameter
496    if (executable == "") {
497        executable = cmd[0];
498    }
499
500    ObjectFile *obj_file = createObjectFile(executable);
501    if (obj_file == nullptr) {
502        fatal("Can't load object file %s", executable);
503    }
504
505#if THE_ISA == ALPHA_ISA
506    if (obj_file->getArch() != ObjectFile::Alpha)
507        fatal("Object file architecture does not match compiled ISA (Alpha).");
508
509    switch (obj_file->getOpSys()) {
510      case ObjectFile::UnknownOpSys:
511        warn("Unknown operating system; assuming Linux.");
512        // fall through
513      case ObjectFile::Linux:
514        process = new AlphaLinuxProcess(this, obj_file);
515        break;
516
517      default:
518        fatal("Unknown/unsupported operating system.");
519    }
520#elif THE_ISA == SPARC_ISA
521    if (obj_file->getArch() != ObjectFile::SPARC64 &&
522        obj_file->getArch() != ObjectFile::SPARC32)
523        fatal("Object file architecture does not match compiled ISA (SPARC).");
524    switch (obj_file->getOpSys()) {
525      case ObjectFile::UnknownOpSys:
526        warn("Unknown operating system; assuming Linux.");
527        // fall through
528      case ObjectFile::Linux:
529        if (obj_file->getArch() == ObjectFile::SPARC64) {
530            process = new Sparc64LinuxProcess(this, obj_file);
531        } else {
532            process = new Sparc32LinuxProcess(this, obj_file);
533        }
534        break;
535
536      case ObjectFile::Solaris:
537        process = new SparcSolarisProcess(this, obj_file);
538        break;
539
540      default:
541        fatal("Unknown/unsupported operating system.");
542    }
543#elif THE_ISA == X86_ISA
544    if (obj_file->getArch() != ObjectFile::X86_64 &&
545        obj_file->getArch() != ObjectFile::I386)
546        fatal("Object file architecture does not match compiled ISA (x86).");
547    switch (obj_file->getOpSys()) {
548      case ObjectFile::UnknownOpSys:
549        warn("Unknown operating system; assuming Linux.");
550        // fall through
551      case ObjectFile::Linux:
552        if (obj_file->getArch() == ObjectFile::X86_64) {
553            process = new X86_64LinuxProcess(this, obj_file);
554        } else {
555            process = new I386LinuxProcess(this, obj_file);
556        }
557        break;
558
559      default:
560        fatal("Unknown/unsupported operating system.");
561    }
562#elif THE_ISA == MIPS_ISA
563    if (obj_file->getArch() != ObjectFile::Mips)
564        fatal("Object file architecture does not match compiled ISA (MIPS).");
565    switch (obj_file->getOpSys()) {
566      case ObjectFile::UnknownOpSys:
567        warn("Unknown operating system; assuming Linux.");
568        // fall through
569      case ObjectFile::Linux:
570        process = new MipsLinuxProcess(this, obj_file);
571        break;
572
573      default:
574        fatal("Unknown/unsupported operating system.");
575    }
576#elif THE_ISA == ARM_ISA
577    ObjectFile::Arch arch = obj_file->getArch();
578    if (arch != ObjectFile::Arm && arch != ObjectFile::Thumb &&
579        arch != ObjectFile::Arm64)
580        fatal("Object file architecture does not match compiled ISA (ARM).");
581    switch (obj_file->getOpSys()) {
582      case ObjectFile::UnknownOpSys:
583        warn("Unknown operating system; assuming Linux.");
584        // fall through
585      case ObjectFile::Linux:
586        if (arch == ObjectFile::Arm64) {
587            process = new ArmLinuxProcess64(this, obj_file,
588                                            obj_file->getArch());
589        } else {
590            process = new ArmLinuxProcess32(this, obj_file,
591                                            obj_file->getArch());
592        }
593        break;
594      case ObjectFile::FreeBSD:
595        if (arch == ObjectFile::Arm64) {
596            process = new ArmFreebsdProcess64(this, obj_file,
597                                              obj_file->getArch());
598        } else {
599            process = new ArmFreebsdProcess32(this, obj_file,
600                                              obj_file->getArch());
601        }
602        break;
603      case ObjectFile::LinuxArmOABI:
604        fatal("M5 does not support ARM OABI binaries. Please recompile with an"
605              " EABI compiler.");
606      default:
607        fatal("Unknown/unsupported operating system.");
608    }
609#elif THE_ISA == POWER_ISA
610    if (obj_file->getArch() != ObjectFile::Power)
611        fatal("Object file architecture does not match compiled ISA (Power).");
612    switch (obj_file->getOpSys()) {
613      case ObjectFile::UnknownOpSys:
614        warn("Unknown operating system; assuming Linux.");
615        // fall through
616      case ObjectFile::Linux:
617        process = new PowerLinuxProcess(this, obj_file);
618        break;
619
620      default:
621        fatal("Unknown/unsupported operating system.");
622    }
623#elif THE_ISA == RISCV_ISA
624    if (obj_file->getArch() != ObjectFile::Riscv)
625        fatal("Object file architecture does not match compiled ISA (RISCV).");
626    switch (obj_file->getOpSys()) {
627      case ObjectFile::UnknownOpSys:
628        warn("Unknown operating system; assuming Linux.");
629        // fall through
630      case ObjectFile::Linux:
631        process = new RiscvLinuxProcess(this, obj_file);
632        break;
633      default:
634        fatal("Unknown/unsupported operating system.");
635    }
636#else
637#error "THE_ISA not set"
638#endif
639
640    if (process == nullptr)
641        fatal("Unknown error creating process object.");
642    return process;
643}
644
645std::string
646Process::fullPath(const std::string &file_name)
647{
648    if (file_name[0] == '/' || cwd.empty())
649        return file_name;
650
651    std::string full = cwd;
652
653    if (cwd[cwd.size() - 1] != '/')
654        full += '/';
655
656    return full + file_name;
657}
658