summaryrefslogtreecommitdiff
path: root/src/sim/process.cc
blob: ee90667ffe46a407e55c96dd65a130ccf1af1bce (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
/*
 * Copyright (c) 2014-2016 Advanced Micro Devices, Inc.
 * Copyright (c) 2012 ARM Limited
 * All rights reserved
 *
 * The license below extends only to copyright in the software and shall
 * not be construed as granting a license to any other intellectual
 * property including but not limited to intellectual property relating
 * to a hardware implementation of the functionality of the software
 * licensed hereunder.  You may use the software subject to the license
 * terms below provided that you ensure that this notice is replicated
 * unmodified and in its entirety in all distributions of the software,
 * modified or unmodified, in source code or in binary form.
 *
 * Copyright (c) 2001-2005 The Regents of The University of Michigan
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are
 * met: redistributions of source code must retain the above copyright
 * notice, this list of conditions and the following disclaimer;
 * redistributions in binary form must reproduce the above copyright
 * notice, this list of conditions and the following disclaimer in the
 * documentation and/or other materials provided with the distribution;
 * neither the name of the copyright holders nor the names of its
 * contributors may be used to endorse or promote products derived from
 * this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 * Authors: Nathan Binkert
 *          Steve Reinhardt
 *          Ali Saidi
 *          Brandon Potter
 */

#include "sim/process.hh"

#include <fcntl.h>
#include <unistd.h>

#include <array>
#include <csignal>
#include <map>
#include <string>
#include <vector>

#include "base/intmath.hh"
#include "base/loader/object_file.hh"
#include "base/loader/symtab.hh"
#include "base/statistics.hh"
#include "config/the_isa.hh"
#include "cpu/thread_context.hh"
#include "mem/page_table.hh"
#include "mem/se_translating_port_proxy.hh"
#include "params/Process.hh"
#include "sim/emul_driver.hh"
#include "sim/fd_array.hh"
#include "sim/fd_entry.hh"
#include "sim/syscall_desc.hh"
#include "sim/system.hh"

#if THE_ISA == ALPHA_ISA
#include "arch/alpha/linux/process.hh"

#elif THE_ISA == SPARC_ISA
#include "arch/sparc/linux/process.hh"
#include "arch/sparc/solaris/process.hh"

#elif THE_ISA == MIPS_ISA
#include "arch/mips/linux/process.hh"

#elif THE_ISA == ARM_ISA
#include "arch/arm/freebsd/process.hh"
#include "arch/arm/linux/process.hh"

#elif THE_ISA == X86_ISA
#include "arch/x86/linux/process.hh"

#elif THE_ISA == POWER_ISA
#include "arch/power/linux/process.hh"

#elif THE_ISA == RISCV_ISA
#include "arch/riscv/linux/process.hh"

#else
#error "THE_ISA not set"
#endif


using namespace std;
using namespace TheISA;

Process::Process(ProcessParams * params, ObjectFile * obj_file)
    : SimObject(params), system(params->system),
      useArchPT(params->useArchPT),
      kvmInSE(params->kvmInSE),
      pTable(useArchPT ?
        static_cast<PageTableBase *>(new ArchPageTable(name(), params->pid,
            system)) :
        static_cast<PageTableBase *>(new FuncPageTable(name(), params->pid))),
      initVirtMem(system->getSystemPort(), this,
                  SETranslatingPortProxy::Always),
      objFile(obj_file),
      argv(params->cmd), envp(params->env), cwd(params->cwd),
      executable(params->executable),
      _uid(params->uid), _euid(params->euid),
      _gid(params->gid), _egid(params->egid),
      _pid(params->pid), _ppid(params->ppid),
      _pgid(params->pgid), drivers(params->drivers),
      fds(make_shared<FDArray>(params->input, params->output, params->errout)),
      childClearTID(0)
{
    if (_pid >= System::maxPID)
        fatal("_pid is too large: %d", _pid);

    auto ret_pair = system->PIDs.emplace(_pid);
    if (!ret_pair.second)
        fatal("_pid %d is already used", _pid);

    /**
     * Linux bundles together processes into this concept called a thread
     * group. The thread group is responsible for recording which processes
     * behave as threads within a process context. The thread group leader
     * is the process who's tgid is equal to its pid. Other processes which
     * belong to the thread group, but do not lead the thread group, are
     * treated as child threads. These threads are created by the clone system
     * call with options specified to create threads (differing from the
     * options used to implement a fork). By default, set up the tgid/pid
     * with a new, equivalent value. If CLONE_THREAD is specified, patch
     * the tgid value with the old process' value.
     */
    _tgid = params->pid;

    exitGroup = new bool();
    sigchld = new bool();

    if (!debugSymbolTable) {
        debugSymbolTable = new SymbolTable();
        if (!objFile->loadGlobalSymbols(debugSymbolTable) ||
            !objFile->loadLocalSymbols(debugSymbolTable) ||
            !objFile->loadWeakSymbols(debugSymbolTable)) {
            delete debugSymbolTable;
            debugSymbolTable = nullptr;
        }
    }
}

void
Process::clone(ThreadContext *otc, ThreadContext *ntc,
               Process *np, TheISA::IntReg flags)
{
#ifndef CLONE_VM
#define CLONE_VM 0
#endif
#ifndef CLONE_FILES
#define CLONE_FILES 0
#endif
#ifndef CLONE_THREAD
#define CLONE_THREAD 0
#endif
    if (CLONE_VM & flags) {
        /**
         * Share the process memory address space between the new process
         * and the old process. Changes in one will be visible in the other
         * due to the pointer use.
         */
        delete np->pTable;
        np->pTable = pTable;
        ntc->getMemProxy().setPageTable(np->pTable);

        np->memState = memState;
    } else {
        /**
         * Duplicate the process memory address space. The state needs to be
         * copied over (rather than using pointers to share everything).
         */
        typedef std::vector<pair<Addr,Addr>> MapVec;
        MapVec mappings;
        pTable->getMappings(&mappings);

        for (auto map : mappings) {
            Addr paddr, vaddr = map.first;
            bool alloc_page = !(np->pTable->translate(vaddr, paddr));
            np->replicatePage(vaddr, paddr, otc, ntc, alloc_page);
        }

        *np->memState = *memState;
    }

    if (CLONE_FILES & flags) {
        /**
         * The parent and child file descriptors are shared because the
         * two FDArray pointers are pointing to the same FDArray. Opening
         * and closing file descriptors will be visible to both processes.
         */
        np->fds = fds;
    } else {
        /**
         * Copy the file descriptors from the old process into the new
         * child process. The file descriptors entry can be opened and
         * closed independently of the other process being considered. The
         * host file descriptors are also dup'd so that the flags for the
         * host file descriptor is independent of the other process.
         */
        for (int tgt_fd = 0; tgt_fd < fds->getSize(); tgt_fd++) {
            std::shared_ptr<FDArray> nfds = np->fds;
            std::shared_ptr<FDEntry> this_fde = (*fds)[tgt_fd];
            if (!this_fde) {
                nfds->setFDEntry(tgt_fd, nullptr);
                continue;
            }
            nfds->setFDEntry(tgt_fd, this_fde->clone());

            auto this_hbfd = std::dynamic_pointer_cast<HBFDEntry>(this_fde);
            if (!this_hbfd)
                continue;

            int this_sim_fd = this_hbfd->getSimFD();
            if (this_sim_fd <= 2)
                continue;

            int np_sim_fd = dup(this_sim_fd);
            assert(np_sim_fd != -1);

            auto nhbfd = std::dynamic_pointer_cast<HBFDEntry>((*nfds)[tgt_fd]);
            nhbfd->setSimFD(np_sim_fd);
        }
    }

    if (CLONE_THREAD & flags) {
        np->_tgid = _tgid;
        delete np->exitGroup;
        np->exitGroup = exitGroup;
    }

    np->argv.insert(np->argv.end(), argv.begin(), argv.end());
    np->envp.insert(np->envp.end(), envp.begin(), envp.end());
}

void
Process::regStats()
{
    SimObject::regStats();

    using namespace Stats;

    numSyscalls
        .name(name() + ".numSyscalls")
        .desc("Number of system calls")
        ;
}

ThreadContext *
Process::findFreeContext()
{
    for (auto &it : system->threadContexts) {
        if (ThreadContext::Halted == it->status())
            return it;
    }
    return nullptr;
}

void
Process::revokeThreadContext(int context_id)
{
    std::vector<ContextID>::iterator it;
    for (it = contextIds.begin(); it != contextIds.end(); it++) {
        if (*it == context_id) {
            contextIds.erase(it);
            return;
        }
    }
    warn("Unable to find thread context to revoke");
}

void
Process::initState()
{
    if (contextIds.empty())
        fatal("Process %s is not associated with any HW contexts!\n", name());

    // first thread context for this process... initialize & enable
    ThreadContext *tc = system->getThreadContext(contextIds[0]);

    // mark this context as active so it will start ticking.
    tc->activate();

    pTable->initState(tc);
}

DrainState
Process::drain()
{
    fds->updateFileOffsets();
    return DrainState::Drained;
}

void
Process::allocateMem(Addr vaddr, int64_t size, bool clobber)
{
    int npages = divCeil(size, (int64_t)PageBytes);
    Addr paddr = system->allocPhysPages(npages);
    pTable->map(vaddr, paddr, size,
                clobber ? PageTableBase::Clobber : PageTableBase::Zero);
}

void
Process::replicatePage(Addr vaddr, Addr new_paddr, ThreadContext *old_tc,
                       ThreadContext *new_tc, bool allocate_page)
{
    if (allocate_page)
        new_paddr = system->allocPhysPages(1);

    // Read from old physical page.
    uint8_t *buf_p = new uint8_t[PageBytes];
    old_tc->getMemProxy().readBlob(vaddr, buf_p, PageBytes);

    // Create new mapping in process address space by clobbering existing
    // mapping (if any existed) and then write to the new physical page.
    bool clobber = true;
    pTable->map(vaddr, new_paddr, PageBytes, clobber);
    new_tc->getMemProxy().writeBlob(vaddr, buf_p, PageBytes);
    delete[] buf_p;
}

bool
Process::fixupStackFault(Addr vaddr)
{
    Addr stack_min = memState->getStackMin();
    Addr stack_base = memState->getStackBase();
    Addr max_stack_size = memState->getMaxStackSize();

    // Check if this is already on the stack and there's just no page there
    // yet.
    if (vaddr >= stack_min && vaddr < stack_base) {
        allocateMem(roundDown(vaddr, PageBytes), PageBytes);
        return true;
    }

    // We've accessed the next page of the stack, so extend it to include
    // this address.
    if (vaddr < stack_min && vaddr >= stack_base - max_stack_size) {
        while (vaddr < stack_min) {
            stack_min -= TheISA::PageBytes;
            if (stack_base - stack_min > max_stack_size)
                fatal("Maximum stack size exceeded\n");
            allocateMem(stack_min, TheISA::PageBytes);
            inform("Increasing stack size by one page.");
        }
        memState->setStackMin(stack_min);
        return true;
    }
    return false;
}

void
Process::serialize(CheckpointOut &cp) const
{
    memState->serialize(cp);
    pTable->serialize(cp);
    /**
     * Checkpoints for file descriptors currently do not work. Need to
     * come back and fix them at a later date.
     */

    warn("Checkpoints for file descriptors currently do not work.");
#if 0
    for (int x = 0; x < fds->getSize(); x++)
        (*fds)[x].serializeSection(cp, csprintf("FDEntry%d", x));
#endif

}

void
Process::unserialize(CheckpointIn &cp)
{
    memState->unserialize(cp);
    pTable->unserialize(cp);
    /**
     * Checkpoints for file descriptors currently do not work. Need to
     * come back and fix them at a later date.
     */
    warn("Checkpoints for file descriptors currently do not work.");
#if 0
    for (int x = 0; x < fds->getSize(); x++)
        (*fds)[x]->unserializeSection(cp, csprintf("FDEntry%d", x));
    fds->restoreFileOffsets();
#endif
    // The above returns a bool so that you could do something if you don't
    // find the param in the checkpoint if you wanted to, like set a default
    // but in this case we'll just stick with the instantiated value if not
    // found.
}

bool
Process::map(Addr vaddr, Addr paddr, int size, bool cacheable)
{
    pTable->map(vaddr, paddr, size,
                cacheable ? PageTableBase::Zero : PageTableBase::Uncacheable);
    return true;
}

void
Process::syscall(int64_t callnum, ThreadContext *tc, Fault *fault)
{
    numSyscalls++;

    SyscallDesc *desc = getDesc(callnum);
    if (desc == nullptr)
        fatal("Syscall %d out of range", callnum);

    desc->doSyscall(callnum, this, tc, fault);
}

IntReg
Process::getSyscallArg(ThreadContext *tc, int &i, int width)
{
    return getSyscallArg(tc, i);
}

EmulatedDriver *
Process::findDriver(std::string filename)
{
    for (EmulatedDriver *d : drivers) {
        if (d->match(filename))
            return d;
    }

    return nullptr;
}

void
Process::updateBias()
{
    ObjectFile *interp = objFile->getInterpreter();

    if (!interp || !interp->relocatable())
        return;

    // Determine how large the interpreters footprint will be in the process
    // address space.
    Addr interp_mapsize = roundUp(interp->mapSize(), TheISA::PageBytes);

    // We are allocating the memory area; set the bias to the lowest address
    // in the allocated memory region.
    Addr mmap_end = memState->getMmapEnd();
    Addr ld_bias = mmapGrowsDown() ? mmap_end - interp_mapsize : mmap_end;

    // Adjust the process mmap area to give the interpreter room; the real
    // execve system call would just invoke the kernel's internal mmap
    // functions to make these adjustments.
    mmap_end = mmapGrowsDown() ? ld_bias : mmap_end + interp_mapsize;
    memState->setMmapEnd(mmap_end);

    interp->updateBias(ld_bias);
}

ObjectFile *
Process::getInterpreter()
{
    return objFile->getInterpreter();
}

Addr
Process::getBias()
{
    ObjectFile *interp = getInterpreter();

    return interp ? interp->bias() : objFile->bias();
}

Addr
Process::getStartPC()
{
    ObjectFile *interp = getInterpreter();

    return interp ? interp->entryPoint() : objFile->entryPoint();
}

Process *
ProcessParams::create()
{
    Process *process = nullptr;

    // If not specified, set the executable parameter equal to the
    // simulated system's zeroth command line parameter
    if (executable == "") {
        executable = cmd[0];
    }

    ObjectFile *obj_file = createObjectFile(executable);
    if (obj_file == nullptr) {
        fatal("Can't load object file %s", executable);
    }

#if THE_ISA == ALPHA_ISA
    if (obj_file->getArch() != ObjectFile::Alpha)
        fatal("Object file architecture does not match compiled ISA (Alpha).");

    switch (obj_file->getOpSys()) {
      case ObjectFile::UnknownOpSys:
        warn("Unknown operating system; assuming Linux.");
        // fall through
      case ObjectFile::Linux:
        process = new AlphaLinuxProcess(this, obj_file);
        break;

      default:
        fatal("Unknown/unsupported operating system.");
    }
#elif THE_ISA == SPARC_ISA
    if (obj_file->getArch() != ObjectFile::SPARC64 &&
        obj_file->getArch() != ObjectFile::SPARC32)
        fatal("Object file architecture does not match compiled ISA (SPARC).");
    switch (obj_file->getOpSys()) {
      case ObjectFile::UnknownOpSys:
        warn("Unknown operating system; assuming Linux.");
        // fall through
      case ObjectFile::Linux:
        if (obj_file->getArch() == ObjectFile::SPARC64) {
            process = new Sparc64LinuxProcess(this, obj_file);
        } else {
            process = new Sparc32LinuxProcess(this, obj_file);
        }
        break;

      case ObjectFile::Solaris:
        process = new SparcSolarisProcess(this, obj_file);
        break;

      default:
        fatal("Unknown/unsupported operating system.");
    }
#elif THE_ISA == X86_ISA
    if (obj_file->getArch() != ObjectFile::X86_64 &&
        obj_file->getArch() != ObjectFile::I386)
        fatal("Object file architecture does not match compiled ISA (x86).");
    switch (obj_file->getOpSys()) {
      case ObjectFile::UnknownOpSys:
        warn("Unknown operating system; assuming Linux.");
        // fall through
      case ObjectFile::Linux:
        if (obj_file->getArch() == ObjectFile::X86_64) {
            process = new X86_64LinuxProcess(this, obj_file);
        } else {
            process = new I386LinuxProcess(this, obj_file);
        }
        break;

      default:
        fatal("Unknown/unsupported operating system.");
    }
#elif THE_ISA == MIPS_ISA
    if (obj_file->getArch() != ObjectFile::Mips)
        fatal("Object file architecture does not match compiled ISA (MIPS).");
    switch (obj_file->getOpSys()) {
      case ObjectFile::UnknownOpSys:
        warn("Unknown operating system; assuming Linux.");
        // fall through
      case ObjectFile::Linux:
        process = new MipsLinuxProcess(this, obj_file);
        break;

      default:
        fatal("Unknown/unsupported operating system.");
    }
#elif THE_ISA == ARM_ISA
    ObjectFile::Arch arch = obj_file->getArch();
    if (arch != ObjectFile::Arm && arch != ObjectFile::Thumb &&
        arch != ObjectFile::Arm64)
        fatal("Object file architecture does not match compiled ISA (ARM).");
    switch (obj_file->getOpSys()) {
      case ObjectFile::UnknownOpSys:
        warn("Unknown operating system; assuming Linux.");
        // fall through
      case ObjectFile::Linux:
        if (arch == ObjectFile::Arm64) {
            process = new ArmLinuxProcess64(this, obj_file,
                                            obj_file->getArch());
        } else {
            process = new ArmLinuxProcess32(this, obj_file,
                                            obj_file->getArch());
        }
        break;
      case ObjectFile::FreeBSD:
        if (arch == ObjectFile::Arm64) {
            process = new ArmFreebsdProcess64(this, obj_file,
                                              obj_file->getArch());
        } else {
            process = new ArmFreebsdProcess32(this, obj_file,
                                              obj_file->getArch());
        }
        break;
      case ObjectFile::LinuxArmOABI:
        fatal("M5 does not support ARM OABI binaries. Please recompile with an"
              " EABI compiler.");
      default:
        fatal("Unknown/unsupported operating system.");
    }
#elif THE_ISA == POWER_ISA
    if (obj_file->getArch() != ObjectFile::Power)
        fatal("Object file architecture does not match compiled ISA (Power).");
    switch (obj_file->getOpSys()) {
      case ObjectFile::UnknownOpSys:
        warn("Unknown operating system; assuming Linux.");
        // fall through
      case ObjectFile::Linux:
        process = new PowerLinuxProcess(this, obj_file);
        break;

      default:
        fatal("Unknown/unsupported operating system.");
    }
#elif THE_ISA == RISCV_ISA
    if (obj_file->getArch() != ObjectFile::Riscv)
        fatal("Object file architecture does not match compiled ISA (RISCV).");
    switch (obj_file->getOpSys()) {
      case ObjectFile::UnknownOpSys:
        warn("Unknown operating system; assuming Linux.");
        // fall through
      case ObjectFile::Linux:
        process = new RiscvLinuxProcess(this, obj_file);
        break;
      default:
        fatal("Unknown/unsupported operating system.");
    }
#else
#error "THE_ISA not set"
#endif

    if (process == nullptr)
        fatal("Unknown error creating process object.");
    return process;
}

std::string
Process::fullPath(const std::string &file_name)
{
    if (file_name[0] == '/' || cwd.empty())
        return file_name;

    std::string full = cwd;

    if (cwd[cwd.size() - 1] != '/')
        full += '/';

    return full + file_name;
}