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 <climits>
54#include <csignal>
55#include <map>
56#include <string>
57#include <vector>
58
59#include "base/intmath.hh"
60#include "base/loader/object_file.hh"
61#include "base/loader/symtab.hh"
62#include "base/statistics.hh"
63#include "config/the_isa.hh"
64#include "cpu/thread_context.hh"
65#include "mem/page_table.hh"
66#include "mem/se_translating_port_proxy.hh"
67#include "params/Process.hh"
68#include "sim/emul_driver.hh"
69#include "sim/fd_array.hh"
70#include "sim/fd_entry.hh"
71#include "sim/redirect_path.hh"
72#include "sim/syscall_desc.hh"
73#include "sim/system.hh"
74
75using namespace std;
76using namespace TheISA;
77
78static std::string
79normalize(std::string& directory)
80{
81 if (directory.back() != '/')
82 directory += '/';
83 return directory;
84}
85
86Process::Process(ProcessParams *params, EmulationPageTable *pTable,
87 ObjectFile *obj_file)
88 : SimObject(params), system(params->system),
89 useArchPT(params->useArchPT),
90 kvmInSE(params->kvmInSE),
91 useForClone(false),
92 pTable(pTable),
93 initVirtMem(system->getSystemPort(), this,
94 SETranslatingPortProxy::Always),
95 objFile(obj_file),
96 argv(params->cmd), envp(params->env),
97 executable(params->executable),
98 tgtCwd(normalize(params->cwd)),
99 hostCwd(checkPathRedirect(tgtCwd)),
| 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 <climits>
54#include <csignal>
55#include <map>
56#include <string>
57#include <vector>
58
59#include "base/intmath.hh"
60#include "base/loader/object_file.hh"
61#include "base/loader/symtab.hh"
62#include "base/statistics.hh"
63#include "config/the_isa.hh"
64#include "cpu/thread_context.hh"
65#include "mem/page_table.hh"
66#include "mem/se_translating_port_proxy.hh"
67#include "params/Process.hh"
68#include "sim/emul_driver.hh"
69#include "sim/fd_array.hh"
70#include "sim/fd_entry.hh"
71#include "sim/redirect_path.hh"
72#include "sim/syscall_desc.hh"
73#include "sim/system.hh"
74
75using namespace std;
76using namespace TheISA;
77
78static std::string
79normalize(std::string& directory)
80{
81 if (directory.back() != '/')
82 directory += '/';
83 return directory;
84}
85
86Process::Process(ProcessParams *params, EmulationPageTable *pTable,
87 ObjectFile *obj_file)
88 : SimObject(params), system(params->system),
89 useArchPT(params->useArchPT),
90 kvmInSE(params->kvmInSE),
91 useForClone(false),
92 pTable(pTable),
93 initVirtMem(system->getSystemPort(), this,
94 SETranslatingPortProxy::Always),
95 objFile(obj_file),
96 argv(params->cmd), envp(params->env),
97 executable(params->executable),
98 tgtCwd(normalize(params->cwd)),
99 hostCwd(checkPathRedirect(tgtCwd)),
|
100 _uid(params->uid), _euid(params->euid),
101 _gid(params->gid), _egid(params->egid),
102 _pid(params->pid), _ppid(params->ppid),
103 _pgid(params->pgid), drivers(params->drivers),
104 fds(make_shared<FDArray>(params->input, params->output, params->errout)),
105 childClearTID(0)
106{
107 if (_pid >= System::maxPID)
108 fatal("_pid is too large: %d", _pid);
109
110 auto ret_pair = system->PIDs.emplace(_pid);
111 if (!ret_pair.second)
112 fatal("_pid %d is already used", _pid);
113
114 /**
115 * Linux bundles together processes into this concept called a thread
116 * group. The thread group is responsible for recording which processes
117 * behave as threads within a process context. The thread group leader
118 * is the process who's tgid is equal to its pid. Other processes which
119 * belong to the thread group, but do not lead the thread group, are
120 * treated as child threads. These threads are created by the clone system
121 * call with options specified to create threads (differing from the
122 * options used to implement a fork). By default, set up the tgid/pid
123 * with a new, equivalent value. If CLONE_THREAD is specified, patch
124 * the tgid value with the old process' value.
125 */
126 _tgid = params->pid;
127
128 exitGroup = new bool();
129 sigchld = new bool();
130
131 if (!debugSymbolTable) {
132 debugSymbolTable = new SymbolTable();
133 if (!objFile->loadGlobalSymbols(debugSymbolTable) ||
134 !objFile->loadLocalSymbols(debugSymbolTable) ||
135 !objFile->loadWeakSymbols(debugSymbolTable)) {
136 delete debugSymbolTable;
137 debugSymbolTable = nullptr;
138 }
139 }
140}
141
142void
143Process::clone(ThreadContext *otc, ThreadContext *ntc,
144 Process *np, RegVal flags)
145{
146#ifndef CLONE_VM
147#define CLONE_VM 0
148#endif
149#ifndef CLONE_FILES
150#define CLONE_FILES 0
151#endif
152#ifndef CLONE_THREAD
153#define CLONE_THREAD 0
154#endif
155 if (CLONE_VM & flags) {
156 /**
157 * Share the process memory address space between the new process
158 * and the old process. Changes in one will be visible in the other
159 * due to the pointer use.
160 */
161 delete np->pTable;
162 np->pTable = pTable;
163 ntc->getMemProxy().setPageTable(np->pTable);
164
165 np->memState = memState;
166 } else {
167 /**
168 * Duplicate the process memory address space. The state needs to be
169 * copied over (rather than using pointers to share everything).
170 */
171 typedef std::vector<pair<Addr,Addr>> MapVec;
172 MapVec mappings;
173 pTable->getMappings(&mappings);
174
175 for (auto map : mappings) {
176 Addr paddr, vaddr = map.first;
177 bool alloc_page = !(np->pTable->translate(vaddr, paddr));
178 np->replicatePage(vaddr, paddr, otc, ntc, alloc_page);
179 }
180
181 *np->memState = *memState;
182 }
183
184 if (CLONE_FILES & flags) {
185 /**
186 * The parent and child file descriptors are shared because the
187 * two FDArray pointers are pointing to the same FDArray. Opening
188 * and closing file descriptors will be visible to both processes.
189 */
190 np->fds = fds;
191 } else {
192 /**
193 * Copy the file descriptors from the old process into the new
194 * child process. The file descriptors entry can be opened and
195 * closed independently of the other process being considered. The
196 * host file descriptors are also dup'd so that the flags for the
197 * host file descriptor is independent of the other process.
198 */
199 for (int tgt_fd = 0; tgt_fd < fds->getSize(); tgt_fd++) {
200 std::shared_ptr<FDArray> nfds = np->fds;
201 std::shared_ptr<FDEntry> this_fde = (*fds)[tgt_fd];
202 if (!this_fde) {
203 nfds->setFDEntry(tgt_fd, nullptr);
204 continue;
205 }
206 nfds->setFDEntry(tgt_fd, this_fde->clone());
207
208 auto this_hbfd = std::dynamic_pointer_cast<HBFDEntry>(this_fde);
209 if (!this_hbfd)
210 continue;
211
212 int this_sim_fd = this_hbfd->getSimFD();
213 if (this_sim_fd <= 2)
214 continue;
215
216 int np_sim_fd = dup(this_sim_fd);
217 assert(np_sim_fd != -1);
218
219 auto nhbfd = std::dynamic_pointer_cast<HBFDEntry>((*nfds)[tgt_fd]);
220 nhbfd->setSimFD(np_sim_fd);
221 }
222 }
223
224 if (CLONE_THREAD & flags) {
225 np->_tgid = _tgid;
226 delete np->exitGroup;
227 np->exitGroup = exitGroup;
228 }
229
230 np->argv.insert(np->argv.end(), argv.begin(), argv.end());
231 np->envp.insert(np->envp.end(), envp.begin(), envp.end());
232}
233
234void
235Process::regStats()
236{
237 SimObject::regStats();
238
239 using namespace Stats;
240
241 numSyscalls
242 .name(name() + ".numSyscalls")
243 .desc("Number of system calls")
244 ;
245}
246
247ThreadContext *
248Process::findFreeContext()
249{
250 for (auto &it : system->threadContexts) {
251 if (ThreadContext::Halted == it->status())
252 return it;
253 }
254 return nullptr;
255}
256
257void
258Process::revokeThreadContext(int context_id)
259{
260 std::vector<ContextID>::iterator it;
261 for (it = contextIds.begin(); it != contextIds.end(); it++) {
262 if (*it == context_id) {
263 contextIds.erase(it);
264 return;
265 }
266 }
267 warn("Unable to find thread context to revoke");
268}
269
270void
271Process::initState()
272{
273 if (contextIds.empty())
274 fatal("Process %s is not associated with any HW contexts!\n", name());
275
276 // first thread context for this process... initialize & enable
277 ThreadContext *tc = system->getThreadContext(contextIds[0]);
278
279 // mark this context as active so it will start ticking.
280 tc->activate();
281
282 pTable->initState(tc);
283}
284
285DrainState
286Process::drain()
287{
288 fds->updateFileOffsets();
289 return DrainState::Drained;
290}
291
292void
293Process::allocateMem(Addr vaddr, int64_t size, bool clobber)
294{
295 int npages = divCeil(size, (int64_t)PageBytes);
296 Addr paddr = system->allocPhysPages(npages);
297 pTable->map(vaddr, paddr, size,
298 clobber ? EmulationPageTable::Clobber :
299 EmulationPageTable::MappingFlags(0));
300}
301
302void
303Process::replicatePage(Addr vaddr, Addr new_paddr, ThreadContext *old_tc,
304 ThreadContext *new_tc, bool allocate_page)
305{
306 if (allocate_page)
307 new_paddr = system->allocPhysPages(1);
308
309 // Read from old physical page.
310 uint8_t *buf_p = new uint8_t[PageBytes];
311 old_tc->getMemProxy().readBlob(vaddr, buf_p, PageBytes);
312
313 // Create new mapping in process address space by clobbering existing
314 // mapping (if any existed) and then write to the new physical page.
315 bool clobber = true;
316 pTable->map(vaddr, new_paddr, PageBytes, clobber);
317 new_tc->getMemProxy().writeBlob(vaddr, buf_p, PageBytes);
318 delete[] buf_p;
319}
320
321bool
322Process::fixupStackFault(Addr vaddr)
323{
324 Addr stack_min = memState->getStackMin();
325 Addr stack_base = memState->getStackBase();
326 Addr max_stack_size = memState->getMaxStackSize();
327
328 // Check if this is already on the stack and there's just no page there
329 // yet.
330 if (vaddr >= stack_min && vaddr < stack_base) {
331 allocateMem(roundDown(vaddr, PageBytes), PageBytes);
332 return true;
333 }
334
335 // We've accessed the next page of the stack, so extend it to include
336 // this address.
337 if (vaddr < stack_min && vaddr >= stack_base - max_stack_size) {
338 while (vaddr < stack_min) {
339 stack_min -= TheISA::PageBytes;
340 if (stack_base - stack_min > max_stack_size)
341 fatal("Maximum stack size exceeded\n");
342 allocateMem(stack_min, TheISA::PageBytes);
343 inform("Increasing stack size by one page.");
344 }
345 memState->setStackMin(stack_min);
346 return true;
347 }
348 return false;
349}
350
351void
352Process::serialize(CheckpointOut &cp) const
353{
354 memState->serialize(cp);
355 pTable->serialize(cp);
356 /**
357 * Checkpoints for file descriptors currently do not work. Need to
358 * come back and fix them at a later date.
359 */
360
361 warn("Checkpoints for file descriptors currently do not work.");
362}
363
364void
365Process::unserialize(CheckpointIn &cp)
366{
367 memState->unserialize(cp);
368 pTable->unserialize(cp);
369 /**
370 * Checkpoints for file descriptors currently do not work. Need to
371 * come back and fix them at a later date.
372 */
373 warn("Checkpoints for file descriptors currently do not work.");
374 // The above returns a bool so that you could do something if you don't
375 // find the param in the checkpoint if you wanted to, like set a default
376 // but in this case we'll just stick with the instantiated value if not
377 // found.
378}
379
380bool
381Process::map(Addr vaddr, Addr paddr, int size, bool cacheable)
382{
383 pTable->map(vaddr, paddr, size,
384 cacheable ? EmulationPageTable::MappingFlags(0) :
385 EmulationPageTable::Uncacheable);
386 return true;
387}
388
389void
390Process::syscall(int64_t callnum, ThreadContext *tc, Fault *fault)
391{
392 numSyscalls++;
393
394 SyscallDesc *desc = getDesc(callnum);
395 if (desc == nullptr)
396 fatal("Syscall %d out of range", callnum);
397
398 desc->doSyscall(callnum, tc, fault);
399}
400
401RegVal
402Process::getSyscallArg(ThreadContext *tc, int &i, int width)
403{
404 return getSyscallArg(tc, i);
405}
406
407EmulatedDriver *
408Process::findDriver(std::string filename)
409{
410 for (EmulatedDriver *d : drivers) {
411 if (d->match(filename))
412 return d;
413 }
414
415 return nullptr;
416}
417
418std::string
419Process::checkPathRedirect(const std::string &filename)
420{
421 // If the input parameter contains a relative path, convert it.
422 // The target version of the current working directory is fine since
423 // we immediately convert it using redirect paths into a host version.
424 auto abs_path = absolutePath(filename, false);
425
426 for (auto path : system->redirectPaths) {
427 // Search through the redirect paths to see if a starting substring of
428 // our path falls into any buckets which need to redirected.
429 if (startswith(abs_path, path->appPath())) {
430 std::string tail = abs_path.substr(path->appPath().size());
431
432 // If this path needs to be redirected, search through a list
433 // of targets to see if we can match a valid file (or directory).
434 for (auto host_path : path->hostPaths()) {
435 if (access((host_path + tail).c_str(), R_OK) == 0) {
436 // Return the valid match.
437 return host_path + tail;
438 }
439 }
440 // The path needs to be redirected, but the file or directory
441 // does not exist on the host filesystem. Return the first
442 // host path as a default.
443 return path->hostPaths()[0] + tail;
444 }
445 }
446
447 // The path does not need to be redirected.
448 return abs_path;
449}
450
451void
452Process::updateBias()
453{
454 ObjectFile *interp = objFile->getInterpreter();
455
456 if (!interp || !interp->relocatable())
457 return;
458
459 // Determine how large the interpreters footprint will be in the process
460 // address space.
461 Addr interp_mapsize = roundUp(interp->mapSize(), TheISA::PageBytes);
462
463 // We are allocating the memory area; set the bias to the lowest address
464 // in the allocated memory region.
465 Addr mmap_end = memState->getMmapEnd();
466 Addr ld_bias = mmapGrowsDown() ? mmap_end - interp_mapsize : mmap_end;
467
468 // Adjust the process mmap area to give the interpreter room; the real
469 // execve system call would just invoke the kernel's internal mmap
470 // functions to make these adjustments.
471 mmap_end = mmapGrowsDown() ? ld_bias : mmap_end + interp_mapsize;
472 memState->setMmapEnd(mmap_end);
473
474 interp->updateBias(ld_bias);
475}
476
477ObjectFile *
478Process::getInterpreter()
479{
480 return objFile->getInterpreter();
481}
482
483Addr
484Process::getBias()
485{
486 ObjectFile *interp = getInterpreter();
487
488 return interp ? interp->bias() : objFile->bias();
489}
490
491Addr
492Process::getStartPC()
493{
494 ObjectFile *interp = getInterpreter();
495
496 return interp ? interp->entryPoint() : objFile->entryPoint();
497}
498
499std::string
500Process::absolutePath(const std::string &filename, bool host_filesystem)
501{
502 if (filename.empty() || startswith(filename, "/"))
503 return filename;
504
505 // Construct the absolute path given the current working directory for
506 // either the host filesystem or target filesystem. The distinction only
507 // matters if filesystem redirection is utilized in the simulation.
508 auto path_base = std::string();
509 if (host_filesystem) {
510 path_base = hostCwd;
511 assert(!hostCwd.empty());
512 } else {
513 path_base = tgtCwd;
514 assert(!tgtCwd.empty());
515 }
516
517 // Add a trailing '/' if the current working directory did not have one.
518 normalize(path_base);
519
520 // Append the filename onto the current working path.
521 auto absolute_path = path_base + filename;
522
523 return absolute_path;
524}
525
526Process *
527ProcessParams::create()
528{
529 Process *process = nullptr;
530
531 // If not specified, set the executable parameter equal to the
532 // simulated system's zeroth command line parameter
533 if (executable == "") {
534 executable = cmd[0];
535 }
536
537 ObjectFile *obj_file = createObjectFile(executable);
538 fatal_if(!obj_file, "Can't load object file %s", executable);
539
540 process = ObjectFile::tryLoaders(this, obj_file);
541 fatal_if(!process, "Unknown error creating process object.");
542
543 return process;
544}
| 101 _uid(params->uid), _euid(params->euid),
102 _gid(params->gid), _egid(params->egid),
103 _pid(params->pid), _ppid(params->ppid),
104 _pgid(params->pgid), drivers(params->drivers),
105 fds(make_shared<FDArray>(params->input, params->output, params->errout)),
106 childClearTID(0)
107{
108 if (_pid >= System::maxPID)
109 fatal("_pid is too large: %d", _pid);
110
111 auto ret_pair = system->PIDs.emplace(_pid);
112 if (!ret_pair.second)
113 fatal("_pid %d is already used", _pid);
114
115 /**
116 * Linux bundles together processes into this concept called a thread
117 * group. The thread group is responsible for recording which processes
118 * behave as threads within a process context. The thread group leader
119 * is the process who's tgid is equal to its pid. Other processes which
120 * belong to the thread group, but do not lead the thread group, are
121 * treated as child threads. These threads are created by the clone system
122 * call with options specified to create threads (differing from the
123 * options used to implement a fork). By default, set up the tgid/pid
124 * with a new, equivalent value. If CLONE_THREAD is specified, patch
125 * the tgid value with the old process' value.
126 */
127 _tgid = params->pid;
128
129 exitGroup = new bool();
130 sigchld = new bool();
131
132 if (!debugSymbolTable) {
133 debugSymbolTable = new SymbolTable();
134 if (!objFile->loadGlobalSymbols(debugSymbolTable) ||
135 !objFile->loadLocalSymbols(debugSymbolTable) ||
136 !objFile->loadWeakSymbols(debugSymbolTable)) {
137 delete debugSymbolTable;
138 debugSymbolTable = nullptr;
139 }
140 }
141}
142
143void
144Process::clone(ThreadContext *otc, ThreadContext *ntc,
145 Process *np, RegVal flags)
146{
147#ifndef CLONE_VM
148#define CLONE_VM 0
149#endif
150#ifndef CLONE_FILES
151#define CLONE_FILES 0
152#endif
153#ifndef CLONE_THREAD
154#define CLONE_THREAD 0
155#endif
156 if (CLONE_VM & flags) {
157 /**
158 * Share the process memory address space between the new process
159 * and the old process. Changes in one will be visible in the other
160 * due to the pointer use.
161 */
162 delete np->pTable;
163 np->pTable = pTable;
164 ntc->getMemProxy().setPageTable(np->pTable);
165
166 np->memState = memState;
167 } else {
168 /**
169 * Duplicate the process memory address space. The state needs to be
170 * copied over (rather than using pointers to share everything).
171 */
172 typedef std::vector<pair<Addr,Addr>> MapVec;
173 MapVec mappings;
174 pTable->getMappings(&mappings);
175
176 for (auto map : mappings) {
177 Addr paddr, vaddr = map.first;
178 bool alloc_page = !(np->pTable->translate(vaddr, paddr));
179 np->replicatePage(vaddr, paddr, otc, ntc, alloc_page);
180 }
181
182 *np->memState = *memState;
183 }
184
185 if (CLONE_FILES & flags) {
186 /**
187 * The parent and child file descriptors are shared because the
188 * two FDArray pointers are pointing to the same FDArray. Opening
189 * and closing file descriptors will be visible to both processes.
190 */
191 np->fds = fds;
192 } else {
193 /**
194 * Copy the file descriptors from the old process into the new
195 * child process. The file descriptors entry can be opened and
196 * closed independently of the other process being considered. The
197 * host file descriptors are also dup'd so that the flags for the
198 * host file descriptor is independent of the other process.
199 */
200 for (int tgt_fd = 0; tgt_fd < fds->getSize(); tgt_fd++) {
201 std::shared_ptr<FDArray> nfds = np->fds;
202 std::shared_ptr<FDEntry> this_fde = (*fds)[tgt_fd];
203 if (!this_fde) {
204 nfds->setFDEntry(tgt_fd, nullptr);
205 continue;
206 }
207 nfds->setFDEntry(tgt_fd, this_fde->clone());
208
209 auto this_hbfd = std::dynamic_pointer_cast<HBFDEntry>(this_fde);
210 if (!this_hbfd)
211 continue;
212
213 int this_sim_fd = this_hbfd->getSimFD();
214 if (this_sim_fd <= 2)
215 continue;
216
217 int np_sim_fd = dup(this_sim_fd);
218 assert(np_sim_fd != -1);
219
220 auto nhbfd = std::dynamic_pointer_cast<HBFDEntry>((*nfds)[tgt_fd]);
221 nhbfd->setSimFD(np_sim_fd);
222 }
223 }
224
225 if (CLONE_THREAD & flags) {
226 np->_tgid = _tgid;
227 delete np->exitGroup;
228 np->exitGroup = exitGroup;
229 }
230
231 np->argv.insert(np->argv.end(), argv.begin(), argv.end());
232 np->envp.insert(np->envp.end(), envp.begin(), envp.end());
233}
234
235void
236Process::regStats()
237{
238 SimObject::regStats();
239
240 using namespace Stats;
241
242 numSyscalls
243 .name(name() + ".numSyscalls")
244 .desc("Number of system calls")
245 ;
246}
247
248ThreadContext *
249Process::findFreeContext()
250{
251 for (auto &it : system->threadContexts) {
252 if (ThreadContext::Halted == it->status())
253 return it;
254 }
255 return nullptr;
256}
257
258void
259Process::revokeThreadContext(int context_id)
260{
261 std::vector<ContextID>::iterator it;
262 for (it = contextIds.begin(); it != contextIds.end(); it++) {
263 if (*it == context_id) {
264 contextIds.erase(it);
265 return;
266 }
267 }
268 warn("Unable to find thread context to revoke");
269}
270
271void
272Process::initState()
273{
274 if (contextIds.empty())
275 fatal("Process %s is not associated with any HW contexts!\n", name());
276
277 // first thread context for this process... initialize & enable
278 ThreadContext *tc = system->getThreadContext(contextIds[0]);
279
280 // mark this context as active so it will start ticking.
281 tc->activate();
282
283 pTable->initState(tc);
284}
285
286DrainState
287Process::drain()
288{
289 fds->updateFileOffsets();
290 return DrainState::Drained;
291}
292
293void
294Process::allocateMem(Addr vaddr, int64_t size, bool clobber)
295{
296 int npages = divCeil(size, (int64_t)PageBytes);
297 Addr paddr = system->allocPhysPages(npages);
298 pTable->map(vaddr, paddr, size,
299 clobber ? EmulationPageTable::Clobber :
300 EmulationPageTable::MappingFlags(0));
301}
302
303void
304Process::replicatePage(Addr vaddr, Addr new_paddr, ThreadContext *old_tc,
305 ThreadContext *new_tc, bool allocate_page)
306{
307 if (allocate_page)
308 new_paddr = system->allocPhysPages(1);
309
310 // Read from old physical page.
311 uint8_t *buf_p = new uint8_t[PageBytes];
312 old_tc->getMemProxy().readBlob(vaddr, buf_p, PageBytes);
313
314 // Create new mapping in process address space by clobbering existing
315 // mapping (if any existed) and then write to the new physical page.
316 bool clobber = true;
317 pTable->map(vaddr, new_paddr, PageBytes, clobber);
318 new_tc->getMemProxy().writeBlob(vaddr, buf_p, PageBytes);
319 delete[] buf_p;
320}
321
322bool
323Process::fixupStackFault(Addr vaddr)
324{
325 Addr stack_min = memState->getStackMin();
326 Addr stack_base = memState->getStackBase();
327 Addr max_stack_size = memState->getMaxStackSize();
328
329 // Check if this is already on the stack and there's just no page there
330 // yet.
331 if (vaddr >= stack_min && vaddr < stack_base) {
332 allocateMem(roundDown(vaddr, PageBytes), PageBytes);
333 return true;
334 }
335
336 // We've accessed the next page of the stack, so extend it to include
337 // this address.
338 if (vaddr < stack_min && vaddr >= stack_base - max_stack_size) {
339 while (vaddr < stack_min) {
340 stack_min -= TheISA::PageBytes;
341 if (stack_base - stack_min > max_stack_size)
342 fatal("Maximum stack size exceeded\n");
343 allocateMem(stack_min, TheISA::PageBytes);
344 inform("Increasing stack size by one page.");
345 }
346 memState->setStackMin(stack_min);
347 return true;
348 }
349 return false;
350}
351
352void
353Process::serialize(CheckpointOut &cp) const
354{
355 memState->serialize(cp);
356 pTable->serialize(cp);
357 /**
358 * Checkpoints for file descriptors currently do not work. Need to
359 * come back and fix them at a later date.
360 */
361
362 warn("Checkpoints for file descriptors currently do not work.");
363}
364
365void
366Process::unserialize(CheckpointIn &cp)
367{
368 memState->unserialize(cp);
369 pTable->unserialize(cp);
370 /**
371 * Checkpoints for file descriptors currently do not work. Need to
372 * come back and fix them at a later date.
373 */
374 warn("Checkpoints for file descriptors currently do not work.");
375 // The above returns a bool so that you could do something if you don't
376 // find the param in the checkpoint if you wanted to, like set a default
377 // but in this case we'll just stick with the instantiated value if not
378 // found.
379}
380
381bool
382Process::map(Addr vaddr, Addr paddr, int size, bool cacheable)
383{
384 pTable->map(vaddr, paddr, size,
385 cacheable ? EmulationPageTable::MappingFlags(0) :
386 EmulationPageTable::Uncacheable);
387 return true;
388}
389
390void
391Process::syscall(int64_t callnum, ThreadContext *tc, Fault *fault)
392{
393 numSyscalls++;
394
395 SyscallDesc *desc = getDesc(callnum);
396 if (desc == nullptr)
397 fatal("Syscall %d out of range", callnum);
398
399 desc->doSyscall(callnum, tc, fault);
400}
401
402RegVal
403Process::getSyscallArg(ThreadContext *tc, int &i, int width)
404{
405 return getSyscallArg(tc, i);
406}
407
408EmulatedDriver *
409Process::findDriver(std::string filename)
410{
411 for (EmulatedDriver *d : drivers) {
412 if (d->match(filename))
413 return d;
414 }
415
416 return nullptr;
417}
418
419std::string
420Process::checkPathRedirect(const std::string &filename)
421{
422 // If the input parameter contains a relative path, convert it.
423 // The target version of the current working directory is fine since
424 // we immediately convert it using redirect paths into a host version.
425 auto abs_path = absolutePath(filename, false);
426
427 for (auto path : system->redirectPaths) {
428 // Search through the redirect paths to see if a starting substring of
429 // our path falls into any buckets which need to redirected.
430 if (startswith(abs_path, path->appPath())) {
431 std::string tail = abs_path.substr(path->appPath().size());
432
433 // If this path needs to be redirected, search through a list
434 // of targets to see if we can match a valid file (or directory).
435 for (auto host_path : path->hostPaths()) {
436 if (access((host_path + tail).c_str(), R_OK) == 0) {
437 // Return the valid match.
438 return host_path + tail;
439 }
440 }
441 // The path needs to be redirected, but the file or directory
442 // does not exist on the host filesystem. Return the first
443 // host path as a default.
444 return path->hostPaths()[0] + tail;
445 }
446 }
447
448 // The path does not need to be redirected.
449 return abs_path;
450}
451
452void
453Process::updateBias()
454{
455 ObjectFile *interp = objFile->getInterpreter();
456
457 if (!interp || !interp->relocatable())
458 return;
459
460 // Determine how large the interpreters footprint will be in the process
461 // address space.
462 Addr interp_mapsize = roundUp(interp->mapSize(), TheISA::PageBytes);
463
464 // We are allocating the memory area; set the bias to the lowest address
465 // in the allocated memory region.
466 Addr mmap_end = memState->getMmapEnd();
467 Addr ld_bias = mmapGrowsDown() ? mmap_end - interp_mapsize : mmap_end;
468
469 // Adjust the process mmap area to give the interpreter room; the real
470 // execve system call would just invoke the kernel's internal mmap
471 // functions to make these adjustments.
472 mmap_end = mmapGrowsDown() ? ld_bias : mmap_end + interp_mapsize;
473 memState->setMmapEnd(mmap_end);
474
475 interp->updateBias(ld_bias);
476}
477
478ObjectFile *
479Process::getInterpreter()
480{
481 return objFile->getInterpreter();
482}
483
484Addr
485Process::getBias()
486{
487 ObjectFile *interp = getInterpreter();
488
489 return interp ? interp->bias() : objFile->bias();
490}
491
492Addr
493Process::getStartPC()
494{
495 ObjectFile *interp = getInterpreter();
496
497 return interp ? interp->entryPoint() : objFile->entryPoint();
498}
499
500std::string
501Process::absolutePath(const std::string &filename, bool host_filesystem)
502{
503 if (filename.empty() || startswith(filename, "/"))
504 return filename;
505
506 // Construct the absolute path given the current working directory for
507 // either the host filesystem or target filesystem. The distinction only
508 // matters if filesystem redirection is utilized in the simulation.
509 auto path_base = std::string();
510 if (host_filesystem) {
511 path_base = hostCwd;
512 assert(!hostCwd.empty());
513 } else {
514 path_base = tgtCwd;
515 assert(!tgtCwd.empty());
516 }
517
518 // Add a trailing '/' if the current working directory did not have one.
519 normalize(path_base);
520
521 // Append the filename onto the current working path.
522 auto absolute_path = path_base + filename;
523
524 return absolute_path;
525}
526
527Process *
528ProcessParams::create()
529{
530 Process *process = nullptr;
531
532 // If not specified, set the executable parameter equal to the
533 // simulated system's zeroth command line parameter
534 if (executable == "") {
535 executable = cmd[0];
536 }
537
538 ObjectFile *obj_file = createObjectFile(executable);
539 fatal_if(!obj_file, "Can't load object file %s", executable);
540
541 process = ObjectFile::tryLoaders(this, obj_file);
542 fatal_if(!process, "Unknown error creating process object.");
543
544 return process;
545}
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