| /* |
| * 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. |
| */ |
| |
| #include "sim/process.hh" |
| |
| #include <fcntl.h> |
| #include <unistd.h> |
| |
| #include <array> |
| #include <climits> |
| #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 "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/redirect_path.hh" |
| #include "sim/syscall_desc.hh" |
| #include "sim/system.hh" |
| |
| namespace gem5 |
| { |
| |
| namespace |
| { |
| |
| typedef std::vector<Process::Loader *> LoaderList; |
| |
| LoaderList & |
| process_loaders() |
| { |
| static LoaderList loaders; |
| return loaders; |
| } |
| |
| } // anonymous namespace |
| |
| Process::Loader::Loader() |
| { |
| process_loaders().emplace_back(this); |
| } |
| |
| Process * |
| Process::tryLoaders(const ProcessParams ¶ms, |
| loader::ObjectFile *obj_file) |
| { |
| for (auto &loader_it : process_loaders()) { |
| Process *p = loader_it->load(params, obj_file); |
| if (p) |
| return p; |
| } |
| |
| return nullptr; |
| } |
| |
| static std::string |
| normalize(const std::string& directory) |
| { |
| if (directory.back() != '/') |
| return directory + '/'; |
| return directory; |
| } |
| |
| Process::Process(const ProcessParams ¶ms, EmulationPageTable *pTable, |
| loader::ObjectFile *obj_file) |
| : SimObject(params), system(params.system), |
| useArchPT(params.useArchPT), |
| kvmInSE(params.kvmInSE), |
| useForClone(false), |
| pTable(pTable), |
| objFile(obj_file), |
| argv(params.cmd), envp(params.env), |
| executable(params.executable == "" ? params.cmd[0] : params.executable), |
| tgtCwd(normalize(params.cwd)), |
| hostCwd(checkPathRedirect(tgtCwd)), |
| release(params.release), |
| _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(std::make_shared<FDArray>( |
| params.input, params.output, params.errout)), |
| childClearTID(0), |
| ADD_STAT(numSyscalls, statistics::units::Count::get(), |
| "Number of system calls") |
| { |
| 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(); |
| |
| image = objFile->buildImage(); |
| |
| if (loader::debugSymbolTable.empty()) |
| loader::debugSymbolTable = objFile->symtab(); |
| } |
| |
| void |
| Process::clone(ThreadContext *otc, ThreadContext *ntc, |
| Process *np, RegVal 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 |
| #ifndef CLONE_VFORK |
| #define CLONE_VFORK 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; |
| |
| 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<std::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. |
| */ |
| std::shared_ptr<FDArray> nfds = np->fds; |
| for (int tgt_fd = 0; tgt_fd < fds->getSize(); tgt_fd++) { |
| 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; |
| } |
| |
| if (CLONE_VFORK & flags) { |
| np->vforkContexts.push_back(otc->contextId()); |
| } |
| |
| np->argv.insert(np->argv.end(), argv.begin(), argv.end()); |
| np->envp.insert(np->envp.end(), envp.begin(), envp.end()); |
| } |
| |
| 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::init() |
| { |
| // Patch the ld_bias for dynamic executables. |
| updateBias(); |
| |
| if (objFile->getInterpreter()) |
| interpImage = objFile->getInterpreter()->buildImage(); |
| } |
| |
| 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->threads[contextIds[0]]; |
| |
| // mark this context as active so it will start ticking. |
| tc->activate(); |
| |
| pTable->initState(); |
| |
| initVirtMem.reset(new SETranslatingPortProxy( |
| tc, SETranslatingPortProxy::Always)); |
| |
| // load object file into target memory |
| image.write(*initVirtMem); |
| interpImage.write(*initVirtMem); |
| } |
| |
| DrainState |
| Process::drain() |
| { |
| fds->updateFileOffsets(); |
| return DrainState::Drained; |
| } |
| |
| void |
| Process::allocateMem(Addr vaddr, int64_t size, bool clobber) |
| { |
| // Check if the page has been mapped by other cores if not to clobber. |
| // When running multithreaded programs in SE-mode with DerivO3CPU model, |
| // there are cases where two or more cores have page faults on the same |
| // page in nearby ticks. When the cores try to handle the faults at the |
| // commit stage (also in nearby ticks/cycles), the first core will ask for |
| // a physical page frame to map with the virtual page. Other cores can |
| // return if the page has been mapped and `!clobber`. |
| if (!clobber) { |
| const EmulationPageTable::Entry *pte = pTable->lookup(vaddr); |
| if (pte) { |
| warn("Process::allocateMem: addr %#x already mapped\n", vaddr); |
| return; |
| } |
| } |
| |
| int npages = divCeil(size, pTable->pageSize()); |
| Addr paddr = system->allocPhysPages(npages); |
| pTable->map(vaddr, paddr, size, |
| clobber ? EmulationPageTable::Clobber : |
| EmulationPageTable::MappingFlags(0)); |
| } |
| |
| 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[pTable->pageSize()]; |
| old_tc->getVirtProxy().readBlob(vaddr, buf_p, sizeof(buf_p)); |
| |
| // 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, sizeof(buf_p), clobber); |
| new_tc->getVirtProxy().writeBlob(vaddr, buf_p, sizeof(buf_p)); |
| } |
| |
| bool |
| Process::fixupFault(Addr vaddr) |
| { |
| return memState->fixupFault(vaddr); |
| } |
| |
| void |
| Process::serialize(CheckpointOut &cp) const |
| { |
| memState->serialize(cp); |
| pTable->serialize(cp); |
| fds->serialize(cp); |
| |
| /** |
| * Checkpoints for pipes, device drivers or sockets currently |
| * do not work. Need to come back and fix them at a later date. |
| */ |
| |
| warn("Checkpoints for pipes, device drivers and sockets do not work."); |
| } |
| |
| void |
| Process::unserialize(CheckpointIn &cp) |
| { |
| memState->unserialize(cp); |
| pTable->unserialize(cp); |
| fds->unserialize(cp); |
| /** |
| * Checkpoints for pipes, device drivers or sockets currently |
| * do not work. Need to come back and fix them at a later date. |
| */ |
| warn("Checkpoints for pipes, device drivers and sockets do not work."); |
| // 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 ? EmulationPageTable::MappingFlags(0) : |
| EmulationPageTable::Uncacheable); |
| return true; |
| } |
| |
| EmulatedDriver * |
| Process::findDriver(std::string filename) |
| { |
| for (EmulatedDriver *d : drivers) { |
| if (d->match(filename)) |
| return d; |
| } |
| |
| return nullptr; |
| } |
| |
| std::string |
| Process::checkPathRedirect(const std::string &filename) |
| { |
| // If the input parameter contains a relative path, convert it. |
| // The target version of the current working directory is fine since |
| // we immediately convert it using redirect paths into a host version. |
| auto abs_path = absolutePath(filename, false); |
| |
| for (auto path : system->redirectPaths) { |
| // Search through the redirect paths to see if a starting substring of |
| // our path falls into any buckets which need to redirected. |
| if (startswith(abs_path, path->appPath())) { |
| std::string tail = abs_path.substr(path->appPath().size()); |
| |
| // If this path needs to be redirected, search through a list |
| // of targets to see if we can match a valid file (or directory). |
| for (auto host_path : path->hostPaths()) { |
| if (access((host_path + tail).c_str(), R_OK) == 0) { |
| // Return the valid match. |
| return host_path + tail; |
| } |
| } |
| // The path needs to be redirected, but the file or directory |
| // does not exist on the host filesystem. Return the first |
| // host path as a default. |
| return path->hostPaths()[0] + tail; |
| } |
| } |
| |
| // The path does not need to be redirected. |
| return abs_path; |
| } |
| |
| void |
| Process::updateBias() |
| { |
| auto *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(), pTable->pageSize()); |
| |
| // 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); |
| } |
| |
| loader::ObjectFile * |
| Process::getInterpreter() |
| { |
| return objFile->getInterpreter(); |
| } |
| |
| Addr |
| Process::getBias() |
| { |
| auto *interp = getInterpreter(); |
| |
| return interp ? interp->bias() : objFile->bias(); |
| } |
| |
| Addr |
| Process::getStartPC() |
| { |
| auto *interp = getInterpreter(); |
| |
| return interp ? interp->entryPoint() : objFile->entryPoint(); |
| } |
| |
| std::string |
| Process::absolutePath(const std::string &filename, bool host_filesystem) |
| { |
| if (filename.empty() || startswith(filename, "/")) |
| return filename; |
| |
| // Construct the absolute path given the current working directory for |
| // either the host filesystem or target filesystem. The distinction only |
| // matters if filesystem redirection is utilized in the simulation. |
| auto path_base = std::string(); |
| if (host_filesystem) { |
| path_base = hostCwd; |
| assert(!hostCwd.empty()); |
| } else { |
| path_base = tgtCwd; |
| assert(!tgtCwd.empty()); |
| } |
| |
| // Add a trailing '/' if the current working directory did not have one. |
| normalize(path_base); |
| |
| // Append the filename onto the current working path. |
| auto absolute_path = path_base + filename; |
| |
| return absolute_path; |
| } |
| |
| Process * |
| ProcessParams::create() const |
| { |
| // If not specified, set the executable parameter equal to the |
| // simulated system's zeroth command line parameter |
| const std::string &exec = (executable == "") ? cmd[0] : executable; |
| |
| auto *obj_file = loader::createObjectFile(exec); |
| fatal_if(!obj_file, "Cannot load object file %s.", exec); |
| |
| Process *process = Process::tryLoaders(*this, obj_file); |
| fatal_if(!process, "Unknown error creating process object."); |
| |
| return process; |
| } |
| |
| } // namespace gem5 |