From 376c7285eedf5b235a414accf9f5253a4d55633e Mon Sep 17 00:00:00 2001 From: Rick Strong Date: Thu, 29 Nov 2007 00:22:46 -0500 Subject: [PATCH] Serialization: Fix serialization of file descriptors. Make sure open file descriptors are reopened and the file pointer is in the same place as when the checkpoint occured. Signed-off by: Ali Saidi --HG-- extra : convert_revision : d9d2cd388c9c02f60e1269d6845891c35f94fc47 --- src/sim/process.cc | 203 ++++++++++++++++++++++++++++++++++++---- src/sim/process.hh | 48 +++++++++- src/sim/syscall_emul.cc | 10 +- src/sim/syscall_emul.hh | 2 +- 4 files changed, 237 insertions(+), 26 deletions(-) diff --git a/src/sim/process.cc b/src/sim/process.cc index 668be367d..d83b0247e 100644 --- a/src/sim/process.cc +++ b/src/sim/process.cc @@ -32,7 +32,6 @@ #include #include - #include #include "arch/remote_gdb.hh" @@ -114,13 +113,32 @@ Process::Process(ProcessParams * params) M5_pid = system->allocatePID(); // initialize first 3 fds (stdin, stdout, stderr) - fd_map[STDIN_FILENO] = stdin_fd; - fd_map[STDOUT_FILENO] = stdout_fd; - fd_map[STDERR_FILENO] = stderr_fd; + Process::FdMap *fdo = &fd_map[STDIN_FILENO]; + fdo->fd = stdin_fd; + fdo->filename = in; + fdo->flags = O_RDONLY; + fdo->mode = -1; + fdo->fileOffset = 0; + + fdo = &fd_map[STDOUT_FILENO]; + fdo->fd = stdout_fd; + fdo->filename = out; + fdo->flags = O_WRONLY | O_CREAT | O_TRUNC; + fdo->mode = 0774; + fdo->fileOffset = 0; + + fdo = &fd_map[STDERR_FILENO]; + fdo->fd = stderr_fd; + fdo->filename = "STDERR"; + fdo->flags = O_WRONLY; + fdo->mode = -1; + fdo->fileOffset = 0; + // mark remaining fds as free for (int i = 3; i <= MAX_FD; ++i) { - fd_map[i] = -1; + Process::FdMap *fdo = &fd_map[i]; + fdo->fd = -1; } mmap_start = mmap_end = 0; @@ -230,22 +248,30 @@ Process::dup_fd(int sim_fd, int tgt_fd) if (tgt_fd < 0 || tgt_fd > MAX_FD) panic("Process::dup_fd tried to dup past MAX_FD (%d)", tgt_fd); - fd_map[tgt_fd] = sim_fd; + Process::FdMap *fdo = &fd_map[tgt_fd]; + fdo->fd = sim_fd; } // generate new target fd for sim_fd int -Process::alloc_fd(int sim_fd) +Process::alloc_fd(int sim_fd, string filename, int flags, int mode, bool pipe) { // in case open() returns an error, don't allocate a new fd if (sim_fd == -1) return -1; // find first free target fd - for (int free_fd = 0; free_fd < MAX_FD; ++free_fd) { - if (fd_map[free_fd] == -1) { - fd_map[free_fd] = sim_fd; + for (int free_fd = 0; free_fd <= MAX_FD; ++free_fd) { + Process::FdMap *fdo = &fd_map[free_fd]; + if (fdo->fd == -1) { + fdo->fd = sim_fd; + fdo->filename = filename; + fdo->mode = mode; + fdo->fileOffset = 0; + fdo->flags = flags; + fdo->isPipe = pipe; + fdo->readPipeSource = 0; return free_fd; } } @@ -258,10 +284,17 @@ Process::alloc_fd(int sim_fd) void Process::free_fd(int tgt_fd) { - if (fd_map[tgt_fd] == -1) + Process::FdMap *fdo = &fd_map[tgt_fd]; + if (fdo->fd == -1) warn("Process::free_fd: request to free unused fd %d", tgt_fd); - fd_map[tgt_fd] = -1; + fdo->fd = -1; + fdo->filename = "NULL"; + fdo->mode = 0; + fdo->fileOffset = 0; + fdo->flags = 0; + fdo->isPipe = false; + fdo->readPipeSource = 0; } @@ -272,9 +305,17 @@ Process::sim_fd(int tgt_fd) if (tgt_fd > MAX_FD) return -1; - return fd_map[tgt_fd]; + return fd_map[tgt_fd].fd; } +Process::FdMap * +Process::sim_fd_obj(int tgt_fd) +{ + if (tgt_fd > MAX_FD) + panic("sim_fd_obj called in fd out of range."); + + return &fd_map[tgt_fd]; +} bool Process::checkAndAllocNextPage(Addr vaddr) { @@ -301,6 +342,127 @@ Process::checkAndAllocNextPage(Addr vaddr) return false; } + // find all offsets for currently open files and save them +void +Process::fix_file_offsets() { + Process::FdMap *fdo_stdin = &fd_map[STDIN_FILENO]; + Process::FdMap *fdo_stdout = &fd_map[STDOUT_FILENO]; + Process::FdMap *fdo_stderr = &fd_map[STDERR_FILENO]; + string in = fdo_stdin->filename; + string out = fdo_stdout->filename; + + // initialize file descriptors to default: same as simulator + int stdin_fd, stdout_fd, stderr_fd; + + if (in == "stdin" || in == "cin") + stdin_fd = STDIN_FILENO; + else if (in == "None") + stdin_fd = -1; + else{ + //OPEN standard in and seek to the right location + stdin_fd = Process::openInputFile(in); + if (lseek(stdin_fd, fdo_stdin->fileOffset, SEEK_SET) < 0) + panic("Unable to seek to correct location in file: %s", in); + } + + if (out == "stdout" || out == "cout") + stdout_fd = STDOUT_FILENO; + else if (out == "stderr" || out == "cerr") + stdout_fd = STDERR_FILENO; + else if (out == "None") + stdout_fd = -1; + else{ + stdout_fd = Process::openOutputFile(out); + if (lseek(stdin_fd, fdo_stdout->fileOffset, SEEK_SET) < 0) + panic("Unable to seek to correct in file: %s", out); + } + + stderr_fd = (stdout_fd != STDOUT_FILENO) ? stdout_fd : STDERR_FILENO; + + fdo_stdin->fd = stdin_fd; + fdo_stdout->fd = stdout_fd; + fdo_stderr->fd = stderr_fd; + + + for (int free_fd = 3; free_fd <= MAX_FD; ++free_fd) { + Process::FdMap *fdo = &fd_map[free_fd]; + if (fdo->fd != -1) { + if (fdo->isPipe){ + if (fdo->filename == "PIPE-WRITE") + continue; + else { + assert (fdo->filename == "PIPE-READ"); + //create a new pipe + int fds[2]; + int pipe_retval = pipe(fds); + + if (pipe_retval < 0) { + // error + panic("Unable to create new pipe."); + } + fdo->fd = fds[0]; //set read pipe + Process::FdMap *fdo_write = &fd_map[fdo->readPipeSource]; + if (fdo_write->filename != "PIPE-WRITE") + panic ("Couldn't find write end of the pipe"); + + fdo_write->fd = fds[1];//set write pipe + } + } else { + //Open file + int fd = open(fdo->filename.c_str(), fdo->flags, fdo->mode); + + if (fd == -1) + panic("Unable to open file: %s", fdo->filename); + fdo->fd = fd; + + //Seek to correct location before checkpoint + if (lseek(fd,fdo->fileOffset, SEEK_SET) < 0) + panic("Unable to seek to correct location in file: %s", fdo->filename); + } + } + } +} +void +Process::find_file_offsets(){ + for (int free_fd = 0; free_fd <= MAX_FD; ++free_fd) { + Process::FdMap *fdo = &fd_map[free_fd]; + if (fdo->fd != -1) { + fdo->fileOffset = lseek(fdo->fd, 0, SEEK_CUR); + } else { + fdo->filename = "NULL"; + fdo->fileOffset = 0; + } + } +} + +void +Process::setReadPipeSource(int read_pipe_fd, int source_fd){ + Process::FdMap *fdo = &fd_map[read_pipe_fd]; + fdo->readPipeSource = source_fd; +} + +void +Process::FdMap::serialize(std::ostream &os) +{ + SERIALIZE_SCALAR(fd); + SERIALIZE_SCALAR(isPipe); + SERIALIZE_SCALAR(filename); + SERIALIZE_SCALAR(flags); + SERIALIZE_SCALAR(readPipeSource); + SERIALIZE_SCALAR(fileOffset); +} + +void +Process::FdMap::unserialize(Checkpoint *cp, const std::string §ion) +{ + UNSERIALIZE_SCALAR(fd); + UNSERIALIZE_SCALAR(isPipe); + UNSERIALIZE_SCALAR(filename); + UNSERIALIZE_SCALAR(flags); + UNSERIALIZE_SCALAR(readPipeSource); + UNSERIALIZE_SCALAR(fileOffset); +} + void Process::serialize(std::ostream &os) { @@ -314,9 +476,13 @@ Process::serialize(std::ostream &os) SERIALIZE_SCALAR(mmap_end); SERIALIZE_SCALAR(nxm_start); SERIALIZE_SCALAR(nxm_end); - SERIALIZE_ARRAY(fd_map, MAX_FD); - + find_file_offsets(); pTable->serialize(os); + for (int x = 0; x <= MAX_FD; x++) { + nameOut(os, csprintf("%s.FdMap%d", name(), x)); + fd_map[x].serialize(os); + } + } void @@ -332,10 +498,11 @@ Process::unserialize(Checkpoint *cp, const std::string §ion) UNSERIALIZE_SCALAR(mmap_end); UNSERIALIZE_SCALAR(nxm_start); UNSERIALIZE_SCALAR(nxm_end); - UNSERIALIZE_ARRAY(fd_map, MAX_FD); - pTable->unserialize(cp, section); - + for (int x = 0; x <= MAX_FD; x++) { + fd_map[x].unserialize(cp, csprintf("%s.FdMap%d", section, x)); + } + fix_file_offsets(); checkpointRestored = true; diff --git a/src/sim/process.hh b/src/sim/process.hh index 0d2db959c..29d6e5aae 100644 --- a/src/sim/process.hh +++ b/src/sim/process.hh @@ -144,10 +144,40 @@ class Process : public SimObject //separated. uint64_t M5_pid; + class FdMap + { + public: + int fd; + std::string filename; + int mode; + int flags; + bool isPipe; + int readPipeSource; + uint64_t fileOffset; + + + FdMap() + { + fd = -1; + filename = "NULL"; + mode = 0; + flags = 0; + isPipe = false; + readPipeSource = 0; + fileOffset = 0; + + } + + void serialize(std::ostream &os); + void unserialize(Checkpoint *cp, const std::string §ion); + + }; + private: // file descriptor remapping support - static const int MAX_FD = 256; // max legal fd value - int fd_map[MAX_FD+1]; + static const int MAX_FD = 256; // max legal fd value + FdMap fd_map[MAX_FD+1]; + public: // static helper functions to generate file descriptors for constructor @@ -168,7 +198,7 @@ class Process : public SimObject void dup_fd(int sim_fd, int tgt_fd); // generate new target fd for sim_fd - int alloc_fd(int sim_fd); + int alloc_fd(int sim_fd, std::string filename, int flags, int mode, bool pipe); // free target fd (e.g., after close) void free_fd(int tgt_fd); @@ -176,6 +206,18 @@ class Process : public SimObject // look up simulator fd for given target fd int sim_fd(int tgt_fd); + // look up simulator fd_map object for a given target fd + FdMap * sim_fd_obj(int tgt_fd); + + // fix all offsets for currently open files and save them + void fix_file_offsets(); + + // find all offsets for currently open files and save them + void find_file_offsets(); + + // set the source of this read pipe for a checkpoint resume + void setReadPipeSource(int read_pipe_fd, int source_fd); + virtual void syscall(int64_t callnum, ThreadContext *tc) = 0; // check if the this addr is on the next available page and allocate it diff --git a/src/sim/syscall_emul.cc b/src/sim/syscall_emul.cc index 876f39e99..f4b9b7ae3 100644 --- a/src/sim/syscall_emul.cc +++ b/src/sim/syscall_emul.cc @@ -350,12 +350,13 @@ SyscallReturn dupFunc(SyscallDesc *desc, int num, LiveProcess *process, ThreadContext *tc) { int fd = process->sim_fd(tc->getSyscallArg(0)); - if (fd < 0) return -EBADF; + Process::FdMap *fdo = process->sim_fd_obj(tc->getSyscallArg(0)); + int result = dup(fd); - return (result == -1) ? -errno : process->alloc_fd(result); + return (result == -1) ? -errno : process->alloc_fd(result, fdo->filename, fdo->flags, fdo->mode, false); } @@ -442,9 +443,10 @@ pipePseudoFunc(SyscallDesc *desc, int callnum, LiveProcess *process, return pipe_retval; } - sim_fds[0] = process->alloc_fd(fds[0]); - sim_fds[1] = process->alloc_fd(fds[1]); + sim_fds[0] = process->alloc_fd(fds[0], "PIPE-READ", O_WRONLY, -1, true); + sim_fds[1] = process->alloc_fd(fds[1], "PIPE-WRITE", O_RDONLY, -1, true); + process->setReadPipeSource(sim_fds[0], sim_fds[1]); // Alpha Linux convention for pipe() is that fd[0] is returned as // the return value of the function, and fd[1] is returned in r20. tc->setIntReg(SyscallPseudoReturnReg, sim_fds[1]); diff --git a/src/sim/syscall_emul.hh b/src/sim/syscall_emul.hh index abab356df..e35b0a75b 100644 --- a/src/sim/syscall_emul.hh +++ b/src/sim/syscall_emul.hh @@ -518,7 +518,7 @@ openFunc(SyscallDesc *desc, int callnum, LiveProcess *process, // open the file int fd = open(path.c_str(), hostFlags, mode); - return (fd == -1) ? -errno : process->alloc_fd(fd); + return (fd == -1) ? -errno : process->alloc_fd(fd,path.c_str(),hostFlags,mode, false); } -- 2.30.2