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authorRick Strong <rstrong@cs.ucsd.edu>2007-11-29 00:22:46 -0500
committerRick Strong <rstrong@cs.ucsd.edu>2007-11-29 00:22:46 -0500
commit376c7285eedf5b235a414accf9f5253a4d55633e (patch)
tree1382af9b9573e5948df9720d0c1a2465aca6bd9d /src/sim
parentab598eadbfeefceb6501d4cca13147b660642d9e (diff)
downloadgem5-376c7285eedf5b235a414accf9f5253a4d55633e.tar.xz
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
Diffstat (limited to 'src/sim')
-rw-r--r--src/sim/process.cc203
-rw-r--r--src/sim/process.hh48
-rw-r--r--src/sim/syscall_emul.cc10
-rw-r--r--src/sim/syscall_emul.hh2
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 <unistd.h>
#include <fcntl.h>
-
#include <string>
#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 &section)
+{
+ 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 &section)
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 &section);
+
+ };
+
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);
}