blob: 794b0bc2c1cb82a4ffd953da2c2202a36e1f0674 [file] [log] [blame]
/*
* Copyright (c) 2003-2005 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: Steve Reinhardt
* Ali Saidi
*/
#include "sim/syscall_emul.hh"
#include <fcntl.h>
#include <syscall.h>
#include <unistd.h>
#include <csignal>
#include <iostream>
#include <mutex>
#include <string>
#include "arch/utility.hh"
#include "base/chunk_generator.hh"
#include "base/trace.hh"
#include "config/the_isa.hh"
#include "cpu/thread_context.hh"
#include "dev/net/dist_iface.hh"
#include "mem/page_table.hh"
#include "sim/byteswap.hh"
#include "sim/process.hh"
#include "sim/sim_exit.hh"
#include "sim/syscall_debug_macros.hh"
#include "sim/syscall_desc.hh"
#include "sim/system.hh"
using namespace std;
using namespace TheISA;
SyscallReturn
unimplementedFunc(SyscallDesc *desc, int callnum, Process *process,
ThreadContext *tc)
{
fatal("syscall %s (#%d) unimplemented.", desc->name(), callnum);
return 1;
}
SyscallReturn
ignoreFunc(SyscallDesc *desc, int callnum, Process *process,
ThreadContext *tc)
{
if (desc->needWarning()) {
warn("ignoring syscall %s(...)%s", desc->name(), desc->warnOnce() ?
"\n (further warnings will be suppressed)" : "");
}
return 0;
}
static void
exitFutexWake(ThreadContext *tc, Addr addr, uint64_t tgid)
{
// Clear value at address pointed to by thread's childClearTID field.
BufferArg ctidBuf(addr, sizeof(long));
long *ctid = (long *)ctidBuf.bufferPtr();
*ctid = 0;
ctidBuf.copyOut(tc->getMemProxy());
FutexMap &futex_map = tc->getSystemPtr()->futexMap;
// Wake one of the waiting threads.
futex_map.wakeup(addr, tgid, 1);
}
static SyscallReturn
exitImpl(SyscallDesc *desc, int callnum, Process *p, ThreadContext *tc,
bool group)
{
int index = 0;
int status = p->getSyscallArg(tc, index);
System *sys = tc->getSystemPtr();
int activeContexts = 0;
for (auto &system: sys->systemList)
activeContexts += system->numRunningContexts();
if (activeContexts == 1) {
/**
* Even though we are terminating the final thread context, dist-gem5
* requires the simulation to remain active and provide
* synchronization messages to the switch process. So we just halt
* the last thread context and return. The simulation will be
* terminated by dist-gem5 in a coordinated manner once all nodes
* have signaled their readiness to exit. For non dist-gem5
* simulations, readyToExit() always returns true.
*/
if (!DistIface::readyToExit(0)) {
tc->halt();
return status;
}
exitSimLoop("exiting with last active thread context", status & 0xff);
return status;
}
if (group)
*p->exitGroup = true;
if (p->childClearTID)
exitFutexWake(tc, p->childClearTID, p->tgid());
bool last_thread = true;
Process *parent = nullptr, *tg_lead = nullptr;
for (int i = 0; last_thread && i < sys->numContexts(); i++) {
Process *walk;
if (!(walk = sys->threadContexts[i]->getProcessPtr()))
continue;
/**
* Threads in a thread group require special handing. For instance,
* we send the SIGCHLD signal so that it appears that it came from
* the head of the group. We also only delete file descriptors if
* we are the last thread in the thread group.
*/
if (walk->pid() == p->tgid())
tg_lead = walk;
if ((sys->threadContexts[i]->status() != ThreadContext::Halted)
&& (walk != p)) {
/**
* Check if we share thread group with the pointer; this denotes
* that we are not the last thread active in the thread group.
* Note that setting this to false also prevents further
* iterations of the loop.
*/
if (walk->tgid() == p->tgid())
last_thread = false;
/**
* A corner case exists which involves execve(). After execve(),
* the execve will enable SIGCHLD in the process. The problem
* occurs when the exiting process is the root process in the
* system; there is no parent to receive the signal. We obviate
* this problem by setting the root process' ppid to zero in the
* Python configuration files. We really should handle the
* root/execve specific case more gracefully.
*/
if (*p->sigchld && (p->ppid() != 0) && (walk->pid() == p->ppid()))
parent = walk;
}
}
if (last_thread) {
if (parent) {
assert(tg_lead);
sys->signalList.push_back(BasicSignal(tg_lead, parent, SIGCHLD));
}
/**
* Run though FD array of the exiting process and close all file
* descriptors except for the standard file descriptors.
* (The standard file descriptors are shared with gem5.)
*/
for (int i = 0; i < p->fds->getSize(); i++) {
if ((*p->fds)[i])
p->fds->closeFDEntry(i);
}
}
tc->halt();
return status;
}
SyscallReturn
exitFunc(SyscallDesc *desc, int callnum, Process *p, ThreadContext *tc)
{
return exitImpl(desc, callnum, p, tc, false);
}
SyscallReturn
exitGroupFunc(SyscallDesc *desc, int callnum, Process *p, ThreadContext *tc)
{
return exitImpl(desc, callnum, p, tc, true);
}
SyscallReturn
getpagesizeFunc(SyscallDesc *desc, int num, Process *p, ThreadContext *tc)
{
return (int)PageBytes;
}
SyscallReturn
brkFunc(SyscallDesc *desc, int num, Process *p, ThreadContext *tc)
{
// change brk addr to first arg
int index = 0;
Addr new_brk = p->getSyscallArg(tc, index);
std::shared_ptr<MemState> mem_state = p->memState;
Addr brk_point = mem_state->getBrkPoint();
// in Linux at least, brk(0) returns the current break value
// (note that the syscall and the glibc function have different behavior)
if (new_brk == 0)
return brk_point;
if (new_brk > brk_point) {
// might need to allocate some new pages
for (ChunkGenerator gen(brk_point,
new_brk - brk_point,
PageBytes); !gen.done(); gen.next()) {
if (!p->pTable->translate(gen.addr()))
p->allocateMem(roundDown(gen.addr(), PageBytes), PageBytes);
// if the address is already there, zero it out
else {
uint8_t zero = 0;
SETranslatingPortProxy &tp = tc->getMemProxy();
// split non-page aligned accesses
Addr next_page = roundUp(gen.addr(), PageBytes);
uint32_t size_needed = next_page - gen.addr();
tp.memsetBlob(gen.addr(), zero, size_needed);
if (gen.addr() + PageBytes > next_page &&
next_page < new_brk &&
p->pTable->translate(next_page)) {
size_needed = PageBytes - size_needed;
tp.memsetBlob(next_page, zero, size_needed);
}
}
}
}
mem_state->setBrkPoint(new_brk);
DPRINTF_SYSCALL(Verbose, "brk: break point changed to: %#X\n",
mem_state->getBrkPoint());
return mem_state->getBrkPoint();
}
SyscallReturn
setTidAddressFunc(SyscallDesc *desc, int callnum, Process *process,
ThreadContext *tc)
{
int index = 0;
uint64_t tidPtr = process->getSyscallArg(tc, index);
process->childClearTID = tidPtr;
return process->pid();
}
SyscallReturn
closeFunc(SyscallDesc *desc, int num, Process *p, ThreadContext *tc)
{
int index = 0;
int tgt_fd = p->getSyscallArg(tc, index);
return p->fds->closeFDEntry(tgt_fd);
}
SyscallReturn
readFunc(SyscallDesc *desc, int num, Process *p, ThreadContext *tc)
{
int index = 0;
int tgt_fd = p->getSyscallArg(tc, index);
Addr buf_ptr = p->getSyscallArg(tc, index);
int nbytes = p->getSyscallArg(tc, index);
auto hbfdp = std::dynamic_pointer_cast<HBFDEntry>((*p->fds)[tgt_fd]);
if (!hbfdp)
return -EBADF;
int sim_fd = hbfdp->getSimFD();
BufferArg bufArg(buf_ptr, nbytes);
int bytes_read = read(sim_fd, bufArg.bufferPtr(), nbytes);
if (bytes_read > 0)
bufArg.copyOut(tc->getMemProxy());
return bytes_read;
}
SyscallReturn
writeFunc(SyscallDesc *desc, int num, Process *p, ThreadContext *tc)
{
int index = 0;
int tgt_fd = p->getSyscallArg(tc, index);
Addr buf_ptr = p->getSyscallArg(tc, index);
int nbytes = p->getSyscallArg(tc, index);
auto hbfdp = std::dynamic_pointer_cast<HBFDEntry>((*p->fds)[tgt_fd]);
if (!hbfdp)
return -EBADF;
int sim_fd = hbfdp->getSimFD();
BufferArg bufArg(buf_ptr, nbytes);
bufArg.copyIn(tc->getMemProxy());
int bytes_written = write(sim_fd, bufArg.bufferPtr(), nbytes);
fsync(sim_fd);
return bytes_written;
}
SyscallReturn
lseekFunc(SyscallDesc *desc, int num, Process *p, ThreadContext *tc)
{
int index = 0;
int tgt_fd = p->getSyscallArg(tc, index);
uint64_t offs = p->getSyscallArg(tc, index);
int whence = p->getSyscallArg(tc, index);
auto ffdp = std::dynamic_pointer_cast<FileFDEntry>((*p->fds)[tgt_fd]);
if (!ffdp)
return -EBADF;
int sim_fd = ffdp->getSimFD();
off_t result = lseek(sim_fd, offs, whence);
return (result == (off_t)-1) ? -errno : result;
}
SyscallReturn
_llseekFunc(SyscallDesc *desc, int num, Process *p, ThreadContext *tc)
{
int index = 0;
int tgt_fd = p->getSyscallArg(tc, index);
uint64_t offset_high = p->getSyscallArg(tc, index);
uint32_t offset_low = p->getSyscallArg(tc, index);
Addr result_ptr = p->getSyscallArg(tc, index);
int whence = p->getSyscallArg(tc, index);
auto ffdp = std::dynamic_pointer_cast<FileFDEntry>((*p->fds)[tgt_fd]);
if (!ffdp)
return -EBADF;
int sim_fd = ffdp->getSimFD();
uint64_t offset = (offset_high << 32) | offset_low;
uint64_t result = lseek(sim_fd, offset, whence);
result = TheISA::htog(result);
if (result == (off_t)-1)
return -errno;
// Assuming that the size of loff_t is 64 bits on the target platform
BufferArg result_buf(result_ptr, sizeof(result));
memcpy(result_buf.bufferPtr(), &result, sizeof(result));
result_buf.copyOut(tc->getMemProxy());
return 0;
}
SyscallReturn
munmapFunc(SyscallDesc *desc, int num, Process *p, ThreadContext *tc)
{
// With mmap more fully implemented, it might be worthwhile to bite
// the bullet and implement munmap. Should allow us to reuse simulated
// memory.
return 0;
}
const char *hostname = "m5.eecs.umich.edu";
SyscallReturn
gethostnameFunc(SyscallDesc *desc, int num, Process *p, ThreadContext *tc)
{
int index = 0;
Addr buf_ptr = p->getSyscallArg(tc, index);
int name_len = p->getSyscallArg(tc, index);
BufferArg name(buf_ptr, name_len);
strncpy((char *)name.bufferPtr(), hostname, name_len);
name.copyOut(tc->getMemProxy());
return 0;
}
SyscallReturn
getcwdFunc(SyscallDesc *desc, int num, Process *p, ThreadContext *tc)
{
int result = 0;
int index = 0;
Addr buf_ptr = p->getSyscallArg(tc, index);
unsigned long size = p->getSyscallArg(tc, index);
BufferArg buf(buf_ptr, size);
// Is current working directory defined?
string cwd = p->getcwd();
if (!cwd.empty()) {
if (cwd.length() >= size) {
// Buffer too small
return -ERANGE;
}
strncpy((char *)buf.bufferPtr(), cwd.c_str(), size);
result = cwd.length();
} else {
if (getcwd((char *)buf.bufferPtr(), size)) {
result = strlen((char *)buf.bufferPtr());
} else {
result = -1;
}
}
buf.copyOut(tc->getMemProxy());
return (result == -1) ? -errno : result;
}
SyscallReturn
readlinkFunc(SyscallDesc *desc, int callnum, Process *process,
ThreadContext *tc)
{
return readlinkFunc(desc, callnum, process, tc, 0);
}
SyscallReturn
readlinkFunc(SyscallDesc *desc, int num, Process *p, ThreadContext *tc,
int index)
{
string path;
if (!tc->getMemProxy().tryReadString(path, p->getSyscallArg(tc, index)))
return -EFAULT;
// Adjust path for current working directory
path = p->fullPath(path);
Addr buf_ptr = p->getSyscallArg(tc, index);
size_t bufsiz = p->getSyscallArg(tc, index);
BufferArg buf(buf_ptr, bufsiz);
int result = -1;
if (path != "/proc/self/exe") {
result = readlink(path.c_str(), (char *)buf.bufferPtr(), bufsiz);
} else {
// Emulate readlink() called on '/proc/self/exe' should return the
// absolute path of the binary running in the simulated system (the
// Process' executable). It is possible that using this path in
// the simulated system will result in unexpected behavior if:
// 1) One binary runs another (e.g., -c time -o "my_binary"), and
// called binary calls readlink().
// 2) The host's full path to the running benchmark changes from one
// simulation to another. This can result in different simulated
// performance since the simulated system will process the binary
// path differently, even if the binary itself does not change.
// Get the absolute canonical path to the running application
char real_path[PATH_MAX];
char *check_real_path = realpath(p->progName(), real_path);
if (!check_real_path) {
fatal("readlink('/proc/self/exe') unable to resolve path to "
"executable: %s", p->progName());
}
strncpy((char*)buf.bufferPtr(), real_path, bufsiz);
size_t real_path_len = strlen(real_path);
if (real_path_len > bufsiz) {
// readlink will truncate the contents of the
// path to ensure it is no more than bufsiz
result = bufsiz;
} else {
result = real_path_len;
}
// Issue a warning about potential unexpected results
warn_once("readlink() called on '/proc/self/exe' may yield unexpected "
"results in various settings.\n Returning '%s'\n",
(char*)buf.bufferPtr());
}
buf.copyOut(tc->getMemProxy());
return (result == -1) ? -errno : result;
}
SyscallReturn
unlinkFunc(SyscallDesc *desc, int num, Process *p, ThreadContext *tc)
{
return unlinkHelper(desc, num, p, tc, 0);
}
SyscallReturn
unlinkHelper(SyscallDesc *desc, int num, Process *p, ThreadContext *tc,
int index)
{
string path;
if (!tc->getMemProxy().tryReadString(path, p->getSyscallArg(tc, index)))
return -EFAULT;
path = p->fullPath(path);
int result = unlink(path.c_str());
return (result == -1) ? -errno : result;
}
SyscallReturn
linkFunc(SyscallDesc *desc, int num, Process *p, ThreadContext *tc)
{
string path;
string new_path;
int index = 0;
auto &virt_mem = tc->getMemProxy();
if (!virt_mem.tryReadString(path, p->getSyscallArg(tc, index)))
return -EFAULT;
if (!virt_mem.tryReadString(new_path, p->getSyscallArg(tc, index)))
return -EFAULT;
path = p->fullPath(path);
new_path = p->fullPath(new_path);
int result = link(path.c_str(), new_path.c_str());
return (result == -1) ? -errno : result;
}
SyscallReturn
symlinkFunc(SyscallDesc *desc, int num, Process *p, ThreadContext *tc)
{
string path;
string new_path;
int index = 0;
auto &virt_mem = tc->getMemProxy();
if (!virt_mem.tryReadString(path, p->getSyscallArg(tc, index)))
return -EFAULT;
if (!virt_mem.tryReadString(new_path, p->getSyscallArg(tc, index)))
return -EFAULT;
path = p->fullPath(path);
new_path = p->fullPath(new_path);
int result = symlink(path.c_str(), new_path.c_str());
return (result == -1) ? -errno : result;
}
SyscallReturn
mkdirFunc(SyscallDesc *desc, int num, Process *p, ThreadContext *tc)
{
string path;
int index = 0;
if (!tc->getMemProxy().tryReadString(path, p->getSyscallArg(tc, index)))
return -EFAULT;
// Adjust path for current working directory
path = p->fullPath(path);
mode_t mode = p->getSyscallArg(tc, index);
int result = mkdir(path.c_str(), mode);
return (result == -1) ? -errno : result;
}
SyscallReturn
renameFunc(SyscallDesc *desc, int num, Process *p, ThreadContext *tc)
{
string old_name;
int index = 0;
if (!tc->getMemProxy().tryReadString(old_name, p->getSyscallArg(tc, index)))
return -EFAULT;
string new_name;
if (!tc->getMemProxy().tryReadString(new_name, p->getSyscallArg(tc, index)))
return -EFAULT;
// Adjust path for current working directory
old_name = p->fullPath(old_name);
new_name = p->fullPath(new_name);
int64_t result = rename(old_name.c_str(), new_name.c_str());
return (result == -1) ? -errno : result;
}
SyscallReturn
truncateFunc(SyscallDesc *desc, int num, Process *p, ThreadContext *tc)
{
string path;
int index = 0;
if (!tc->getMemProxy().tryReadString(path, p->getSyscallArg(tc, index)))
return -EFAULT;
off_t length = p->getSyscallArg(tc, index);
// Adjust path for current working directory
path = p->fullPath(path);
int result = truncate(path.c_str(), length);
return (result == -1) ? -errno : result;
}
SyscallReturn
ftruncateFunc(SyscallDesc *desc, int num, Process *p, ThreadContext *tc)
{
int index = 0;
int tgt_fd = p->getSyscallArg(tc, index);
off_t length = p->getSyscallArg(tc, index);
auto ffdp = std::dynamic_pointer_cast<FileFDEntry>((*p->fds)[tgt_fd]);
if (!ffdp)
return -EBADF;
int sim_fd = ffdp->getSimFD();
int result = ftruncate(sim_fd, length);
return (result == -1) ? -errno : result;
}
SyscallReturn
truncate64Func(SyscallDesc *desc, int num,
Process *process, ThreadContext *tc)
{
int index = 0;
string path;
if (!tc->getMemProxy().tryReadString(path, process->getSyscallArg(tc, index)))
return -EFAULT;
int64_t length = process->getSyscallArg(tc, index, 64);
// Adjust path for current working directory
path = process->fullPath(path);
#if NO_STAT64
int result = truncate(path.c_str(), length);
#else
int result = truncate64(path.c_str(), length);
#endif
return (result == -1) ? -errno : result;
}
SyscallReturn
ftruncate64Func(SyscallDesc *desc, int num, Process *p, ThreadContext *tc)
{
int index = 0;
int tgt_fd = p->getSyscallArg(tc, index);
int64_t length = p->getSyscallArg(tc, index, 64);
auto ffdp = std::dynamic_pointer_cast<FileFDEntry>((*p->fds)[tgt_fd]);
if (!ffdp)
return -EBADF;
int sim_fd = ffdp->getSimFD();
#if NO_STAT64
int result = ftruncate(sim_fd, length);
#else
int result = ftruncate64(sim_fd, length);
#endif
return (result == -1) ? -errno : result;
}
SyscallReturn
umaskFunc(SyscallDesc *desc, int num, Process *process, ThreadContext *tc)
{
// Letting the simulated program change the simulator's umask seems like
// a bad idea. Compromise by just returning the current umask but not
// changing anything.
mode_t oldMask = umask(0);
umask(oldMask);
return (int)oldMask;
}
SyscallReturn
chownFunc(SyscallDesc *desc, int num, Process *p, ThreadContext *tc)
{
string path;
int index = 0;
if (!tc->getMemProxy().tryReadString(path, p->getSyscallArg(tc, index)))
return -EFAULT;
/* XXX endianess */
uint32_t owner = p->getSyscallArg(tc, index);
uid_t hostOwner = owner;
uint32_t group = p->getSyscallArg(tc, index);
gid_t hostGroup = group;
// Adjust path for current working directory
path = p->fullPath(path);
int result = chown(path.c_str(), hostOwner, hostGroup);
return (result == -1) ? -errno : result;
}
SyscallReturn
fchownFunc(SyscallDesc *desc, int num, Process *p, ThreadContext *tc)
{
int index = 0;
int tgt_fd = p->getSyscallArg(tc, index);
auto ffdp = std::dynamic_pointer_cast<FileFDEntry>((*p->fds)[tgt_fd]);
if (!ffdp)
return -EBADF;
int sim_fd = ffdp->getSimFD();
/* XXX endianess */
uint32_t owner = p->getSyscallArg(tc, index);
uid_t hostOwner = owner;
uint32_t group = p->getSyscallArg(tc, index);
gid_t hostGroup = group;
int result = fchown(sim_fd, hostOwner, hostGroup);
return (result == -1) ? -errno : result;
}
/**
* FIXME: The file description is not shared among file descriptors created
* with dup. Really, it's difficult to maintain fields like file offset or
* flags since an update to such a field won't be reflected in the metadata
* for the fd entries that we maintain for checkpoint restoration.
*/
SyscallReturn
dupFunc(SyscallDesc *desc, int num, Process *p, ThreadContext *tc)
{
int index = 0;
int tgt_fd = p->getSyscallArg(tc, index);
auto old_hbfdp = std::dynamic_pointer_cast<HBFDEntry>((*p->fds)[tgt_fd]);
if (!old_hbfdp)
return -EBADF;
int sim_fd = old_hbfdp->getSimFD();
int result = dup(sim_fd);
if (result == -1)
return -errno;
auto new_hbfdp = std::dynamic_pointer_cast<HBFDEntry>(old_hbfdp->clone());
new_hbfdp->setSimFD(result);
new_hbfdp->setCOE(false);
return p->fds->allocFD(new_hbfdp);
}
SyscallReturn
dup2Func(SyscallDesc *desc, int num, Process *p, ThreadContext *tc)
{
int index = 0;
int old_tgt_fd = p->getSyscallArg(tc, index);
auto old_hbp = std::dynamic_pointer_cast<HBFDEntry>((*p->fds)[old_tgt_fd]);
if (!old_hbp)
return -EBADF;
int old_sim_fd = old_hbp->getSimFD();
/**
* We need a valid host file descriptor number to be able to pass into
* the second parameter for dup2 (newfd), but we don't know what the
* viable numbers are; we execute the open call to retrieve one.
*/
int res_fd = dup2(old_sim_fd, open("/dev/null", O_RDONLY));
if (res_fd == -1)
return -errno;
int new_tgt_fd = p->getSyscallArg(tc, index);
auto new_hbp = std::dynamic_pointer_cast<HBFDEntry>((*p->fds)[new_tgt_fd]);
if (new_hbp)
p->fds->closeFDEntry(new_tgt_fd);
new_hbp = std::dynamic_pointer_cast<HBFDEntry>(old_hbp->clone());
new_hbp->setSimFD(res_fd);
new_hbp->setCOE(false);
return p->fds->allocFD(new_hbp);
}
SyscallReturn
fcntlFunc(SyscallDesc *desc, int num, Process *p, ThreadContext *tc)
{
int arg;
int index = 0;
int tgt_fd = p->getSyscallArg(tc, index);
int cmd = p->getSyscallArg(tc, index);
auto hbfdp = std::dynamic_pointer_cast<HBFDEntry>((*p->fds)[tgt_fd]);
if (!hbfdp)
return -EBADF;
int sim_fd = hbfdp->getSimFD();
int coe = hbfdp->getCOE();
switch (cmd) {
case F_GETFD:
return coe & FD_CLOEXEC;
case F_SETFD: {
arg = p->getSyscallArg(tc, index);
arg ? hbfdp->setCOE(true) : hbfdp->setCOE(false);
return 0;
}
// Rely on the host to maintain the file status flags for this file
// description rather than maintain it ourselves. Admittedly, this
// is suboptimal (and possibly error prone), but it is difficult to
// maintain the flags by tracking them across the different descriptors
// (that refer to this file description) caused by clone, dup, and
// subsequent fcntls.
case F_GETFL:
case F_SETFL: {
arg = p->getSyscallArg(tc, index);
int rv = fcntl(sim_fd, cmd, arg);
return (rv == -1) ? -errno : rv;
}
default:
warn("fcntl: unsupported command %d\n", cmd);
return 0;
}
}
SyscallReturn
fcntl64Func(SyscallDesc *desc, int num, Process *p, ThreadContext *tc)
{
int index = 0;
int tgt_fd = p->getSyscallArg(tc, index);
auto hbfdp = std::dynamic_pointer_cast<HBFDEntry>((*p->fds)[tgt_fd]);
if (!hbfdp)
return -EBADF;
int sim_fd = hbfdp->getSimFD();
int cmd = p->getSyscallArg(tc, index);
switch (cmd) {
case 33: //F_GETLK64
warn("fcntl64(%d, F_GETLK64) not supported, error returned\n", tgt_fd);
return -EMFILE;
case 34: // F_SETLK64
case 35: // F_SETLKW64
warn("fcntl64(%d, F_SETLK(W)64) not supported, error returned\n",
tgt_fd);
return -EMFILE;
default:
// not sure if this is totally valid, but we'll pass it through
// to the underlying OS
warn("fcntl64(%d, %d) passed through to host\n", tgt_fd, cmd);
return fcntl(sim_fd, cmd);
}
}
SyscallReturn
pipeImpl(SyscallDesc *desc, int callnum, Process *p, ThreadContext *tc,
bool pseudoPipe)
{
Addr tgt_addr = 0;
if (!pseudoPipe) {
int index = 0;
tgt_addr = p->getSyscallArg(tc, index);
}
int sim_fds[2], tgt_fds[2];
int pipe_retval = pipe(sim_fds);
if (pipe_retval == -1)
return -errno;
auto rend = PipeFDEntry::EndType::read;
auto rpfd = std::make_shared<PipeFDEntry>(sim_fds[0], O_WRONLY, rend);
tgt_fds[0] = p->fds->allocFD(rpfd);
auto wend = PipeFDEntry::EndType::write;
auto wpfd = std::make_shared<PipeFDEntry>(sim_fds[1], O_RDONLY, wend);
tgt_fds[1] = p->fds->allocFD(wpfd);
/**
* Now patch the read object to record the target file descriptor chosen
* as the write end of the pipe.
*/
rpfd->setPipeReadSource(tgt_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.
*/
if (pseudoPipe) {
tc->setIntReg(SyscallPseudoReturnReg, tgt_fds[1]);
return tgt_fds[0];
}
/**
* Copy the target file descriptors into buffer space and then copy
* the buffer space back into the target address space.
*/
BufferArg tgt_handle(tgt_addr, sizeof(int[2]));
int *buf_ptr = (int*)tgt_handle.bufferPtr();
buf_ptr[0] = tgt_fds[0];
buf_ptr[1] = tgt_fds[1];
tgt_handle.copyOut(tc->getMemProxy());
return 0;
}
SyscallReturn
pipePseudoFunc(SyscallDesc *desc, int callnum, Process *process,
ThreadContext *tc)
{
return pipeImpl(desc, callnum, process, tc, true);
}
SyscallReturn
pipeFunc(SyscallDesc *desc, int callnum, Process *process, ThreadContext *tc)
{
return pipeImpl(desc, callnum, process, tc, false);
}
SyscallReturn
setpgidFunc(SyscallDesc *desc, int callnum, Process *process,
ThreadContext *tc)
{
int index = 0;
int pid = process->getSyscallArg(tc, index);
int pgid = process->getSyscallArg(tc, index);
if (pgid < 0)
return -EINVAL;
if (pid == 0) {
process->setpgid(process->pid());
return 0;
}
Process *matched_ph = nullptr;
System *sysh = tc->getSystemPtr();
// Retrieves process pointer from active/suspended thread contexts.
for (int i = 0; i < sysh->numContexts(); i++) {
if (sysh->threadContexts[i]->status() != ThreadContext::Halted) {
Process *temp_h = sysh->threadContexts[i]->getProcessPtr();
Process *walk_ph = (Process*)temp_h;
if (walk_ph && walk_ph->pid() == process->pid())
matched_ph = walk_ph;
}
}
assert(matched_ph);
matched_ph->setpgid((pgid == 0) ? matched_ph->pid() : pgid);
return 0;
}
SyscallReturn
getpidPseudoFunc(SyscallDesc *desc, int callnum, Process *process,
ThreadContext *tc)
{
// Make up a PID. There's no interprocess communication in
// fake_syscall mode, so there's no way for a process to know it's
// not getting a unique value.
tc->setIntReg(SyscallPseudoReturnReg, process->ppid());
return process->pid();
}
SyscallReturn
getuidPseudoFunc(SyscallDesc *desc, int callnum, Process *process,
ThreadContext *tc)
{
// Make up a UID and EUID... it shouldn't matter, and we want the
// simulation to be deterministic.
// EUID goes in r20.
tc->setIntReg(SyscallPseudoReturnReg, process->euid()); // EUID
return process->uid(); // UID
}
SyscallReturn
getgidPseudoFunc(SyscallDesc *desc, int callnum, Process *process,
ThreadContext *tc)
{
// Get current group ID. EGID goes in r20.
tc->setIntReg(SyscallPseudoReturnReg, process->egid()); // EGID
return process->gid();
}
SyscallReturn
setuidFunc(SyscallDesc *desc, int callnum, Process *process,
ThreadContext *tc)
{
// can't fathom why a benchmark would call this.
int index = 0;
warn("Ignoring call to setuid(%d)\n", process->getSyscallArg(tc, index));
return 0;
}
SyscallReturn
getpidFunc(SyscallDesc *desc, int callnum, Process *process,
ThreadContext *tc)
{
return process->tgid();
}
SyscallReturn
gettidFunc(SyscallDesc *desc, int callnum, Process *process,
ThreadContext *tc)
{
return process->pid();
}
SyscallReturn
getppidFunc(SyscallDesc *desc, int callnum, Process *process,
ThreadContext *tc)
{
return process->ppid();
}
SyscallReturn
getuidFunc(SyscallDesc *desc, int callnum, Process *process,
ThreadContext *tc)
{
return process->uid(); // UID
}
SyscallReturn
geteuidFunc(SyscallDesc *desc, int callnum, Process *process,
ThreadContext *tc)
{
return process->euid(); // UID
}
SyscallReturn
getgidFunc(SyscallDesc *desc, int callnum, Process *process,
ThreadContext *tc)
{
return process->gid();
}
SyscallReturn
getegidFunc(SyscallDesc *desc, int callnum, Process *process,
ThreadContext *tc)
{
return process->egid();
}
SyscallReturn
fallocateFunc(SyscallDesc *desc, int callnum, Process *p, ThreadContext *tc)
{
#if NO_FALLOCATE
warn("Host OS cannot support calls to fallocate. Ignoring syscall");
#else
int index = 0;
int tgt_fd = p->getSyscallArg(tc, index);
int mode = p->getSyscallArg(tc, index);
off_t offset = p->getSyscallArg(tc, index);
off_t len = p->getSyscallArg(tc, index);
auto ffdp = std::dynamic_pointer_cast<FileFDEntry>((*p->fds)[tgt_fd]);
if (!ffdp)
return -EBADF;
int sim_fd = ffdp->getSimFD();
int result = fallocate(sim_fd, mode, offset, len);
if (result < 0)
return -errno;
#endif
return 0;
}
SyscallReturn
accessFunc(SyscallDesc *desc, int callnum, Process *p, ThreadContext *tc,
int index)
{
string path;
if (!tc->getMemProxy().tryReadString(path, p->getSyscallArg(tc, index)))
return -EFAULT;
// Adjust path for current working directory
path = p->fullPath(path);
mode_t mode = p->getSyscallArg(tc, index);
int result = access(path.c_str(), mode);
return (result == -1) ? -errno : result;
}
SyscallReturn
accessFunc(SyscallDesc *desc, int callnum, Process *p, ThreadContext *tc)
{
return accessFunc(desc, callnum, p, tc, 0);
}
SyscallReturn
mknodFunc(SyscallDesc *desc, int num, Process *p, ThreadContext *tc)
{
int index = 0;
std::string path;
if (!tc->getMemProxy().tryReadString(path, p->getSyscallArg(tc, index)))
return -EFAULT;
path = p->fullPath(path);
mode_t mode = p->getSyscallArg(tc, index);
dev_t dev = p->getSyscallArg(tc, index);
auto result = mknod(path.c_str(), mode, dev);
return (result == -1) ? -errno : result;
}
SyscallReturn
chdirFunc(SyscallDesc *desc, int num, Process *p, ThreadContext *tc)
{
int index = 0;
std::string path;
if (!tc->getMemProxy().tryReadString(path, p->getSyscallArg(tc, index)))
return -EFAULT;
path = p->fullPath(path);
auto result = chdir(path.c_str());
return (result == -1) ? -errno : result;
}
SyscallReturn
rmdirFunc(SyscallDesc *desc, int num, Process *p, ThreadContext *tc)
{
int index = 0;
std::string path;
if (!tc->getMemProxy().tryReadString(path, p->getSyscallArg(tc, index)))
return -EFAULT;
path = p->fullPath(path);
auto result = rmdir(path.c_str());
return (result == -1) ? -errno : result;
}
SyscallReturn
getdentsFunc(SyscallDesc *desc, int callnum, Process *p, ThreadContext *tc)
{
int index = 0;
int tgt_fd = p->getSyscallArg(tc, index);
Addr buf_ptr = p->getSyscallArg(tc, index);
unsigned count = p->getSyscallArg(tc, index);
auto hbfdp = std::dynamic_pointer_cast<HBFDEntry>((*p->fds)[tgt_fd]);
if (!hbfdp)
return -EBADF;
int sim_fd = hbfdp->getSimFD();
BufferArg buf_arg(buf_ptr, count);
auto status = syscall(SYS_getdents, sim_fd, buf_arg.bufferPtr(), count);
if (status == -1)
return -errno;
typedef struct linux_dirent {
unsigned long d_ino;
unsigned long d_off;
unsigned short d_reclen;
char dname[];
} LinDent;
unsigned traversed = 0;
while (traversed < status) {
LinDent *buffer = (LinDent*)((Addr)buf_arg.bufferPtr() + traversed);
auto host_reclen = buffer->d_reclen;
/**
* Convert the byte ordering from the host to the target before
* passing the data back into the target's address space to preserve
* endianness.
*/
buffer->d_ino = htog(buffer->d_ino);
buffer->d_off = htog(buffer->d_off);
buffer->d_reclen = htog(buffer->d_reclen);
traversed += host_reclen;
}
buf_arg.copyOut(tc->getMemProxy());
return status;
}