gem5/src/sim/syscall_emul.cc
2009-11-14 11:49:01 -06:00

837 lines
24 KiB
C++

/*
* 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 <fcntl.h>
#include <unistd.h>
#include <cstdio>
#include <iostream>
#include <string>
#include "sim/syscall_emul.hh"
#include "base/chunk_generator.hh"
#include "base/trace.hh"
#include "config/the_isa.hh"
#include "cpu/thread_context.hh"
#include "cpu/base.hh"
#include "mem/page_table.hh"
#include "sim/process.hh"
#include "sim/system.hh"
#include "sim/sim_exit.hh"
using namespace std;
using namespace TheISA;
void
SyscallDesc::doSyscall(int callnum, LiveProcess *process, ThreadContext *tc)
{
#if TRACING_ON
int index = 0;
#endif
DPRINTFR(SyscallVerbose,
"%d: %s: syscall %s called w/arguments %d,%d,%d,%d\n",
curTick, tc->getCpuPtr()->name(), name,
process->getSyscallArg(tc, index),
process->getSyscallArg(tc, index),
process->getSyscallArg(tc, index),
process->getSyscallArg(tc, index));
SyscallReturn retval = (*funcPtr)(this, callnum, process, tc);
DPRINTFR(SyscallVerbose, "%d: %s: syscall %s returns %d\n",
curTick,tc->getCpuPtr()->name(), name, retval.value());
if (!(flags & SyscallDesc::SuppressReturnValue))
process->setSyscallReturn(tc, retval);
}
SyscallReturn
unimplementedFunc(SyscallDesc *desc, int callnum, LiveProcess *process,
ThreadContext *tc)
{
fatal("syscall %s (#%d) unimplemented.", desc->name, callnum);
return 1;
}
SyscallReturn
ignoreFunc(SyscallDesc *desc, int callnum, LiveProcess *process,
ThreadContext *tc)
{
int index = 0;
warn("ignoring syscall %s(%d, %d, ...)", desc->name,
process->getSyscallArg(tc, index), process->getSyscallArg(tc, index));
return 0;
}
SyscallReturn
exitFunc(SyscallDesc *desc, int callnum, LiveProcess *process,
ThreadContext *tc)
{
if (process->system->numRunningContexts() == 1) {
// Last running context... exit simulator
int index = 0;
exitSimLoop("target called exit()",
process->getSyscallArg(tc, index) & 0xff);
} else {
// other running threads... just halt this one
tc->halt();
}
return 1;
}
SyscallReturn
exitGroupFunc(SyscallDesc *desc, int callnum, LiveProcess *process,
ThreadContext *tc)
{
// really should just halt all thread contexts belonging to this
// process in case there's another process running...
int index = 0;
exitSimLoop("target called exit()",
process->getSyscallArg(tc, index) & 0xff);
return 1;
}
SyscallReturn
getpagesizeFunc(SyscallDesc *desc, int num, LiveProcess *p, ThreadContext *tc)
{
return (int)VMPageSize;
}
SyscallReturn
brkFunc(SyscallDesc *desc, int num, LiveProcess *p, ThreadContext *tc)
{
// change brk addr to first arg
int index = 0;
Addr new_brk = p->getSyscallArg(tc, index);
// 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 p->brk_point;
if (new_brk > p->brk_point) {
// might need to allocate some new pages
for (ChunkGenerator gen(p->brk_point, new_brk - p->brk_point,
VMPageSize); !gen.done(); gen.next()) {
if (!p->pTable->translate(gen.addr()))
p->pTable->allocate(roundDown(gen.addr(), VMPageSize),
VMPageSize);
// if the address is already there, zero it out
else {
uint8_t zero = 0;
TranslatingPort *tp = tc->getMemPort();
// split non-page aligned accesses
Addr next_page = roundUp(gen.addr(), VMPageSize);
uint32_t size_needed = next_page - gen.addr();
tp->memsetBlob(gen.addr(), zero, size_needed);
if (gen.addr() + VMPageSize > next_page &&
next_page < new_brk &&
p->pTable->translate(next_page))
{
size_needed = VMPageSize - size_needed;
tp->memsetBlob(next_page, zero, size_needed);
}
}
}
}
p->brk_point = new_brk;
DPRINTF(SyscallVerbose, "Break Point changed to: %#X\n", p->brk_point);
return p->brk_point;
}
SyscallReturn
closeFunc(SyscallDesc *desc, int num, LiveProcess *p, ThreadContext *tc)
{
int index = 0;
int target_fd = p->getSyscallArg(tc, index);
int status = close(p->sim_fd(target_fd));
if (status >= 0)
p->free_fd(target_fd);
return status;
}
SyscallReturn
readFunc(SyscallDesc *desc, int num, LiveProcess *p, ThreadContext *tc)
{
int index = 0;
int fd = p->sim_fd(p->getSyscallArg(tc, index));
Addr bufPtr = p->getSyscallArg(tc, index);
int nbytes = p->getSyscallArg(tc, index);
BufferArg bufArg(bufPtr, nbytes);
int bytes_read = read(fd, bufArg.bufferPtr(), nbytes);
if (bytes_read != -1)
bufArg.copyOut(tc->getMemPort());
return bytes_read;
}
SyscallReturn
writeFunc(SyscallDesc *desc, int num, LiveProcess *p, ThreadContext *tc)
{
int index = 0;
int fd = p->sim_fd(p->getSyscallArg(tc, index));
Addr bufPtr = p->getSyscallArg(tc, index);
int nbytes = p->getSyscallArg(tc, index);
BufferArg bufArg(bufPtr, nbytes);
bufArg.copyIn(tc->getMemPort());
int bytes_written = write(fd, bufArg.bufferPtr(), nbytes);
fsync(fd);
return bytes_written;
}
SyscallReturn
lseekFunc(SyscallDesc *desc, int num, LiveProcess *p, ThreadContext *tc)
{
int index = 0;
int fd = p->sim_fd(p->getSyscallArg(tc, index));
uint64_t offs = p->getSyscallArg(tc, index);
int whence = p->getSyscallArg(tc, index);
off_t result = lseek(fd, offs, whence);
return (result == (off_t)-1) ? -errno : result;
}
SyscallReturn
_llseekFunc(SyscallDesc *desc, int num, LiveProcess *p, ThreadContext *tc)
{
int index = 0;
int fd = p->sim_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);
uint64_t offset = (offset_high << 32) | offset_low;
uint64_t result = lseek(fd, offset, whence);
result = TheISA::htog(result);
if (result == (off_t)-1) {
//The seek failed.
return -errno;
} else {
// The seek succeeded.
// Copy "result" to "result_ptr"
// XXX We'll assume 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->getMemPort());
return 0;
}
return (result == (off_t)-1) ? -errno : result;
}
SyscallReturn
munmapFunc(SyscallDesc *desc, int num, LiveProcess *p, ThreadContext *tc)
{
// given that we don't really implement mmap, munmap is really easy
return 0;
}
const char *hostname = "m5.eecs.umich.edu";
SyscallReturn
gethostnameFunc(SyscallDesc *desc, int num, LiveProcess *p, ThreadContext *tc)
{
int index = 0;
Addr bufPtr = p->getSyscallArg(tc, index);
int name_len = p->getSyscallArg(tc, index);
BufferArg name(bufPtr, name_len);
strncpy((char *)name.bufferPtr(), hostname, name_len);
name.copyOut(tc->getMemPort());
return 0;
}
SyscallReturn
getcwdFunc(SyscallDesc *desc, int num, LiveProcess *p, ThreadContext *tc)
{
int result = 0;
int index = 0;
Addr bufPtr = p->getSyscallArg(tc, index);
unsigned long size = p->getSyscallArg(tc, index);
BufferArg buf(bufPtr, 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) != NULL) {
result = strlen((char *)buf.bufferPtr());
}
else {
result = -1;
}
}
buf.copyOut(tc->getMemPort());
return (result == -1) ? -errno : result;
}
SyscallReturn
readlinkFunc(SyscallDesc *desc, int num, LiveProcess *p, ThreadContext *tc)
{
string path;
int index = 0;
if (!tc->getMemPort()->tryReadString(path, p->getSyscallArg(tc, index)))
return (TheISA::IntReg)-EFAULT;
// Adjust path for current working directory
path = p->fullPath(path);
Addr bufPtr = p->getSyscallArg(tc, index);
size_t bufsiz = p->getSyscallArg(tc, index);
BufferArg buf(bufPtr, bufsiz);
int result = readlink(path.c_str(), (char *)buf.bufferPtr(), bufsiz);
buf.copyOut(tc->getMemPort());
return (result == -1) ? -errno : result;
}
SyscallReturn
unlinkFunc(SyscallDesc *desc, int num, LiveProcess *p, ThreadContext *tc)
{
string path;
int index = 0;
if (!tc->getMemPort()->tryReadString(path, p->getSyscallArg(tc, index)))
return (TheISA::IntReg)-EFAULT;
// Adjust path for current working directory
path = p->fullPath(path);
int result = unlink(path.c_str());
return (result == -1) ? -errno : result;
}
SyscallReturn
mkdirFunc(SyscallDesc *desc, int num, LiveProcess *p, ThreadContext *tc)
{
string path;
int index = 0;
if (!tc->getMemPort()->tryReadString(path, p->getSyscallArg(tc, index)))
return (TheISA::IntReg)-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, LiveProcess *p, ThreadContext *tc)
{
string old_name;
int index = 0;
if (!tc->getMemPort()->tryReadString(old_name, p->getSyscallArg(tc, index)))
return -EFAULT;
string new_name;
if (!tc->getMemPort()->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, LiveProcess *p, ThreadContext *tc)
{
string path;
int index = 0;
if (!tc->getMemPort()->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,
LiveProcess *process, ThreadContext *tc)
{
int index = 0;
int fd = process->sim_fd(process->getSyscallArg(tc, index));
if (fd < 0)
return -EBADF;
off_t length = process->getSyscallArg(tc, index);
int result = ftruncate(fd, length);
return (result == -1) ? -errno : result;
}
SyscallReturn
truncate64Func(SyscallDesc *desc, int num,
LiveProcess *process, ThreadContext *tc)
{
int index = 0;
string path;
if (!tc->getMemPort()->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,
LiveProcess *process, ThreadContext *tc)
{
int index = 0;
int fd = process->sim_fd(process->getSyscallArg(tc, index));
if (fd < 0)
return -EBADF;
int64_t length = process->getSyscallArg(tc, index, 64);
#if NO_STAT64
int result = ftruncate(fd, length);
#else
int result = ftruncate64(fd, length);
#endif
return (result == -1) ? -errno : result;
}
SyscallReturn
umaskFunc(SyscallDesc *desc, int num, LiveProcess *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, LiveProcess *p, ThreadContext *tc)
{
string path;
int index = 0;
if (!tc->getMemPort()->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, LiveProcess *process, ThreadContext *tc)
{
int index = 0;
int fd = process->sim_fd(process->getSyscallArg(tc, index));
if (fd < 0)
return -EBADF;
/* XXX endianess */
uint32_t owner = process->getSyscallArg(tc, index);
uid_t hostOwner = owner;
uint32_t group = process->getSyscallArg(tc, index);
gid_t hostGroup = group;
int result = fchown(fd, hostOwner, hostGroup);
return (result == -1) ? -errno : result;
}
SyscallReturn
dupFunc(SyscallDesc *desc, int num, LiveProcess *process, ThreadContext *tc)
{
int index = 0;
int fd = process->sim_fd(process->getSyscallArg(tc, index));
if (fd < 0)
return -EBADF;
Process::FdMap *fdo = process->sim_fd_obj(fd);
int result = dup(fd);
return (result == -1) ? -errno :
process->alloc_fd(result, fdo->filename, fdo->flags, fdo->mode, false);
}
SyscallReturn
fcntlFunc(SyscallDesc *desc, int num, LiveProcess *process,
ThreadContext *tc)
{
int index = 0;
int fd = process->getSyscallArg(tc, index);
if (fd < 0 || process->sim_fd(fd) < 0)
return -EBADF;
int cmd = process->getSyscallArg(tc, index);
switch (cmd) {
case 0: // F_DUPFD
// if we really wanted to support this, we'd need to do it
// in the target fd space.
warn("fcntl(%d, F_DUPFD) not supported, error returned\n", fd);
return -EMFILE;
case 1: // F_GETFD (get close-on-exec flag)
case 2: // F_SETFD (set close-on-exec flag)
return 0;
case 3: // F_GETFL (get file flags)
case 4: // F_SETFL (set file flags)
// not sure if this is totally valid, but we'll pass it through
// to the underlying OS
warn("fcntl(%d, %d) passed through to host\n", fd, cmd);
return fcntl(process->sim_fd(fd), cmd);
// return 0;
case 7: // F_GETLK (get lock)
case 8: // F_SETLK (set lock)
case 9: // F_SETLKW (set lock and wait)
// don't mess with file locking... just act like it's OK
warn("File lock call (fcntl(%d, %d)) ignored.\n", fd, cmd);
return 0;
default:
warn("Unknown fcntl command %d\n", cmd);
return 0;
}
}
SyscallReturn
fcntl64Func(SyscallDesc *desc, int num, LiveProcess *process,
ThreadContext *tc)
{
int index = 0;
int fd = process->getSyscallArg(tc, index);
if (fd < 0 || process->sim_fd(fd) < 0)
return -EBADF;
int cmd = process->getSyscallArg(tc, index);
switch (cmd) {
case 33: //F_GETLK64
warn("fcntl64(%d, F_GETLK64) not supported, error returned\n", fd);
return -EMFILE;
case 34: // F_SETLK64
case 35: // F_SETLKW64
warn("fcntl64(%d, F_SETLK(W)64) not supported, error returned\n", 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", fd, cmd);
return fcntl(process->sim_fd(fd), cmd);
// return 0;
}
}
SyscallReturn
pipePseudoFunc(SyscallDesc *desc, int callnum, LiveProcess *process,
ThreadContext *tc)
{
int fds[2], sim_fds[2];
int pipe_retval = pipe(fds);
if (pipe_retval < 0) {
// error
return pipe_retval;
}
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]);
return sim_fds[0];
}
SyscallReturn
getpidPseudoFunc(SyscallDesc *desc, int callnum, LiveProcess *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, LiveProcess *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, LiveProcess *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, LiveProcess *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, LiveProcess *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()); //PID
return process->pid();
}
SyscallReturn
getppidFunc(SyscallDesc *desc, int callnum, LiveProcess *process,
ThreadContext *tc)
{
return process->ppid();
}
SyscallReturn
getuidFunc(SyscallDesc *desc, int callnum, LiveProcess *process,
ThreadContext *tc)
{
return process->uid(); // UID
}
SyscallReturn
geteuidFunc(SyscallDesc *desc, int callnum, LiveProcess *process,
ThreadContext *tc)
{
return process->euid(); // UID
}
SyscallReturn
getgidFunc(SyscallDesc *desc, int callnum, LiveProcess *process,
ThreadContext *tc)
{
return process->gid();
}
SyscallReturn
getegidFunc(SyscallDesc *desc, int callnum, LiveProcess *process,
ThreadContext *tc)
{
return process->egid();
}
SyscallReturn
cloneFunc(SyscallDesc *desc, int callnum, LiveProcess *process,
ThreadContext *tc)
{
int index = 0;
IntReg flags = process->getSyscallArg(tc, index);
IntReg newStack = process->getSyscallArg(tc, index);
DPRINTF(SyscallVerbose, "In sys_clone:\n");
DPRINTF(SyscallVerbose, " Flags=%llx\n", flags);
DPRINTF(SyscallVerbose, " Child stack=%llx\n", newStack);
if (flags != 0x10f00) {
warn("This sys_clone implementation assumes flags "
"CLONE_VM|CLONE_FS|CLONE_FILES|CLONE_SIGHAND|CLONE_THREAD "
"(0x10f00), and may not work correctly with given flags "
"0x%llx\n", flags);
}
ThreadContext* ctc; // child thread context
if ( ( ctc = process->findFreeContext() ) != NULL ) {
DPRINTF(SyscallVerbose, " Found unallocated thread context\n");
ctc->clearArchRegs();
// Arch-specific cloning code
#if THE_ISA == ALPHA_ISA or THE_ISA == X86_ISA
// Cloning the misc. regs for these archs is enough
TheISA::copyMiscRegs(tc, ctc);
#elif THE_ISA == SPARC_ISA
TheISA::copyRegs(tc, ctc);
// TODO: Explain what this code actually does :-)
ctc->setIntReg(NumIntArchRegs + 6, 0);
ctc->setIntReg(NumIntArchRegs + 4, 0);
ctc->setIntReg(NumIntArchRegs + 3, NWindows - 2);
ctc->setIntReg(NumIntArchRegs + 5, NWindows);
ctc->setMiscReg(MISCREG_CWP, 0);
ctc->setIntReg(NumIntArchRegs + 7, 0);
ctc->setMiscRegNoEffect(MISCREG_TL, 0);
ctc->setMiscRegNoEffect(MISCREG_ASI, ASI_PRIMARY);
for (int y = 8; y < 32; y++)
ctc->setIntReg(y, tc->readIntReg(y));
#else
fatal("sys_clone is not implemented for this ISA\n");
#endif
// Set up stack register
ctc->setIntReg(TheISA::StackPointerReg, newStack);
// Set up syscall return values in parent and child
ctc->setIntReg(ReturnValueReg, 0); // return value, child
// Alpha needs SyscallSuccessReg=0 in child
#if THE_ISA == ALPHA_ISA
ctc->setIntReg(TheISA::SyscallSuccessReg, 0);
#endif
// In SPARC/Linux, clone returns 0 on pseudo-return register if
// parent, non-zero if child
#if THE_ISA == SPARC_ISA
tc->setIntReg(TheISA::SyscallPseudoReturnReg, 0);
ctc->setIntReg(TheISA::SyscallPseudoReturnReg, 1);
#endif
ctc->setPC(tc->readNextPC());
ctc->setNextPC(tc->readNextPC() + sizeof(TheISA::MachInst));
ctc->setNextNPC(tc->readNextNPC() + sizeof(TheISA::MachInst));
ctc->activate();
// Should return nonzero child TID in parent's syscall return register,
// but for our pthread library any non-zero value will work
return 1;
} else {
fatal("Called sys_clone, but no unallocated thread contexts found!\n");
return 0;
}
}