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bc74c58eaf55005a6a4b2e67657da4121554943c
gem5/src/sim/syscall_emul.hh
Brandon Potter bc74c58eaf sim-se: add syscalls related to polling 
Fix poll so that it will use the syscall retry capability
instead of causing a blocking call.

Add the accept and wait4 system calls.

Add polling to read to remove deadlocks that occur in the
event queue that are caused by blocking system calls.

Modify the write system call to return an error number in
case of error.

Change-Id: I0b4091a2e41e4187ebf69d63e0088f988f37d5da
Reviewed-on: https://gem5-review.googlesource.com/c/12115
Reviewed-by: Anthony Gutierrez <anthony.gutierrez@amd.com>
Maintainer: Anthony Gutierrez <anthony.gutierrez@amd.com>
2019-01-22 02:05:48 +00:00

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/*
* Copyright (c) 2012-2013, 2015 ARM Limited
* Copyright (c) 2015 Advanced Micro Devices, Inc.
* 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) 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
* Kevin Lim
*/
#ifndef __SIM_SYSCALL_EMUL_HH__
#define __SIM_SYSCALL_EMUL_HH__
#if (defined(__APPLE__) || defined(__OpenBSD__) || \
defined(__FreeBSD__) || defined(__CYGWIN__) || \
defined(__NetBSD__))
#define NO_STAT64 1
#else
#define NO_STAT64 0
#endif
#if (defined(__APPLE__) || defined(__OpenBSD__) || \
defined(__FreeBSD__) || defined(__NetBSD__))
#define NO_STATFS 1
#else
#define NO_STATFS 0
#endif
#if (defined(__APPLE__) || defined(__OpenBSD__) || \
defined(__FreeBSD__) || defined(__NetBSD__))
#define NO_FALLOCATE 1
#else
#define NO_FALLOCATE 0
#endif
///
/// @file syscall_emul.hh
///
/// This file defines objects used to emulate syscalls from the target
/// application on the host machine.
#ifdef __CYGWIN32__
#include <sys/fcntl.h>
#endif
#include <fcntl.h>
#include <poll.h>
#include <sys/mman.h>
#include <sys/socket.h>
#include <sys/stat.h>
#if (NO_STATFS == 0)
#include <sys/statfs.h>
#else
#include <sys/mount.h>
#endif
#include <sys/time.h>
#include <sys/types.h>
#include <sys/uio.h>
#include <unistd.h>
#include <cerrno>
#include <memory>
#include <string>
#include "arch/generic/tlb.hh"
#include "arch/utility.hh"
#include "base/intmath.hh"
#include "base/loader/object_file.hh"
#include "base/logging.hh"
#include "base/trace.hh"
#include "base/types.hh"
#include "config/the_isa.hh"
#include "cpu/base.hh"
#include "cpu/thread_context.hh"
#include "mem/page_table.hh"
#include "params/Process.hh"
#include "sim/emul_driver.hh"
#include "sim/futex_map.hh"
#include "sim/process.hh"
#include "sim/syscall_debug_macros.hh"
#include "sim/syscall_desc.hh"
#include "sim/syscall_emul_buf.hh"
#include "sim/syscall_return.hh"
//////////////////////////////////////////////////////////////////////
//
// The following emulation functions are generic enough that they
// don't need to be recompiled for different emulated OS's. They are
// defined in sim/syscall_emul.cc.
//
//////////////////////////////////////////////////////////////////////
/// Handler for unimplemented syscalls that we haven't thought about.
SyscallReturn unimplementedFunc(SyscallDesc *desc, int num,
Process *p, ThreadContext *tc);
/// Handler for unimplemented syscalls that we never intend to
/// implement (signal handling, etc.) and should not affect the correct
/// behavior of the program. Print a warning only if the appropriate
/// trace flag is enabled. Return success to the target program.
SyscallReturn ignoreFunc(SyscallDesc *desc, int num,
Process *p, ThreadContext *tc);
// Target fallocateFunc() handler.
SyscallReturn fallocateFunc(SyscallDesc *desc, int num,
Process *p, ThreadContext *tc);
/// Target exit() handler: terminate current context.
SyscallReturn exitFunc(SyscallDesc *desc, int num,
Process *p, ThreadContext *tc);
/// Target exit_group() handler: terminate simulation. (exit all threads)
SyscallReturn exitGroupFunc(SyscallDesc *desc, int num,
Process *p, ThreadContext *tc);
/// Target set_tid_address() handler.
SyscallReturn setTidAddressFunc(SyscallDesc *desc, int num,
Process *p, ThreadContext *tc);
/// Target getpagesize() handler.
SyscallReturn getpagesizeFunc(SyscallDesc *desc, int num,
Process *p, ThreadContext *tc);
/// Target brk() handler: set brk address.
SyscallReturn brkFunc(SyscallDesc *desc, int num,
Process *p, ThreadContext *tc);
/// Target close() handler.
SyscallReturn closeFunc(SyscallDesc *desc, int num,
Process *p, ThreadContext *tc);
/// Target lseek() handler.
SyscallReturn lseekFunc(SyscallDesc *desc, int num,
Process *p, ThreadContext *tc);
/// Target _llseek() handler.
SyscallReturn _llseekFunc(SyscallDesc *desc, int num,
Process *p, ThreadContext *tc);
/// Target munmap() handler.
SyscallReturn munmapFunc(SyscallDesc *desc, int num,
Process *p, ThreadContext *tc);
/// Target shutdown() handler.
SyscallReturn shutdownFunc(SyscallDesc *desc, int num,
Process *p, ThreadContext *tc);
/// Target gethostname() handler.
SyscallReturn gethostnameFunc(SyscallDesc *desc, int num,
Process *p, ThreadContext *tc);
/// Target getcwd() handler.
SyscallReturn getcwdFunc(SyscallDesc *desc, int num,
Process *p, ThreadContext *tc);
/// Target readlink() handler.
SyscallReturn readlinkFunc(SyscallDesc *desc, int num,
Process *p, ThreadContext *tc,
int index = 0);
SyscallReturn readlinkFunc(SyscallDesc *desc, int num,
Process *p, ThreadContext *tc);
/// Target unlink() handler.
SyscallReturn unlinkHelper(SyscallDesc *desc, int num,
Process *p, ThreadContext *tc,
int index);
SyscallReturn unlinkFunc(SyscallDesc *desc, int num,
Process *p, ThreadContext *tc);
/// Target link() handler
SyscallReturn linkFunc(SyscallDesc *desc, int num, Process *p,
ThreadContext *tc);
/// Target symlink() handler.
SyscallReturn symlinkFunc(SyscallDesc *desc, int num, Process *p,
ThreadContext *tc);
/// Target mkdir() handler.
SyscallReturn mkdirFunc(SyscallDesc *desc, int num,
Process *p, ThreadContext *tc);
/// Target mknod() handler.
SyscallReturn mknodFunc(SyscallDesc *desc, int num,
Process *p, ThreadContext *tc);
/// Target chdir() handler.
SyscallReturn chdirFunc(SyscallDesc *desc, int num,
Process *p, ThreadContext *tc);
// Target rmdir() handler.
SyscallReturn rmdirFunc(SyscallDesc *desc, int num,
Process *p, ThreadContext *tc);
/// Target rename() handler.
SyscallReturn renameFunc(SyscallDesc *desc, int num,
Process *p, ThreadContext *tc);
/// Target truncate() handler.
SyscallReturn truncateFunc(SyscallDesc *desc, int num,
Process *p, ThreadContext *tc);
/// Target ftruncate() handler.
SyscallReturn ftruncateFunc(SyscallDesc *desc, int num,
Process *p, ThreadContext *tc);
/// Target truncate64() handler.
SyscallReturn truncate64Func(SyscallDesc *desc, int num,
Process *p, ThreadContext *tc);
/// Target ftruncate64() handler.
SyscallReturn ftruncate64Func(SyscallDesc *desc, int num,
Process *p, ThreadContext *tc);
/// Target umask() handler.
SyscallReturn umaskFunc(SyscallDesc *desc, int num,
Process *p, ThreadContext *tc);
/// Target gettid() handler.
SyscallReturn gettidFunc(SyscallDesc *desc, int num,
Process *p, ThreadContext *tc);
/// Target chown() handler.
SyscallReturn chownFunc(SyscallDesc *desc, int num,
Process *p, ThreadContext *tc);
/// Target setpgid() handler.
SyscallReturn setpgidFunc(SyscallDesc *desc, int num,
Process *p, ThreadContext *tc);
/// Target fchown() handler.
SyscallReturn fchownFunc(SyscallDesc *desc, int num,
Process *p, ThreadContext *tc);
/// Target dup() handler.
SyscallReturn dupFunc(SyscallDesc *desc, int num,
Process *process, ThreadContext *tc);
/// Target dup2() handler.
SyscallReturn dup2Func(SyscallDesc *desc, int num,
Process *process, ThreadContext *tc);
/// Target fcntl() handler.
SyscallReturn fcntlFunc(SyscallDesc *desc, int num,
Process *process, ThreadContext *tc);
/// Target fcntl64() handler.
SyscallReturn fcntl64Func(SyscallDesc *desc, int num,
Process *process, ThreadContext *tc);
/// Target setuid() handler.
SyscallReturn setuidFunc(SyscallDesc *desc, int num,
Process *p, ThreadContext *tc);
/// Target pipe() handler.
SyscallReturn pipeFunc(SyscallDesc *desc, int num,
Process *p, ThreadContext *tc);
/// Internal pipe() handler.
SyscallReturn pipeImpl(SyscallDesc *desc, int num, Process *p,
ThreadContext *tc, bool pseudoPipe);
/// Target getpid() handler.
SyscallReturn getpidFunc(SyscallDesc *desc, int num,
Process *p, ThreadContext *tc);
// Target bind() handler.
SyscallReturn bindFunc(SyscallDesc *desc, int num,
Process *p, ThreadContext *tc);
// Target listen() handler.
SyscallReturn listenFunc(SyscallDesc *desc, int num,
Process *p, ThreadContext *tc);
// Target connect() handler.
SyscallReturn connectFunc(SyscallDesc *desc, int num,
Process *p, ThreadContext *tc);
#if defined(SYS_getdents)
// Target getdents() handler.
SyscallReturn getdentsFunc(SyscallDesc *desc, int num,
Process *p, ThreadContext *tc);
#endif
#if defined(SYS_getdents64)
// Target getdents() handler.
SyscallReturn getdents64Func(SyscallDesc *desc, int num,
Process *p, ThreadContext *tc);
#endif
// Target sendto() handler.
SyscallReturn sendtoFunc(SyscallDesc *desc, int num,
Process *p, ThreadContext *tc);
// Target recvfrom() handler.
SyscallReturn recvfromFunc(SyscallDesc *desc, int num,
Process *p, ThreadContext *tc);
// Target recvmsg() handler.
SyscallReturn recvmsgFunc(SyscallDesc *desc, int num,
Process *p, ThreadContext *tc);
// Target sendmsg() handler.
SyscallReturn sendmsgFunc(SyscallDesc *desc, int num,
Process *p, ThreadContext *tc);
// Target getuid() handler.
SyscallReturn getuidFunc(SyscallDesc *desc, int num,
Process *p, ThreadContext *tc);
/// Target getgid() handler.
SyscallReturn getgidFunc(SyscallDesc *desc, int num,
Process *p, ThreadContext *tc);
/// Target getppid() handler.
SyscallReturn getppidFunc(SyscallDesc *desc, int num,
Process *p, ThreadContext *tc);
/// Target geteuid() handler.
SyscallReturn geteuidFunc(SyscallDesc *desc, int num,
Process *p, ThreadContext *tc);
/// Target getegid() handler.
SyscallReturn getegidFunc(SyscallDesc *desc, int num,
Process *p, ThreadContext *tc);
/// Target access() handler
SyscallReturn accessFunc(SyscallDesc *desc, int num,
Process *p, ThreadContext *tc);
SyscallReturn accessFunc(SyscallDesc *desc, int num,
Process *p, ThreadContext *tc,
int index);
/// Futex system call
/// Implemented by Daniel Sanchez
/// Used by printf's in multi-threaded apps
template <class OS>
SyscallReturn
futexFunc(SyscallDesc *desc, int callnum, Process *process,
ThreadContext *tc)
{
using namespace std;
int index = 0;
Addr uaddr = process->getSyscallArg(tc, index);
int op = process->getSyscallArg(tc, index);
int val = process->getSyscallArg(tc, index);
/*
* Unsupported option that does not affect the correctness of the
* application. This is a performance optimization utilized by Linux.
*/
op &= ~OS::TGT_FUTEX_PRIVATE_FLAG;
FutexMap &futex_map = tc->getSystemPtr()->futexMap;
if (OS::TGT_FUTEX_WAIT == op) {
// Ensure futex system call accessed atomically.
BufferArg buf(uaddr, sizeof(int));
buf.copyIn(tc->getMemProxy());
int mem_val = *(int*)buf.bufferPtr();
/*
* The value in memory at uaddr is not equal with the expected val
* (a different thread must have changed it before the system call was
* invoked). In this case, we need to throw an error.
*/
if (val != mem_val)
return -OS::TGT_EWOULDBLOCK;
futex_map.suspend(uaddr, process->tgid(), tc);
return 0;
} else if (OS::TGT_FUTEX_WAKE == op) {
return futex_map.wakeup(uaddr, process->tgid(), val);
}
warn("futex: op %d not implemented; ignoring.", op);
return -ENOSYS;
}
/// Pseudo Funcs - These functions use a different return convension,
/// returning a second value in a register other than the normal return register
SyscallReturn pipePseudoFunc(SyscallDesc *desc, int num,
Process *process, ThreadContext *tc);
/// Target getpidPseudo() handler.
SyscallReturn getpidPseudoFunc(SyscallDesc *desc, int num,
Process *p, ThreadContext *tc);
/// Target getuidPseudo() handler.
SyscallReturn getuidPseudoFunc(SyscallDesc *desc, int num,
Process *p, ThreadContext *tc);
/// Target getgidPseudo() handler.
SyscallReturn getgidPseudoFunc(SyscallDesc *desc, int num,
Process *p, ThreadContext *tc);
/// A readable name for 1,000,000, for converting microseconds to seconds.
const int one_million = 1000000;
/// A readable name for 1,000,000,000, for converting nanoseconds to seconds.
const int one_billion = 1000000000;
/// Approximate seconds since the epoch (1/1/1970). About a billion,
/// by my reckoning. We want to keep this a constant (not use the
/// real-world time) to keep simulations repeatable.
const unsigned seconds_since_epoch = 1000000000;
/// Helper function to convert current elapsed time to seconds and
/// microseconds.
template <class T1, class T2>
void
getElapsedTimeMicro(T1 &sec, T2 &usec)
{
uint64_t elapsed_usecs = curTick() / SimClock::Int::us;
sec = elapsed_usecs / one_million;
usec = elapsed_usecs % one_million;
}
/// Helper function to convert current elapsed time to seconds and
/// nanoseconds.
template <class T1, class T2>
void
getElapsedTimeNano(T1 &sec, T2 &nsec)
{
uint64_t elapsed_nsecs = curTick() / SimClock::Int::ns;
sec = elapsed_nsecs / one_billion;
nsec = elapsed_nsecs % one_billion;
}
//////////////////////////////////////////////////////////////////////
//
// The following emulation functions are generic, but need to be
// templated to account for differences in types, constants, etc.
//
//////////////////////////////////////////////////////////////////////
typedef struct statfs hst_statfs;
#if NO_STAT64
typedef struct stat hst_stat;
typedef struct stat hst_stat64;
#else
typedef struct stat hst_stat;
typedef struct stat64 hst_stat64;
#endif
//// Helper function to convert a host stat buffer to a target stat
//// buffer. Also copies the target buffer out to the simulated
//// memory space. Used by stat(), fstat(), and lstat().
template <typename target_stat, typename host_stat>
void
convertStatBuf(target_stat &tgt, host_stat *host, bool fakeTTY = false)
{
using namespace TheISA;
if (fakeTTY)
tgt->st_dev = 0xA;
else
tgt->st_dev = host->st_dev;
tgt->st_dev = TheISA::htog(tgt->st_dev);
tgt->st_ino = host->st_ino;
tgt->st_ino = TheISA::htog(tgt->st_ino);
tgt->st_mode = host->st_mode;
if (fakeTTY) {
// Claim to be a character device
tgt->st_mode &= ~S_IFMT; // Clear S_IFMT
tgt->st_mode |= S_IFCHR; // Set S_IFCHR
}
tgt->st_mode = TheISA::htog(tgt->st_mode);
tgt->st_nlink = host->st_nlink;
tgt->st_nlink = TheISA::htog(tgt->st_nlink);
tgt->st_uid = host->st_uid;
tgt->st_uid = TheISA::htog(tgt->st_uid);
tgt->st_gid = host->st_gid;
tgt->st_gid = TheISA::htog(tgt->st_gid);
if (fakeTTY)
tgt->st_rdev = 0x880d;
else
tgt->st_rdev = host->st_rdev;
tgt->st_rdev = TheISA::htog(tgt->st_rdev);
tgt->st_size = host->st_size;
tgt->st_size = TheISA::htog(tgt->st_size);
tgt->st_atimeX = host->st_atime;
tgt->st_atimeX = TheISA::htog(tgt->st_atimeX);
tgt->st_mtimeX = host->st_mtime;
tgt->st_mtimeX = TheISA::htog(tgt->st_mtimeX);
tgt->st_ctimeX = host->st_ctime;
tgt->st_ctimeX = TheISA::htog(tgt->st_ctimeX);
// Force the block size to be 8KB. This helps to ensure buffered io works
// consistently across different hosts.
tgt->st_blksize = 0x2000;
tgt->st_blksize = TheISA::htog(tgt->st_blksize);
tgt->st_blocks = host->st_blocks;
tgt->st_blocks = TheISA::htog(tgt->st_blocks);
}
// Same for stat64
template <typename target_stat, typename host_stat64>
void
convertStat64Buf(target_stat &tgt, host_stat64 *host, bool fakeTTY = false)
{
using namespace TheISA;
convertStatBuf<target_stat, host_stat64>(tgt, host, fakeTTY);
#if defined(STAT_HAVE_NSEC)
tgt->st_atime_nsec = host->st_atime_nsec;
tgt->st_atime_nsec = TheISA::htog(tgt->st_atime_nsec);
tgt->st_mtime_nsec = host->st_mtime_nsec;
tgt->st_mtime_nsec = TheISA::htog(tgt->st_mtime_nsec);
tgt->st_ctime_nsec = host->st_ctime_nsec;
tgt->st_ctime_nsec = TheISA::htog(tgt->st_ctime_nsec);
#else
tgt->st_atime_nsec = 0;
tgt->st_mtime_nsec = 0;
tgt->st_ctime_nsec = 0;
#endif
}
// Here are a couple of convenience functions
template<class OS>
void
copyOutStatBuf(SETranslatingPortProxy &mem, Addr addr,
hst_stat *host, bool fakeTTY = false)
{
typedef TypedBufferArg<typename OS::tgt_stat> tgt_stat_buf;
tgt_stat_buf tgt(addr);
convertStatBuf<tgt_stat_buf, hst_stat>(tgt, host, fakeTTY);
tgt.copyOut(mem);
}
template<class OS>
void
copyOutStat64Buf(SETranslatingPortProxy &mem, Addr addr,
hst_stat64 *host, bool fakeTTY = false)
{
typedef TypedBufferArg<typename OS::tgt_stat64> tgt_stat_buf;
tgt_stat_buf tgt(addr);
convertStat64Buf<tgt_stat_buf, hst_stat64>(tgt, host, fakeTTY);
tgt.copyOut(mem);
}
template <class OS>
void
copyOutStatfsBuf(SETranslatingPortProxy &mem, Addr addr,
hst_statfs *host)
{
TypedBufferArg<typename OS::tgt_statfs> tgt(addr);
tgt->f_type = TheISA::htog(host->f_type);
#if defined(__FreeBSD__) || defined(__NetBSD__) || defined(__OpenBSD__)
tgt->f_bsize = TheISA::htog(host->f_iosize);
#else
tgt->f_bsize = TheISA::htog(host->f_bsize);
#endif
tgt->f_blocks = TheISA::htog(host->f_blocks);
tgt->f_bfree = TheISA::htog(host->f_bfree);
tgt->f_bavail = TheISA::htog(host->f_bavail);
tgt->f_files = TheISA::htog(host->f_files);
tgt->f_ffree = TheISA::htog(host->f_ffree);
memcpy(&tgt->f_fsid, &host->f_fsid, sizeof(host->f_fsid));
#if defined(__FreeBSD__) || defined(__NetBSD__) || defined(__OpenBSD__)
tgt->f_namelen = TheISA::htog(host->f_namemax);
tgt->f_frsize = TheISA::htog(host->f_bsize);
#elif defined(__APPLE__)
tgt->f_namelen = 0;
tgt->f_frsize = 0;
#else
tgt->f_namelen = TheISA::htog(host->f_namelen);
tgt->f_frsize = TheISA::htog(host->f_frsize);
#endif
#if defined(__linux__)
memcpy(&tgt->f_spare, &host->f_spare, sizeof(host->f_spare));
#else
/*
* The fields are different sizes per OS. Don't bother with
* f_spare or f_reserved on non-Linux for now.
*/
memset(&tgt->f_spare, 0, sizeof(tgt->f_spare));
#endif
tgt.copyOut(mem);
}
/// Target ioctl() handler. For the most part, programs call ioctl()
/// only to find out if their stdout is a tty, to determine whether to
/// do line or block buffering. We always claim that output fds are
/// not TTYs to provide repeatable results.
template <class OS>
SyscallReturn
ioctlFunc(SyscallDesc *desc, int callnum, Process *p, ThreadContext *tc)
{
int index = 0;
int tgt_fd = p->getSyscallArg(tc, index);
unsigned req = p->getSyscallArg(tc, index);
DPRINTF(SyscallVerbose, "ioctl(%d, 0x%x, ...)\n", tgt_fd, req);
if (OS::isTtyReq(req))
return -ENOTTY;
auto dfdp = std::dynamic_pointer_cast<DeviceFDEntry>((*p->fds)[tgt_fd]);
if (!dfdp)
return -EBADF;
/**
* If the driver is valid, issue the ioctl through it. Otherwise,
* there's an implicit assumption that the device is a TTY type and we
* return that we do not have a valid TTY.
*/
EmulatedDriver *emul_driver = dfdp->getDriver();
if (emul_driver)
return emul_driver->ioctl(p, tc, req);
/**
* For lack of a better return code, return ENOTTY. Ideally, we should
* return something better here, but at least we issue the warning.
*/
warn("Unsupported ioctl call (return ENOTTY): ioctl(%d, 0x%x, ...) @ \n",
tgt_fd, req, tc->pcState());
return -ENOTTY;
}
template <class OS>
SyscallReturn
openImpl(SyscallDesc *desc, int callnum, Process *p, ThreadContext *tc,
bool isopenat)
{
int index = 0;
int tgt_dirfd = -1;
/**
* If using the openat variant, read in the target directory file
* descriptor from the simulated process.
*/
if (isopenat)
tgt_dirfd = p->getSyscallArg(tc, index);
/**
* Retrieve the simulated process' memory proxy and then read in the path
* string from that memory space into the host's working memory space.
*/
std::string path;
if (!tc->getMemProxy().tryReadString(path, p->getSyscallArg(tc, index)))
return -EFAULT;
#ifdef __CYGWIN32__
int host_flags = O_BINARY;
#else
int host_flags = 0;
#endif
/**
* Translate target flags into host flags. Flags exist which are not
* ported between architectures which can cause check failures.
*/
int tgt_flags = p->getSyscallArg(tc, index);
for (int i = 0; i < OS::NUM_OPEN_FLAGS; i++) {
if (tgt_flags & OS::openFlagTable[i].tgtFlag) {
tgt_flags &= ~OS::openFlagTable[i].tgtFlag;
host_flags |= OS::openFlagTable[i].hostFlag;
}
}
if (tgt_flags) {
warn("open%s: cannot decode flags 0x%x",
isopenat ? "at" : "", tgt_flags);
}
#ifdef __CYGWIN32__
host_flags |= O_BINARY;
#endif
int mode = p->getSyscallArg(tc, index);
/**
* If the simulated process called open or openat with AT_FDCWD specified,
* take the current working directory value which was passed into the
* process class as a Python parameter and append the current path to
* create a full path.
* Otherwise, openat with a valid target directory file descriptor has
* been called. If the path option, which was passed in as a parameter,
* is not absolute, retrieve the directory file descriptor's path and
* prepend it to the path passed in as a parameter.
* In every case, we should have a full path (which is relevant to the
* host) to work with after this block has been passed.
*/
if (!isopenat || (isopenat && tgt_dirfd == OS::TGT_AT_FDCWD)) {
path = p->fullPath(path);
} else if (!startswith(path, "/")) {
std::shared_ptr<FDEntry> fdep = ((*p->fds)[tgt_dirfd]);
auto ffdp = std::dynamic_pointer_cast<FileFDEntry>(fdep);
if (!ffdp)
return -EBADF;
path.insert(0, ffdp->getFileName() + "/");
}
/**
* Since this is an emulated environment, we create pseudo file
* descriptors for device requests that have been registered with
* the process class through Python; this allows us to create a file
* descriptor for subsequent ioctl or mmap calls.
*/
if (startswith(path, "/dev/")) {
std::string filename = path.substr(strlen("/dev/"));
EmulatedDriver *drv = p->findDriver(filename);
if (drv) {
DPRINTF_SYSCALL(Verbose, "open%s: passing call to "
"driver open with path[%s]\n",
isopenat ? "at" : "", path.c_str());
return drv->open(p, tc, mode, host_flags);
}
/**
* Fall through here for pass through to host devices, such
* as /dev/zero
*/
}
/**
* Some special paths and files cannot be called on the host and need
* to be handled as special cases inside the simulator.
* If the full path that was created above does not match any of the
* special cases, pass it through to the open call on the host to let
* the host open the file on our behalf.
* If the host cannot open the file, return the host's error code back
* through the system call to the simulated process.
*/
int sim_fd = -1;
std::vector<std::string> special_paths =
{ "/proc/", "/system/", "/sys/", "/platform/", "/etc/passwd" };
for (auto entry : special_paths) {
if (startswith(path, entry))
sim_fd = OS::openSpecialFile(path, p, tc);
}
if (sim_fd == -1) {
sim_fd = open(path.c_str(), host_flags, mode);
}
if (sim_fd == -1) {
int local = -errno;
DPRINTF_SYSCALL(Verbose, "open%s: failed -> path:%s\n",
isopenat ? "at" : "", path.c_str());
return local;
}
/**
* The file was opened successfully and needs to be recorded in the
* process' file descriptor array so that it can be retrieved later.
* The target file descriptor that is chosen will be the lowest unused
* file descriptor.
* Return the indirect target file descriptor back to the simulated
* process to act as a handle for the opened file.
*/
auto ffdp = std::make_shared<FileFDEntry>(sim_fd, host_flags, path, 0);
int tgt_fd = p->fds->allocFD(ffdp);
DPRINTF_SYSCALL(Verbose, "open%s: sim_fd[%d], target_fd[%d] -> path:%s\n",
isopenat ? "at" : "", sim_fd, tgt_fd, path.c_str());
return tgt_fd;
}
/// Target open() handler.
template <class OS>
SyscallReturn
openFunc(SyscallDesc *desc, int callnum, Process *process,
ThreadContext *tc)
{
return openImpl<OS>(desc, callnum, process, tc, false);
}
/// Target openat() handler.
template <class OS>
SyscallReturn
openatFunc(SyscallDesc *desc, int callnum, Process *process,
ThreadContext *tc)
{
return openImpl<OS>(desc, callnum, process, tc, true);
}
/// Target unlinkat() handler.
template <class OS>
SyscallReturn
unlinkatFunc(SyscallDesc *desc, int callnum, Process *process,
ThreadContext *tc)
{
int index = 0;
int dirfd = process->getSyscallArg(tc, index);
if (dirfd != OS::TGT_AT_FDCWD)
warn("unlinkat: first argument not AT_FDCWD; unlikely to work");
return unlinkHelper(desc, callnum, process, tc, 1);
}
/// Target facessat() handler
template <class OS>
SyscallReturn
faccessatFunc(SyscallDesc *desc, int callnum, Process *process,
ThreadContext *tc)
{
int index = 0;
int dirfd = process->getSyscallArg(tc, index);
if (dirfd != OS::TGT_AT_FDCWD)
warn("faccessat: first argument not AT_FDCWD; unlikely to work");
return accessFunc(desc, callnum, process, tc, 1);
}
/// Target readlinkat() handler
template <class OS>
SyscallReturn
readlinkatFunc(SyscallDesc *desc, int callnum, Process *process,
ThreadContext *tc)
{
int index = 0;
int dirfd = process->getSyscallArg(tc, index);
if (dirfd != OS::TGT_AT_FDCWD)
warn("openat: first argument not AT_FDCWD; unlikely to work");
return readlinkFunc(desc, callnum, process, tc, 1);
}
/// Target renameat() handler.
template <class OS>
SyscallReturn
renameatFunc(SyscallDesc *desc, int callnum, Process *process,
ThreadContext *tc)
{
int index = 0;
int olddirfd = process->getSyscallArg(tc, index);
if (olddirfd != OS::TGT_AT_FDCWD)
warn("renameat: first argument not AT_FDCWD; unlikely to work");
std::string old_name;
if (!tc->getMemProxy().tryReadString(old_name,
process->getSyscallArg(tc, index)))
return -EFAULT;
int newdirfd = process->getSyscallArg(tc, index);
if (newdirfd != OS::TGT_AT_FDCWD)
warn("renameat: third argument not AT_FDCWD; unlikely to work");
std::string new_name;
if (!tc->getMemProxy().tryReadString(new_name,
process->getSyscallArg(tc, index)))
return -EFAULT;
// Adjust path for current working directory
old_name = process->fullPath(old_name);
new_name = process->fullPath(new_name);
int result = rename(old_name.c_str(), new_name.c_str());
return (result == -1) ? -errno : result;
}
/// Target sysinfo() handler.
template <class OS>
SyscallReturn
sysinfoFunc(SyscallDesc *desc, int callnum, Process *process,
ThreadContext *tc)
{
int index = 0;
TypedBufferArg<typename OS::tgt_sysinfo>
sysinfo(process->getSyscallArg(tc, index));
sysinfo->uptime = seconds_since_epoch;
sysinfo->totalram = process->system->memSize();
sysinfo->mem_unit = 1;
sysinfo.copyOut(tc->getMemProxy());
return 0;
}
/// Target chmod() handler.
template <class OS>
SyscallReturn
chmodFunc(SyscallDesc *desc, int callnum, Process *process,
ThreadContext *tc)
{
std::string path;
int index = 0;
if (!tc->getMemProxy().tryReadString(path,
process->getSyscallArg(tc, index))) {
return -EFAULT;
}
uint32_t mode = process->getSyscallArg(tc, index);
mode_t hostMode = 0;
// XXX translate mode flags via OS::something???
hostMode = mode;
// Adjust path for current working directory
path = process->fullPath(path);
// do the chmod
int result = chmod(path.c_str(), hostMode);
if (result < 0)
return -errno;
return 0;
}
template <class OS>
SyscallReturn
pollFunc(SyscallDesc *desc, int num, Process *p, ThreadContext *tc)
{
int index = 0;
Addr fdsPtr = p->getSyscallArg(tc, index);
int nfds = p->getSyscallArg(tc, index);
int tmout = p->getSyscallArg(tc, index);
BufferArg fdsBuf(fdsPtr, sizeof(struct pollfd) * nfds);
fdsBuf.copyIn(tc->getMemProxy());
/**
* Record the target file descriptors in a local variable. We need to
* replace them with host file descriptors but we need a temporary copy
* for later. Afterwards, replace each target file descriptor in the
* poll_fd array with its host_fd.
*/
int temp_tgt_fds[nfds];
for (index = 0; index < nfds; index++) {
temp_tgt_fds[index] = ((struct pollfd *)fdsBuf.bufferPtr())[index].fd;
auto tgt_fd = temp_tgt_fds[index];
auto hbfdp = std::dynamic_pointer_cast<HBFDEntry>((*p->fds)[tgt_fd]);
if (!hbfdp)
return -EBADF;
auto host_fd = hbfdp->getSimFD();
((struct pollfd *)fdsBuf.bufferPtr())[index].fd = host_fd;
}
/**
* We cannot allow an infinite poll to occur or it will inevitably cause
* a deadlock in the gem5 simulator with clone. We must pass in tmout with
* a non-negative value, however it also makes no sense to poll on the
* underlying host for any other time than tmout a zero timeout.
*/
int status;
if (tmout < 0) {
status = poll((struct pollfd *)fdsBuf.bufferPtr(), nfds, 0);
if (status == 0) {
/**
* If blocking indefinitely, check the signal list to see if a
* signal would break the poll out of the retry cycle and try
* to return the signal interrupt instead.
*/
System *sysh = tc->getSystemPtr();
std::list<BasicSignal>::iterator it;
for (it=sysh->signalList.begin(); it!=sysh->signalList.end(); it++)
if (it->receiver == p)
return -EINTR;
return SyscallReturn::retry();
}
} else
status = poll((struct pollfd *)fdsBuf.bufferPtr(), nfds, 0);
if (status == -1)
return -errno;
/**
* Replace each host_fd in the returned poll_fd array with its original
* target file descriptor.
*/
for (index = 0; index < nfds; index++) {
auto tgt_fd = temp_tgt_fds[index];
((struct pollfd *)fdsBuf.bufferPtr())[index].fd = tgt_fd;
}
/**
* Copy out the pollfd struct because the host may have updated fields
* in the structure.
*/
fdsBuf.copyOut(tc->getMemProxy());
return status;
}
/// Target fchmod() handler.
template <class OS>
SyscallReturn
fchmodFunc(SyscallDesc *desc, int callnum, Process *p, ThreadContext *tc)
{
int index = 0;
int tgt_fd = p->getSyscallArg(tc, index);
uint32_t mode = p->getSyscallArg(tc, index);
auto ffdp = std::dynamic_pointer_cast<FileFDEntry>((*p->fds)[tgt_fd]);
if (!ffdp)
return -EBADF;
int sim_fd = ffdp->getSimFD();
mode_t hostMode = mode;
int result = fchmod(sim_fd, hostMode);
return (result < 0) ? -errno : 0;
}
/// Target mremap() handler.
template <class OS>
SyscallReturn
mremapFunc(SyscallDesc *desc, int callnum, Process *process, ThreadContext *tc)
{
int index = 0;
Addr start = process->getSyscallArg(tc, index);
uint64_t old_length = process->getSyscallArg(tc, index);
uint64_t new_length = process->getSyscallArg(tc, index);
uint64_t flags = process->getSyscallArg(tc, index);
uint64_t provided_address = 0;
bool use_provided_address = flags & OS::TGT_MREMAP_FIXED;
if (use_provided_address)
provided_address = process->getSyscallArg(tc, index);
if ((start % TheISA::PageBytes != 0) ||
(provided_address % TheISA::PageBytes != 0)) {
warn("mremap failing: arguments not page aligned");
return -EINVAL;
}
new_length = roundUp(new_length, TheISA::PageBytes);
if (new_length > old_length) {
std::shared_ptr<MemState> mem_state = process->memState;
Addr mmap_end = mem_state->getMmapEnd();
if ((start + old_length) == mmap_end &&
(!use_provided_address || provided_address == start)) {
// This case cannot occur when growing downward, as
// start is greater than or equal to mmap_end.
uint64_t diff = new_length - old_length;
process->allocateMem(mmap_end, diff);
mem_state->setMmapEnd(mmap_end + diff);
return start;
} else {
if (!use_provided_address && !(flags & OS::TGT_MREMAP_MAYMOVE)) {
warn("can't remap here and MREMAP_MAYMOVE flag not set\n");
return -ENOMEM;
} else {
uint64_t new_start = provided_address;
if (!use_provided_address) {
new_start = process->mmapGrowsDown() ?
mmap_end - new_length : mmap_end;
mmap_end = process->mmapGrowsDown() ?
new_start : mmap_end + new_length;
mem_state->setMmapEnd(mmap_end);
}
process->pTable->remap(start, old_length, new_start);
warn("mremapping to new vaddr %08p-%08p, adding %d\n",
new_start, new_start + new_length,
new_length - old_length);
// add on the remaining unallocated pages
process->allocateMem(new_start + old_length,
new_length - old_length,
use_provided_address /* clobber */);
if (use_provided_address &&
((new_start + new_length > mem_state->getMmapEnd() &&
!process->mmapGrowsDown()) ||
(new_start < mem_state->getMmapEnd() &&
process->mmapGrowsDown()))) {
// something fishy going on here, at least notify the user
// @todo: increase mmap_end?
warn("mmap region limit exceeded with MREMAP_FIXED\n");
}
warn("returning %08p as start\n", new_start);
return new_start;
}
}
} else {
if (use_provided_address && provided_address != start)
process->pTable->remap(start, new_length, provided_address);
process->pTable->unmap(start + new_length, old_length - new_length);
return use_provided_address ? provided_address : start;
}
}
/// Target stat() handler.
template <class OS>
SyscallReturn
statFunc(SyscallDesc *desc, int callnum, Process *process,
ThreadContext *tc)
{
std::string path;
int index = 0;
if (!tc->getMemProxy().tryReadString(path,
process->getSyscallArg(tc, index))) {
return -EFAULT;
}
Addr bufPtr = process->getSyscallArg(tc, index);
// Adjust path for current working directory
path = process->fullPath(path);
struct stat hostBuf;
int result = stat(path.c_str(), &hostBuf);
if (result < 0)
return -errno;
copyOutStatBuf<OS>(tc->getMemProxy(), bufPtr, &hostBuf);
return 0;
}
/// Target stat64() handler.
template <class OS>
SyscallReturn
stat64Func(SyscallDesc *desc, int callnum, Process *process,
ThreadContext *tc)
{
std::string path;
int index = 0;
if (!tc->getMemProxy().tryReadString(path,
process->getSyscallArg(tc, index)))
return -EFAULT;
Addr bufPtr = process->getSyscallArg(tc, index);
// Adjust path for current working directory
path = process->fullPath(path);
#if NO_STAT64
struct stat hostBuf;
int result = stat(path.c_str(), &hostBuf);
#else
struct stat64 hostBuf;
int result = stat64(path.c_str(), &hostBuf);
#endif
if (result < 0)
return -errno;
copyOutStat64Buf<OS>(tc->getMemProxy(), bufPtr, &hostBuf);
return 0;
}
/// Target fstatat64() handler.
template <class OS>
SyscallReturn
fstatat64Func(SyscallDesc *desc, int callnum, Process *process,
ThreadContext *tc)
{
int index = 0;
int dirfd = process->getSyscallArg(tc, index);
if (dirfd != OS::TGT_AT_FDCWD)
warn("fstatat64: first argument not AT_FDCWD; unlikely to work");
std::string path;
if (!tc->getMemProxy().tryReadString(path,
process->getSyscallArg(tc, index)))
return -EFAULT;
Addr bufPtr = process->getSyscallArg(tc, index);
// Adjust path for current working directory
path = process->fullPath(path);
#if NO_STAT64
struct stat hostBuf;
int result = stat(path.c_str(), &hostBuf);
#else
struct stat64 hostBuf;
int result = stat64(path.c_str(), &hostBuf);
#endif
if (result < 0)
return -errno;
copyOutStat64Buf<OS>(tc->getMemProxy(), bufPtr, &hostBuf);
return 0;
}
/// Target fstat64() handler.
template <class OS>
SyscallReturn
fstat64Func(SyscallDesc *desc, int callnum, Process *p, ThreadContext *tc)
{
int index = 0;
int tgt_fd = p->getSyscallArg(tc, index);
Addr bufPtr = p->getSyscallArg(tc, index);
auto ffdp = std::dynamic_pointer_cast<FileFDEntry>((*p->fds)[tgt_fd]);
if (!ffdp)
return -EBADF;
int sim_fd = ffdp->getSimFD();
#if NO_STAT64
struct stat hostBuf;
int result = fstat(sim_fd, &hostBuf);
#else
struct stat64 hostBuf;
int result = fstat64(sim_fd, &hostBuf);
#endif
if (result < 0)
return -errno;
copyOutStat64Buf<OS>(tc->getMemProxy(), bufPtr, &hostBuf, (sim_fd == 1));
return 0;
}
/// Target lstat() handler.
template <class OS>
SyscallReturn
lstatFunc(SyscallDesc *desc, int callnum, Process *process,
ThreadContext *tc)
{
std::string path;
int index = 0;
if (!tc->getMemProxy().tryReadString(path,
process->getSyscallArg(tc, index))) {
return -EFAULT;
}
Addr bufPtr = process->getSyscallArg(tc, index);
// Adjust path for current working directory
path = process->fullPath(path);
struct stat hostBuf;
int result = lstat(path.c_str(), &hostBuf);
if (result < 0)
return -errno;
copyOutStatBuf<OS>(tc->getMemProxy(), bufPtr, &hostBuf);
return 0;
}
/// Target lstat64() handler.
template <class OS>
SyscallReturn
lstat64Func(SyscallDesc *desc, int callnum, Process *process,
ThreadContext *tc)
{
std::string path;
int index = 0;
if (!tc->getMemProxy().tryReadString(path,
process->getSyscallArg(tc, index))) {
return -EFAULT;
}
Addr bufPtr = process->getSyscallArg(tc, index);
// Adjust path for current working directory
path = process->fullPath(path);
#if NO_STAT64
struct stat hostBuf;
int result = lstat(path.c_str(), &hostBuf);
#else
struct stat64 hostBuf;
int result = lstat64(path.c_str(), &hostBuf);
#endif
if (result < 0)
return -errno;
copyOutStat64Buf<OS>(tc->getMemProxy(), bufPtr, &hostBuf);
return 0;
}
/// Target fstat() handler.
template <class OS>
SyscallReturn
fstatFunc(SyscallDesc *desc, int callnum, Process *p, ThreadContext *tc)
{
int index = 0;
int tgt_fd = p->getSyscallArg(tc, index);
Addr bufPtr = p->getSyscallArg(tc, index);
DPRINTF_SYSCALL(Verbose, "fstat(%d, ...)\n", tgt_fd);
auto ffdp = std::dynamic_pointer_cast<FileFDEntry>((*p->fds)[tgt_fd]);
if (!ffdp)
return -EBADF;
int sim_fd = ffdp->getSimFD();
struct stat hostBuf;
int result = fstat(sim_fd, &hostBuf);
if (result < 0)
return -errno;
copyOutStatBuf<OS>(tc->getMemProxy(), bufPtr, &hostBuf, (sim_fd == 1));
return 0;
}
/// Target statfs() handler.
template <class OS>
SyscallReturn
statfsFunc(SyscallDesc *desc, int callnum, Process *process,
ThreadContext *tc)
{
#if NO_STATFS
warn("Host OS cannot support calls to statfs. Ignoring syscall");
#else
std::string path;
int index = 0;
if (!tc->getMemProxy().tryReadString(path,
process->getSyscallArg(tc, index))) {
return -EFAULT;
}
Addr bufPtr = process->getSyscallArg(tc, index);
// Adjust path for current working directory
path = process->fullPath(path);
struct statfs hostBuf;
int result = statfs(path.c_str(), &hostBuf);
if (result < 0)
return -errno;
copyOutStatfsBuf<OS>(tc->getMemProxy(), bufPtr, &hostBuf);
#endif
return 0;
}
template <class OS>
SyscallReturn
cloneFunc(SyscallDesc *desc, int callnum, Process *p, ThreadContext *tc)
{
int index = 0;
RegVal flags = p->getSyscallArg(tc, index);
RegVal newStack = p->getSyscallArg(tc, index);
Addr ptidPtr = p->getSyscallArg(tc, index);
#if THE_ISA == RISCV_ISA or THE_ISA == ARM_ISA
/**
* Linux sets CLONE_BACKWARDS flag for RISC-V and Arm.
* The flag defines the list of clone() arguments in the following
* order: flags -> newStack -> ptidPtr -> tlsPtr -> ctidPtr
*/
Addr tlsPtr = p->getSyscallArg(tc, index);
Addr ctidPtr = p->getSyscallArg(tc, index);
#else
Addr ctidPtr = p->getSyscallArg(tc, index);
Addr tlsPtr = p->getSyscallArg(tc, index);
#endif
if (((flags & OS::TGT_CLONE_SIGHAND)&& !(flags & OS::TGT_CLONE_VM)) ||
((flags & OS::TGT_CLONE_THREAD) && !(flags & OS::TGT_CLONE_SIGHAND)) ||
((flags & OS::TGT_CLONE_FS) && (flags & OS::TGT_CLONE_NEWNS)) ||
((flags & OS::TGT_CLONE_NEWIPC) && (flags & OS::TGT_CLONE_SYSVSEM)) ||
((flags & OS::TGT_CLONE_NEWPID) && (flags & OS::TGT_CLONE_THREAD)) ||
((flags & OS::TGT_CLONE_VM) && !(newStack)))
return -EINVAL;
ThreadContext *ctc;
if (!(ctc = p->findFreeContext()))
fatal("clone: no spare thread context in system");
/**
* Note that ProcessParams is generated by swig and there are no other
* examples of how to create anything but this default constructor. The
* fields are manually initialized instead of passing parameters to the
* constructor.
*/
ProcessParams *pp = new ProcessParams();
pp->executable.assign(*(new std::string(p->progName())));
pp->cmd.push_back(*(new std::string(p->progName())));
pp->system = p->system;
pp->cwd.assign(p->getcwd());
pp->input.assign("stdin");
pp->output.assign("stdout");
pp->errout.assign("stderr");
pp->uid = p->uid();
pp->euid = p->euid();
pp->gid = p->gid();
pp->egid = p->egid();
/* Find the first free PID that's less than the maximum */
std::set<int> const& pids = p->system->PIDs;
int temp_pid = *pids.begin();
do {
temp_pid++;
} while (pids.find(temp_pid) != pids.end());
if (temp_pid >= System::maxPID)
fatal("temp_pid is too large: %d", temp_pid);
pp->pid = temp_pid;
pp->ppid = (flags & OS::TGT_CLONE_THREAD) ? p->ppid() : p->pid();
Process *cp = pp->create();
delete pp;
Process *owner = ctc->getProcessPtr();
ctc->setProcessPtr(cp);
cp->assignThreadContext(ctc->contextId());
owner->revokeThreadContext(ctc->contextId());
if (flags & OS::TGT_CLONE_PARENT_SETTID) {
BufferArg ptidBuf(ptidPtr, sizeof(long));
long *ptid = (long *)ptidBuf.bufferPtr();
*ptid = cp->pid();
ptidBuf.copyOut(tc->getMemProxy());
}
cp->initState();
p->clone(tc, ctc, cp, flags);
if (flags & OS::TGT_CLONE_THREAD) {
delete cp->sigchld;
cp->sigchld = p->sigchld;
} else if (flags & OS::TGT_SIGCHLD) {
*cp->sigchld = true;
}
if (flags & OS::TGT_CLONE_CHILD_SETTID) {
BufferArg ctidBuf(ctidPtr, sizeof(long));
long *ctid = (long *)ctidBuf.bufferPtr();
*ctid = cp->pid();
ctidBuf.copyOut(ctc->getMemProxy());
}
if (flags & OS::TGT_CLONE_CHILD_CLEARTID)
cp->childClearTID = (uint64_t)ctidPtr;
ctc->clearArchRegs();
OS::archClone(flags, p, cp, tc, ctc, newStack, tlsPtr);
cp->setSyscallReturn(ctc, 0);
#if THE_ISA == ALPHA_ISA
ctc->setIntReg(TheISA::SyscallSuccessReg, 0);
#elif THE_ISA == SPARC_ISA
tc->setIntReg(TheISA::SyscallPseudoReturnReg, 0);
ctc->setIntReg(TheISA::SyscallPseudoReturnReg, 1);
#endif
TheISA::PCState cpc = tc->pcState();
cpc.advance();
ctc->pcState(cpc);
ctc->activate();
return cp->pid();
}
/// Target fstatfs() handler.
template <class OS>
SyscallReturn
fstatfsFunc(SyscallDesc *desc, int callnum, Process *p, ThreadContext *tc)
{
int index = 0;
int tgt_fd = p->getSyscallArg(tc, index);
Addr bufPtr = p->getSyscallArg(tc, index);
auto ffdp = std::dynamic_pointer_cast<FileFDEntry>((*p->fds)[tgt_fd]);
if (!ffdp)
return -EBADF;
int sim_fd = ffdp->getSimFD();
struct statfs hostBuf;
int result = fstatfs(sim_fd, &hostBuf);
if (result < 0)
return -errno;
copyOutStatfsBuf<OS>(tc->getMemProxy(), bufPtr, &hostBuf);
return 0;
}
/// Target writev() handler.
template <class OS>
SyscallReturn
writevFunc(SyscallDesc *desc, int callnum, 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();
SETranslatingPortProxy &prox = tc->getMemProxy();
uint64_t tiov_base = p->getSyscallArg(tc, index);
size_t count = p->getSyscallArg(tc, index);
struct iovec hiov[count];
for (size_t i = 0; i < count; ++i) {
typename OS::tgt_iovec tiov;
prox.readBlob(tiov_base + i*sizeof(typename OS::tgt_iovec),
(uint8_t*)&tiov, sizeof(typename OS::tgt_iovec));
hiov[i].iov_len = TheISA::gtoh(tiov.iov_len);
hiov[i].iov_base = new char [hiov[i].iov_len];
prox.readBlob(TheISA::gtoh(tiov.iov_base), (uint8_t *)hiov[i].iov_base,
hiov[i].iov_len);
}
int result = writev(sim_fd, hiov, count);
for (size_t i = 0; i < count; ++i)
delete [] (char *)hiov[i].iov_base;
if (result < 0)
return -errno;
return result;
}
/// Real mmap handler.
template <class OS>
SyscallReturn
mmapImpl(SyscallDesc *desc, int num, Process *p, ThreadContext *tc,
bool is_mmap2)
{
int index = 0;
Addr start = p->getSyscallArg(tc, index);
uint64_t length = p->getSyscallArg(tc, index);
int prot = p->getSyscallArg(tc, index);
int tgt_flags = p->getSyscallArg(tc, index);
int tgt_fd = p->getSyscallArg(tc, index);
int offset = p->getSyscallArg(tc, index);
if (is_mmap2)
offset *= TheISA::PageBytes;
if (start & (TheISA::PageBytes - 1) ||
offset & (TheISA::PageBytes - 1) ||
(tgt_flags & OS::TGT_MAP_PRIVATE &&
tgt_flags & OS::TGT_MAP_SHARED) ||
(!(tgt_flags & OS::TGT_MAP_PRIVATE) &&
!(tgt_flags & OS::TGT_MAP_SHARED)) ||
!length) {
return -EINVAL;
}
if ((prot & PROT_WRITE) && (tgt_flags & OS::TGT_MAP_SHARED)) {
// With shared mmaps, there are two cases to consider:
// 1) anonymous: writes should modify the mapping and this should be
// visible to observers who share the mapping. Currently, it's
// difficult to update the shared mapping because there's no
// structure which maintains information about the which virtual
// memory areas are shared. If that structure existed, it would be
// possible to make the translations point to the same frames.
// 2) file-backed: writes should modify the mapping and the file
// which is backed by the mapping. The shared mapping problem is the
// same as what was mentioned about the anonymous mappings. For
// file-backed mappings, the writes to the file are difficult
// because it requires syncing what the mapping holds with the file
// that resides on the host system. So, any write on a real system
// would cause the change to be propagated to the file mapping at
// some point in the future (the inode is tracked along with the
// mapping). This isn't guaranteed to always happen, but it usually
// works well enough. The guarantee is provided by the msync system
// call. We could force the change through with shared mappings with
// a call to msync, but that again would require more information
// than we currently maintain.
warn("mmap: writing to shared mmap region is currently "
"unsupported. The write succeeds on the target, but it "
"will not be propagated to the host or shared mappings");
}
length = roundUp(length, TheISA::PageBytes);
int sim_fd = -1;
uint8_t *pmap = nullptr;
if (!(tgt_flags & OS::TGT_MAP_ANONYMOUS)) {
std::shared_ptr<FDEntry> fdep = (*p->fds)[tgt_fd];
auto dfdp = std::dynamic_pointer_cast<DeviceFDEntry>(fdep);
if (dfdp) {
EmulatedDriver *emul_driver = dfdp->getDriver();
return emul_driver->mmap(p, tc, start, length, prot,
tgt_flags, tgt_fd, offset);
}
auto ffdp = std::dynamic_pointer_cast<FileFDEntry>(fdep);
if (!ffdp)
return -EBADF;
sim_fd = ffdp->getSimFD();
pmap = (decltype(pmap))mmap(nullptr, length, PROT_READ, MAP_PRIVATE,
sim_fd, offset);
if (pmap == (decltype(pmap))-1) {
warn("mmap: failed to map file into host address space");
return -errno;
}
}
// Extend global mmap region if necessary. Note that we ignore the
// start address unless MAP_FIXED is specified.
if (!(tgt_flags & OS::TGT_MAP_FIXED)) {
std::shared_ptr<MemState> mem_state = p->memState;
Addr mmap_end = mem_state->getMmapEnd();
start = p->mmapGrowsDown() ? mmap_end - length : mmap_end;
mmap_end = p->mmapGrowsDown() ? start : mmap_end + length;
mem_state->setMmapEnd(mmap_end);
}
DPRINTF_SYSCALL(Verbose, " mmap range is 0x%x - 0x%x\n",
start, start + length - 1);
// We only allow mappings to overwrite existing mappings if
// TGT_MAP_FIXED is set. Otherwise it shouldn't be a problem
// because we ignore the start hint if TGT_MAP_FIXED is not set.
int clobber = tgt_flags & OS::TGT_MAP_FIXED;
if (clobber) {
for (auto tc : p->system->threadContexts) {
// If we might be overwriting old mappings, we need to
// invalidate potentially stale mappings out of the TLBs.
tc->getDTBPtr()->flushAll();
tc->getITBPtr()->flushAll();
}
}
// Allocate physical memory and map it in. If the page table is already
// mapped and clobber is not set, the simulator will issue throw a
// fatal and bail out of the simulation.
p->allocateMem(start, length, clobber);
// Transfer content into target address space.
SETranslatingPortProxy &tp = tc->getMemProxy();
if (tgt_flags & OS::TGT_MAP_ANONYMOUS) {
// In general, we should zero the mapped area for anonymous mappings,
// with something like:
// tp.memsetBlob(start, 0, length);
// However, given that we don't support sparse mappings, and
// some applications can map a couple of gigabytes of space
// (intending sparse usage), that can get painfully expensive.
// Fortunately, since we don't properly implement munmap either,
// there's no danger of remapping used memory, so for now all
// newly mapped memory should already be zeroed so we can skip it.
} else {
// It is possible to mmap an area larger than a file, however
// accessing unmapped portions the system triggers a "Bus error"
// on the host. We must know when to stop copying the file from
// the host into the target address space.
struct stat file_stat;
if (fstat(sim_fd, &file_stat) > 0)
fatal("mmap: cannot stat file");
// Copy the portion of the file that is resident. This requires
// checking both the mmap size and the filesize that we are
// trying to mmap into this space; the mmap size also depends
// on the specified offset into the file.
uint64_t size = std::min((uint64_t)file_stat.st_size - offset,
length);
tp.writeBlob(start, pmap, size);
// Cleanup the mmap region before exiting this function.
munmap(pmap, length);
// Maintain the symbol table for dynamic executables.
// The loader will call mmap to map the images into its address
// space and we intercept that here. We can verify that we are
// executing inside the loader by checking the program counter value.
// XXX: with multiprogrammed workloads or multi-node configurations,
// this will not work since there is a single global symbol table.
ObjectFile *interpreter = p->getInterpreter();
if (interpreter) {
Addr text_start = interpreter->textBase();
Addr text_end = text_start + interpreter->textSize();
Addr pc = tc->pcState().pc();
if (pc >= text_start && pc < text_end) {
std::shared_ptr<FDEntry> fdep = (*p->fds)[tgt_fd];
auto ffdp = std::dynamic_pointer_cast<FileFDEntry>(fdep);
ObjectFile *lib = createObjectFile(ffdp->getFileName());
if (lib) {
lib->loadAllSymbols(debugSymbolTable,
lib->textBase(), start);
}
}
}
// Note that we do not zero out the remainder of the mapping. This
// is done by a real system, but it probably will not affect
// execution (hopefully).
}
return start;
}
template <class OS>
SyscallReturn
pwrite64Func(SyscallDesc *desc, int num, Process *p, ThreadContext *tc)
{
int index = 0;
int tgt_fd = p->getSyscallArg(tc, index);
Addr bufPtr = p->getSyscallArg(tc, index);
int nbytes = p->getSyscallArg(tc, index);
int offset = p->getSyscallArg(tc, index);
auto ffdp = std::dynamic_pointer_cast<FileFDEntry>((*p->fds)[tgt_fd]);
if (!ffdp)
return -EBADF;
int sim_fd = ffdp->getSimFD();
BufferArg bufArg(bufPtr, nbytes);
bufArg.copyIn(tc->getMemProxy());
int bytes_written = pwrite(sim_fd, bufArg.bufferPtr(), nbytes, offset);
return (bytes_written == -1) ? -errno : bytes_written;
}
/// Target mmap() handler.
template <class OS>
SyscallReturn
mmapFunc(SyscallDesc *desc, int num, Process *p, ThreadContext *tc)
{
return mmapImpl<OS>(desc, num, p, tc, false);
}
/// Target mmap2() handler.
template <class OS>
SyscallReturn
mmap2Func(SyscallDesc *desc, int num, Process *p, ThreadContext *tc)
{
return mmapImpl<OS>(desc, num, p, tc, true);
}
/// Target getrlimit() handler.
template <class OS>
SyscallReturn
getrlimitFunc(SyscallDesc *desc, int callnum, Process *process,
ThreadContext *tc)
{
int index = 0;
unsigned resource = process->getSyscallArg(tc, index);
TypedBufferArg<typename OS::rlimit> rlp(process->getSyscallArg(tc, index));
switch (resource) {
case OS::TGT_RLIMIT_STACK:
// max stack size in bytes: make up a number (8MB for now)
rlp->rlim_cur = rlp->rlim_max = 8 * 1024 * 1024;
rlp->rlim_cur = TheISA::htog(rlp->rlim_cur);
rlp->rlim_max = TheISA::htog(rlp->rlim_max);
break;
case OS::TGT_RLIMIT_DATA:
// max data segment size in bytes: make up a number
rlp->rlim_cur = rlp->rlim_max = 256 * 1024 * 1024;
rlp->rlim_cur = TheISA::htog(rlp->rlim_cur);
rlp->rlim_max = TheISA::htog(rlp->rlim_max);
break;
default:
warn("getrlimit: unimplemented resource %d", resource);
return -EINVAL;
break;
}
rlp.copyOut(tc->getMemProxy());
return 0;
}
template <class OS>
SyscallReturn
prlimitFunc(SyscallDesc *desc, int callnum, Process *process,
ThreadContext *tc)
{
int index = 0;
if (process->getSyscallArg(tc, index) != 0)
{
warn("prlimit: ignoring rlimits for nonzero pid");
return -EPERM;
}
int resource = process->getSyscallArg(tc, index);
Addr n = process->getSyscallArg(tc, index);
if (n != 0)
warn("prlimit: ignoring new rlimit");
Addr o = process->getSyscallArg(tc, index);
if (o != 0)
{
TypedBufferArg<typename OS::rlimit> rlp(o);
switch (resource) {
case OS::TGT_RLIMIT_STACK:
// max stack size in bytes: make up a number (8MB for now)
rlp->rlim_cur = rlp->rlim_max = 8 * 1024 * 1024;
rlp->rlim_cur = TheISA::htog(rlp->rlim_cur);
rlp->rlim_max = TheISA::htog(rlp->rlim_max);
break;
case OS::TGT_RLIMIT_DATA:
// max data segment size in bytes: make up a number
rlp->rlim_cur = rlp->rlim_max = 256*1024*1024;
rlp->rlim_cur = TheISA::htog(rlp->rlim_cur);
rlp->rlim_max = TheISA::htog(rlp->rlim_max);
break;
default:
warn("prlimit: unimplemented resource %d", resource);
return -EINVAL;
break;
}
rlp.copyOut(tc->getMemProxy());
}
return 0;
}
/// Target clock_gettime() function.
template <class OS>
SyscallReturn
clock_gettimeFunc(SyscallDesc *desc, int num, Process *p, ThreadContext *tc)
{
int index = 1;
//int clk_id = p->getSyscallArg(tc, index);
TypedBufferArg<typename OS::timespec> tp(p->getSyscallArg(tc, index));
getElapsedTimeNano(tp->tv_sec, tp->tv_nsec);
tp->tv_sec += seconds_since_epoch;
tp->tv_sec = TheISA::htog(tp->tv_sec);
tp->tv_nsec = TheISA::htog(tp->tv_nsec);
tp.copyOut(tc->getMemProxy());
return 0;
}
/// Target clock_getres() function.
template <class OS>
SyscallReturn
clock_getresFunc(SyscallDesc *desc, int num, Process *p, ThreadContext *tc)
{
int index = 1;
TypedBufferArg<typename OS::timespec> tp(p->getSyscallArg(tc, index));
// Set resolution at ns, which is what clock_gettime() returns
tp->tv_sec = 0;
tp->tv_nsec = 1;
tp.copyOut(tc->getMemProxy());
return 0;
}
/// Target gettimeofday() handler.
template <class OS>
SyscallReturn
gettimeofdayFunc(SyscallDesc *desc, int callnum, Process *process,
ThreadContext *tc)
{
int index = 0;
TypedBufferArg<typename OS::timeval> tp(process->getSyscallArg(tc, index));
getElapsedTimeMicro(tp->tv_sec, tp->tv_usec);
tp->tv_sec += seconds_since_epoch;
tp->tv_sec = TheISA::htog(tp->tv_sec);
tp->tv_usec = TheISA::htog(tp->tv_usec);
tp.copyOut(tc->getMemProxy());
return 0;
}
/// Target utimes() handler.
template <class OS>
SyscallReturn
utimesFunc(SyscallDesc *desc, int callnum, Process *process,
ThreadContext *tc)
{
std::string path;
int index = 0;
if (!tc->getMemProxy().tryReadString(path,
process->getSyscallArg(tc, index))) {
return -EFAULT;
}
TypedBufferArg<typename OS::timeval [2]>
tp(process->getSyscallArg(tc, index));
tp.copyIn(tc->getMemProxy());
struct timeval hostTimeval[2];
for (int i = 0; i < 2; ++i) {
hostTimeval[i].tv_sec = TheISA::gtoh((*tp)[i].tv_sec);
hostTimeval[i].tv_usec = TheISA::gtoh((*tp)[i].tv_usec);
}
// Adjust path for current working directory
path = process->fullPath(path);
int result = utimes(path.c_str(), hostTimeval);
if (result < 0)
return -errno;
return 0;
}
template <class OS>
SyscallReturn
execveFunc(SyscallDesc *desc, int callnum, Process *p, ThreadContext *tc)
{
desc->setFlags(0);
int index = 0;
std::string path;
SETranslatingPortProxy & mem_proxy = tc->getMemProxy();
if (!mem_proxy.tryReadString(path, p->getSyscallArg(tc, index)))
return -EFAULT;
if (access(path.c_str(), F_OK) == -1)
return -EACCES;
auto read_in = [](std::vector<std::string> & vect,
SETranslatingPortProxy & mem_proxy,
Addr mem_loc)
{
for (int inc = 0; ; inc++) {
BufferArg b((mem_loc + sizeof(Addr) * inc), sizeof(Addr));
b.copyIn(mem_proxy);
if (!*(Addr*)b.bufferPtr())
break;
vect.push_back(std::string());
mem_proxy.tryReadString(vect[inc], *(Addr*)b.bufferPtr());
}
};
/**
* Note that ProcessParams is generated by swig and there are no other
* examples of how to create anything but this default constructor. The
* fields are manually initialized instead of passing parameters to the
* constructor.
*/
ProcessParams *pp = new ProcessParams();
pp->executable = path;
Addr argv_mem_loc = p->getSyscallArg(tc, index);
read_in(pp->cmd, mem_proxy, argv_mem_loc);
Addr envp_mem_loc = p->getSyscallArg(tc, index);
read_in(pp->env, mem_proxy, envp_mem_loc);
pp->uid = p->uid();
pp->egid = p->egid();
pp->euid = p->euid();
pp->gid = p->gid();
pp->ppid = p->ppid();
pp->pid = p->pid();
pp->input.assign("cin");
pp->output.assign("cout");
pp->errout.assign("cerr");
pp->cwd.assign(p->getcwd());
pp->system = p->system;
/**
* Prevent process object creation with identical PIDs (which will trip
* a fatal check in Process constructor). The execve call is supposed to
* take over the currently executing process' identity but replace
* whatever it is doing with a new process image. Instead of hijacking
* the process object in the simulator, we create a new process object
* and bind to the previous process' thread below (hijacking the thread).
*/
p->system->PIDs.erase(p->pid());
Process *new_p = pp->create();
delete pp;
/**
* Work through the file descriptor array and close any files marked
* close-on-exec.
*/
new_p->fds = p->fds;
for (int i = 0; i < new_p->fds->getSize(); i++) {
std::shared_ptr<FDEntry> fdep = (*new_p->fds)[i];
if (fdep && fdep->getCOE())
new_p->fds->closeFDEntry(i);
}
*new_p->sigchld = true;
delete p;
tc->clearArchRegs();
tc->setProcessPtr(new_p);
new_p->assignThreadContext(tc->contextId());
new_p->initState();
tc->activate();
TheISA::PCState pcState = tc->pcState();
tc->setNPC(pcState.instAddr());
desc->setFlags(SyscallDesc::SuppressReturnValue);
return 0;
}
/// Target getrusage() function.
template <class OS>
SyscallReturn
getrusageFunc(SyscallDesc *desc, int callnum, Process *process,
ThreadContext *tc)
{
int index = 0;
int who = process->getSyscallArg(tc, index); // THREAD, SELF, or CHILDREN
TypedBufferArg<typename OS::rusage> rup(process->getSyscallArg(tc, index));
rup->ru_utime.tv_sec = 0;
rup->ru_utime.tv_usec = 0;
rup->ru_stime.tv_sec = 0;
rup->ru_stime.tv_usec = 0;
rup->ru_maxrss = 0;
rup->ru_ixrss = 0;
rup->ru_idrss = 0;
rup->ru_isrss = 0;
rup->ru_minflt = 0;
rup->ru_majflt = 0;
rup->ru_nswap = 0;
rup->ru_inblock = 0;
rup->ru_oublock = 0;
rup->ru_msgsnd = 0;
rup->ru_msgrcv = 0;
rup->ru_nsignals = 0;
rup->ru_nvcsw = 0;
rup->ru_nivcsw = 0;
switch (who) {
case OS::TGT_RUSAGE_SELF:
getElapsedTimeMicro(rup->ru_utime.tv_sec, rup->ru_utime.tv_usec);
rup->ru_utime.tv_sec = TheISA::htog(rup->ru_utime.tv_sec);
rup->ru_utime.tv_usec = TheISA::htog(rup->ru_utime.tv_usec);
break;
case OS::TGT_RUSAGE_CHILDREN:
// do nothing. We have no child processes, so they take no time.
break;
default:
// don't really handle THREAD or CHILDREN, but just warn and
// plow ahead
warn("getrusage() only supports RUSAGE_SELF. Parameter %d ignored.",
who);
}
rup.copyOut(tc->getMemProxy());
return 0;
}
/// Target times() function.
template <class OS>
SyscallReturn
timesFunc(SyscallDesc *desc, int callnum, Process *process,
ThreadContext *tc)
{
int index = 0;
TypedBufferArg<typename OS::tms> bufp(process->getSyscallArg(tc, index));
// Fill in the time structure (in clocks)
int64_t clocks = curTick() * OS::M5_SC_CLK_TCK / SimClock::Int::s;
bufp->tms_utime = clocks;
bufp->tms_stime = 0;
bufp->tms_cutime = 0;
bufp->tms_cstime = 0;
// Convert to host endianness
bufp->tms_utime = TheISA::htog(bufp->tms_utime);
// Write back
bufp.copyOut(tc->getMemProxy());
// Return clock ticks since system boot
return clocks;
}
/// Target time() function.
template <class OS>
SyscallReturn
timeFunc(SyscallDesc *desc, int callnum, Process *process, ThreadContext *tc)
{
typename OS::time_t sec, usec;
getElapsedTimeMicro(sec, usec);
sec += seconds_since_epoch;
int index = 0;
Addr taddr = (Addr)process->getSyscallArg(tc, index);
if (taddr != 0) {
typename OS::time_t t = sec;
t = TheISA::htog(t);
SETranslatingPortProxy &p = tc->getMemProxy();
p.writeBlob(taddr, (uint8_t*)&t, (int)sizeof(typename OS::time_t));
}
return sec;
}
template <class OS>
SyscallReturn
tgkillFunc(SyscallDesc *desc, int num, Process *process, ThreadContext *tc)
{
int index = 0;
int tgid = process->getSyscallArg(tc, index);
int tid = process->getSyscallArg(tc, index);
int sig = process->getSyscallArg(tc, index);
/**
* This system call is intended to allow killing a specific thread
* within an arbitrary thread group if sanctioned with permission checks.
* It's usually true that threads share the termination signal as pointed
* out by the pthread_kill man page and this seems to be the intended
* usage. Due to this being an emulated environment, assume the following:
* Threads are allowed to call tgkill because the EUID for all threads
* should be the same. There is no signal handling mechanism for kernel
* registration of signal handlers since signals are poorly supported in
* emulation mode. Since signal handlers cannot be registered, all
* threads within in a thread group must share the termination signal.
* We never exhaust PIDs so there's no chance of finding the wrong one
* due to PID rollover.
*/
System *sys = tc->getSystemPtr();
Process *tgt_proc = nullptr;
for (int i = 0; i < sys->numContexts(); i++) {
Process *temp = sys->threadContexts[i]->getProcessPtr();
if (temp->pid() == tid) {
tgt_proc = temp;
break;
}
}
if (sig != 0 || sig != OS::TGT_SIGABRT)
return -EINVAL;
if (tgt_proc == nullptr)
return -ESRCH;
if (tgid != -1 && tgt_proc->tgid() != tgid)
return -ESRCH;
if (sig == OS::TGT_SIGABRT)
exitGroupFunc(desc, 252, process, tc);
return 0;
}
template <class OS>
SyscallReturn
socketFunc(SyscallDesc *desc, int num, Process *p, ThreadContext *tc)
{
int index = 0;
int domain = p->getSyscallArg(tc, index);
int type = p->getSyscallArg(tc, index);
int prot = p->getSyscallArg(tc, index);
int sim_fd = socket(domain, type, prot);
if (sim_fd == -1)
return -errno;
auto sfdp = std::make_shared<SocketFDEntry>(sim_fd, domain, type, prot);
int tgt_fd = p->fds->allocFD(sfdp);
return tgt_fd;
}
template <class OS>
SyscallReturn
socketpairFunc(SyscallDesc *desc, int num, Process *p, ThreadContext *tc)
{
int index = 0;
int domain = p->getSyscallArg(tc, index);
int type = p->getSyscallArg(tc, index);
int prot = p->getSyscallArg(tc, index);
Addr svPtr = p->getSyscallArg(tc, index);
BufferArg svBuf((Addr)svPtr, 2 * sizeof(int));
int status = socketpair(domain, type, prot, (int *)svBuf.bufferPtr());
if (status == -1)
return -errno;
int *fds = (int *)svBuf.bufferPtr();
auto sfdp1 = std::make_shared<SocketFDEntry>(fds[0], domain, type, prot);
fds[0] = p->fds->allocFD(sfdp1);
auto sfdp2 = std::make_shared<SocketFDEntry>(fds[1], domain, type, prot);
fds[1] = p->fds->allocFD(sfdp2);
svBuf.copyOut(tc->getMemProxy());
return status;
}
template <class OS>
SyscallReturn
selectFunc(SyscallDesc *desc, int callnum, Process *p, ThreadContext *tc)
{
int retval;
int index = 0;
int nfds_t = p->getSyscallArg(tc, index);
Addr fds_read_ptr = p->getSyscallArg(tc, index);
Addr fds_writ_ptr = p->getSyscallArg(tc, index);
Addr fds_excp_ptr = p->getSyscallArg(tc, index);
Addr time_val_ptr = p->getSyscallArg(tc, index);
TypedBufferArg<typename OS::fd_set> rd_t(fds_read_ptr);
TypedBufferArg<typename OS::fd_set> wr_t(fds_writ_ptr);
TypedBufferArg<typename OS::fd_set> ex_t(fds_excp_ptr);
TypedBufferArg<typename OS::timeval> tp(time_val_ptr);
/**
* Host fields. Notice that these use the definitions from the system
* headers instead of the gem5 headers and libraries. If the host and
* target have different header file definitions, this will not work.
*/
fd_set rd_h;
FD_ZERO(&rd_h);
fd_set wr_h;
FD_ZERO(&wr_h);
fd_set ex_h;
FD_ZERO(&ex_h);
/**
* Copy in the fd_set from the target.
*/
if (fds_read_ptr)
rd_t.copyIn(tc->getMemProxy());
if (fds_writ_ptr)
wr_t.copyIn(tc->getMemProxy());
if (fds_excp_ptr)
ex_t.copyIn(tc->getMemProxy());
/**
* We need to translate the target file descriptor set into a host file
* descriptor set. This involves both our internal process fd array
* and the fd_set defined in Linux header files. The nfds field also
* needs to be updated as it will be only target specific after
* retrieving it from the target; the nfds value is expected to be the
* highest file descriptor that needs to be checked, so we need to extend
* it out for nfds_h when we do the update.
*/
int nfds_h = 0;
std::map<int, int> trans_map;
auto try_add_host_set = [&](fd_set *tgt_set_entry,
fd_set *hst_set_entry,
int iter) -> bool
{
/**
* By this point, we know that we are looking at a valid file
* descriptor set on the target. We need to check if the target file
* descriptor value passed in as iter is part of the set.
*/
if (FD_ISSET(iter, tgt_set_entry)) {
/**
* We know that the target file descriptor belongs to the set,
* but we do not yet know if the file descriptor is valid or
* that we have a host mapping. Check that now.
*/
auto hbfdp = std::dynamic_pointer_cast<HBFDEntry>((*p->fds)[iter]);
if (!hbfdp)
return true;
auto sim_fd = hbfdp->getSimFD();
/**
* Add the sim_fd to tgt_fd translation into trans_map for use
* later when we need to zero the target fd_set structures and
* then update them with hits returned from the host select call.
*/
trans_map[sim_fd] = iter;
/**
* We know that the host file descriptor exists so now we check
* if we need to update the max count for nfds_h before passing
* the duplicated structure into the host.
*/
nfds_h = std::max(nfds_h - 1, sim_fd + 1);
/**
* Add the host file descriptor to the set that we are going to
* pass into the host.
*/
FD_SET(sim_fd, hst_set_entry);
}
return false;
};
for (int i = 0; i < nfds_t; i++) {
if (fds_read_ptr) {
bool ebadf = try_add_host_set((fd_set*)&*rd_t, &rd_h, i);
if (ebadf) return -EBADF;
}
if (fds_writ_ptr) {
bool ebadf = try_add_host_set((fd_set*)&*wr_t, &wr_h, i);
if (ebadf) return -EBADF;
}
if (fds_excp_ptr) {
bool ebadf = try_add_host_set((fd_set*)&*ex_t, &ex_h, i);
if (ebadf) return -EBADF;
}
}
if (time_val_ptr) {
/**
* It might be possible to decrement the timeval based on some
* derivation of wall clock determined from elapsed simulator ticks
* but that seems like overkill. Rather, we just set the timeval with
* zero timeout. (There is no reason to block during the simulation
* as it only decreases simulator performance.)
*/
tp->tv_sec = 0;
tp->tv_usec = 0;
retval = select(nfds_h,
fds_read_ptr ? &rd_h : nullptr,
fds_writ_ptr ? &wr_h : nullptr,
fds_excp_ptr ? &ex_h : nullptr,
(timeval*)&*tp);
} else {
/**
* If the timeval pointer is null, setup a new timeval structure to
* pass into the host select call. Unfortunately, we will need to
* manually check the return value and throw a retry fault if the
* return value is zero. Allowing the system call to block will
* likely deadlock the event queue.
*/
struct timeval tv = { 0, 0 };
retval = select(nfds_h,
fds_read_ptr ? &rd_h : nullptr,
fds_writ_ptr ? &wr_h : nullptr,
fds_excp_ptr ? &ex_h : nullptr,
&tv);
if (retval == 0) {
/**
* If blocking indefinitely, check the signal list to see if a
* signal would break the poll out of the retry cycle and try to
* return the signal interrupt instead.
*/
for (auto sig : tc->getSystemPtr()->signalList)
if (sig.receiver == p)
return -EINTR;
return SyscallReturn::retry();
}
}
if (retval == -1)
return -errno;
FD_ZERO((fd_set*)&*rd_t);
FD_ZERO((fd_set*)&*wr_t);
FD_ZERO((fd_set*)&*ex_t);
/**
* We need to translate the host file descriptor set into a target file
* descriptor set. This involves both our internal process fd array
* and the fd_set defined in header files.
*/
for (int i = 0; i < nfds_h; i++) {
if (fds_read_ptr) {
if (FD_ISSET(i, &rd_h))
FD_SET(trans_map[i], (fd_set*)&*rd_t);
}
if (fds_writ_ptr) {
if (FD_ISSET(i, &wr_h))
FD_SET(trans_map[i], (fd_set*)&*wr_t);
}
if (fds_excp_ptr) {
if (FD_ISSET(i, &ex_h))
FD_SET(trans_map[i], (fd_set*)&*ex_t);
}
}
if (fds_read_ptr)
rd_t.copyOut(tc->getMemProxy());
if (fds_writ_ptr)
wr_t.copyOut(tc->getMemProxy());
if (fds_excp_ptr)
ex_t.copyOut(tc->getMemProxy());
if (time_val_ptr)
tp.copyOut(tc->getMemProxy());
return retval;
}
template <class OS>
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();
struct pollfd pfd;
pfd.fd = sim_fd;
pfd.events = POLLIN | POLLPRI;
if ((poll(&pfd, 1, 0) == 0)
&& !(hbfdp->getFlags() & OS::TGT_O_NONBLOCK))
return SyscallReturn::retry();
BufferArg buf_arg(buf_ptr, nbytes);
int bytes_read = read(sim_fd, buf_arg.bufferPtr(), nbytes);
if (bytes_read > 0)
buf_arg.copyOut(tc->getMemProxy());
return (bytes_read == -1) ? -errno : bytes_read;
}
template <class OS>
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 buf_arg(buf_ptr, nbytes);
buf_arg.copyIn(tc->getMemProxy());
struct pollfd pfd;
pfd.fd = sim_fd;
pfd.events = POLLOUT;
/**
* We don't want to poll on /dev/random. The kernel will not enable the
* file descriptor for writing unless the entropy in the system falls
* below write_wakeup_threshold. This is not guaranteed to happen
* depending on host settings.
*/
auto ffdp = std::dynamic_pointer_cast<FileFDEntry>(hbfdp);
if (ffdp && (ffdp->getFileName() != "/dev/random")) {
if (!poll(&pfd, 1, 0) && !(ffdp->getFlags() & OS::TGT_O_NONBLOCK))
return SyscallReturn::retry();
}
int bytes_written = write(sim_fd, buf_arg.bufferPtr(), nbytes);
if (bytes_written != -1)
fsync(sim_fd);
return (bytes_written == -1) ? -errno : bytes_written;
}
template <class OS>
SyscallReturn
wait4Func(SyscallDesc *desc, int num, Process *p, ThreadContext *tc)
{
int index = 0;
pid_t pid = p->getSyscallArg(tc, index);
Addr statPtr = p->getSyscallArg(tc, index);
int options = p->getSyscallArg(tc, index);
Addr rusagePtr = p->getSyscallArg(tc, index);
if (rusagePtr)
DPRINTFR(SyscallVerbose,
"%d: %s: syscall wait4: rusage pointer provided however "
"functionality not supported. Ignoring rusage pointer.\n",
curTick(), tc->getCpuPtr()->name());
/**
* Currently, wait4 is only implemented so that it will wait for children
* exit conditions which are denoted by a SIGCHLD signals posted into the
* system signal list. We return no additional information via any of the
* parameters supplied to wait4. If nothing is found in the system signal
* list, we will wait indefinitely for SIGCHLD to post by retrying the
* call.
*/
System *sysh = tc->getSystemPtr();
std::list<BasicSignal>::iterator iter;
for (iter=sysh->signalList.begin(); iter!=sysh->signalList.end(); iter++) {
if (iter->receiver == p) {
if (pid < -1) {
if ((iter->sender->pgid() == -pid)
&& (iter->signalValue == OS::TGT_SIGCHLD))
goto success;
} else if (pid == -1) {
if (iter->signalValue == OS::TGT_SIGCHLD)
goto success;
} else if (pid == 0) {
if ((iter->sender->pgid() == p->pgid())
&& (iter->signalValue == OS::TGT_SIGCHLD))
goto success;
} else {
if ((iter->sender->pid() == pid)
&& (iter->signalValue == OS::TGT_SIGCHLD))
goto success;
}
}
}
return (options & OS::TGT_WNOHANG) ? 0 : SyscallReturn::retry();
success:
// Set status to EXITED for WIFEXITED evaluations.
const int EXITED = 0;
BufferArg statusBuf(statPtr, sizeof(int));
*(int *)statusBuf.bufferPtr() = EXITED;
statusBuf.copyOut(tc->getMemProxy());
// Return the child PID.
pid_t retval = iter->sender->pid();
sysh->signalList.erase(iter);
return retval;
}
template <class OS>
SyscallReturn
acceptFunc(SyscallDesc *desc, int num, Process *p, ThreadContext *tc)
{
struct sockaddr sa;
socklen_t addrLen;
int host_fd;
int index = 0;
int tgt_fd = p->getSyscallArg(tc, index);
Addr addrPtr = p->getSyscallArg(tc, index);
Addr lenPtr = p->getSyscallArg(tc, index);
BufferArg *lenBufPtr = nullptr;
BufferArg *addrBufPtr = nullptr;
auto sfdp = std::dynamic_pointer_cast<SocketFDEntry>((*p->fds)[tgt_fd]);
if (!sfdp)
return -EBADF;
int sim_fd = sfdp->getSimFD();
/**
* We poll the socket file descriptor first to guarantee that we do not
* block on our accept call. The socket can be opened without the
* non-blocking flag (it blocks). This will cause deadlocks between
* communicating processes.
*/
struct pollfd pfd;
pfd.fd = sim_fd;
pfd.events = POLLIN | POLLPRI;
if ((poll(&pfd, 1, 0) == 0)
&& !(sfdp->getFlags() & OS::TGT_O_NONBLOCK))
return SyscallReturn::retry();
if (lenPtr) {
lenBufPtr = new BufferArg(lenPtr, sizeof(socklen_t));
lenBufPtr->copyIn(tc->getMemProxy());
memcpy(&addrLen, (socklen_t *)lenBufPtr->bufferPtr(),
sizeof(socklen_t));
}
if (addrPtr) {
addrBufPtr = new BufferArg(addrPtr, sizeof(struct sockaddr));
addrBufPtr->copyIn(tc->getMemProxy());
memcpy(&sa, (struct sockaddr *)addrBufPtr->bufferPtr(),
sizeof(struct sockaddr));
}
host_fd = accept(sim_fd, &sa, &addrLen);
if (host_fd == -1)
return -errno;
if (addrPtr) {
memcpy(addrBufPtr->bufferPtr(), &sa, sizeof(sa));
addrBufPtr->copyOut(tc->getMemProxy());
delete(addrBufPtr);
}
if (lenPtr) {
*(socklen_t *)lenBufPtr->bufferPtr() = addrLen;
lenBufPtr->copyOut(tc->getMemProxy());
delete(lenBufPtr);
}
auto afdp = std::make_shared<SocketFDEntry>(host_fd, sfdp->_domain,
sfdp->_type, sfdp->_protocol);
return p->fds->allocFD(afdp);
}
#endif // __SIM_SYSCALL_EMUL_HH__
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