Google Git
Sign in
gem5 / public / gem5 / 81779301d8d131b50a661d64b18412a318c34023 / . / src / sim / syscall_emul.hh
blob: 05a29f9feb85f10dbb864971322d51712827d55f [file] [log] [blame]
/*
* Copyright (c) 2012-2013, 2015, 2019-2020 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.
*/
#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
///
/// @file syscall_emul.hh
///
/// This file defines objects used to emulate syscalls from the target
/// application on the host machine.
#if defined(__linux__)
#include <sys/eventfd.h>
#include <sys/statfs.h>
#else
#include <sys/mount.h>
#endif
#ifdef __CYGWIN32__
#include <sys/fcntl.h>
#endif
#include <fcntl.h>
#include <net/if.h>
#include <poll.h>
#include <sys/ioctl.h>
#include <sys/mman.h>
#include <sys/socket.h>
#include <sys/stat.h>
#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 "kern/linux/linux.hh"
#include "mem/page_table.hh"
#include "params/Process.hh"
#include "sim/emul_driver.hh"
#include "sim/futex_map.hh"
#include "sim/guest_abi.hh"
#include "sim/process.hh"
#include "sim/proxy_ptr.hh"
#include "sim/syscall_debug_macros.hh"
#include "sim/syscall_desc.hh"
#include "sim/syscall_emul_buf.hh"
#include "sim/syscall_return.hh"
#if defined(__APPLE__) && defined(__MACH__) && !defined(CMSG_ALIGN)
#define CMSG_ALIGN(len) (((len) + sizeof(size_t) - 1) & ~(sizeof(size_t) - 1))
#endif
//////////////////////////////////////////////////////////////////////
//
// 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.
//
//////////////////////////////////////////////////////////////////////
void warnUnsupportedOS(std::string syscall_name);
/// Handler for unimplemented syscalls that we haven't thought about.
SyscallReturn unimplementedFunc(SyscallDesc *desc, 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. Prints a warning. Return success to the target
/// program.
SyscallReturn ignoreFunc(SyscallDesc *desc, ThreadContext *tc);
/// Like above, but only prints a warning once per syscall desc it's used with.
SyscallReturn
ignoreWarnOnceFunc(SyscallDesc *desc, ThreadContext *tc);
// Target fallocateFunc() handler.
SyscallReturn fallocateFunc(SyscallDesc *desc, ThreadContext *tc,
int tgt_fd, int mode, off_t offset, off_t len);
/// Target exit() handler: terminate current context.
SyscallReturn exitFunc(SyscallDesc *desc, ThreadContext *tc, int status);
/// Target exit_group() handler: terminate simulation. (exit all threads)
SyscallReturn exitGroupFunc(SyscallDesc *desc, ThreadContext *tc, int status);
/// Target set_tid_address() handler.
SyscallReturn setTidAddressFunc(SyscallDesc *desc, ThreadContext *tc,
uint64_t tidPtr);
/// Target getpagesize() handler.
SyscallReturn getpagesizeFunc(SyscallDesc *desc, ThreadContext *tc);
/// Target brk() handler: set brk address.
SyscallReturn brkFunc(SyscallDesc *desc, ThreadContext *tc, Addr new_brk);
/// Target close() handler.
SyscallReturn closeFunc(SyscallDesc *desc, ThreadContext *tc, int tgt_fd);
/// Target lseek() handler.
SyscallReturn lseekFunc(SyscallDesc *desc, ThreadContext *tc,
int tgt_fd, uint64_t offs, int whence);
/// Target _llseek() handler.
SyscallReturn _llseekFunc(SyscallDesc *desc, ThreadContext *tc,
int tgt_fd, uint64_t offset_high,
uint32_t offset_low, Addr result_ptr, int whence);
/// Target munmap() handler.
SyscallReturn munmapFunc(SyscallDesc *desc, ThreadContext *tc, Addr start,
size_t length);
/// Target shutdown() handler.
SyscallReturn shutdownFunc(SyscallDesc *desc, ThreadContext *tc,
int tgt_fd, int how);
/// Target gethostname() handler.
SyscallReturn gethostnameFunc(SyscallDesc *desc, ThreadContext *tc,
Addr buf_ptr, int name_len);
/// Target getcwd() handler.
SyscallReturn getcwdFunc(SyscallDesc *desc, ThreadContext *tc,
Addr buf_ptr, unsigned long size);
/// Target readlink() handler.
SyscallReturn readlinkFunc(SyscallDesc *desc, ThreadContext *tc,
Addr pathname, Addr buf, size_t bufsiz);
/// Target unlink() handler.
SyscallReturn unlinkFunc(SyscallDesc *desc, ThreadContext *tc, Addr pathname);
/// Target link() handler
SyscallReturn linkFunc(SyscallDesc *desc, ThreadContext *tc,
Addr pathname, Addr new_pathname);
/// Target symlink() handler.
SyscallReturn symlinkFunc(SyscallDesc *desc, ThreadContext *tc,
Addr pathname, Addr new_pathname);
/// Target mkdir() handler.
SyscallReturn mkdirFunc(SyscallDesc *desc, ThreadContext *tc,
Addr pathname, mode_t mode);
/// Target mknod() handler.
SyscallReturn mknodFunc(SyscallDesc *desc, ThreadContext *tc,
Addr pathname, mode_t mode, dev_t dev);
/// Target chdir() handler.
SyscallReturn chdirFunc(SyscallDesc *desc, ThreadContext *tc, Addr pathname);
// Target rmdir() handler.
SyscallReturn rmdirFunc(SyscallDesc *desc, ThreadContext *tc, Addr pathname);
/// Target rename() handler.
SyscallReturn renameFunc(SyscallDesc *desc, ThreadContext *tc,
Addr oldpath, Addr newpath);
/// Target truncate() handler.
SyscallReturn truncateFunc(SyscallDesc *desc, ThreadContext *tc,
Addr pathname, off_t length);
/// Target ftruncate() handler.
SyscallReturn ftruncateFunc(SyscallDesc *desc, ThreadContext *tc,
int tgt_fd, off_t length);
/// Target truncate64() handler.
SyscallReturn truncate64Func(SyscallDesc *desc, ThreadContext *tc,
Addr pathname, int64_t length);
/// Target ftruncate64() handler.
SyscallReturn ftruncate64Func(SyscallDesc *desc, ThreadContext *tc,
int tgt_fd, int64_t length);
/// Target umask() handler.
SyscallReturn umaskFunc(SyscallDesc *desc, ThreadContext *tc);
/// Target gettid() handler.
SyscallReturn gettidFunc(SyscallDesc *desc, ThreadContext *tc);
/// Target chown() handler.
SyscallReturn chownFunc(SyscallDesc *desc, ThreadContext *tc,
Addr pathname, uint32_t owner, uint32_t group);
/// Target getpgrpFunc() handler.
SyscallReturn getpgrpFunc(SyscallDesc *desc, ThreadContext *tc);
/// Target setpgid() handler.
SyscallReturn setpgidFunc(SyscallDesc *desc, ThreadContext *tc,
int pid, int pgid);
/// Target fchown() handler.
SyscallReturn fchownFunc(SyscallDesc *desc, ThreadContext *tc,
int tgt_fd, uint32_t owner, uint32_t group);
/// Target dup() handler.
SyscallReturn dupFunc(SyscallDesc *desc, ThreadContext *tc,
int tgt_fd);
/// Target dup2() handler.
SyscallReturn dup2Func(SyscallDesc *desc, ThreadContext *tc,
int old_tgt_fd, int new_tgt_fd);
/// Target fcntl() handler.
SyscallReturn fcntlFunc(SyscallDesc *desc, ThreadContext *tc,
int tgt_fd, int cmd, GuestABI::VarArgs<int> varargs);
/// Target fcntl64() handler.
SyscallReturn fcntl64Func(SyscallDesc *desc, ThreadContext *tc,
int tgt_fd, int cmd);
/// Target pipe() handler.
SyscallReturn pipeFunc(SyscallDesc *desc, ThreadContext *tc, Addr tgt_addr);
/// Target pipe() handler.
SyscallReturn pipe2Func(SyscallDesc *desc, ThreadContext *tc,
Addr tgt_addr, int flags);
/// Target getpid() handler.
SyscallReturn getpidFunc(SyscallDesc *desc, ThreadContext *tc);
// Target getpeername() handler.
SyscallReturn getpeernameFunc(SyscallDesc *desc, ThreadContext *tc,
int tgt_fd, Addr sockAddrPtr, Addr addrlenPtr);
// Target bind() handler.
SyscallReturn bindFunc(SyscallDesc *desc, ThreadContext *tc,
int tgt_fd, Addr buf_ptr, int addrlen);
// Target listen() handler.
SyscallReturn listenFunc(SyscallDesc *desc, ThreadContext *tc,
int tgt_fd, int backlog);
// Target connect() handler.
SyscallReturn connectFunc(SyscallDesc *desc, ThreadContext *tc,
int tgt_fd, Addr buf_ptr, int addrlen);
#if defined(SYS_getdents)
// Target getdents() handler.
SyscallReturn getdentsFunc(SyscallDesc *desc, ThreadContext *tc,
int tgt_fd, Addr buf_ptr, unsigned count);
#endif
#if defined(SYS_getdents64)
// Target getdents() handler.
SyscallReturn getdents64Func(SyscallDesc *desc, ThreadContext *tc,
int tgt_fd, Addr buf_ptr, unsigned count);
#endif
// Target sendto() handler.
SyscallReturn sendtoFunc(SyscallDesc *desc, ThreadContext *tc,
int tgt_fd, Addr bufrPtr, size_t bufrLen, int flags,
Addr addrPtr, socklen_t addrLen);
// Target recvfrom() handler.
SyscallReturn recvfromFunc(SyscallDesc *desc, ThreadContext *tc,
int tgt_fd, Addr bufrPtr, size_t bufrLen,
int flags, Addr addrPtr, Addr addrlenPtr);
// Target recvmsg() handler.
SyscallReturn recvmsgFunc(SyscallDesc *desc, ThreadContext *tc,
int tgt_fd, Addr msgPtr, int flags);
// Target sendmsg() handler.
SyscallReturn sendmsgFunc(SyscallDesc *desc, ThreadContext *tc,
int tgt_fd, Addr msgPtr, int flags);
// Target getuid() handler.
SyscallReturn getuidFunc(SyscallDesc *desc, ThreadContext *tc);
/// Target getgid() handler.
SyscallReturn getgidFunc(SyscallDesc *desc, ThreadContext *tc);
/// Target getppid() handler.
SyscallReturn getppidFunc(SyscallDesc *desc, ThreadContext *tc);
/// Target geteuid() handler.
SyscallReturn geteuidFunc(SyscallDesc *desc, ThreadContext *tc);
/// Target getegid() handler.
SyscallReturn getegidFunc(SyscallDesc *desc, ThreadContext *tc);
/// Target access() handler
SyscallReturn accessFunc(SyscallDesc *desc, ThreadContext *tc,
Addr pathname, mode_t mode);
// Target getsockopt() handler.
SyscallReturn getsockoptFunc(SyscallDesc *desc, ThreadContext *tc,
int tgt_fd, int level, int optname,
Addr valPtr, Addr lenPtr);
// Target setsockopt() handler.
SyscallReturn setsockoptFunc(SyscallDesc *desc, ThreadContext *tc,
int tgt_fd, int level, int optname,
Addr valPtr, socklen_t len);
SyscallReturn getcpuFunc(SyscallDesc *desc, ThreadContext *tc,
VPtr<uint32_t> cpu, VPtr<uint32_t> node,
VPtr<uint32_t> tcache);
// Target getsockname() handler.
SyscallReturn getsocknameFunc(SyscallDesc *desc, ThreadContext *tc,
int tgt_fd, Addr addrPtr, Addr lenPtr);
/// Futex system call
/// Implemented by Daniel Sanchez
/// Used by printf's in multi-threaded apps
template <class OS>
SyscallReturn
futexFunc(SyscallDesc *desc, ThreadContext *tc,
Addr uaddr, int op, int val, int timeout, Addr uaddr2, int val3)
{
using namespace std;
auto process = tc->getProcessPtr();
/*
* 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;
op &= ~OS::TGT_FUTEX_CLOCK_REALTIME_FLAG;
FutexMap &futex_map = tc->getSystemPtr()->futexMap;
if (OS::TGT_FUTEX_WAIT == op || OS::TGT_FUTEX_WAIT_BITSET == op) {
// Ensure futex system call accessed atomically.
BufferArg buf(uaddr, sizeof(int));
buf.copyIn(tc->getVirtProxy());
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;
if (OS::TGT_FUTEX_WAIT == op) {
futex_map.suspend(uaddr, process->tgid(), tc);
} else {
futex_map.suspend_bitset(uaddr, process->tgid(), tc, val3);
}
return 0;
} else if (OS::TGT_FUTEX_WAKE == op) {
return futex_map.wakeup(uaddr, process->tgid(), val);
} else if (OS::TGT_FUTEX_WAKE_BITSET == op) {
return futex_map.wakeup_bitset(uaddr, process->tgid(), val3);
} else if (OS::TGT_FUTEX_REQUEUE == op ||
OS::TGT_FUTEX_CMP_REQUEUE == op) {
// Ensure futex system call accessed atomically.
BufferArg buf(uaddr, sizeof(int));
buf.copyIn(tc->getVirtProxy());
int mem_val = *(int*)buf.bufferPtr();
/*
* For CMP_REQUEUE, the whole operation is only started only if
* val3 is still the value of the futex pointed to by uaddr.
*/
if (OS::TGT_FUTEX_CMP_REQUEUE && val3 != mem_val)
return -OS::TGT_EWOULDBLOCK;
return futex_map.requeue(uaddr, process->tgid(), val, timeout, uaddr2);
} else if (OS::TGT_FUTEX_WAKE_OP == op) {
/*
* The FUTEX_WAKE_OP operation is equivalent to executing the
* following code atomically and totally ordered with respect to
* other futex operations on any of the two supplied futex words:
*
* int oldval = *(int *) addr2;
* *(int *) addr2 = oldval op oparg;
* futex(addr1, FUTEX_WAKE, val, 0, 0, 0);
* if (oldval cmp cmparg)
* futex(addr2, FUTEX_WAKE, val2, 0, 0, 0);
*
* (op, oparg, cmp, cmparg are encoded in val3)
*
* +---+---+-----------+-----------+
* |op |cmp| oparg | cmparg |
* +---+---+-----------+-----------+
* 4 4 12 12 <== # of bits
*
* reference: http://man7.org/linux/man-pages/man2/futex.2.html
*
*/
// get value from simulated-space
BufferArg buf(uaddr2, sizeof(int));
buf.copyIn(tc->getVirtProxy());
int oldval = *(int*)buf.bufferPtr();
int newval = oldval;
// extract op, oparg, cmp, cmparg from val3
int wake_cmparg = val3 & 0xfff;
int wake_oparg = (val3 & 0xfff000) >> 12;
int wake_cmp = (val3 & 0xf000000) >> 24;
int wake_op = (val3 & 0xf0000000) >> 28;
if ((wake_op & OS::TGT_FUTEX_OP_ARG_SHIFT) >> 3 == 1)
wake_oparg = (1 << wake_oparg);
wake_op &= ~OS::TGT_FUTEX_OP_ARG_SHIFT;
// perform operation on the value of the second futex
if (wake_op == OS::TGT_FUTEX_OP_SET)
newval = wake_oparg;
else if (wake_op == OS::TGT_FUTEX_OP_ADD)
newval += wake_oparg;
else if (wake_op == OS::TGT_FUTEX_OP_OR)
newval |= wake_oparg;
else if (wake_op == OS::TGT_FUTEX_OP_ANDN)
newval &= ~wake_oparg;
else if (wake_op == OS::TGT_FUTEX_OP_XOR)
newval ^= wake_oparg;
// copy updated value back to simulated-space
*(int*)buf.bufferPtr() = newval;
buf.copyOut(tc->getVirtProxy());
// perform the first wake-up
int woken1 = futex_map.wakeup(uaddr, process->tgid(), val);
int woken2 = 0;
// calculate the condition of the second wake-up
bool is_wake2 = false;
if (wake_cmp == OS::TGT_FUTEX_OP_CMP_EQ)
is_wake2 = oldval == wake_cmparg;
else if (wake_cmp == OS::TGT_FUTEX_OP_CMP_NE)
is_wake2 = oldval != wake_cmparg;
else if (wake_cmp == OS::TGT_FUTEX_OP_CMP_LT)
is_wake2 = oldval < wake_cmparg;
else if (wake_cmp == OS::TGT_FUTEX_OP_CMP_LE)
is_wake2 = oldval <= wake_cmparg;
else if (wake_cmp == OS::TGT_FUTEX_OP_CMP_GT)
is_wake2 = oldval > wake_cmparg;
else if (wake_cmp == OS::TGT_FUTEX_OP_CMP_GE)
is_wake2 = oldval >= wake_cmparg;
// perform the second wake-up
if (is_wake2)
woken2 = futex_map.wakeup(uaddr2, process->tgid(), timeout);
return woken1 + woken2;
}
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, ThreadContext *tc);
/// 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 = 1000 * 1000 * 1000;
/// Helper function to convert current elapsed time to seconds and
/// microseconds.
template <class T1, class T2>
void
getElapsedTimeMicro(T1 &sec, T2 &usec)
{
static const int OneMillion = 1000 * 1000;
uint64_t elapsed_usecs = curTick() / SimClock::Int::us;
sec = elapsed_usecs / OneMillion;
usec = elapsed_usecs % OneMillion;
}
/// Helper function to convert current elapsed time to seconds and
/// nanoseconds.
template <class T1, class T2>
void
getElapsedTimeNano(T1 &sec, T2 &nsec)
{
static const int OneBillion = 1000 * 1000 * 1000;
uint64_t elapsed_nsecs = curTick() / SimClock::Int::ns;
sec = elapsed_nsecs / OneBillion;
nsec = elapsed_nsecs % OneBillion;
}
//////////////////////////////////////////////////////////////////////
//
// 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 OS, typename TgtStatPtr, typename HostStatPtr>
void
copyOutStatBuf(TgtStatPtr tgt, HostStatPtr host, bool fakeTTY=false)
{
constexpr ByteOrder bo = OS::byteOrder;
if (fakeTTY)
tgt->st_dev = 0xA;
else
tgt->st_dev = host->st_dev;
tgt->st_dev = htog(tgt->st_dev, bo);
tgt->st_ino = host->st_ino;
tgt->st_ino = htog(tgt->st_ino, bo);
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 = htog(tgt->st_mode, bo);
tgt->st_nlink = host->st_nlink;
tgt->st_nlink = htog(tgt->st_nlink, bo);
tgt->st_uid = host->st_uid;
tgt->st_uid = htog(tgt->st_uid, bo);
tgt->st_gid = host->st_gid;
tgt->st_gid = htog(tgt->st_gid, bo);
if (fakeTTY)
tgt->st_rdev = 0x880d;
else
tgt->st_rdev = host->st_rdev;
tgt->st_rdev = htog(tgt->st_rdev, bo);
tgt->st_size = host->st_size;
tgt->st_size = htog(tgt->st_size, bo);
tgt->st_atimeX = host->st_atime;
tgt->st_atimeX = htog(tgt->st_atimeX, bo);
tgt->st_mtimeX = host->st_mtime;
tgt->st_mtimeX = htog(tgt->st_mtimeX, bo);
tgt->st_ctimeX = host->st_ctime;
tgt->st_ctimeX = htog(tgt->st_ctimeX, bo);
// 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 = htog(tgt->st_blksize, bo);
tgt->st_blocks = host->st_blocks;
tgt->st_blocks = htog(tgt->st_blocks, bo);
}
// Same for stat64
template <typename OS, typename TgtStatPtr, typename HostStatPtr>
void
copyOutStat64Buf(TgtStatPtr tgt, HostStatPtr host,
bool fakeTTY=false)
{
copyOutStatBuf<OS>(tgt, host, fakeTTY);
#if defined(STAT_HAVE_NSEC)
constexpr ByteOrder bo = OS::byteOrder;
tgt->st_atime_nsec = host->st_atime_nsec;
tgt->st_atime_nsec = htog(tgt->st_atime_nsec, bo);
tgt->st_mtime_nsec = host->st_mtime_nsec;
tgt->st_mtime_nsec = htog(tgt->st_mtime_nsec, bo);
tgt->st_ctime_nsec = host->st_ctime_nsec;
tgt->st_ctime_nsec = htog(tgt->st_ctime_nsec, bo);
#else
tgt->st_atime_nsec = 0;
tgt->st_mtime_nsec = 0;
tgt->st_ctime_nsec = 0;
#endif
}
template <class OS, typename TgtStatPtr, typename HostStatPtr>
void
copyOutStatfsBuf(TgtStatPtr tgt, HostStatPtr host)
{
constexpr ByteOrder bo = OS::byteOrder;
tgt->f_type = htog(host->f_type, bo);
#if defined(__FreeBSD__) || defined(__NetBSD__) || defined(__OpenBSD__)
tgt->f_bsize = htog(host->f_iosize, bo);
#else
tgt->f_bsize = htog(host->f_bsize, bo);
#endif
tgt->f_blocks = htog(host->f_blocks, bo);
tgt->f_bfree = htog(host->f_bfree, bo);
tgt->f_bavail = htog(host->f_bavail, bo);
tgt->f_files = htog(host->f_files, bo);
tgt->f_ffree = htog(host->f_ffree, bo);
memcpy(&tgt->f_fsid, &host->f_fsid, sizeof(host->f_fsid));
#if defined(__FreeBSD__) || defined(__NetBSD__) || defined(__OpenBSD__)
tgt->f_namelen = htog(host->f_namemax, bo);
tgt->f_frsize = htog(host->f_bsize, bo);
#elif defined(__APPLE__)
tgt->f_namelen = 0;
tgt->f_frsize = 0;
#else
tgt->f_namelen = htog(host->f_namelen, bo);
tgt->f_frsize = htog(host->f_frsize, bo);
#endif
#if defined(__linux__)
memcpy(&tgt->f_spare, &host->f_spare,
std::min(sizeof(host->f_spare), sizeof(tgt->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
}
/// 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, ThreadContext *tc,
int tgt_fd, unsigned req, Addr addr)
{
auto p = tc->getProcessPtr();
DPRINTF_SYSCALL(Verbose, "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) {
EmulatedDriver *emul_driver = dfdp->getDriver();
if (emul_driver)
return emul_driver->ioctl(tc, req, addr);
}
auto sfdp = std::dynamic_pointer_cast<SocketFDEntry>((*p->fds)[tgt_fd]);
if (sfdp) {
int status;
switch (req) {
case SIOCGIFCONF: {
BufferArg conf_arg(addr, sizeof(ifconf));
conf_arg.copyIn(tc->getVirtProxy());
ifconf *conf = (ifconf*)conf_arg.bufferPtr();
Addr ifc_buf_addr = (Addr)conf->ifc_buf;
BufferArg ifc_buf_arg(ifc_buf_addr, conf->ifc_len);
ifc_buf_arg.copyIn(tc->getVirtProxy());
conf->ifc_buf = (char*)ifc_buf_arg.bufferPtr();
status = ioctl(sfdp->getSimFD(), req, conf_arg.bufferPtr());
if (status != -1) {
conf->ifc_buf = (char*)ifc_buf_addr;
ifc_buf_arg.copyOut(tc->getVirtProxy());
conf_arg.copyOut(tc->getVirtProxy());
}
return status;
}
case SIOCGIFFLAGS:
#if defined(__linux__)
case SIOCGIFINDEX:
#endif
case SIOCGIFNETMASK:
case SIOCGIFADDR:
#if defined(__linux__)
case SIOCGIFHWADDR:
#endif
case SIOCGIFMTU: {
BufferArg req_arg(addr, sizeof(ifreq));
req_arg.copyIn(tc->getVirtProxy());
status = ioctl(sfdp->getSimFD(), req, req_arg.bufferPtr());
if (status != -1)
req_arg.copyOut(tc->getVirtProxy());
return status;
}
}
}
/**
* 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;
}
/// Target open() handler.
template <class OS>
SyscallReturn
openatFunc(SyscallDesc *desc, ThreadContext *tc,
int tgt_dirfd, Addr pathname, int tgt_flags, int mode)
{
auto p = tc->getProcessPtr();
/**
* 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->getVirtProxy().tryReadString(path, pathname))
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.
*/
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("%s: cannot decode flags %#x", desc->name(), tgt_flags);
#ifdef __CYGWIN32__
host_flags |= O_BINARY;
#endif
/**
* 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.
*/
std::string redir_path = path;
std::string abs_path = path;
if (tgt_dirfd == OS::TGT_AT_FDCWD) {
abs_path = p->absolutePath(path, true);
redir_path = p->checkPathRedirect(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;
abs_path = ffdp->getFileName() + path;
redir_path = p->checkPathRedirect(abs_path);
}
/**
* 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(abs_path, "/dev/")) {
std::string filename = abs_path.substr(strlen("/dev/"));
EmulatedDriver *drv = p->findDriver(filename);
if (drv) {
DPRINTF_SYSCALL(Verbose, "%s: passing call to "
"driver open with path[%s]\n",
desc->name(), abs_path.c_str());
return drv->open(tc, mode, host_flags);
}
/**
* Fall through here for pass through to host devices, such
* as /dev/zero
*/
}
/**
* We make several attempts resolve a call to open.
*
* 1) Resolve any path redirection before hand. This will set the path
* up with variable 'redir_path' which may contain a modified path or
* the original path value. This should already be done in prior code.
* 2) Try to handle the access using 'special_paths'. Some special_paths
* and files cannot be called on the host and need to be handled as
* special cases inside the simulator. These special_paths are handled by
* C++ routines to provide output back to userspace.
* 3) 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. Again, the openImpl tries to
* USE_THE_HOST_FILESYSTEM_OPEN (with a possible redirection to the
* faux-filesystem files). The faux-filesystem is dynamically created
* during simulator configuration using Python functions.
* 4) If the host cannot open the file, the open attempt failed in "3)".
* Return the host's error code back through the system call to the
* simulated process. If running a debug trace, also notify the user that
* the open call failed.
*
* Any success will set sim_fd to something other than -1 and skip the
* next conditions effectively bypassing them.
*/
int sim_fd = -1;
std::string used_path;
std::vector<std::string> special_paths =
{ "/proc/meminfo/", "/system/", "/platform/", "/etc/passwd",
"/proc/self/maps", "/dev/urandom",
"/sys/devices/system/cpu/online" };
for (auto entry : special_paths) {
if (startswith(path, entry)) {
sim_fd = OS::openSpecialFile(abs_path, p, tc);
used_path = abs_path;
}
}
if (sim_fd == -1) {
sim_fd = open(redir_path.c_str(), host_flags, mode);
used_path = redir_path;
}
if (sim_fd == -1) {
int local = -errno;
DPRINTF_SYSCALL(Verbose, "%s: failed -> path:%s "
"(inferred from:%s)\n", desc->name(),
used_path.c_str(), 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, "%s: sim_fd[%d], target_fd[%d] -> path:%s\n"
"(inferred from:%s)\n", desc->name(),
sim_fd, tgt_fd, used_path.c_str(), path.c_str());
return tgt_fd;
}
/// Target open() handler.
template <class OS>
SyscallReturn
openFunc(SyscallDesc *desc, ThreadContext *tc,
Addr pathname, int tgt_flags, int mode)
{
return openatFunc<OS>(
desc, tc, OS::TGT_AT_FDCWD, pathname, tgt_flags, mode);
}
/// Target unlinkat() handler.
template <class OS>
SyscallReturn
unlinkatFunc(SyscallDesc *desc, ThreadContext *tc, int dirfd, Addr pathname)
{
if (dirfd != OS::TGT_AT_FDCWD)
warn("unlinkat: first argument not AT_FDCWD; unlikely to work");
return unlinkFunc(desc, tc, pathname);
}
/// Target facessat() handler
template <class OS>
SyscallReturn
faccessatFunc(SyscallDesc *desc, ThreadContext *tc,
int dirfd, Addr pathname, int mode)
{
if (dirfd != OS::TGT_AT_FDCWD)
warn("faccessat: first argument not AT_FDCWD; unlikely to work");
return accessFunc(desc, tc, pathname, mode);
}
/// Target readlinkat() handler
template <class OS>
SyscallReturn
readlinkatFunc(SyscallDesc *desc, ThreadContext *tc,
int dirfd, Addr pathname, Addr buf, size_t bufsiz)
{
if (dirfd != OS::TGT_AT_FDCWD)
warn("openat: first argument not AT_FDCWD; unlikely to work");
return readlinkFunc(desc, tc, pathname, buf, bufsiz);
}
/// Target renameat() handler.
template <class OS>
SyscallReturn
renameatFunc(SyscallDesc *desc, ThreadContext *tc,
int olddirfd, Addr oldpath, int newdirfd, Addr newpath)
{
if (olddirfd != OS::TGT_AT_FDCWD)
warn("renameat: first argument not AT_FDCWD; unlikely to work");
if (newdirfd != OS::TGT_AT_FDCWD)
warn("renameat: third argument not AT_FDCWD; unlikely to work");
return renameFunc(desc, tc, oldpath, newpath);
}
/// Target sysinfo() handler.
template <class OS>
SyscallReturn
sysinfoFunc(SyscallDesc *desc, ThreadContext *tc,
VPtr<typename OS::tgt_sysinfo> sysinfo)
{
auto process = tc->getProcessPtr();
sysinfo->uptime = seconds_since_epoch;
sysinfo->totalram = process->system->memSize();
sysinfo->mem_unit = 1;
return 0;
}
/// Target chmod() handler.
template <class OS>
SyscallReturn
chmodFunc(SyscallDesc *desc, ThreadContext *tc, Addr pathname, mode_t mode)
{
std::string path;
auto process = tc->getProcessPtr();
if (!tc->getVirtProxy().tryReadString(path, pathname))
return -EFAULT;
mode_t hostMode = 0;
// XXX translate mode flags via OS::something???
hostMode = mode;
// Adjust path for cwd and redirection
path = process->checkPathRedirect(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, ThreadContext *tc,
Addr fdsPtr, int nfds, int tmout)
{
auto p = tc->getProcessPtr();
BufferArg fdsBuf(fdsPtr, sizeof(struct pollfd) * nfds);
fdsBuf.copyIn(tc->getVirtProxy());
/**
* 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 (int 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 (int 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->getVirtProxy());
return status;
}
/// Target fchmod() handler.
template <class OS>
SyscallReturn
fchmodFunc(SyscallDesc *desc, ThreadContext *tc, int tgt_fd, uint32_t mode)
{
auto p = tc->getProcessPtr();
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, ThreadContext *tc,
Addr start, uint64_t old_length, uint64_t new_length, uint64_t flags,
GuestABI::VarArgs<uint64_t> varargs)
{
auto p = tc->getProcessPtr();
Addr page_bytes = tc->getSystemPtr()->getPageBytes();
uint64_t provided_address = 0;
bool use_provided_address = flags & OS::TGT_MREMAP_FIXED;
if (use_provided_address)
provided_address = varargs.get<uint64_t>();
if ((start % page_bytes != 0) ||
(provided_address % page_bytes != 0)) {
warn("mremap failing: arguments not page aligned");
return -EINVAL;
}
new_length = roundUp(new_length, page_bytes);
if (new_length > old_length) {
Addr mmap_end = p->memState->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;
p->memState->mapRegion(mmap_end, diff, "remapped");
p->memState->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 = p->mmapGrowsDown() ?
mmap_end - new_length : mmap_end;
mmap_end = p->mmapGrowsDown() ?
new_start : mmap_end + new_length;
p->memState->setMmapEnd(mmap_end);
}
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
p->allocateMem(new_start + old_length,
new_length - old_length,
use_provided_address /* clobber */);
if (use_provided_address &&
((new_start + new_length > p->memState->getMmapEnd() &&
!p->mmapGrowsDown()) ||
(new_start < p->memState->getMmapEnd() &&
p->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);
p->memState->remapRegion(start, new_start, old_length);
return new_start;
}
}
} else {
// Shrink a region
if (use_provided_address && provided_address != start)
p->memState->remapRegion(start, provided_address, new_length);
if (new_length != old_length)
p->memState->unmapRegion(start + new_length,
old_length - new_length);
return use_provided_address ? provided_address : start;
}
}
/// Target stat() handler.
template <class OS>
SyscallReturn
statFunc(SyscallDesc *desc, ThreadContext *tc,
Addr pathname, VPtr<typename OS::tgt_stat> tgt_stat)
{
std::string path;
auto process = tc->getProcessPtr();
if (!tc->getVirtProxy().tryReadString(path, pathname))
return -EFAULT;
// Adjust path for cwd and redirection
path = process->checkPathRedirect(path);
struct stat hostBuf;
int result = stat(path.c_str(), &hostBuf);
if (result < 0)
return -errno;
copyOutStatBuf<OS>(tgt_stat, &hostBuf);
return 0;
}
/// Target stat64() handler.
template <class OS>
SyscallReturn
stat64Func(SyscallDesc *desc, ThreadContext *tc,
Addr pathname, VPtr<typename OS::tgt_stat64> tgt_stat)
{
std::string path;
auto process = tc->getProcessPtr();
if (!tc->getVirtProxy().tryReadString(path, pathname))
return -EFAULT;
// Adjust path for cwd and redirection
path = process->checkPathRedirect(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>(tgt_stat, &hostBuf);
return 0;
}
/// Target fstatat64() handler.
template <class OS>
SyscallReturn
fstatat64Func(SyscallDesc *desc, ThreadContext *tc,
int dirfd, Addr pathname, VPtr<typename OS::tgt_stat64> tgt_stat)
{
auto process = tc->getProcessPtr();
if (dirfd != OS::TGT_AT_FDCWD)
warn("fstatat64: first argument not AT_FDCWD; unlikely to work");
std::string path;
if (!tc->getVirtProxy().tryReadString(path, pathname))
return -EFAULT;
// Adjust path for cwd and redirection
path = process->checkPathRedirect(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>(tgt_stat, &hostBuf);
return 0;
}
/// Target fstat64() handler.
template <class OS>
SyscallReturn
fstat64Func(SyscallDesc *desc, ThreadContext *tc,
int tgt_fd, VPtr<typename OS::tgt_stat64> tgt_stat)
{
auto p = tc->getProcessPtr();
auto ffdp = std::dynamic_pointer_cast<HBFDEntry>((*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>(tgt_stat, &hostBuf, (sim_fd == 1));
return 0;
}
/// Target lstat() handler.
template <class OS>
SyscallReturn
lstatFunc(SyscallDesc *desc, ThreadContext *tc,
Addr pathname, VPtr<typename OS::tgt_stat> tgt_stat)
{
std::string path;
auto process = tc->getProcessPtr();
if (!tc->getVirtProxy().tryReadString(path, pathname))
return -EFAULT;
// Adjust path for cwd and redirection
path = process->checkPathRedirect(path);
struct stat hostBuf;
int result = lstat(path.c_str(), &hostBuf);
if (result < 0)
return -errno;
copyOutStatBuf<OS>(tgt_stat, &hostBuf);
return 0;
}
/// Target lstat64() handler.
template <class OS>
SyscallReturn
lstat64Func(SyscallDesc *desc, ThreadContext *tc,
Addr pathname, VPtr<typename OS::tgt_stat64> tgt_stat)
{
std::string path;
auto process = tc->getProcessPtr();
if (!tc->getVirtProxy().tryReadString(path, pathname))
return -EFAULT;
// Adjust path for cwd and redirection
path = process->checkPathRedirect(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>(tgt_stat, &hostBuf);
return 0;
}
/// Target fstat() handler.
template <class OS>
SyscallReturn
fstatFunc(SyscallDesc *desc, ThreadContext *tc,
int tgt_fd, VPtr<typename OS::tgt_stat> tgt_stat)
{
auto p = tc->getProcessPtr();
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>(tgt_stat, &hostBuf, (sim_fd == 1));
return 0;
}
/// Target statfs() handler.
template <class OS>
SyscallReturn
statfsFunc(SyscallDesc *desc, ThreadContext *tc,
Addr pathname, VPtr<typename OS::tgt_statfs> tgt_stat)
{
#if defined(__linux__)
std::string path;
auto process = tc->getProcessPtr();
if (!tc->getVirtProxy().tryReadString(path, pathname))
return -EFAULT;
// Adjust path for cwd and redirection
path = process->checkPathRedirect(path);
struct statfs hostBuf;
int result = statfs(path.c_str(), &hostBuf);
if (result < 0)
return -errno;
copyOutStatfsBuf<OS>(tgt_stat, &hostBuf);
return 0;
#else
warnUnsupportedOS("statfs");
return -1;
#endif
}
template <class OS>
SyscallReturn
cloneFunc(SyscallDesc *desc, ThreadContext *tc, RegVal flags, RegVal newStack,
Addr ptidPtr, Addr ctidPtr, Addr tlsPtr)
{
auto p = tc->getProcessPtr();
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 = tc->getSystemPtr()->threads.findFree())) {
DPRINTF_SYSCALL(Verbose, "clone: no spare thread context in system"
"[cpu %d, thread %d]", tc->cpuId(), tc->threadId());
return -EAGAIN;
}
/**
* 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->tgtCwd);
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();
pp->useArchPT = p->useArchPT;
pp->kvmInSE = p->kvmInSE;
Process *cp = pp->create();
// TODO: there is no way to know when the Process SimObject is done with
// the params pointer. Both the params pointer (pp) and the process
// pointer (cp) are normally managed in python and are never cleaned up.
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->getVirtProxy());
}
if (flags & OS::TGT_CLONE_THREAD) {
cp->pTable->shared = true;
cp->useForClone = true;
}
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->getVirtProxy());
}
if (flags & OS::TGT_CLONE_CHILD_CLEARTID)
cp->childClearTID = (uint64_t)ctidPtr;
ctc->clearArchRegs();
OS::archClone(flags, p, cp, tc, ctc, newStack, tlsPtr);
desc->returnInto(ctc, 0);
#if THE_ISA == SPARC_ISA
tc->setIntReg(TheISA::SyscallPseudoReturnReg, 0);
ctc->setIntReg(TheISA::SyscallPseudoReturnReg, 1);
#endif
TheISA::PCState cpc = tc->pcState();
if (!p->kvmInSE)
cpc.advance();
ctc->pcState(cpc);
ctc->activate();
return cp->pid();
}
template <class OS>
SyscallReturn
cloneBackwardsFunc(SyscallDesc *desc, ThreadContext *tc, RegVal flags,
RegVal newStack, Addr ptidPtr, Addr tlsPtr, Addr ctidPtr)
{
return cloneFunc<OS>(desc, tc, flags, newStack, ptidPtr, ctidPtr, tlsPtr);
}
/// Target fstatfs() handler.
template <class OS>
SyscallReturn
fstatfsFunc(SyscallDesc *desc, ThreadContext *tc,
int tgt_fd, VPtr<typename OS::tgt_statfs> tgt_stat)
{
auto p = tc->getProcessPtr();
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>(tgt_stat, &hostBuf);
return 0;
}
/// Target readv() handler.
template <class OS>
SyscallReturn
readvFunc(SyscallDesc *desc, ThreadContext *tc,
int tgt_fd, uint64_t tiov_base, size_t count)
{
auto p = tc->getProcessPtr();
auto ffdp = std::dynamic_pointer_cast<FileFDEntry>((*p->fds)[tgt_fd]);
if (!ffdp)
return -EBADF;
int sim_fd = ffdp->getSimFD();
PortProxy &prox = tc->getVirtProxy();
typename OS::tgt_iovec tiov[count];
struct iovec hiov[count];
for (size_t i = 0; i < count; ++i) {
prox.readBlob(tiov_base + (i * sizeof(typename OS::tgt_iovec)),
&tiov[i], sizeof(typename OS::tgt_iovec));
hiov[i].iov_len = gtoh(tiov[i].iov_len, OS::byteOrder);
hiov[i].iov_base = new char [hiov[i].iov_len];
}
int result = readv(sim_fd, hiov, count);
int local_errno = errno;
for (size_t i = 0; i < count; ++i) {
if (result != -1) {
prox.writeBlob(htog(tiov[i].iov_base, OS::byteOrder),
hiov[i].iov_base, hiov[i].iov_len);
}
delete [] (char *)hiov[i].iov_base;
}
return (result == -1) ? -local_errno : result;
}
/// Target writev() handler.
template <class OS>
SyscallReturn
writevFunc(SyscallDesc *desc, ThreadContext *tc,
int tgt_fd, uint64_t tiov_base, size_t count)
{
auto p = tc->getProcessPtr();
auto hbfdp = std::dynamic_pointer_cast<HBFDEntry>((*p->fds)[tgt_fd]);
if (!hbfdp)
return -EBADF;
int sim_fd = hbfdp->getSimFD();
PortProxy &prox = tc->getVirtProxy();
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),
&tiov, sizeof(typename OS::tgt_iovec));
hiov[i].iov_len = gtoh(tiov.iov_len, OS::byteOrder);
hiov[i].iov_base = new char [hiov[i].iov_len];
prox.readBlob(gtoh(tiov.iov_base, OS::byteOrder), 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;
return (result == -1) ? -errno : result;
}
/// Target mmap() handler.
template <class OS>
SyscallReturn
mmapFunc(SyscallDesc *desc, ThreadContext *tc,
Addr start, typename OS::size_t length, int prot,
int tgt_flags, int tgt_fd, typename OS::off_t offset)
{
auto p = tc->getProcessPtr();
Addr page_bytes = tc->getSystemPtr()->getPageBytes();
if (start & (page_bytes - 1) ||
offset & (page_bytes - 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_once("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, page_bytes);
int sim_fd = -1;
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(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();
/**
* 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.
*/
if (p->interpImage.contains(tc->pcState().instAddr())) {
std::shared_ptr<FDEntry> fdep = (*p->fds)[tgt_fd];
auto ffdp = std::dynamic_pointer_cast<FileFDEntry>(fdep);
auto *lib = Loader::createObjectFile(p->checkPathRedirect(
ffdp->getFileName()));
DPRINTF_SYSCALL(Verbose, "Loading symbols from %s\n",
ffdp->getFileName());
if (lib) {
Addr offset = lib->buildImage().minAddr() + start;
Loader::debugSymbolTable.insert(*lib->symtab().offset(offset));
}
}
}
/**
* Not TGT_MAP_FIXED means we can start wherever we want.
*/
if (!(tgt_flags & OS::TGT_MAP_FIXED)) {
/**
* If the application provides us with a hint, we should make some
* small amount of effort to accomodate it. Basically, we check if
* every single VA within the requested range is unused. If it is,
* we give the application the range. If not, we fall back to
* extending the global mmap region.
*/
if (!(start && p->memState->isUnmapped(start, length))) {
/**
* Extend global mmap region to give us some room for the app.
*/
start = p->memState->extendMmap(length);
}
}
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.
*/
if (tgt_flags & OS::TGT_MAP_FIXED) {
/**
* We might already have some old VMAs mapped to this region, so
* make sure to clear em out!
*/
p->memState->unmapRegion(start, length);
}
/**
* Figure out a human-readable name for the mapping.
*/
std::string region_name;
if (tgt_flags & OS::TGT_MAP_ANONYMOUS) {
region_name = "anon";
} else {
std::shared_ptr<FDEntry> fdep = (*p->fds)[tgt_fd];
auto ffdp = std::dynamic_pointer_cast<FileFDEntry>(fdep);
region_name = ffdp->getFileName();
}
/**
* Setup the correct VMA for this region. The physical pages will be
* mapped lazily.
*/
p->memState->mapRegion(start, length, region_name, sim_fd, offset);
return start;
}
template <class OS>
SyscallReturn
pread64Func(SyscallDesc *desc, ThreadContext *tc,
int tgt_fd, Addr bufPtr, int nbytes, int offset)
{
auto p = tc->getProcessPtr();
auto ffdp = std::dynamic_pointer_cast<FileFDEntry>((*p->fds)[tgt_fd]);
if (!ffdp)
return -EBADF;
int sim_fd = ffdp->getSimFD();
BufferArg bufArg(bufPtr, nbytes);
int bytes_read = pread(sim_fd, bufArg.bufferPtr(), nbytes, offset);
bufArg.copyOut(tc->getVirtProxy());
return (bytes_read == -1) ? -errno : bytes_read;
}
template <class OS>
SyscallReturn
pwrite64Func(SyscallDesc *desc, ThreadContext *tc,
int tgt_fd, Addr bufPtr, int nbytes, int offset)
{
auto p = tc->getProcessPtr();
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->getVirtProxy());
int bytes_written = pwrite(sim_fd, bufArg.bufferPtr(), nbytes, offset);
return (bytes_written == -1) ? -errno : bytes_written;
}
/// Target mmap2() handler.
template <class OS>
SyscallReturn
mmap2Func(SyscallDesc *desc, ThreadContext *tc,
Addr start, typename OS::size_t length, int prot,
int tgt_flags, int tgt_fd, typename OS::off_t offset)
{
return mmapFunc<OS>(desc, tc, start, length, prot, tgt_flags,
tgt_fd, offset * tc->getSystemPtr()->getPageBytes());
}
/// Target getrlimit() handler.
template <class OS>
SyscallReturn
getrlimitFunc(SyscallDesc *desc, ThreadContext *tc,
unsigned resource, VPtr<typename OS::rlimit> rlp)
{
const ByteOrder bo = OS::byteOrder;
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 = htog(rlp->rlim_cur, bo);
rlp->rlim_max = htog(rlp->rlim_max, bo);
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 = htog(rlp->rlim_cur, bo);
rlp->rlim_max = htog(rlp->rlim_max, bo);
break;
case OS::TGT_RLIMIT_NPROC:
rlp->rlim_cur = rlp->rlim_max = tc->getSystemPtr()->threads.size();
rlp->rlim_cur = htog(rlp->rlim_cur, bo);
rlp->rlim_max = htog(rlp->rlim_max, bo);
break;
default:
warn("getrlimit: unimplemented resource %d", resource);
return -EINVAL;
break;
}
return 0;
}
template <class OS>
SyscallReturn
prlimitFunc(SyscallDesc *desc, ThreadContext *tc,
int pid, int resource, Addr n, VPtr<typename OS::rlimit> rlp)
{
if (pid != 0) {
warn("prlimit: ignoring rlimits for nonzero pid");
return -EPERM;
}
if (n)
warn("prlimit: ignoring new rlimit");
if (rlp) {
const ByteOrder bo = OS::byteOrder;
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 = htog(rlp->rlim_cur, bo);
rlp->rlim_max = htog(rlp->rlim_max, bo);
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 = htog(rlp->rlim_cur, bo);
rlp->rlim_max = htog(rlp->rlim_max, bo);
break;
default:
warn("prlimit: unimplemented resource %d", resource);
return -EINVAL;
break;
}
}
return 0;
}
/// Target clock_gettime() function.
template <class OS>
SyscallReturn
clock_gettimeFunc(SyscallDesc *desc, ThreadContext *tc,
int clk_id, VPtr<typename OS::timespec> tp)
{
getElapsedTimeNano(tp->tv_sec, tp->tv_nsec);
tp->tv_sec += seconds_since_epoch;
tp->tv_sec = htog(tp->tv_sec, OS::byteOrder);
tp->tv_nsec = htog(tp->tv_nsec, OS::byteOrder);
return 0;
}
/// Target clock_getres() function.
template <class OS>
SyscallReturn
clock_getresFunc(SyscallDesc *desc, ThreadContext *tc, int clk_id,
VPtr<typename OS::timespec> tp)
{
// Set resolution at ns, which is what clock_gettime() returns
tp->tv_sec = 0;
tp->tv_nsec = 1;
return 0;
}
/// Target gettimeofday() handler.
template <class OS>
SyscallReturn
gettimeofdayFunc(SyscallDesc *desc, ThreadContext *tc,
VPtr<typename OS::timeval> tp, Addr tz_ptr)
{
getElapsedTimeMicro(tp->tv_sec, tp->tv_usec);
tp->tv_sec += seconds_since_epoch;
tp->tv_sec = htog(tp->tv_sec, OS::byteOrder);
tp->tv_usec = htog(tp->tv_usec, OS::byteOrder);
return 0;
}
/// Target utimes() handler.
template <class OS>
SyscallReturn
utimesFunc(SyscallDesc *desc, ThreadContext *tc, Addr pathname,
VPtr<typename OS::timeval [2]> tp)
{
std::string path;
auto process = tc->getProcessPtr();
if (!tc->getVirtProxy().tryReadString(path, pathname))
return -EFAULT;
struct timeval hostTimeval[2];
for (int i = 0; i < 2; ++i) {
hostTimeval[i].tv_sec = gtoh((*tp)[i].tv_sec, OS::byteOrder);
hostTimeval[i].tv_usec = gtoh((*tp)[i].tv_usec, OS::byteOrder);
}
// Adjust path for cwd and redirection
path = process->checkPathRedirect(path);
int result = utimes(path.c_str(), hostTimeval);
if (result < 0)
return -errno;
return 0;
}
template <class OS>
SyscallReturn
execveFunc(SyscallDesc *desc, ThreadContext *tc,
Addr pathname, Addr argv_mem_loc, Addr envp_mem_loc)
{
auto p = tc->getProcessPtr();
std::string path;
PortProxy & mem_proxy = tc->getVirtProxy();
if (!mem_proxy.tryReadString(path, pathname))
return -EFAULT;
if (access(path.c_str(), F_OK) == -1)
return -EACCES;
auto read_in = [](std::vector<std::string> &vect,
PortProxy &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;
read_in(pp->cmd, mem_proxy, argv_mem_loc);
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->tgtCwd);
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());
return SyscallReturn();
}
/// Target getrusage() function.
template <class OS>
SyscallReturn
getrusageFunc(SyscallDesc *desc, ThreadContext *tc,
int who /* THREAD, SELF, or CHILDREN */,
VPtr<typename OS::rusage> rup)
{
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 = htog(rup->ru_utime.tv_sec, OS::byteOrder);
rup->ru_utime.tv_usec = htog(rup->ru_utime.tv_usec, OS::byteOrder);
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);
}
return 0;
}
/// Target times() function.
template <class OS>
SyscallReturn
timesFunc(SyscallDesc *desc, ThreadContext *tc, VPtr<typename OS::tms> bufp)
{
// 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 = htog(bufp->tms_utime, OS::byteOrder);
// Return clock ticks since system boot
return clocks;
}
/// Target time() function.
template <class OS>
SyscallReturn
timeFunc(SyscallDesc *desc, ThreadContext *tc, Addr taddr)
{
typename OS::time_t sec, usec;
getElapsedTimeMicro(sec, usec);
sec += seconds_since_epoch;
if (taddr != 0) {
typename OS::time_t t = sec;
t = htog(t, OS::byteOrder);
PortProxy &p = tc->getVirtProxy();
p.writeBlob(taddr, &t, (int)sizeof(typename OS::time_t));
}
return sec;
}
template <class OS>
SyscallReturn
tgkillFunc(SyscallDesc *desc, ThreadContext *tc, int tgid, int tid, int sig)
{
/**
* 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 (auto *tc: sys->threads) {
Process *temp = tc->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, tc, 0);
return 0;
}
template <class OS>
SyscallReturn
socketFunc(SyscallDesc *desc, ThreadContext *tc,
int domain, int type, int prot)
{
auto p = tc->getProcessPtr();
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, ThreadContext *tc,
int domain, int type, int prot, Addr svPtr)
{
auto p = tc->getProcessPtr();
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->getVirtProxy());
return status;
}
template <class OS>
SyscallReturn
selectFunc(SyscallDesc *desc, ThreadContext *tc, int nfds,
VPtr<typename OS::fd_set> readfds,
VPtr<typename OS::fd_set> writefds,
VPtr<typename OS::fd_set> errorfds,
VPtr<typename OS::timeval> timeout)
{
int retval;
auto p = tc->getProcessPtr();
/**
* 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 readfds_h;
FD_ZERO(&readfds_h);
fd_set writefds_h;
FD_ZERO(&writefds_h);
fd_set errorfds_h;
FD_ZERO(&errorfds_h);
/**
* 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 = [&](typename OS::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, (fd_set *)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; i++) {
if (readfds) {
bool ebadf = try_add_host_set(readfds, &readfds_h, i);
if (ebadf)
return -EBADF;
}
if (writefds) {
bool ebadf = try_add_host_set(writefds, &writefds_h, i);
if (ebadf)
return -EBADF;
}
if (errorfds) {
bool ebadf = try_add_host_set(errorfds, &errorfds_h, i);
if (ebadf)
return -EBADF;
}
}
if (timeout) {
/**
* 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.)
*/
timeout->tv_sec = 0;
timeout->tv_usec = 0;
retval = select(nfds_h,
readfds ? &readfds_h : nullptr,
writefds ? &writefds_h : nullptr,
errorfds ? &errorfds_h : nullptr,
(timeval *)(typename OS::timeval *)timeout);
} 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,
readfds ? &readfds_h : nullptr,
readfds ? &writefds_h : nullptr,
readfds ? &errorfds_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(reinterpret_cast<fd_set *>((typename OS::fd_set *)readfds));
FD_ZERO(reinterpret_cast<fd_set *>((typename OS::fd_set *)writefds));
FD_ZERO(reinterpret_cast<fd_set *>((typename OS::fd_set *)errorfds));
/**
* 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 (readfds && FD_ISSET(i, &readfds_h))
FD_SET(trans_map[i], readfds);
if (writefds && FD_ISSET(i, &writefds_h))
FD_SET(trans_map[i], writefds);
if (errorfds && FD_ISSET(i, &errorfds_h))
FD_SET(trans_map[i], errorfds);
}
return retval;
}
template <class OS>
SyscallReturn
readFunc(SyscallDesc *desc, ThreadContext *tc,
int tgt_fd, Addr buf_ptr, int nbytes)
{
auto p = tc->getProcessPtr();
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->getVirtProxy());
return (bytes_read == -1) ? -errno : bytes_read;
}
template <class OS>
SyscallReturn
writeFunc(SyscallDesc *desc, ThreadContext *tc,
int tgt_fd, Addr buf_ptr, int nbytes)
{
auto p = tc->getProcessPtr();
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->getVirtProxy());
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, ThreadContext *tc,
pid_t pid, Addr statPtr, int options, Addr rusagePtr)
{
auto p = tc->getProcessPtr();
if (rusagePtr)
DPRINTF_SYSCALL(Verbose, "wait4: rusage pointer provided %lx, however "
"functionality not supported. Ignoring rusage pointer.\n",
rusagePtr);
/**
* 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->getVirtProxy());
// Return the child PID.
pid_t retval = iter->sender->pid();
sysh->signalList.erase(iter);
return retval;
}
template <class OS>
SyscallReturn
acceptFunc(SyscallDesc *desc, ThreadContext *tc,
int tgt_fd, Addr addrPtr, Addr lenPtr)
{
struct sockaddr sa;
socklen_t addrLen;
int host_fd;
auto p = tc->getProcessPtr();
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->getVirtProxy());
memcpy(&addrLen, (socklen_t *)lenBufPtr->bufferPtr(),
sizeof(socklen_t));
}
if (addrPtr) {
addrBufPtr = new BufferArg(addrPtr, sizeof(struct sockaddr));
addrBufPtr->copyIn(tc->getVirtProxy());
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->getVirtProxy());
delete(addrBufPtr);
}
if (lenPtr) {
*(socklen_t *)lenBufPtr->bufferPtr() = addrLen;
lenBufPtr->copyOut(tc->getVirtProxy());
delete(lenBufPtr);
}
auto afdp = std::make_shared<SocketFDEntry>(host_fd, sfdp->_domain,
sfdp->_type, sfdp->_protocol);
return p->fds->allocFD(afdp);
}
/// Target eventfd() function.
template <class OS>
SyscallReturn
eventfdFunc(SyscallDesc *desc, ThreadContext *tc,
unsigned initval, int in_flags)
{
#if defined(__linux__)
auto p = tc->getProcessPtr();
int sim_fd = eventfd(initval, in_flags);
if (sim_fd == -1)
return -errno;
bool cloexec = in_flags & OS::TGT_O_CLOEXEC;
int flags = cloexec ? OS::TGT_O_CLOEXEC : 0;
flags |= (in_flags & OS::TGT_O_NONBLOCK) ? OS::TGT_O_NONBLOCK : 0;
auto hbfdp = std::make_shared<HBFDEntry>(flags, sim_fd, cloexec);
int tgt_fd = p->fds->allocFD(hbfdp);
return tgt_fd;
#else
warnUnsupportedOS("eventfd");
return -1;
#endif
}
#endif // __SIM_SYSCALL_EMUL_HH__