Google Git
Sign in
gem5 / arm / gem5 / 7352324d4dda31ffb6fb5997e0fe2378c27e96b9 / . / src / sim / syscall_emul.hh
blob: eaa5e542cced7573d1505c5ae54d4f19f4bb7a50 [file] [log] [blame]
/*
* 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 <sys/mman.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/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 read() handler.
SyscallReturn readFunc(SyscallDesc *desc, int num,
Process *p, ThreadContext *tc);
/// Target write() handler.
SyscallReturn writeFunc(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 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 mkdir() handler.
SyscallReturn mkdirFunc(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 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;
}
/// 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;
TheISA::IntReg flags = p->getSyscallArg(tc, index);
TheISA::IntReg newStack = p->getSyscallArg(tc, index);
Addr ptidPtr = p->getSyscallArg(tc, index);
#if THE_ISA == RISCV_ISA
/**
* Linux kernel 4.15 sets CLONE_BACKWARDS flag for RISC-V.
* The flag defines the list of clone() arguments in the following
* order: flags -> newStack -> ptidPtr -> tlsPtr -> ctidPtr
*/
Addr tlsPtr M5_VAR_USED = p->getSyscallArg(tc, index);
Addr ctidPtr = p->getSyscallArg(tc, index);
#else
Addr ctidPtr = p->getSyscallArg(tc, index);
Addr tlsPtr M5_VAR_USED = 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();
#if THE_ISA == ALPHA_ISA
TheISA::copyMiscRegs(tc, ctc);
#elif THE_ISA == SPARC_ISA
TheISA::copyRegs(tc, ctc);
ctc->setIntReg(TheISA::NumIntArchRegs + 6, 0);
ctc->setIntReg(TheISA::NumIntArchRegs + 4, 0);
ctc->setIntReg(TheISA::NumIntArchRegs + 3, TheISA::NWindows - 2);
ctc->setIntReg(TheISA::NumIntArchRegs + 5, TheISA::NWindows);
ctc->setMiscReg(TheISA::MISCREG_CWP, 0);
ctc->setIntReg(TheISA::NumIntArchRegs + 7, 0);
ctc->setMiscRegNoEffect(TheISA::MISCREG_TL, 0);
ctc->setMiscReg(TheISA::MISCREG_ASI, TheISA::ASI_PRIMARY);
for (int y = 8; y < 32; y++)
ctc->setIntReg(y, tc->readIntReg(y));
#elif THE_ISA == ARM_ISA or THE_ISA == X86_ISA or THE_ISA == RISCV_ISA
TheISA::copyRegs(tc, ctc);
#endif
#if THE_ISA == X86_ISA
if (flags & OS::TGT_CLONE_SETTLS) {
ctc->setMiscRegNoEffect(TheISA::MISCREG_FS_BASE, tlsPtr);
ctc->setMiscRegNoEffect(TheISA::MISCREG_FS_EFF_BASE, tlsPtr);
}
#endif
if (newStack)
ctc->setIntReg(TheISA::StackPointerReg, newStack);
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
ctc->pcState(tc->nextInstAddr());
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);
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;
}
#endif // __SIM_SYSCALL_EMUL_HH__