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dbe4ab5c0f4c0699df70a20875520ffc56cea31a
gem5/src/sim/syscall_emul.hh
Xiongfei 088c8a224c cpu-minor: this is a bug fix for MinorCPU for thread cloning. 
Inside the code of cloneFunc(…)  //syscall_emul.hh

    cp->initState();  //line 1483
    p->clone(tc, ctc, cp, flags);  //line 1484
    …
    ctc->clearArchRegs(); //line 1503

    OS::archClone(flags, p, cp, tc, ctc, newStack, tlsPtr); //line 1505
    …

At line 1483, initState() is called and the activateContext() of the
corresponding MinorCPU is eventually called. The actual architecture
clone happens at line 1505 where PC of the new thread could have a
correct value.

In the existing implementation of MinorCPU::activateContext(ThreadID
thread_id), the below line 275 is called
    pipeline->wakeupFetch(thread_id);
to start fetching instruction with current value of PC, which is 0x0,
leading to panic “Page table fault when accessing virtual address 0”.

This is because the OS::archClone() is not yet called. So, the below bug
fix handles the wakeup fetch for a thread for two scenarios:
   ...
    if (!threads[thread_id]->getUseForClone())
    { //the thread is not cloned
        pipeline->wakeupFetch(thread_id);
    } else {//the thread from clone
        if (fetchEventWrapper != NULL)
            delete fetchEventWrapper;
        fetchEventWrapper = new EventFunctionWrapper([this, thread_id]
          {pipeline->wakeupFetch(thread_id);}, "wakeupFetch");
        schedule(*fetchEventWrapper, clockEdge(Cycles(0)));
    }
    ...
If a thread is not cloned, pipeline->wakeupFetch() is called
immediately.
For the cloned thread, the above bug fix delays the execution of
    pipeline->wakeupFetch()
after the OS::archClone is done. ThreadContext::getUseForClone() return
true if a thread is cloned.

A member variable fetchEventWrapper is added to MinorCPU class for
delayed fetch event.

A member variable useForClone and its corresponding get/set methods are
added to ThreadContext class. This approach allows future reuse of this
useForClone variable by other CPU models if needed and also avoid lots
of changes resulted by modifying parameters of activateContext () and
activate() which are defined as override.

Inside the syscall cloneFunc, the useForClone member of a ThreadContext
object is set via its set method right before Process's initState() is
called, shown as below.
    ctc->setUseForClone(true);
    cp->initState();
    p->clone(tc, ctc, cp, flags);

A few previously failed RISC-V ASM tests have been open in tests.py file
after the bug fix works.

JIRA issue: https://gem5.atlassian.net/browse/GEM5-374

Change-Id: Ibffe46522e2617443d29f49df180692c54830f14
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/37315
Reviewed-by: Bobby R. Bruce <bbruce@ucdavis.edu>
Maintainer: Bobby R. Bruce <bbruce@ucdavis.edu>
Tested-by: kokoro <noreply+kokoro@google.com>
2020-11-19 02:47:48 +00:00

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/*
* 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 = p->pTable->pageSize();
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;
}
ctc->setUseForClone(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);
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 = p->pTable->pageSize();
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)
{
auto page_size = tc->getProcessPtr()->pTable->pageSize();
return mmapFunc<OS>(desc, tc, start, length, prot, tgt_flags,
tgt_fd, offset * page_size);
}
/// 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__
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