freebsd-skq/sys/compat/linux/linux_fork.c

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/*-
* Copyright (c) 2004 Tim J. Robbins
* Copyright (c) 2002 Doug Rabson
* Copyright (c) 2000 Marcel Moolenaar
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer
* in this position and unchanged.
* 2. 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.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 AUTHOR 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.
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include "opt_compat.h"
#include "opt_kdtrace.h"
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/imgact.h>
#include <sys/lock.h>
#include <sys/mutex.h>
#include <sys/proc.h>
#include <sys/sched.h>
#include <sys/sdt.h>
#include <sys/sx.h>
#include <sys/unistd.h>
#ifdef COMPAT_LINUX32
#include <machine/../linux32/linux.h>
#include <machine/../linux32/linux32_proto.h>
#else
#include <machine/../linux/linux.h>
#include <machine/../linux/linux_proto.h>
#endif
#include <compat/linux/linux_dtrace.h>
#include <compat/linux/linux_signal.h>
#include <compat/linux/linux_emul.h>
/* DTrace init */
LIN_SDT_PROVIDER_DECLARE(LINUX_DTRACE);
/* Linuxulator-global DTrace probes */
LIN_SDT_PROBE_DECLARE(locks, emul_lock, locked);
LIN_SDT_PROBE_DECLARE(locks, emul_lock, unlock);
int
linux_fork(struct thread *td, struct linux_fork_args *args)
{
int error;
struct proc *p2;
struct thread *td2;
#ifdef DEBUG
if (ldebug(fork))
printf(ARGS(fork, ""));
#endif
if ((error = fork1(td, RFFDG | RFPROC | RFSTOPPED, 0, &p2, NULL, 0))
!= 0)
return (error);
td->td_retval[0] = p2->p_pid;
td->td_retval[1] = 0;
error = linux_proc_init(td, td->td_retval[0], 0);
if (error)
return (error);
td2 = FIRST_THREAD_IN_PROC(p2);
/*
* Make this runnable after we are finished with it.
*/
thread_lock(td2);
TD_SET_CAN_RUN(td2);
sched_add(td2, SRQ_BORING);
thread_unlock(td2);
return (0);
}
int
linux_vfork(struct thread *td, struct linux_vfork_args *args)
{
int error;
struct proc *p2;
struct thread *td2;
#ifdef DEBUG
if (ldebug(vfork))
printf(ARGS(vfork, ""));
#endif
/* Exclude RFPPWAIT */
if ((error = fork1(td, RFFDG | RFPROC | RFMEM | RFSTOPPED, 0, &p2,
NULL, 0)) != 0)
return (error);
td->td_retval[0] = p2->p_pid;
error = linux_proc_init(td, td->td_retval[0], 0);
if (error)
return (error);
PROC_LOCK(p2);
p2->p_flag |= P_PPWAIT;
PROC_UNLOCK(p2);
td2 = FIRST_THREAD_IN_PROC(p2);
/*
* Make this runnable after we are finished with it.
*/
thread_lock(td2);
TD_SET_CAN_RUN(td2);
sched_add(td2, SRQ_BORING);
thread_unlock(td2);
/* wait for the children to exit, ie. emulate vfork */
PROC_LOCK(p2);
while (p2->p_flag & P_PPWAIT)
cv_wait(&p2->p_pwait, &p2->p_mtx);
PROC_UNLOCK(p2);
return (0);
}
int
linux_clone(struct thread *td, struct linux_clone_args *args)
{
int error, ff = RFPROC | RFSTOPPED;
struct proc *p2;
struct thread *td2;
int exit_signal;
struct linux_emuldata *em;
#ifdef DEBUG
if (ldebug(clone)) {
printf(ARGS(clone, "flags %x, stack %p, parent tid: %p, "
"child tid: %p"), (unsigned)args->flags,
args->stack, args->parent_tidptr, args->child_tidptr);
}
#endif
exit_signal = args->flags & 0x000000ff;
if (LINUX_SIG_VALID(exit_signal)) {
if (exit_signal <= LINUX_SIGTBLSZ)
exit_signal =
linux_to_bsd_signal[_SIG_IDX(exit_signal)];
} else if (exit_signal != 0)
return (EINVAL);
if (args->flags & LINUX_CLONE_VM)
ff |= RFMEM;
if (args->flags & LINUX_CLONE_SIGHAND)
ff |= RFSIGSHARE;
/*
* XXX: In Linux, sharing of fs info (chroot/cwd/umask)
* and open files is independant. In FreeBSD, its in one
* structure but in reality it does not cause any problems
* because both of these flags are usually set together.
*/
if (!(args->flags & (LINUX_CLONE_FILES | LINUX_CLONE_FS)))
ff |= RFFDG;
/*
* Attempt to detect when linux_clone(2) is used for creating
* kernel threads. Unfortunately despite the existence of the
* CLONE_THREAD flag, version of linuxthreads package used in
* most popular distros as of beginning of 2005 doesn't make
* any use of it. Therefore, this detection relies on
* empirical observation that linuxthreads sets certain
* combination of flags, so that we can make more or less
* precise detection and notify the FreeBSD kernel that several
* processes are in fact part of the same threading group, so
* that special treatment is necessary for signal delivery
* between those processes and fd locking.
*/
if ((args->flags & 0xffffff00) == LINUX_THREADING_FLAGS)
ff |= RFTHREAD;
if (args->flags & LINUX_CLONE_PARENT_SETTID)
if (args->parent_tidptr == NULL)
return (EINVAL);
error = fork1(td, ff, 0, &p2, NULL, 0);
if (error)
return (error);
if (args->flags & (LINUX_CLONE_PARENT | LINUX_CLONE_THREAD)) {
sx_xlock(&proctree_lock);
PROC_LOCK(p2);
proc_reparent(p2, td->td_proc->p_pptr);
PROC_UNLOCK(p2);
sx_xunlock(&proctree_lock);
}
/* create the emuldata */
error = linux_proc_init(td, p2->p_pid, args->flags);
/* reference it - no need to check this */
em = em_find(p2, EMUL_DOLOCK);
KASSERT(em != NULL, ("clone: emuldata not found."));
/* and adjust it */
if (args->flags & LINUX_CLONE_THREAD) {
#ifdef notyet
PROC_LOCK(p2);
p2->p_pgrp = td->td_proc->p_pgrp;
PROC_UNLOCK(p2);
#endif
exit_signal = 0;
}
if (args->flags & LINUX_CLONE_CHILD_SETTID)
em->child_set_tid = args->child_tidptr;
else
em->child_set_tid = NULL;
if (args->flags & LINUX_CLONE_CHILD_CLEARTID)
em->child_clear_tid = args->child_tidptr;
else
em->child_clear_tid = NULL;
EMUL_UNLOCK(&emul_lock);
if (args->flags & LINUX_CLONE_PARENT_SETTID) {
error = copyout(&p2->p_pid, args->parent_tidptr,
sizeof(p2->p_pid));
if (error)
printf(LMSG("copyout failed!"));
}
PROC_LOCK(p2);
p2->p_sigparent = exit_signal;
PROC_UNLOCK(p2);
td2 = FIRST_THREAD_IN_PROC(p2);
/*
* In a case of stack = NULL, we are supposed to COW calling process
* stack. This is what normal fork() does, so we just keep tf_rsp arg
* intact.
*/
if (args->stack)
linux_set_upcall_kse(td2, PTROUT(args->stack));
if (args->flags & LINUX_CLONE_SETTLS)
linux_set_cloned_tls(td2, args->tls);
#ifdef DEBUG
if (ldebug(clone))
printf(LMSG("clone: successful rfork to %d, "
"stack %p sig = %d"), (int)p2->p_pid, args->stack,
exit_signal);
#endif
if (args->flags & LINUX_CLONE_VFORK) {
PROC_LOCK(p2);
p2->p_flag |= P_PPWAIT;
PROC_UNLOCK(p2);
}
/*
* Make this runnable after we are finished with it.
*/
thread_lock(td2);
TD_SET_CAN_RUN(td2);
sched_add(td2, SRQ_BORING);
thread_unlock(td2);
td->td_retval[0] = p2->p_pid;
td->td_retval[1] = 0;
if (args->flags & LINUX_CLONE_VFORK) {
/* wait for the children to exit, ie. emulate vfork */
PROC_LOCK(p2);
while (p2->p_flag & P_PPWAIT)
cv_wait(&p2->p_pwait, &p2->p_mtx);
PROC_UNLOCK(p2);
}
return (0);
}