freebsd-skq/sys/compat/linux/linux_emul.c
dchagin 5f069937a3 Implement epoll family system calls. This is a tiny wrapper
around kqueue() to implement epoll subset of functionality.
The kqueue user data are 32bit on i386 which is not enough for
epoll user data, so we keep user data in the proc emuldata.

Initial patch developed by rdivacky@ in 2007, then extended
by Yuri Victorovich @ r255672 and finished by me
in collaboration with mjg@ and jillies@.

Differential Revision:	https://reviews.freebsd.org/D1092
2015-05-24 16:41:39 +00:00

275 lines
6.6 KiB
C

/*-
* Copyright (c) 2006 Roman Divacky
* Copyright (c) 2013 Dmitry Chagin
* 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.
* 3. The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission
*
* 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 <sys/param.h>
#include <sys/systm.h>
#include <sys/imgact.h>
#include <sys/kernel.h>
#include <sys/ktr.h>
#include <sys/lock.h>
#include <sys/malloc.h>
#include <sys/mutex.h>
#include <sys/sx.h>
#include <sys/proc.h>
#include <sys/syscallsubr.h>
#include <sys/sysent.h>
#include <compat/linux/linux_emul.h>
#include <compat/linux/linux_misc.h>
#include <compat/linux/linux_util.h>
/*
* This returns reference to the thread emuldata entry (if found)
*
* Hold PROC_LOCK when referencing emuldata from other threads.
*/
struct linux_emuldata *
em_find(struct thread *td)
{
struct linux_emuldata *em;
em = td->td_emuldata;
return (em);
}
/*
* This returns reference to the proc pemuldata entry (if found)
*
* Hold PROC_LOCK when referencing proc pemuldata from other threads.
* Hold LINUX_PEM_LOCK wher referencing pemuldata members.
*/
struct linux_pemuldata *
pem_find(struct proc *p)
{
struct linux_pemuldata *pem;
pem = p->p_emuldata;
return (pem);
}
void
linux_proc_init(struct thread *td, struct thread *newtd, int flags)
{
struct linux_emuldata *em;
struct linux_pemuldata *pem;
struct epoll_emuldata *emd;
if (newtd != NULL) {
/* non-exec call */
em = malloc(sizeof(*em), M_TEMP, M_WAITOK | M_ZERO);
em->pdeath_signal = 0;
em->robust_futexes = NULL;
if (flags & LINUX_CLONE_THREAD) {
LINUX_CTR1(proc_init, "thread newtd(%d)",
newtd->td_tid);
em->em_tid = newtd->td_tid;
} else {
LINUX_CTR1(proc_init, "fork newtd(%d)",
newtd->td_proc->p_pid);
em->em_tid = newtd->td_proc->p_pid;
pem = malloc(sizeof(*pem), M_LINUX, M_WAITOK | M_ZERO);
sx_init(&pem->pem_sx, "lpemlk");
newtd->td_proc->p_emuldata = pem;
}
newtd->td_emuldata = em;
} else {
/* exec */
LINUX_CTR1(proc_init, "exec newtd(%d)",
td->td_proc->p_pid);
/* lookup the old one */
em = em_find(td);
KASSERT(em != NULL, ("proc_init: emuldata not found in exec case.\n"));
em->em_tid = td->td_proc->p_pid;
/* epoll should be destroyed in a case of exec. */
pem = pem_find(td->td_proc);
KASSERT(pem != NULL, ("proc_exit: proc emuldata not found.\n"));
if (pem->epoll != NULL) {
emd = pem->epoll;
pem->epoll = NULL;
free(emd, M_EPOLL);
}
}
em->child_clear_tid = NULL;
em->child_set_tid = NULL;
}
void
linux_proc_exit(void *arg __unused, struct proc *p)
{
struct linux_pemuldata *pem;
struct epoll_emuldata *emd;
struct thread *td = curthread;
if (__predict_false(SV_CURPROC_ABI() != SV_ABI_LINUX))
return;
pem = pem_find(p);
if (pem == NULL)
return;
(p->p_sysent->sv_thread_detach)(td);
p->p_emuldata = NULL;
if (pem->epoll != NULL) {
emd = pem->epoll;
pem->epoll = NULL;
free(emd, M_EPOLL);
}
sx_destroy(&pem->pem_sx);
free(pem, M_LINUX);
}
int
linux_common_execve(struct thread *td, struct image_args *eargs)
{
struct linux_pemuldata *pem;
struct epoll_emuldata *emd;
struct linux_emuldata *em;
struct proc *p;
int error;
p = td->td_proc;
/*
* Unlike FreeBSD abort all other threads before
* proceeding exec.
*/
PROC_LOCK(p);
/* See exit1() comments. */
thread_suspend_check(0);
while (p->p_flag & P_HADTHREADS) {
if (!thread_single(p, SINGLE_EXIT))
break;
thread_suspend_check(0);
}
PROC_UNLOCK(p);
error = kern_execve(td, eargs, NULL);
if (error != 0)
return (error);
/*
* In a case of transition from Linux binary execing to
* FreeBSD binary we destroy linux emuldata thread & proc entries.
*/
if (SV_CURPROC_ABI() != SV_ABI_LINUX) {
PROC_LOCK(p);
em = em_find(td);
KASSERT(em != NULL, ("proc_exec: thread emuldata not found.\n"));
td->td_emuldata = NULL;
pem = pem_find(p);
KASSERT(pem != NULL, ("proc_exec: proc pemuldata not found.\n"));
p->p_emuldata = NULL;
PROC_UNLOCK(p);
if (pem->epoll != NULL) {
emd = pem->epoll;
pem->epoll = NULL;
free(emd, M_EPOLL);
}
free(em, M_TEMP);
free(pem, M_LINUX);
}
return (0);
}
void
linux_proc_exec(void *arg __unused, struct proc *p, struct image_params *imgp)
{
struct thread *td = curthread;
/*
* In a case of execing to linux binary we create linux
* emuldata thread entry.
*/
if (__predict_false((imgp->sysent->sv_flags & SV_ABI_MASK) ==
SV_ABI_LINUX)) {
if (SV_PROC_ABI(p) == SV_ABI_LINUX)
linux_proc_init(td, NULL, 0);
else
linux_proc_init(td, td, 0);
}
}
void
linux_thread_dtor(void *arg __unused, struct thread *td)
{
struct linux_emuldata *em;
em = em_find(td);
if (em == NULL)
return;
td->td_emuldata = NULL;
LINUX_CTR1(exit, "thread dtor(%d)", em->em_tid);
free(em, M_TEMP);
}
void
linux_schedtail(struct thread *td)
{
struct linux_emuldata *em;
struct proc *p;
int error = 0;
int *child_set_tid;
p = td->td_proc;
em = em_find(td);
KASSERT(em != NULL, ("linux_schedtail: thread emuldata not found.\n"));
child_set_tid = em->child_set_tid;
if (child_set_tid != NULL) {
error = copyout(&em->em_tid, (int *)child_set_tid,
sizeof(em->em_tid));
LINUX_CTR4(clone, "schedtail(%d) %p stored %d error %d",
td->td_tid, child_set_tid, em->em_tid, error);
} else
LINUX_CTR1(clone, "schedtail(%d)", em->em_tid);
}