NetBSD/sys/kern/kern_syscall.c
christos fae991ec2f Add a new type of syscall "EXTERN" which is meant for modules that live
outside the tree (in pkgsrc). Use it to define afssys (210) which has
been reserved for years, and make it autoload the "openafs" module.
2012-05-05 19:37:37 +00:00

337 lines
11 KiB
C

/* $NetBSD: kern_syscall.c,v 1.7 2012/05/05 19:37:37 christos Exp $ */
/*-
* Copyright (c) 2008 The NetBSD Foundation, Inc.
* All rights reserved.
*
* This code is derived from software developed for The NetBSD Foundation
* by Andrew Doran.
*
* 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.
* 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 NETBSD FOUNDATION, INC. 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 FOUNDATION 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.
*/
#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: kern_syscall.c,v 1.7 2012/05/05 19:37:37 christos Exp $");
#include "opt_modular.h"
/* XXX To get syscall prototypes. */
#define SYSVSHM
#define SYSVSEM
#define SYSVMSG
#include <sys/param.h>
#include <sys/module.h>
#include <sys/sched.h>
#include <sys/syscall.h>
#include <sys/syscallargs.h>
#include <sys/syscallvar.h>
#include <sys/systm.h>
#include <sys/xcall.h>
int
sys_nomodule(struct lwp *l, const void *v, register_t *retval)
{
#ifdef MODULAR
static struct {
u_int al_code;
const char *al_module;
} const autoload[] = {
{ SYS_aio_cancel, "aio" },
{ SYS_aio_error, "aio" },
{ SYS_aio_fsync, "aio" },
{ SYS_aio_read, "aio" },
{ SYS_aio_return, "aio" },
{ SYS___aio_suspend50, "aio" },
{ SYS_aio_write, "aio" },
{ SYS_lio_listio, "aio" },
{ SYS_mq_open, "mqueue" },
{ SYS_mq_close, "mqueue" },
{ SYS_mq_unlink, "mqueue" },
{ SYS_mq_getattr, "mqueue" },
{ SYS_mq_setattr, "mqueue" },
{ SYS_mq_notify, "mqueue" },
{ SYS_mq_send, "mqueue" },
{ SYS_mq_receive, "mqueue" },
{ SYS___mq_timedsend50, "mqueue" },
{ SYS___mq_timedreceive50, "mqueue" },
{ SYS_compat_43_fstat43, "compat" },
{ SYS_compat_43_lstat43, "compat" },
{ SYS_compat_43_oaccept, "compat" },
{ SYS_compat_43_ocreat, "compat" },
{ SYS_compat_43_oftruncate, "compat" },
{ SYS_compat_43_ogetdirentries, "compat" },
{ SYS_compat_43_ogetdtablesize, "compat" },
{ SYS_compat_43_ogethostid, "compat" },
{ SYS_compat_43_ogethostname, "compat" },
{ SYS_compat_43_ogetkerninfo, "compat" },
{ SYS_compat_43_ogetpagesize, "compat" },
{ SYS_compat_43_ogetpeername, "compat" },
{ SYS_compat_43_ogetrlimit, "compat" },
{ SYS_compat_43_ogetsockname, "compat" },
{ SYS_compat_43_okillpg, "compat" },
{ SYS_compat_43_olseek, "compat" },
{ SYS_compat_43_ommap, "compat" },
{ SYS_compat_43_oquota, "compat" },
{ SYS_compat_43_orecv, "compat" },
{ SYS_compat_43_orecvfrom, "compat" },
{ SYS_compat_43_orecvmsg, "compat" },
{ SYS_compat_43_osend, "compat" },
{ SYS_compat_43_osendmsg, "compat" },
{ SYS_compat_43_osethostid, "compat" },
{ SYS_compat_43_osethostname, "compat" },
{ SYS_compat_43_osetrlimit, "compat" },
{ SYS_compat_43_osigblock, "compat" },
{ SYS_compat_43_osigsetmask, "compat" },
{ SYS_compat_43_osigstack, "compat" },
{ SYS_compat_43_osigvec, "compat" },
{ SYS_compat_43_otruncate, "compat" },
{ SYS_compat_43_owait, "compat" },
{ SYS_compat_43_stat43, "compat" },
{ SYS_compat_09_ogetdomainname, "compat" },
{ SYS_compat_09_osetdomainname, "compat" },
{ SYS_compat_09_ouname, "compat" },
#ifndef _LP64
{ SYS_compat_10_omsgsys, "compat" },
{ SYS_compat_10_osemsys, "compat" },
{ SYS_compat_10_oshmsys, "compat" },
#endif
{ SYS_compat_12_fstat12, "compat" },
{ SYS_compat_12_getdirentries, "compat" },
{ SYS_compat_12_lstat12, "compat" },
{ SYS_compat_12_msync, "compat" },
{ SYS_compat_12_oreboot, "compat" },
{ SYS_compat_12_oswapon, "compat" },
{ SYS_compat_12_stat12, "compat" },
{ SYS_compat_13_sigaction13, "compat" },
{ SYS_compat_13_sigaltstack13, "compat" },
{ SYS_compat_13_sigpending13, "compat" },
{ SYS_compat_13_sigprocmask13, "compat" },
{ SYS_compat_13_sigreturn13, "compat" },
{ SYS_compat_13_sigsuspend13, "compat" },
{ SYS_compat_14___semctl, "compat" },
{ SYS_compat_14_msgctl, "compat" },
{ SYS_compat_14_shmctl, "compat" },
{ SYS_compat_16___sigaction14, "compat" },
{ SYS_compat_16___sigreturn14, "compat" },
{ SYS_compat_20_fhstatfs, "compat" },
{ SYS_compat_20_fstatfs, "compat" },
{ SYS_compat_20_getfsstat, "compat" },
{ SYS_compat_20_statfs, "compat" },
{ SYS_compat_30___fhstat30, "compat" },
{ SYS_compat_30___fstat13, "compat" },
{ SYS_compat_30___lstat13, "compat" },
{ SYS_compat_30___stat13, "compat" },
{ SYS_compat_30_fhopen, "compat" },
{ SYS_compat_30_fhstat, "compat" },
{ SYS_compat_30_fhstatvfs1, "compat" },
{ SYS_compat_30_getdents, "compat" },
{ SYS_compat_30_getfh, "compat" },
{ SYS_compat_30_socket, "compat" },
{ SYS_compat_40_mount, "compat" },
{ SYS_compat_50_wait4, "compat" },
{ SYS_compat_50_mknod, "compat" },
{ SYS_compat_50_setitimer, "compat" },
{ SYS_compat_50_getitimer, "compat" },
{ SYS_compat_50_select, "compat" },
{ SYS_compat_50_gettimeofday, "compat" },
{ SYS_compat_50_getrusage, "compat" },
{ SYS_compat_50_settimeofday, "compat" },
{ SYS_compat_50_utimes, "compat" },
{ SYS_compat_50_adjtime, "compat" },
{ SYS_compat_50_lfs_segwait, "compat" },
{ SYS_compat_50_futimes, "compat" },
{ SYS_compat_50_clock_gettime, "compat" },
{ SYS_compat_50_clock_settime, "compat" },
{ SYS_compat_50_clock_getres, "compat" },
{ SYS_compat_50_timer_settime, "compat" },
{ SYS_compat_50_timer_gettime, "compat" },
{ SYS_compat_50_nanosleep, "compat" },
{ SYS_compat_50___sigtimedwait, "compat" },
{ SYS_compat_50_mq_timedsend, "compat" },
{ SYS_compat_50_mq_timedreceive, "compat" },
{ SYS_compat_50_lutimes, "compat" },
{ SYS_compat_50_____semctl13, "compat" },
{ SYS_compat_50___msgctl13, "compat" },
{ SYS_compat_50___shmctl13, "compat" },
{ SYS_compat_50__lwp_park, "compat" },
{ SYS_compat_50_kevent, "compat" },
{ SYS_compat_50_pselect, "compat" },
{ SYS_compat_50_pollts, "compat" },
{ SYS_compat_50___stat30, "compat" },
{ SYS_compat_50___fstat30, "compat" },
{ SYS_compat_50___lstat30, "compat" },
{ SYS_compat_50___ntp_gettime30, "compat" },
{ SYS_compat_50___fhstat40, "compat" },
{ SYS_compat_50_aio_suspend, "compat" },
{ SYS__ksem_init, "ksem" },
{ SYS__ksem_open, "ksem" },
{ SYS__ksem_unlink, "ksem" },
{ SYS__ksem_close, "ksem" },
{ SYS__ksem_post, "ksem" },
{ SYS__ksem_wait, "ksem" },
{ SYS__ksem_trywait, "ksem" },
{ SYS__ksem_getvalue, "ksem" },
{ SYS__ksem_destroy, "ksem" },
{ SYS__ksem_timedwait, "ksem" },
{ SYS_nfssvc, "nfsserver" },
{ SYS_afssys, "openafs" },
};
const struct sysent *sy;
const struct emul *em;
int code, i;
/*
* Restart the syscall if we interrupted a module unload that
* failed. Acquiring kernconfig_lock delays us until any unload
* has been completed or rolled back.
*/
kernconfig_lock();
sy = l->l_sysent;
if (sy->sy_call != sys_nomodule) {
kernconfig_unlock();
return ERESTART;
}
/*
* Try to autoload a module to satisfy the request. If it
* works, retry the request.
*/
em = l->l_proc->p_emul;
if (em == &emul_netbsd) {
code = sy - em->e_sysent;
for (i = 0; i < __arraycount(autoload); i++) {
if (autoload[i].al_code != code) {
continue;
}
if (module_autoload(autoload[i].al_module,
MODULE_CLASS_ANY) != 0 ||
sy->sy_call == sys_nomodule) {
break;
}
kernconfig_unlock();
return ERESTART;
}
}
kernconfig_unlock();
#endif /* MODULAR */
return sys_nosys(l, v, retval);
}
int
syscall_establish(const struct emul *em, const struct syscall_package *sp)
{
struct sysent *sy;
int i;
KASSERT(kernconfig_is_held());
if (em == NULL) {
em = &emul_netbsd;
}
sy = em->e_sysent;
/*
* Ensure that all preconditions are valid, since this is
* an all or nothing deal. Once a system call is entered,
* it can become busy and we could be unable to remove it
* on error.
*/
for (i = 0; sp[i].sp_call != NULL; i++) {
if (sy[sp[i].sp_code].sy_call != sys_nomodule) {
#ifdef DIAGNOSTIC
printf("syscall %d is busy\n", sp[i].sp_code);
#endif
return EBUSY;
}
}
/* Everything looks good, patch them in. */
for (i = 0; sp[i].sp_call != NULL; i++) {
sy[sp[i].sp_code].sy_call = sp[i].sp_call;
}
return 0;
}
int
syscall_disestablish(const struct emul *em, const struct syscall_package *sp)
{
struct sysent *sy;
uint64_t where;
lwp_t *l;
int i;
KASSERT(kernconfig_is_held());
if (em == NULL) {
em = &emul_netbsd;
}
sy = em->e_sysent;
/*
* First, patch the system calls to sys_nomodule to gate further
* activity.
*/
for (i = 0; sp[i].sp_call != NULL; i++) {
KASSERT(sy[sp[i].sp_code].sy_call == sp[i].sp_call);
sy[sp[i].sp_code].sy_call = sys_nomodule;
}
/*
* Run a cross call to cycle through all CPUs. This does two
* things: lock activity provides a barrier and makes our update
* of sy_call visible to all CPUs, and upon return we can be sure
* that we see pertinent values of l_sysent posted by remote CPUs.
*/
where = xc_broadcast(0, (xcfunc_t)nullop, NULL, NULL);
xc_wait(where);
/*
* Now it's safe to check l_sysent. Run through all LWPs and see
* if anyone is still using the system call.
*/
for (i = 0; sp[i].sp_call != NULL; i++) {
mutex_enter(proc_lock);
LIST_FOREACH(l, &alllwp, l_list) {
if (l->l_sysent == &sy[sp[i].sp_code]) {
break;
}
}
mutex_exit(proc_lock);
if (l == NULL) {
continue;
}
/*
* We lose: one or more calls are still in use. Put back
* the old entrypoints and act like nothing happened.
* When we drop kernconfig_lock, any system calls held in
* sys_nomodule() will be restarted.
*/
for (i = 0; sp[i].sp_call != NULL; i++) {
sy[sp[i].sp_code].sy_call = sp[i].sp_call;
}
return EBUSY;
}
return 0;
}