/*- * Copyright (c) 1999 Assar Westerlund * 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. * 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 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 AUTHOR 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. * * $FreeBSD$ */ #include <sys/param.h> #include <sys/sysproto.h> #include <sys/sysent.h> #include <sys/syscall.h> #include <sys/lock.h> #include <sys/mutex.h> #include <sys/sx.h> #include <sys/module.h> /* * Acts like "nosys" but can be identified in sysent for dynamic call * number assignment for a limited number of calls. * * Place holder for system call slots reserved for loadable modules. */ int lkmnosys(struct thread *td, struct nosys_args *args) { return(nosys(td, args)); } int lkmressys(struct thread *td, struct nosys_args *args) { return(nosys(td, args)); } int syscall_register(int *offset, struct sysent *new_sysent, struct sysent *old_sysent) { if (*offset == NO_SYSCALL) { int i; for (i = 1; i < SYS_MAXSYSCALL; ++i) if (sysent[i].sy_call == (sy_call_t *)lkmnosys) break; if (i == SYS_MAXSYSCALL) return ENFILE; *offset = i; } else if (*offset < 0 || *offset >= SYS_MAXSYSCALL) return EINVAL; else if (sysent[*offset].sy_call != (sy_call_t *)lkmnosys && sysent[*offset].sy_call != (sy_call_t *)lkmressys) return EEXIST; *old_sysent = sysent[*offset]; sysent[*offset] = *new_sysent; return 0; } int syscall_deregister(int *offset, struct sysent *old_sysent) { if (*offset) sysent[*offset] = *old_sysent; return 0; } int syscall_module_handler(struct module *mod, int what, void *arg) { struct syscall_module_data *data = (struct syscall_module_data*)arg; modspecific_t ms; int error; switch (what) { case MOD_LOAD : error = syscall_register(data->offset, data->new_sysent, &data->old_sysent); if (error) return error; ms.intval = *data->offset; MOD_XLOCK; module_setspecific(mod, &ms); MOD_XUNLOCK; if (data->chainevh) error = data->chainevh(mod, what, data->chainarg); return error; case MOD_UNLOAD : if (data->chainevh) { error = data->chainevh(mod, what, data->chainarg); if (error) return error; } error = syscall_deregister(data->offset, &data->old_sysent); return error; } if (data->chainevh) return data->chainevh(mod, what, data->chainarg); else return 0; }