25a6daa828
all the global bits of ``module'' data. This commit adds a few generic macros, MOD_SLOCK, MOD_XLOCK, etc., that are meant to be used as ways of accessing the SX lock. It is also the first step in helping to lock down the kernel linker and module systems. Reviewed by: jhb, jake, smp@
124 lines
3.9 KiB
C
124 lines
3.9 KiB
C
/*-
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* Copyright (c) 1999 Assar Westerlund
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* All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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*
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* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
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* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
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* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* SUCH DAMAGE.
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*
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* $FreeBSD$
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*/
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#include <sys/param.h>
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#include <sys/sysproto.h>
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#include <sys/sysent.h>
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#include <sys/syscall.h>
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#include <sys/lock.h>
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#include <sys/mutex.h>
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#include <sys/sx.h>
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#include <sys/module.h>
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/*
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* Acts like "nosys" but can be identified in sysent for dynamic call
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* number assignment for a limited number of calls.
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*
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* Place holder for system call slots reserved for loadable modules.
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*/
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int
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lkmnosys(struct thread *td, struct nosys_args *args)
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{
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return(nosys(td, args));
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}
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int
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lkmressys(struct thread *td, struct nosys_args *args)
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{
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return(nosys(td, args));
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}
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int
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syscall_register(int *offset, struct sysent *new_sysent,
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struct sysent *old_sysent)
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{
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if (*offset == NO_SYSCALL) {
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int i;
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for (i = 1; i < SYS_MAXSYSCALL; ++i)
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if (sysent[i].sy_call == (sy_call_t *)lkmnosys)
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break;
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if (i == SYS_MAXSYSCALL)
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return ENFILE;
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*offset = i;
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} else if (*offset < 0 || *offset >= SYS_MAXSYSCALL)
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return EINVAL;
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else if (sysent[*offset].sy_call != (sy_call_t *)lkmnosys &&
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sysent[*offset].sy_call != (sy_call_t *)lkmressys)
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return EEXIST;
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*old_sysent = sysent[*offset];
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sysent[*offset] = *new_sysent;
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return 0;
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}
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int
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syscall_deregister(int *offset, struct sysent *old_sysent)
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{
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if (*offset)
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sysent[*offset] = *old_sysent;
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return 0;
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}
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int
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syscall_module_handler(struct module *mod, int what, void *arg)
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{
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struct syscall_module_data *data = (struct syscall_module_data*)arg;
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modspecific_t ms;
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int error;
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switch (what) {
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case MOD_LOAD :
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error = syscall_register(data->offset, data->new_sysent,
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&data->old_sysent);
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if (error)
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return error;
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ms.intval = *data->offset;
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MOD_XLOCK;
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module_setspecific(mod, &ms);
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MOD_XUNLOCK;
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if (data->chainevh)
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error = data->chainevh(mod, what, data->chainarg);
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return error;
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case MOD_UNLOAD :
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if (data->chainevh) {
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error = data->chainevh(mod, what, data->chainarg);
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if (error)
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return error;
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}
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error = syscall_deregister(data->offset, &data->old_sysent);
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return error;
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}
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if (data->chainevh)
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return data->chainevh(mod, what, data->chainarg);
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else
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return 0;
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}
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