diff options
Diffstat (limited to 'sys/kern/kern_syscalls.c')
-rw-r--r-- | sys/kern/kern_syscalls.c | 111 |
1 files changed, 111 insertions, 0 deletions
diff --git a/sys/kern/kern_syscalls.c b/sys/kern/kern_syscalls.c new file mode 100644 index 0000000..72b01c8 --- /dev/null +++ b/sys/kern/kern_syscalls.c @@ -0,0 +1,111 @@ +/*- + * 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/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 proc *p, struct nosys_args *args) +{ + return(nosys(p, 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) + 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; + module_setspecific(mod, &ms); + 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; +} |