1.\" -*- nroff -*- 2.\" 3.\" Copyright (c) 2001 Alexander Langer 4.\" 5.\" All rights reserved. 6.\" 7.\" This program is free software. 8.\" 9.\" Redistribution and use in source and binary forms, with or without 10.\" modification, are permitted provided that the following conditions 11.\" are met: 12.\" 1. Redistributions of source code must retain the above copyright 13.\" notice, this list of conditions and the following disclaimer. 14.\" 2. Redistributions in binary form must reproduce the above copyright 15.\" notice, this list of conditions and the following disclaimer in the 16.\" documentation and/or other materials provided with the distribution. 17.\" 18.\" THIS SOFTWARE IS PROVIDED BY THE DEVELOPERS ``AS IS'' AND ANY EXPRESS OR 19.\" IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 20.\" OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 21.\" IN NO EVENT SHALL THE DEVELOPERS BE LIABLE FOR ANY DIRECT, INDIRECT, 22.\" INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 23.\" NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 24.\" DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 25.\" THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 26.\" (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 27.\" THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 28.\" 29.Dd June 15, 2023 30.Dt SYSCALL_MODULE 9 31.Os 32.Sh NAME 33.Nm SYSCALL_MODULE 34.Nd syscall kernel module declaration macro 35.Sh SYNOPSIS 36.In sys/param.h 37.In sys/kernel.h 38.In sys/proc.h 39.In sys/module.h 40.In sys/sysent.h 41.Fn SYSCALL_MODULE name "int *offset" "struct sysent *new_sysent" "modeventhand_t evh" "void *arg" 42.Sh DESCRIPTION 43The 44.Fn SYSCALL_MODULE 45macro declares a new syscall. 46.Fn SYSCALL_MODULE 47expands into a kernel module declaration with name 48.Ql sys/ Ns Fa name . 49.Pp 50The rest of the arguments expected by this macro are: 51.Bl -tag -width ".Fa new_sysent" 52.It Fa offset 53A pointer to an 54.Vt int 55which saves the offset in 56.Vt "struct sysent" 57where the syscall is allocated. 58If the location pointed to by 59.Fa offset 60holds a non 0 number it will be used if possible. 61If it holds 0 then one will be assigned. 62.It Fa new_sysent 63is a pointer to a structure that specifies the function implementing 64the syscall and the number of arguments this function needs (see 65.In sys/sysent.h ) . 66.It Fa evh 67A pointer to the kernel module event handler function with the argument 68.Fa arg . 69Please refer to 70.Xr module 9 71for more information. 72.It Fa arg 73The argument passed to the callback functions of the 74.Fa evh 75event handler when it is called. 76.El 77.Pp 78The syscall number assigned to the module can be retrieved using the 79.Xr modstat 2 80and 81.Xr modfind 2 82system calls. 83The MACRO 84.Fn SYSCALL_MODULE_HELPER 85includes 86.Fn SYSCALL_MODULE 87and much of its boilerplate code. 88.Sh EXAMPLES 89A minimal example for a syscall module can be found in 90.Pa /usr/share/examples/kld/syscall/module/syscall.c . 91.Sh SEE ALSO 92.Xr module 9 93.Pp 94.Pa /usr/share/examples/kld/syscall/module/syscall.c 95.Sh AUTHORS 96This manual page was written by 97.An Alexander Langer Aq Mt alex@FreeBSD.org . 98