Copyright (c) 2001 Alexander Langer All rights reserved. This program is free software. 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 disclaim...
NAMESYSCALL_MODULE - syscall kernel module declaration macro
SYNOPSISIn sys/param.h In sys/kernel.h In sys/proc.h In sys/module.h In sys/sysent.h Fn SYSCALL_MODULE name int *offset struct sysent *new_sysent modeventhand_t evh void *arg
DESCRIPTIONThe Fn SYSCALL_MODULE macro declares a new syscall. Fn SYSCALL_MODULE expands into a kernel module declaration with name `sys/' Ns Fa name .
The rest of the arguments expected by this macro are:
- Fa offset
- A pointer to an Vt int which saves the offset in Vt struct sysent where the syscall is allocated. If the location pointed to by Fa offset holds a non 0 number it will be used if possible. If it holds 0 then one will be assigned.
- Fa new_sysent
- is a pointer to a structure that specifies the function implementing the syscall and the number of arguments this function needs (see In sys/sysent.h ) .
- Fa evh
- A pointer to the kernel module event handler function with the argument Fa arg . Please refer to module(9) for more information.
- Fa arg
- The argument passed to the callback functions of the Fa evh event handler when it is called.
The syscall number assigned to the module can be retrieved using the modstat(3) and modfind(3) library functions in libc. The MACRO Fn SYSCALL_MODULE_HELPER includes Fn SYSCALL_MODULE and much of its boilerplate code.
EXAMPLESA minimal example for a syscall module can be found in /usr/share/examples/kld/syscall/module/syscall.c