diff options
| author | christos <christos@NetBSD.org> | 2000-01-31 15:15:07 +0000 |
|---|---|---|
| committer | christos <christos@NetBSD.org> | 2000-01-31 15:15:07 +0000 |
| commit | f9be3e6b20f7e7717db9849c7de8504e3fcbf8ce (patch) | |
| tree | 2f9fe2979834c0fe831643ed2e9614cea3a2a32d /lib/libc/sys | |
| parent | 618e1b562825c3bc5befc63621729c0a4917dd49 (diff) | |
Explain why we don't want to pass structs and unions to syscalls, and
how to find the proper args for a syscall.
Diffstat (limited to 'lib/libc/sys')
| -rw-r--r-- | lib/libc/sys/syscall.2 | 11 |
1 files changed, 10 insertions, 1 deletions
diff --git a/lib/libc/sys/syscall.2 b/lib/libc/sys/syscall.2 index cb9044bb78e..9d18003a45c 100644 --- a/lib/libc/sys/syscall.2 +++ b/lib/libc/sys/syscall.2 @@ -1,4 +1,4 @@ -.\" $NetBSD: syscall.2,v 1.8 1999/12/02 21:42:40 kleink Exp $ +.\" $NetBSD: syscall.2,v 1.9 2000/01/31 15:15:07 christos Exp $ .\" .\" Copyright (c) 1980, 1991, 1993 .\" The Regents of the University of California. All rights reserved. @@ -73,6 +73,15 @@ and an error code is stored in There is no way to simulate system calls that have multiple return values such as .Xr pipe 2 . +.Pp +Due to ABI implementation differences in passing struct or union +type arguments to system calls between different processors, all +system calls pass instead pointers to such structs or unions, even +when the documentation of the system call mentions otherwise. The +conversion between passing structs and unions is handled normally +via userland stubs. The correct arguments for the kernel entry +points for each system call can be found in the header file +.Ao Pa sys/syscallargs.h Ac .Sh HISTORY The .Fn syscall |
