freebsd-dev/share/man/man9/CONDSPLASSERT.9
Bruce Evans 1c171d7474 Abuse .Fn for macros better (don't hand-format the parameter string by
quoting it all and adding commas).

Don't say that the expression in KASSERT() is an int.  It is a collection
of tokens forming a C expression that can be compared with 0.
2000-05-11 16:54:52 +00:00

109 lines
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.\" Copyright (c) 2000 Jeroen Ruigrok van der Werven,
.\" Jonathan M. Bresler
.\"
.\" All rights reserved.
.\"
.\" This program is free software.
.\"
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.\" modification, are permitted provided that the following conditions
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.\" notice, this list of conditions and the following disclaimer.
.\" 2. Redistributions in binary form must reproduce the above copyright
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.\" documentation and/or other materials provided with the distribution.
.\"
.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR(S) ``AS IS'' AND ANY EXPRESS OR
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.\" INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
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.\" $FreeBSD$
.\"
.Dd March 19 2000
.Os
.Dt CONDSPLASSERT 9
.Sh NAME
.Nm CONDSPLASSERT
.Nd conditional kernel spl level verification macro
.Sh SYNOPSIS
.Cd options INVARIANTS
.Cd options INVARIANT_SUPPORT
.Fn CONDSPLASSERT condition level "const char *msg"
.Sh DESCRIPTION
In a kernel compiled with both "options INVARIANTS"
and "options INVARIANT_SUPPORT",
the
.Fn CONDSPLASSERT
macro compares the current spl level of the kernel with the spl
.Ar level
specified in the macro
.Fn CONDSPLASSERT
if the specified condition is met.
If the specified
.Ar level
is not active
.Fn CONDSPLASSERT
calls the
.Fn KASSERT
macro with the
.Ar msg,
terminating the running system.
.Pp
In a kernel that does not have both "options INVARIANTS"
and "options INVARIANT_SUPPORT",
the
.Fn CONDSPLASSERT
macro is defined to be a no-op.
.Pp
The behaviour of
.Fn CONDSPLASSERT
is tunable by means of the
.Xr sysctl 8
knob kern.splassertmode.
When set to 0 the
.Fn CONDSPLASSERT
macro is defined to be a no-op.
When set to 1 the
.Fn CONDSPLASSERT
macro is defined to log information to the console.
When set to 2 the
.Fn CONDSPLASSERT
macro is defined to
.Xr panic 9 .
.Sh EXAMPLES
The kernel function
.Fn swp_pager_meta_build
must be called
.Fn splvm
and has to match a certain object type:
.Bd -literal -offset indent
CONDSPLASSERT(object->type == OBJT_SWAP, vm,
"swp_pager_meta_build");
if (object->type != OBJT_SWAP) {
object->type = OBJT_SWAP;
object->un_pager.swp.swp_bcount = 0;
.Ed
.Pp
.Sh SEE ALSO
.Xr config 8 ,
.Xr KASSERT 9 ,
.Xr panic 9 ,
.Xr SPLASSERT 9
.Sh AUTHORS
This manual page was written by
.An Jeroen Ruigrok van der Werven
.Aq asmodai@FreeBSD.org ,
based on the
.Xr SPLASSERT 9
manpage by
.An Jonathan M. Bresler
.Aq jmb@FreeBSD.org .