149 lines
4.4 KiB
Groff
149 lines
4.4 KiB
Groff
.\"
|
|
.\" Copyright (c) 2007-2009 Robert N. M. Watson
|
|
.\" 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(s), this list of conditions and the following disclaimer as
|
|
.\" the first lines of this file unmodified other than the possible
|
|
.\" addition of one or more copyright notices.
|
|
.\" 2. Redistributions in binary form must reproduce the above copyright
|
|
.\" notice(s), 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 COPYRIGHT HOLDER(S) ``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 COPYRIGHT HOLDER(S) 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.
|
|
.\"
|
|
.\" $FreeBSD$
|
|
.\"
|
|
.Dd November 16, 2011
|
|
.Dt STACK 9
|
|
.Os
|
|
.Sh NAME
|
|
.Nm stack
|
|
.Nd kernel thread stack tracing routines
|
|
.Sh SYNOPSIS
|
|
.In sys/param.h
|
|
.In sys/stack.h
|
|
In the kernel configuration file:
|
|
.Cd "options DDB"
|
|
.Cd "options STACK"
|
|
.Ft struct stack *
|
|
.Fn stack_create "void"
|
|
.Ft void
|
|
.Fn stack_destroy "struct stack *st"
|
|
.Ft int
|
|
.Fn stack_put "struct stack *st" "vm_offset_t pc"
|
|
.Ft void
|
|
.Fn stack_copy "const struct stack *src" "struct stack dst"
|
|
.Ft void
|
|
.Fn stack_zero "struct stack *st"
|
|
.Ft void
|
|
.Fn stack_print "const struct stack *st"
|
|
.Ft void
|
|
.Fn stack_print_ddb "const struct stack *st"
|
|
.Ft void
|
|
.Fn stack_print_short "const struct stack *st"
|
|
.Ft void
|
|
.Fn stack_print_short_ddb "const struct stack *st"
|
|
.Ft void
|
|
.Fn stack_sbuf_print "struct sbuf sb*" "const struct stack *st"
|
|
.Ft void
|
|
.Fn stack_sbuf_print_ddb "struct sbuf sb*" "const struct stack *st"
|
|
.Ft void
|
|
.Fn stack_save "struct stack *st"
|
|
.Sh DESCRIPTION
|
|
The
|
|
.Nm
|
|
KPI allows querying of kernel stack trace information and the automated
|
|
generation of kernel stack trace strings for the purposes of debugging and
|
|
tracing.
|
|
To use the KPI, at least one of
|
|
.Cd "options DDB"
|
|
and
|
|
.Cd "options STACK"
|
|
must be compiled into the kernel.
|
|
.Pp
|
|
Each stack trace is described by a
|
|
.Vt "struct stack" .
|
|
Before a trace may be created or otherwise manipulated, storage for the trace
|
|
must be allocated with
|
|
.Fn stack_create ,
|
|
which may sleep.
|
|
Memory associated with a trace is freed by calling
|
|
.Fn stack_destroy .
|
|
.Pp
|
|
A trace of the current kernel thread's call stack may be captured using
|
|
.Fn stack_save .
|
|
.Pp
|
|
.Fn stack_print
|
|
and
|
|
.Fn stack_print_short
|
|
may be used to print a stack trace using the kernel
|
|
.Xr printf 9 ,
|
|
and may sleep as a result of acquiring
|
|
.Xr sx 9
|
|
locks in the kernel linker while looking up symbol names.
|
|
In locking-sensitive environments, the unsynchronized
|
|
.Fn stack_print_ddb
|
|
and
|
|
.Fn stack_print_short_ddb
|
|
variants may be invoked.
|
|
This function bypasses kernel linker locking, making it usable in
|
|
.Xr ddb 4 ,
|
|
but not in a live system where linker data structures may change.
|
|
.Pp
|
|
.Fn stack_sbuf_print
|
|
may be used to construct a human-readable string, including conversion (where
|
|
possible) from a simple kernel instruction pointer to a named symbol and
|
|
offset.
|
|
The argument
|
|
.Ar sb
|
|
must be an initialized
|
|
.Dv struct sbuf
|
|
as described in
|
|
.Xr sbuf 9 .
|
|
This function may sleep if an auto-extending
|
|
.Dv struct sbuf
|
|
is used, or due to kernel linker locking.
|
|
In locking-sensitive environments, such as
|
|
.Xr ddb 4 ,
|
|
the unsynchronized
|
|
.Fn stack_sbuf_print_ddb
|
|
variant may be invoked to avoid kernel linker locking; it should be used with
|
|
a fixed-length sbuf.
|
|
.Pp
|
|
The utility functions
|
|
.Nm stack_zero ,
|
|
.Nm stack_copy ,
|
|
and
|
|
.Nm stack_put
|
|
may be used to manipulate stack data structures directly.
|
|
.Sh SEE ALSO
|
|
.Xr ddb 4 ,
|
|
.Xr printf 9 ,
|
|
.Xr sbuf 9 ,
|
|
.Xr sx 9
|
|
.Sh AUTHORS
|
|
.An -nosplit
|
|
The
|
|
.Xr stack 9
|
|
function suite was created by
|
|
.An Antoine Brodin .
|
|
.Xr stack 9
|
|
was extended by
|
|
.An Robert Watson
|
|
for general-purpose use outside of
|
|
.Xr ddb 4 .
|