2fe8fb192f
There is important information about booting non-ack images in docs/UPDATING. ack/aout-format images can't be built any more, and booting clang/ELF-format ones is a little different. Updating to the new boot monitor is recommended. Changes in this commit: . drop boot monitor -> allowing dropping ack support . facility to copy ELF boot files to /boot so that old boot monitor can still boot fairly easily, see UPDATING . no more ack-format libraries -> single-case libraries . some cleanup of OBJECT_FMT, COMPILER_TYPE, etc cases . drop several ack toolchain commands, but not all support commands (e.g. aal is gone but acksize is not yet). . a few libc files moved to netbsd libc dir . new /bin/date as minix date used code in libc/ . test compile fix . harmonize includes . /usr/lib is no longer special: without ack, /usr/lib plays no kind of special bootstrapping role any more and bootstrapping is done exclusively through packages, so releases depend even less on the state of the machine making them now. . rename nbsd_lib* to lib* . reduce mtree
153 lines
3.8 KiB
Groff
153 lines
3.8 KiB
Groff
.\" $NetBSD: getcontext.2,v 1.7 2010/04/29 06:07:35 jruoho Exp $
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.\"
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.\" Copyright (c) 1999 The NetBSD Foundation, Inc.
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.\" All rights reserved.
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.\"
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.\" This code is derived from software contributed to The NetBSD Foundation
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.\" by Klaus Klein.
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.\"
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.\" Redistribution and use in source and binary forms, with or without
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.\" modification, are permitted provided that the following conditions
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.\" are met:
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.\" 1. Redistributions of source code must retain the above copyright
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.\" notice, this list of conditions and the following disclaimer.
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.\" 2. Redistributions in binary form must reproduce the above copyright
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.\" notice, this list of conditions and the following disclaimer in the
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.\" documentation and/or other materials provided with the distribution.
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.\"
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.\" THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
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.\" ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
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.\" TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
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.\" PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
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.\" BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
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.\" CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
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.\" SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
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.\" INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
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.\" CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
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.\" ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
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.\" POSSIBILITY OF SUCH DAMAGE.
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.\"
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.Dd April 28, 2010
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.Dt GETCONTEXT 2
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.Os
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.Sh NAME
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.Nm getcontext ,
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.Nm setcontext
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.Nd get and set current user context
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.Sh LIBRARY
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.Lb libc
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.Sh SYNOPSIS
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.In ucontext.h
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.Ft int
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.Fn getcontext "ucontext_t *ucp"
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.Ft int
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.Fn setcontext "const ucontext_t *ucp"
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.Sh DESCRIPTION
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The
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.Fn getcontext
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function initializes the object pointed to by
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.Fa ucp
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to the current user context of the calling thread.
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The user context defines a thread's execution environment and includes
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the contents of its machine registers,
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its signal mask,
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and its current execution stack.
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.Pp
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The
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.Fn setcontext
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function restores the user context defined in the object pointed to by
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.Fa ucp
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as most recently initialized by a previous call to either
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.Fn getcontext
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or
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.Xr makecontext 3 .
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.\" TODO: signal handler
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If successful, execution of the program resumes as defined in the
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.Fa ucp
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argument, and
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.Fn setcontext
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will not return.
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If
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.Fa ucp
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was initialized by the
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.Fn getcontext
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function, program execution continues as if the corresponding invocation of
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.Fn getcontext
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had just returned (successfully).
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If
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.Fa ucp
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was initialized by the
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.Xr makecontext 3
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function, program execution continues with the function (and function
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arguments) passed to
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.Xr makecontext 3 .
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.Sh RETURN VALUES
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On successful completion,
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.Fn getcontext
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returns 0 and
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.Fn setcontext
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does not return.
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Otherwise a value of \-1 is returned and
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.Va errno
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is set to indicate the error.
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.Sh ERRORS
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The
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.Fn getcontext
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and
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.Fn setcontext
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functions will fail if:
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.Bl -tag -width Er
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.It Bq Er EFAULT
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The
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.Fa ucp
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argument points to an invalid address.
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.El
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.Pp
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The
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.Fn setcontext
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function will fail if:
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.Bl -tag -width Er
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.It Bq Er EINVAL
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The contents of the datum pointed to by
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.Fa ucp
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are invalid.
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.El
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.Sh SEE ALSO
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.Xr sigprocmask 2 ,
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.Xr longjmp 3 ,
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.Xr makecontext 3 ,
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.Xr setjmp 3 ,
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.Xr swapcontext 3
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.Sh STANDARDS
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The
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.Fn getcontext
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and
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.Fn setcontext
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functions conform to
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.St -xsh5
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and
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.St -p1003.1-2001 .
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The
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.Va errno
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indications are an extension to the standard.
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.Pp
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The
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.St -p1003.1-2004
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revision marked the functions
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.Fn getcontext
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and
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.Fn setcontext
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as obsolete, citing portability issues and recommending the use of
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.Tn POSIX
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threads instead.
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The
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.St -p1003.1-2008
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revision removed the functions from the specification.
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.Sh HISTORY
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The
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.Fn getcontext
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and
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.Fn setcontext
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functions first appeared in
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.At V.4 .
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