3d51b3a280
syscall return values should be cleared. The system calls getcontext() and swapcontext() want to return 0 on success but these contexts can be switched to at a later time so the return values need to be cleared in the saved register sets. Other callers of get_mcontext() would normally want the context without clearing the return values. Remove the i386-specific context saving from the KSE code. get_mcontext() is not i386-specific any more. Fix a bad pointer in the alpha get_mcontext() code. The context was being bcopy()'d from &td->tf_frame, but tf_frame is itself a pointer, so the thread was being copied instead. Spotted by jake. Glanced at by: jake Reviewed by: bde (months ago)
138 lines
3.5 KiB
C
138 lines
3.5 KiB
C
/*-
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* Copyright (c) 2002 Daniel M. Eischen <deischen@freebsd.org>
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* All rights reserved.
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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 AUTHOR AND CONTRIBUTORS ``AS IS'' AND
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* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
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* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* SUCH DAMAGE.
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*
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*/
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/*
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* $FreeBSD$
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*/
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#include <sys/param.h>
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#include <sys/kernel.h>
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#include <sys/lock.h>
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#include <sys/mutex.h>
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#include <sys/proc.h>
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#include <sys/sysent.h>
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#include <sys/systm.h>
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#include <sys/sysproto.h>
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#include <sys/signalvar.h>
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#include <sys/ucontext.h>
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/*
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* The first two fields of a ucontext_t are the signal mask and
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* the machine context. The next field is uc_link; we want to
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* avoid destroying the link when copying out contexts.
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*/
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#define UC_COPY_SIZE offsetof(ucontext_t, uc_link)
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#ifndef _SYS_SYSPROTO_H_
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struct getcontext_args {
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struct __ucontext *ucp;
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}
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struct setcontext_args {
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const struct __ucontext_t *ucp;
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}
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struct swapcontext_args {
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struct __ucontext *oucp;
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const struct __ucontext_t *ucp;
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}
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#endif
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/*
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* MPSAFE
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*/
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int
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getcontext(struct thread *td, struct getcontext_args *uap)
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{
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ucontext_t uc;
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int ret;
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if (uap->ucp == NULL)
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ret = EINVAL;
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else {
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get_mcontext(td, &uc.uc_mcontext, 1);
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PROC_LOCK(td->td_proc);
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uc.uc_sigmask = td->td_sigmask;
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PROC_UNLOCK(td->td_proc);
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ret = copyout(&uc, uap->ucp, UC_COPY_SIZE);
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}
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return (ret);
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}
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/*
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* MPSAFE
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*/
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int
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setcontext(struct thread *td, struct setcontext_args *uap)
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{
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ucontext_t uc;
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int ret;
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if (uap->ucp == NULL)
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ret = EINVAL;
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else {
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ret = copyin(uap->ucp, &uc, UC_COPY_SIZE);
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if (ret == 0) {
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ret = set_mcontext(td, &uc.uc_mcontext);
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if (ret == 0) {
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SIG_CANTMASK(uc.uc_sigmask);
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PROC_LOCK(td->td_proc);
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td->td_sigmask = uc.uc_sigmask;
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PROC_UNLOCK(td->td_proc);
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}
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}
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}
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return (ret == 0 ? EJUSTRETURN : ret);
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}
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int
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swapcontext(struct thread *td, struct swapcontext_args *uap)
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{
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ucontext_t uc;
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int ret;
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if (uap->oucp == NULL || uap->ucp == NULL)
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ret = EINVAL;
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else {
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get_mcontext(td, &uc.uc_mcontext, 1);
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PROC_LOCK(td->td_proc);
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uc.uc_sigmask = td->td_sigmask;
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PROC_UNLOCK(td->td_proc);
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ret = copyout(&uc, uap->oucp, UC_COPY_SIZE);
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if (ret == 0) {
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ret = copyin(uap->ucp, &uc, UC_COPY_SIZE);
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if (ret == 0) {
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ret = set_mcontext(td, &uc.uc_mcontext);
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if (ret == 0) {
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SIG_CANTMASK(uc.uc_sigmask);
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PROC_LOCK(td->td_proc);
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td->td_sigmask = uc.uc_sigmask;
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PROC_UNLOCK(td->td_proc);
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}
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}
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}
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}
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return (ret == 0 ? EJUSTRETURN : ret);
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}
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