Date: Thu, 10 Jan 2002 14:37:56 -0500 (EST) From: Daniel Eischen <eischen@pcnet1.pcnet.com> To: Terry Lambert <tlambert2@mindspring.com> Cc: Dan Eischen <eischen@vigrid.com>, Peter Wemm <peter@wemm.org>, Nate Williams <nate@yogotech.com>, Archie Cobbs <archie@dellroad.org>, Alfred Perlstein <bright@mu.org>, arch@FreeBSD.ORG Subject: Re: Request for review: getcontext, setcontext, etc Message-ID: <Pine.SUN.3.91.1020110143509.987C-100000@pcnet1.pcnet.com> In-Reply-To: <3C3DE891.99C85D24@mindspring.com>
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On Thu, 10 Jan 2002, Terry Lambert wrote: > Dan Eischen wrote: > > I think we determined that the only time we care about the FP state is > > when sending a signal. In that case, the kernel should know how to > > get the FPU state and copy it out to the context. If there are > > different FPU formats, there is a flags word that can be set accordingly > > and the userland setcontext() can be made to account for different > > floating point formats. > > > > Currently the kernel doesn't save the FPU state in the sigcontext, > > but it should. Wouldn't this solve the problem? > > What problem? > > Using FP code in signal handlers isn't legal. Why does everyone > want to do Bezier curves in signal handlers? It's not so you can do FP in signal handlers. You have to be able to resume the context passed to the signal handler at a later point in time. You are allowed to resume any context you want from the signal handler, but when you finally resume the context that was interrupted by the signal, then the FPU state had better be in the context. -- Dan Eischen To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-arch" in the body of the message
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