From: "H. Peter Anvin" <h.peter.anvin@intel.com>
To: Linus Torvalds <torvalds@linux-foundation.org>,
Andy Lutomirski <luto@amacapital.net>
Cc: Thomas Gleixner <tglx@linutronix.de>,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
the arch/x86 maintainers <x86@kernel.org>,
Steven Rostedt <rostedt@goodmis.org>,
Gleb Natapov <gleb@kernel.org>,
Paolo Bonzini <pbonzini@redhat.com>
Subject: Re: [RFC/HACK] x86: Fast return to kernel
Date: Fri, 02 May 2014 14:37:57 -0700 [thread overview]
Message-ID: <53641035.4040202@intel.com> (raw)
In-Reply-To: <CA+55aFzQiryYPsUTK-yS_rt=MGtzJZBBrj3waGq6Ez3GUqfMnw@mail.gmail.com>
On 05/02/2014 02:07 PM, Linus Torvalds wrote:
> On Fri, May 2, 2014 at 2:04 PM, Andy Lutomirski <luto@amacapital.net> wrote:
>>
>> Because otherwise I'd have to keep track of whether it's a zeroentry
>> or an errorentry. I can't stuff the offset in a register without even
>> more stack hackery, since there are no available registers there. I
>> could split the whole thing into two code paths, I guess.
>
> Ahh. Never mind. I didn't think about the fact that the error entry
> case had one more field on the stack. Your approach is all fine, it
> was me not seeing the problem.
>
I have to admit to being rather partial to the idea of simply doing
"push $0" on entry for the vectors that don't push an error code, like
the early exception handling code does.
-hpa
next prev parent reply other threads:[~2014-05-02 21:38 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-05-02 19:04 [RFC/HACK] x86: Fast return to kernel Andy Lutomirski
2014-05-02 19:31 ` Linus Torvalds
2014-05-02 19:50 ` Andy Lutomirski
2014-05-04 18:40 ` Ingo Molnar
2014-05-04 19:59 ` H. Peter Anvin
2014-05-04 21:31 ` Linus Torvalds
2014-05-04 22:01 ` H. Peter Anvin
2014-05-02 19:51 ` Linus Torvalds
2014-05-02 20:07 ` H. Peter Anvin
2014-05-02 20:30 ` Thomas Gleixner
2014-05-02 21:01 ` Linus Torvalds
2014-05-02 21:04 ` Andy Lutomirski
2014-05-02 21:07 ` Linus Torvalds
2014-05-02 21:37 ` H. Peter Anvin [this message]
2014-05-02 21:42 ` Andy Lutomirski
2014-05-02 21:44 ` H. Peter Anvin
2014-05-02 21:28 ` Thomas Gleixner
2014-05-04 23:46 ` Paolo Bonzini
2014-05-04 23:49 ` H. Peter Anvin
2014-05-02 20:19 ` Steven Rostedt
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