From: Peter Zijlstra <peterz@infradead.org>
To: Andy Lutomirski <luto@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>,
Josh Poimboeuf <jpoimboe@redhat.com>,
Nadav Amit <namit@vmware.com>,
the arch/x86 maintainers <x86@kernel.org>,
Linux List Kernel Mailing <linux-kernel@vger.kernel.org>,
Ard Biesheuvel <ard.biesheuvel@linaro.org>,
Steven Rostedt <rostedt@goodmis.org>,
Ingo Molnar <mingo@kernel.org>,
Thomas Gleixner <tglx@linutronix.de>,
Masami Hiramatsu <mhiramat@kernel.org>,
Jason Baron <jbaron@akamai.com>, Jiri Kosina <jkosina@suse.cz>,
David Laight <David.Laight@aculab.com>,
Borislav Petkov <bp@alien8.de>, Julia Cartwright <julia@ni.com>,
Jessica Yu <jeyu@kernel.org>, "H. Peter Anvin" <hpa@zytor.com>,
Rasmus Villemoes <linux@rasmusvillemoes.dk>,
Edward Cree <ecree@solarflare.com>,
Daniel Bristot de Oliveira <bristot@redhat.com>
Subject: Re: [PATCH v3 0/6] Static calls
Date: Mon, 14 Jan 2019 13:28:56 +0100 [thread overview]
Message-ID: <20190114122856.GA20726@hirez.programming.kicks-ass.net> (raw)
In-Reply-To: <CALCETrXZdzNS=Bbv=qyM8iBC82QWOQqcfN1GFfcn6UHvePatHQ@mail.gmail.com>
On Fri, Jan 11, 2019 at 01:05:20PM -0800, Andy Lutomirski wrote:
> On Fri, Jan 11, 2019 at 12:54 PM Linus Torvalds
> <torvalds@linux-foundation.org> wrote:
> >
> > On Fri, Jan 11, 2019 at 12:31 PM Josh Poimboeuf <jpoimboe@redhat.com> wrote:
> > >
> > > I was referring to the fact that a single static call key update will
> > > usually result in patching multiple call sites. But you're right, it's
> > > only 1-2 trampolines per text_poke_bp() invocation. Though eventually
> > > we may want to batch all the writes like what Daniel has proposed for
> > > jump labels, to reduce IPIs.
> >
> > Yeah, my suggestion doesn't allow for batching, since it would
> > basically generate one trampoline for every rewritten instruction.
>
> Sure it does. Just make 1000 trampolines and patch 1000 sites in a
> batch :) As long as the number of trampolines is smallish (e.g. fits
> in a page), then we should be in good shape.
Much easier still would be to make the ARCH_DEFINE_STATIC_TRAMP thing
generate the two trampolines per callsite and simply keep them around.
Another advantage is that you then only have to patch the JMP target,
since the return address will always stay the same (since these things
are generated per call-site).
Anyway... the STI-shadow thing is very clever. But I'm with Josh in that
I think I prefer the IRET frame offset thing -- but yes, I've read
Linus' argument against that.
next prev parent reply other threads:[~2019-01-14 12:29 UTC|newest]
Thread overview: 90+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-01-09 22:59 Josh Poimboeuf
2019-01-09 22:59 ` [PATCH v3 1/6] compiler.h: Make __ADDRESSABLE() symbol truly unique Josh Poimboeuf
2019-01-09 22:59 ` [PATCH v3 2/6] static_call: Add basic static call infrastructure Josh Poimboeuf
2019-01-10 14:03 ` Edward Cree
2019-01-10 18:37 ` Josh Poimboeuf
2019-01-09 22:59 ` [PATCH v3 3/6] x86/static_call: Add out-of-line static call implementation Josh Poimboeuf
2019-01-10 0:16 ` Nadav Amit
2019-01-10 16:28 ` Josh Poimboeuf
2019-01-09 22:59 ` [PATCH v3 4/6] static_call: Add inline static call infrastructure Josh Poimboeuf
2019-01-09 22:59 ` [PATCH v3 5/6] x86/alternative: Use a single access in text_poke() where possible Josh Poimboeuf
2019-01-10 9:32 ` Nadav Amit
2019-01-10 17:20 ` Josh Poimboeuf
2019-01-10 17:29 ` Nadav Amit
2019-01-10 17:32 ` Steven Rostedt
2019-01-10 17:42 ` Sean Christopherson
2019-01-10 17:57 ` Steven Rostedt
2019-01-10 18:04 ` Sean Christopherson
2019-01-10 18:21 ` Josh Poimboeuf
2019-01-10 18:24 ` Steven Rostedt
2019-01-11 12:10 ` Alexandre Chartre
2019-01-11 15:28 ` Josh Poimboeuf
2019-01-11 16:46 ` Alexandre Chartre
2019-01-11 16:57 ` Josh Poimboeuf
2019-01-11 17:41 ` Jason Baron
2019-01-11 17:54 ` Nadav Amit
2019-01-15 11:10 ` Alexandre Chartre
2019-01-15 16:19 ` Steven Rostedt
2019-01-15 16:45 ` Alexandre Chartre
2019-01-11 0:59 ` hpa
2019-01-11 1:34 ` Sean Christopherson
2019-01-11 8:13 ` hpa
2019-01-09 22:59 ` [PATCH v3 6/6] x86/static_call: Add inline static call implementation for x86-64 Josh Poimboeuf
2019-01-10 1:21 ` [PATCH v3 0/6] Static calls Nadav Amit
2019-01-10 16:44 ` Josh Poimboeuf
2019-01-10 17:32 ` Nadav Amit
2019-01-10 18:18 ` Josh Poimboeuf
2019-01-10 19:45 ` Nadav Amit
2019-01-10 20:32 ` Josh Poimboeuf
2019-01-10 20:48 ` Nadav Amit
2019-01-10 20:57 ` Josh Poimboeuf
2019-01-10 21:47 ` Nadav Amit
2019-01-10 17:31 ` Linus Torvalds
2019-01-10 20:51 ` H. Peter Anvin
2019-01-10 20:30 ` Peter Zijlstra
2019-01-10 20:52 ` Josh Poimboeuf
2019-01-10 23:02 ` Linus Torvalds
2019-01-11 0:56 ` Andy Lutomirski
2019-01-11 1:47 ` Nadav Amit
2019-01-11 15:15 ` Josh Poimboeuf
2019-01-11 15:48 ` Nadav Amit
2019-01-11 16:07 ` Josh Poimboeuf
2019-01-11 17:23 ` Nadav Amit
2019-01-11 19:03 ` Linus Torvalds
2019-01-11 19:17 ` Nadav Amit
2019-01-11 19:23 ` hpa
2019-01-11 19:33 ` Nadav Amit
2019-01-11 19:34 ` Linus Torvalds
2019-01-13 0:34 ` hpa
2019-01-13 0:36 ` hpa
2019-01-11 19:39 ` Jiri Kosina
2019-01-14 2:31 ` H. Peter Anvin
2019-01-14 2:40 ` H. Peter Anvin
2019-01-14 20:11 ` Andy Lutomirski
2019-01-14 22:00 ` H. Peter Anvin
2019-01-14 22:54 ` H. Peter Anvin
2019-01-15 3:05 ` Andy Lutomirski
2019-01-15 5:01 ` H. Peter Anvin
2019-01-15 5:37 ` H. Peter Anvin
2019-01-14 23:27 ` Andy Lutomirski
2019-01-14 23:51 ` Nadav Amit
2019-01-15 2:28 ` hpa
2019-01-11 20:04 ` Josh Poimboeuf
2019-01-11 20:12 ` Linus Torvalds
2019-01-11 20:31 ` Josh Poimboeuf
2019-01-11 20:46 ` Linus Torvalds
2019-01-11 21:05 ` Andy Lutomirski
2019-01-11 21:10 ` Linus Torvalds
2019-01-11 21:32 ` Josh Poimboeuf
2019-01-14 12:28 ` Peter Zijlstra [this message]
2019-01-11 21:22 ` Josh Poimboeuf
2019-01-11 21:23 ` Josh Poimboeuf
2019-01-11 21:25 ` Josh Poimboeuf
2019-01-11 21:36 ` Nadav Amit
2019-01-11 21:41 ` Josh Poimboeuf
2019-01-11 21:55 ` Steven Rostedt
2019-01-11 21:59 ` Nadav Amit
2019-01-11 21:56 ` Nadav Amit
2019-01-12 23:54 ` Andy Lutomirski
2020-02-17 21:10 ` Jann Horn
2020-02-17 21:57 ` Steven Rostedt
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20190114122856.GA20726@hirez.programming.kicks-ass.net \
--to=peterz@infradead.org \
--cc=David.Laight@aculab.com \
--cc=ard.biesheuvel@linaro.org \
--cc=bp@alien8.de \
--cc=bristot@redhat.com \
--cc=ecree@solarflare.com \
--cc=hpa@zytor.com \
--cc=jbaron@akamai.com \
--cc=jeyu@kernel.org \
--cc=jkosina@suse.cz \
--cc=jpoimboe@redhat.com \
--cc=julia@ni.com \
--cc=linux-kernel@vger.kernel.org \
--cc=linux@rasmusvillemoes.dk \
--cc=luto@kernel.org \
--cc=mhiramat@kernel.org \
--cc=mingo@kernel.org \
--cc=namit@vmware.com \
--cc=rostedt@goodmis.org \
--cc=tglx@linutronix.de \
--cc=torvalds@linux-foundation.org \
--cc=x86@kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox
all inboxes | Powered by JetHome®