From: Ard Biesheuvel <ard.biesheuvel@linaro.org>
To: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
"the arch/x86 maintainers" <x86@kernel.org>,
Andy Lutomirski <luto@kernel.org>,
Steven Rostedt <rostedt@goodmis.org>,
Peter Zijlstra <peterz@infradead.org>,
Ingo Molnar <mingo@kernel.org>,
Thomas Gleixner <tglx@linutronix.de>,
Linus Torvalds <torvalds@linux-foundation.org>,
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>
Subject: Re: [RFC PATCH 1/3] static_call: Add static call infrastructure
Date: Fri, 9 Nov 2018 20:12:26 +0100 [thread overview]
Message-ID: <CAKv+Gu_REsDKZ4q4xSTTO8y7ZMMYd6kormb5NE5D-eV=GnwcZg@mail.gmail.com> (raw)
In-Reply-To: <20181109190320.tn3fpaegg5dkgvdb@treble>
On 9 November 2018 at 20:03, Josh Poimboeuf <jpoimboe@redhat.com> wrote:
> On Fri, Nov 09, 2018 at 06:53:21PM +0100, Ard Biesheuvel wrote:
>> > It's a bit fiddly since inline and out-of-line both use
>> > arch_static_call_transform(), but what I need to do is basically:
>> >
>> > - for out-of-line, the trampoline needs to be patched into a
>> > movn/movk/movk/br sequence if the target is too far
>> > - for inline, the trampoline itself needs to be patched from
>> > adrp/ldr/br (which does a load and a indirect branch) to
>> > movn/movk/movk/br (which uses immediates), and the call sites need to
>> > be patched into calls to the veneer if the target is out of range.
>> >
>> > So arch_static_call_transform() needs to know where the trampoline is
>> > for this use case, so could we perhaps add a 'void *orig' in the key
>> > struct that keeps track of the original value of 'addr' ?
>>
>> ... and pass it to arch_static_call_transform
>
> Ok. So in both cases, you need both the call site address and the tramp
> address, right? We could add a 'tramp' pointer to the key struct -- I
> assume that's what you mean?
>
Yes.
> And also change
>
> void arch_static_call_transform(unsigned long insn, void *dest)
>
> to
>
> void arch_static_call_transform(void *call_site, void *tramp, void *dest)
>
Indeed.
next prev parent reply other threads:[~2018-11-09 19:12 UTC|newest]
Thread overview: 57+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-11-08 21:15 [PATCH RFC 0/3] Static calls Josh Poimboeuf
2018-11-08 21:15 ` [RFC PATCH 1/3] static_call: Add static call infrastructure Josh Poimboeuf
2018-11-09 9:51 ` Ard Biesheuvel
2018-11-09 14:55 ` Josh Poimboeuf
2018-11-09 13:39 ` Ard Biesheuvel
2018-11-09 15:10 ` Josh Poimboeuf
2018-11-09 15:14 ` Ard Biesheuvel
2018-11-09 17:25 ` Ard Biesheuvel
2018-11-09 17:31 ` Josh Poimboeuf
2018-11-09 17:33 ` Ard Biesheuvel
2018-11-09 17:46 ` Josh Poimboeuf
2018-11-09 17:52 ` Ard Biesheuvel
2018-11-09 17:53 ` Ard Biesheuvel
2018-11-09 19:03 ` Josh Poimboeuf
2018-11-09 19:12 ` Ard Biesheuvel [this message]
2018-11-09 17:33 ` Josh Poimboeuf
2018-11-09 18:33 ` Steven Rostedt
2018-11-09 19:35 ` Josh Poimboeuf
2018-11-09 19:57 ` Steven Rostedt
2018-11-09 20:34 ` Josh Poimboeuf
2018-11-10 5:10 ` Steven Rostedt
2018-11-10 11:58 ` Ard Biesheuvel
2018-11-10 13:09 ` Steven Rostedt
2018-11-12 3:07 ` Josh Poimboeuf
2018-11-12 4:39 ` Ard Biesheuvel
2018-11-12 4:56 ` Josh Poimboeuf
2018-11-12 5:02 ` Ard Biesheuvel
2018-11-10 11:56 ` Ard Biesheuvel
2018-11-08 21:15 ` [RFC PATCH 2/3] x86/static_call: Add x86 unoptimized static call implementation Josh Poimboeuf
2018-11-08 21:15 ` [RFC PATCH 3/3] x86/static_call: Add optimized static call implementation for 64-bit Josh Poimboeuf
2018-11-08 21:24 ` [PATCH RFC 0/3] Static calls Josh Poimboeuf
2018-11-09 7:28 ` Ingo Molnar
2018-11-09 7:50 ` Ingo Molnar
2018-11-09 13:50 ` Ard Biesheuvel
2018-11-09 15:20 ` Josh Poimboeuf
2018-11-10 23:20 ` Peter Zijlstra
2018-11-11 13:42 ` Ard Biesheuvel
2018-11-11 14:25 ` Peter Zijlstra
2018-11-09 14:45 ` Josh Poimboeuf
2018-11-12 5:02 ` Ingo Molnar
2018-11-12 5:30 ` Josh Poimboeuf
2018-11-12 9:39 ` Ard Biesheuvel
2018-11-12 22:52 ` Josh Poimboeuf
2018-11-12 17:03 ` Steven Rostedt
2018-11-12 22:56 ` Josh Poimboeuf
2018-11-12 5:34 ` Andy Lutomirski
2018-11-09 15:16 ` Andy Lutomirski
2018-11-09 15:21 ` Josh Poimboeuf
2018-11-09 16:41 ` Josh Poimboeuf
2018-11-09 18:42 ` Steven Rostedt
2018-11-09 19:05 ` Andy Lutomirski
2018-11-09 19:37 ` Steven Rostedt
2018-11-09 19:44 ` Josh Poimboeuf
2018-11-09 19:59 ` Steven Rostedt
2018-11-09 20:36 ` Josh Poimboeuf
2018-11-10 15:13 ` Masami Hiramatsu
2018-11-09 20:53 ` Rasmus Villemoes
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='CAKv+Gu_REsDKZ4q4xSTTO8y7ZMMYd6kormb5NE5D-eV=GnwcZg@mail.gmail.com' \
--to=ard.biesheuvel@linaro.org \
--cc=David.Laight@aculab.com \
--cc=bp@alien8.de \
--cc=jbaron@akamai.com \
--cc=jkosina@suse.cz \
--cc=jpoimboe@redhat.com \
--cc=linux-kernel@vger.kernel.org \
--cc=luto@kernel.org \
--cc=mhiramat@kernel.org \
--cc=mingo@kernel.org \
--cc=peterz@infradead.org \
--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;
as well as URLs for NNTP newsgroup(s).