linux-toolchains.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Segher Boessenkool <segher@kernel.crashing.org>
To: Borislav Petkov <bp@alien8.de>
Cc: X86 ML <x86@kernel.org>, Michael Matz <matz@suse.de>,
	linux-toolchains@vger.kernel.org,
	LKML <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH] x86/sev: Mark snp_abort() noreturn
Date: Wed, 24 Aug 2022 12:29:29 -0500	[thread overview]
Message-ID: <20220824172929.GA25951@gate.crashing.org> (raw)
In-Reply-To: <20220824152420.20547-1-bp@alien8.de>

Hi!

On Wed, Aug 24, 2022 at 05:24:20PM +0200, Borislav Petkov wrote:
> Mark both the function prototype and definition as noreturn in order to
> prevent the compiler from doing transformations which confuse objtool
> like so:
> 
>   vmlinux.o: warning: objtool: sme_enable+0x71: unreachable instruction

Would -Wmissing-noreturn have caught this?  It sounds like you need this
(and then fix all resulting warnings) to not upset objtool?

It is nice to have this anyway (if there aren't a zillion false
positives), but it seems objtool is very fragile.


Segher

  parent reply	other threads:[~2022-08-24 17:32 UTC|newest]

Thread overview: 17+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-08-24 15:24 [PATCH] x86/sev: Mark snp_abort() noreturn Borislav Petkov
2022-08-24 15:38 ` Peter Zijlstra
2022-08-24 15:48   ` Borislav Petkov
2022-08-24 16:16     ` Peter Zijlstra
2022-08-24 16:43       ` [PATCH v2] " Borislav Petkov
2022-08-24 17:29 ` Segher Boessenkool [this message]
2022-08-24 18:23   ` [PATCH] " Borislav Petkov
2022-08-24 18:44   ` Nick Desaulniers
2022-08-24 19:43     ` Segher Boessenkool
2022-08-24 20:45   ` Peter Zijlstra
2022-08-24 22:41     ` Segher Boessenkool
2022-08-25  6:41       ` Peter Zijlstra
2022-08-25 12:29         ` Michael Matz
2022-08-25 12:58         ` Segher Boessenkool
2022-08-25 13:12         ` David Laight
2022-08-30  4:48           ` Josh Poimboeuf
2022-08-30  4:46     ` Josh Poimboeuf

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=20220824172929.GA25951@gate.crashing.org \
    --to=segher@kernel.crashing.org \
    --cc=bp@alien8.de \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-toolchains@vger.kernel.org \
    --cc=matz@suse.de \
    --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).