From: Masami Hiramatsu <mhiramat@kernel.org>
To: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>,
Peter Zijlstra <peterz@infradead.org>,
linux-kernel@vger.kernel.org, linux-tip-commits@vger.kernel.org,
Martin Schwidefsky <schwidefsky@de.ibm.com>,
Vasily Gorbik <gor@linux.ibm.com>, x86 <x86@kernel.org>
Subject: Re: [tip: objtool/core] x86/insn: Support big endian cross-compiles
Date: Wed, 14 Oct 2020 16:28:59 +0900 [thread overview]
Message-ID: <20201014162859.987d5f71f5e5456ffb812abc@kernel.org> (raw)
In-Reply-To: <20201012153949.jfwa7rgpzu5b7ld4@treble>
On Mon, 12 Oct 2020 10:39:49 -0500
Josh Poimboeuf <jpoimboe@redhat.com> wrote:
> On Mon, Oct 12, 2020 at 09:12:36AM +0900, Masami Hiramatsu wrote:
> > On Sat, 10 Oct 2020 12:44:15 -0500
> > Josh Poimboeuf <jpoimboe@redhat.com> wrote:
> >
> > > On Fri, Oct 09, 2020 at 10:49:21PM +0200, Borislav Petkov wrote:
> > > > On Fri, Oct 09, 2020 at 10:38:22PM +0200, Peter Zijlstra wrote:
> > > > > On Wed, Oct 07, 2020 at 04:20:19PM -0000, tip-bot2 for Martin Schwidefsky wrote:
> > > > > > The following commit has been merged into the objtool/core branch of tip:
> > > > > >
> > > > > > Commit-ID: 2a522b53c47051d3bf98748418f4f8e5f20d2c04
> > > > > > Gitweb: https://git.kernel.org/tip/2a522b53c47051d3bf98748418f4f8e5f20d2c04
> > > > > > Author: Martin Schwidefsky <schwidefsky@de.ibm.com>
> > > > > > AuthorDate: Mon, 05 Oct 2020 17:50:31 +02:00
> > > > > > Committer: Josh Poimboeuf <jpoimboe@redhat.com>
> > > > > > CommitterDate: Tue, 06 Oct 2020 09:32:29 -05:00
> > > > > >
> > > > > > x86/insn: Support big endian cross-compiles
> > > > > >
> > > > > > x86 instruction decoder code is shared across the kernel source and the
> > > > > > tools. Currently objtool seems to be the only tool from build tools needed
> > > > > > which breaks x86 cross compilation on big endian systems. Make the x86
> > > > > > instruction decoder build host endianness agnostic to support x86 cross
> > > > > > compilation and enable objtool to implement endianness awareness for
> > > > > > big endian architectures support.
> > > > > >
> > > > > > Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
> > > > > > Co-developed-by: Vasily Gorbik <gor@linux.ibm.com>
> > > > > > Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
> > > > > > Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
> > > > > > Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
> > > > >
> > > > > This commit breaks the x86 build with CONFIG_X86_DECODER_SELFTEST=y.
> > > > >
> > > > > I've asked Boris to truncate tip/objtool/core.
> > > >
> > > > Yeah, top 4 are gone until this is resolved.
> > >
> > > Masami, I wonder if we even need these selftests anymore? Objtool
> > > already decodes the entire kernel.
> >
> > No, they have different roles. The selftest checks if the decoder
> > works correctly by comparing with the output of objdump.
> >
> > As far as I can see, the objtool relies on the sanity of the decoder
> > (it trusts the output of the decoder).
>
> Ok. I wonder if we should move the decoder selftest to the 'tools'
> subdirectory.
It is in the arch/x86/tools, so it is already in a kind of tools :)
But yeah, it was considered to be used only on x86. But if someone
start trying to run it on non-x86, cross compiling, we need to
reconsider that.
Thank you,
--
Masami Hiramatsu <mhiramat@kernel.org>
next prev parent reply other threads:[~2020-10-14 7:29 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-10-07 16:20 [tip: objtool/core] x86/insn: Support big endian cross-compiles tip-bot2 for Martin Schwidefsky
2020-10-09 20:38 ` Peter Zijlstra
2020-10-09 20:49 ` Borislav Petkov
2020-10-10 14:02 ` Vasily Gorbik
2020-10-11 14:40 ` Borislav Petkov
2020-10-12 0:02 ` Masami Hiramatsu
2020-10-10 17:44 ` Josh Poimboeuf
2020-10-12 0:12 ` Masami Hiramatsu
2020-10-12 15:39 ` Josh Poimboeuf
2020-10-14 7:28 ` Masami Hiramatsu [this message]
2020-10-15 6:24 ` Ian Rogers
2020-11-03 19:35 ` Vasily Gorbik
2020-11-03 19:35 ` [PATCH 1/1] x86/tools: Use tools headers for instruction decoder selftests Vasily Gorbik
2020-11-04 9:11 ` kernel test robot
2020-11-04 9:18 ` Vasily Gorbik
2020-11-06 2:24 ` Masami Hiramatsu
2020-11-06 17:52 ` Josh Poimboeuf
2020-11-04 11:54 ` kernel test robot
2021-01-18 10:13 [tip: objtool/core] x86/insn: Support big endian cross-compiles tip-bot2 for Martin Schwidefsky
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=20201014162859.987d5f71f5e5456ffb812abc@kernel.org \
--to=mhiramat@kernel.org \
--cc=bp@alien8.de \
--cc=gor@linux.ibm.com \
--cc=jpoimboe@redhat.com \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-tip-commits@vger.kernel.org \
--cc=peterz@infradead.org \
--cc=schwidefsky@de.ibm.com \
--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).