From: Thorsten Glaser <tg@debian.org>
To: Steven Rostedt <rostedt@goodmis.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>,
Peter Zijlstra <peterz@infradead.org>,
x86@kernel.org, torvalds@linuxfoundation.org,
linux-kernel@vger.kernel.org, linux-toolchains@vger.kernel.org,
jpoimboe@redhat.com, alexei.starovoitov@gmail.com,
mhiramat@kernel.org
Subject: Re: [PATCH 1/2] x86: Remove dynamic NOP selection
Date: Mon, 22 Jan 2024 01:17:36 +0000 (UTC) [thread overview]
Message-ID: <Pine.BSM.4.64L.2401220106590.999@herc.mirbsd.org> (raw)
In-Reply-To: <20240121195649.7355e1d5@rorschach.local.home>
Steven Rostedt dixit:
>> >This was, incidentally, triggered by looking into a problem report that
>> >something did *not* work on a Geode LX system.
>
>What problem happened?
It turned out to be a compiler issue (GCC thinks i686 means PPro,
not 686-class CPUs, and -fcf-protection causes long NOPs, which
not all 686-class CPUs support, to be inserted). This turned out
to break a large part of Debian stable on OLPCs and other systems,
and the kernel’s changes in nopl handling were tabled as arguments.
https://www.jookia.org/wiki/Nopl has a longer writeup on the nopl
history.
bye,
//mirabilos
--
<igli> exceptions: a truly awful implementation of quite a nice idea.
<igli> just about the worst way you could do something like that, afaic.
<igli> it's like anti-design. <mirabilos> that too… may I quote you on that?
<igli> sure, tho i doubt anyone will listen ;)
next prev parent reply other threads:[~2024-01-22 1:18 UTC|newest]
Thread overview: 51+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-03-12 11:32 [PATCH 0/2] x86: Remove ideal_nops[] Peter Zijlstra
2021-03-12 11:32 ` [PATCH 1/2] x86: Remove dynamic NOP selection Peter Zijlstra
2021-03-12 12:09 ` Peter Zijlstra
2021-03-12 20:36 ` Linus Torvalds
2024-01-20 6:58 ` Thorsten Glaser
2024-01-20 8:22 ` H. Peter Anvin
2024-01-20 16:53 ` Thorsten Glaser
2024-01-21 23:21 ` H. Peter Anvin
2024-01-21 23:58 ` Thorsten Glaser
2024-01-22 0:15 ` H. Peter Anvin
2024-01-22 0:56 ` Steven Rostedt
2024-01-22 1:17 ` Thorsten Glaser [this message]
2024-01-22 2:04 ` H. Peter Anvin
2024-01-22 2:15 ` H. Peter Anvin
2024-01-22 2:22 ` Steven Rostedt
2024-01-22 2:31 ` H. Peter Anvin
2024-01-20 17:00 ` Linus Torvalds
2024-01-20 17:19 ` Thorsten Glaser
2024-01-20 18:21 ` disassemblers (was Re: [PATCH 1/2] x86: Remove dynamic NOP selection) Thorsten Glaser
2024-01-21 22:36 ` [PATCH 1/2] x86: Remove dynamic NOP selection David Laight
2024-01-21 23:10 ` H. Peter Anvin
2021-03-12 11:32 ` [PATCH 2/2] objtool,x86: Use asm/nops.h Peter Zijlstra
2021-03-12 14:29 ` [PATCH 0/2] x86: Remove ideal_nops[] Sedat Dilek
2021-03-12 14:47 ` Borislav Petkov
2021-03-12 17:26 ` Steven Rostedt
2021-03-12 17:35 ` Sedat Dilek
2021-03-12 17:46 ` Borislav Petkov
2021-03-12 17:47 ` Steven Rostedt
2021-03-12 18:13 ` Sedat Dilek
2021-03-12 19:03 ` Sedat Dilek
2021-03-12 20:59 ` Borislav Petkov
[not found] ` <CA+icZUWSCS6vAQOXoG6nsW+Dbnogivzf+rmegCTMjz5hjE5cKQ@mail.gmail.com>
2021-03-13 8:49 ` Borislav Petkov
2021-03-13 11:23 ` Borislav Petkov
2021-03-13 12:10 ` Sedat Dilek
2021-03-13 12:15 ` Borislav Petkov
2021-03-13 12:38 ` Sedat Dilek
2021-03-13 12:49 ` Borislav Petkov
2021-03-13 12:58 ` Sedat Dilek
2021-03-13 13:29 ` Borislav Petkov
2021-03-13 13:47 ` Sedat Dilek
2021-03-15 17:04 ` Sedat Dilek
2021-03-15 17:15 ` Borislav Petkov
2021-03-15 17:19 ` Sedat Dilek
2021-03-15 17:23 ` Borislav Petkov
2021-03-15 18:10 ` Peter Zijlstra
2021-03-15 18:23 ` Sedat Dilek
2021-03-15 22:14 ` Peter Zijlstra
2021-03-16 5:56 ` Sedat Dilek
2021-03-27 12:08 ` Sedat Dilek
2021-03-27 20:02 ` Linus Torvalds
2021-03-30 12:31 ` Sedat Dilek
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