From: Pavel Machek <pavel@ucw.cz>
To: Sedat Dilek <sedat.dilek@gmail.com>
Cc: Segher Boessenkool <segher@kernel.crashing.org>,
Arvind Sankar <nivedita@alum.mit.edu>,
Thomas Gleixner <tglx@linutronix.de>,
Nick Desaulniers <ndesaulniers@google.com>,
"Paul E. McKenney" <paulmck@kernel.org>,
Ingo Molnar <mingo@redhat.com>, Arnd Bergmann <arnd@arndb.de>,
Borislav Petkov <bp@alien8.de>,
"maintainer:X86 ARCHITECTURE (32-BIT AND 64-BIT)"
<x86@kernel.org>, "H. Peter Anvin" <hpa@zytor.com>,
"Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>,
Zhenzhong Duan <zhenzhong.duan@oracle.com>,
Kees Cook <keescook@chromium.org>,
Peter Zijlstra <peterz@infradead.org>,
Juergen Gross <jgross@suse.com>,
Andy Lutomirski <luto@kernel.org>,
Andrew Cooper <andrew.cooper3@citrix.com>,
LKML <linux-kernel@vger.kernel.org>,
clang-built-linux <clang-built-linux@googlegroups.com>,
Will Deacon <will@kernel.org>,
Linus Torvalds <torvalds@linux-foundation.org>,
Miguel Ojeda <miguel.ojeda.sandonis@gmail.com>
Subject: Re: [PATCH] x86: work around clang IAS bug referencing __force_order
Date: Wed, 9 Sep 2020 00:25:24 +0200 [thread overview]
Message-ID: <20200908222524.GE1005@bug> (raw)
In-Reply-To: <CA+icZUWGHo3mkN4=ZYeU37p8KJhxTXS5QKcAvq_HaqTHmFkw2g@mail.gmail.com>
On Sat 2020-08-22 11:51:56, Sedat Dilek wrote:
> On Sat, Aug 22, 2020 at 11:23 AM Sedat Dilek <sedat.dilek@gmail.com> wrote:
> >
> > On Sat, Aug 22, 2020 at 10:42 AM Segher Boessenkool
> > <segher@kernel.crashing.org> wrote:
> > >
> > > Hi Arvind,
> > >
> > > On Fri, Aug 21, 2020 at 11:55:52PM -0400, Arvind Sankar wrote:
> > > > Cc Segher.
> > > >
> > > > Segher, we were looking at gcc PR82602, where IRA could reorder volatile
> > > > asm's (reported on ARM). The fix was backported to gcc-6.
> > >
> > > I know ;-)
> > >
> > > > Do you know if
> > > > there is any reason the problem couldn't occur on x86 on older gcc
> > > > without the fix?
> > >
> > > No, I see no particular reason, at least GCC 5 seems vulnerable. (The
> > > GCC 5 release branch was closed at the time this bug report was made,
> > > already). There is no reason I see why it would work on x86 but fail
> > > elsewhere, either.
> > >
> >
> > [1] says:
> >
> > Current Minimal Requirements
> > ...
> > ====================== =============== ========================================
> > Program Minimal version Command to check the version
> > ====================== =============== ========================================
> > GNU C 4.9 gcc --version
> >
> > - Sedat -
> >
> > [1] https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/Documentation/process/changes.rst#n32
>
> [ CC Miguel Ojeda (Compiler Attributes maintainer) ]
>
> There exist gcc-4.8 and gcc-4.9 for Debian/jessie where EOL was June
> 30, 2020 (see [1] and [2]).
>
> In the latest available version "4.9.2-10+deb8u1" I see no PR82602 was
> backported (see [3] and [4]).
>
> I am asking myself who is using such ancient compilers?
> Recently, I threw away GCC-8 from my Debian system.
I do have 4.9.2 on some systems. They work well, and are likely to compile
significantly faster than newer ones.
Please don't break them.
Pavel
--
(english) http://www.livejournal.com/~pavelmachek
(cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html
prev parent reply other threads:[~2020-09-08 22:25 UTC|newest]
Thread overview: 63+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-05-27 13:53 [PATCH] x86: work around clang IAS bug referencing __force_order Arnd Bergmann
2020-08-01 11:50 ` Sedat Dilek
2020-08-06 22:13 ` Thomas Gleixner
2020-08-07 7:03 ` Sedat Dilek
2020-08-04 0:09 ` Nick Desaulniers
2020-08-14 17:29 ` Sedat Dilek
2020-08-14 21:19 ` Sedat Dilek
2020-08-14 22:57 ` Nick Desaulniers
2020-08-15 0:26 ` Nick Desaulniers
2020-08-15 3:28 ` Sedat Dilek
2020-08-15 8:23 ` Sedat Dilek
2020-08-15 10:46 ` Sedat Dilek
2020-08-15 14:39 ` Sedat Dilek
2020-08-16 9:37 ` Sedat Dilek
2020-08-06 22:11 ` Thomas Gleixner
2020-08-13 0:12 ` Nick Desaulniers
2020-08-13 8:49 ` David Laight
2020-08-13 17:20 ` Arvind Sankar
2020-08-13 17:28 ` Thomas Gleixner
2020-08-13 17:37 ` Paul E. McKenney
2020-08-13 18:09 ` Arvind Sankar
2020-08-13 18:20 ` Paul E. McKenney
2020-08-20 10:44 ` Thomas Gleixner
2020-08-20 13:06 ` Arvind Sankar
2020-08-21 0:37 ` Thomas Gleixner
2020-08-21 23:04 ` Arvind Sankar
2020-08-21 23:16 ` Nick Desaulniers
2020-08-21 23:25 ` Arvind Sankar
2020-08-22 0:43 ` Thomas Gleixner
2020-08-22 3:55 ` Arvind Sankar
2020-08-22 8:41 ` Segher Boessenkool
2020-08-22 9:23 ` Sedat Dilek
2020-08-22 9:51 ` Sedat Dilek
2020-08-22 10:26 ` Segher Boessenkool
2020-08-22 10:35 ` Arnd Bergmann
2020-08-22 18:17 ` Miguel Ojeda
2020-08-22 21:08 ` Linus Torvalds
2020-08-22 23:10 ` Arvind Sankar
2020-08-23 0:10 ` Linus Torvalds
2020-08-23 1:16 ` Arvind Sankar
2020-08-23 21:25 ` [PATCH] x86/asm: Replace __force_order with memory clobber Arvind Sankar
2020-08-24 17:50 ` Nathan Chancellor
2020-08-24 19:13 ` Miguel Ojeda
2020-08-25 15:19 ` Arvind Sankar
2020-08-25 15:21 ` Sedat Dilek
2020-09-02 15:33 ` [PATCH v2] " Arvind Sankar
2020-09-02 15:58 ` David Laight
2020-09-02 16:14 ` Arvind Sankar
2020-09-02 16:08 ` Arvind Sankar
2020-09-02 20:26 ` David Laight
2020-09-02 17:16 ` Segher Boessenkool
2020-09-02 17:36 ` Arvind Sankar
2020-09-02 18:19 ` Miguel Ojeda
2020-09-02 18:24 ` Arvind Sankar
2020-09-02 23:21 ` [PATCH v3] " Arvind Sankar
2020-09-03 2:17 ` Kees Cook
2020-09-03 5:34 ` Miguel Ojeda
2020-09-30 20:50 ` Kees Cook
2020-10-01 10:12 ` [tip: x86/asm] x86/asm: Replace __force_order with a " tip-bot2 for Arvind Sankar
2020-10-13 9:30 ` tip-bot2 for Arvind Sankar
2020-08-22 21:17 ` [PATCH] x86: work around clang IAS bug referencing __force_order Arvind Sankar
2020-08-23 13:31 ` David Laight
2020-09-08 22:25 ` Pavel Machek [this message]
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=20200908222524.GE1005@bug \
--to=pavel@ucw.cz \
--cc=andrew.cooper3@citrix.com \
--cc=arnd@arndb.de \
--cc=bp@alien8.de \
--cc=clang-built-linux@googlegroups.com \
--cc=hpa@zytor.com \
--cc=jgross@suse.com \
--cc=keescook@chromium.org \
--cc=kirill.shutemov@linux.intel.com \
--cc=linux-kernel@vger.kernel.org \
--cc=luto@kernel.org \
--cc=miguel.ojeda.sandonis@gmail.com \
--cc=mingo@redhat.com \
--cc=ndesaulniers@google.com \
--cc=nivedita@alum.mit.edu \
--cc=paulmck@kernel.org \
--cc=peterz@infradead.org \
--cc=sedat.dilek@gmail.com \
--cc=segher@kernel.crashing.org \
--cc=tglx@linutronix.de \
--cc=torvalds@linux-foundation.org \
--cc=will@kernel.org \
--cc=x86@kernel.org \
--cc=zhenzhong.duan@oracle.com \
/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).