From: Michael Matz <matz@suse.de>
To: "Martin Liška" <mliska@suse.cz>
Cc: Jakub Jelinek <jakub@redhat.com>, Borislav Petkov <bp@alien8.de>,
Peter Zijlstra <peterz@infradead.org>,
Nick Desaulniers <ndesaulniers@google.com>,
Sergei Trofimovich <slyfox@gentoo.org>,
LKML <linux-kernel@vger.kernel.org>,
Thomas Gleixner <tglx@linutronix.de>,
Ingo Molnar <mingo@redhat.com>, "H. Peter Anvin" <hpa@zytor.com>,
Andy Lutomirski <luto@kernel.org>,
"maintainer:X86 ARCHITECTURE (32-BIT AND 64-BIT)"
<x86@kernel.org>,
clang-built-linux <clang-built-linux@googlegroups.com>
Subject: Re: [PATCH v2] x86: fix early boot crash on gcc-10
Date: Wed, 22 Apr 2020 15:06:36 +0000 (UTC) [thread overview]
Message-ID: <alpine.LSU.2.21.2004221501440.11688@wotan.suse.de> (raw)
In-Reply-To: <20a91f2e-0f25-8dba-e441-3233cc1ef398@suse.cz>
[-- Attachment #1: Type: text/plain, Size: 888 bytes --]
Hello,
On Wed, 22 Apr 2020, Martin Liška wrote:
> One possible solution can be usage of a GCC pragma that will disable the
> tail-call optimization:
>
> $ cat tail.c
> int foo(int);
>
> #pragma GCC push_options
> #pragma GCC optimize("-fno-optimize-sibling-calls")
As we determined upthread (and the reason why we even still have this
thread): the optimize attribute (and pragma) reset flags from the command
line (the case in point was -fno-omit-frame-pointer). So, that's not a
solution for now.
> And as I talked to Boris, I would recommend to come up with a
> "configure" check that a compiler does not optimize the key code
> sequence:
Right. I think the traditional asm (i.e. one without operands) is good
enough for the forseeable future from GCCs side: it relies on documented
behaviour of traditional asms, and hence would be very hard to change.
Ciao,
Michael.
next prev parent reply other threads:[~2020-04-22 15:06 UTC|newest]
Thread overview: 79+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-03-14 16:44 [PATCH] x86: fix early boot crash on gcc-10 Sergei Trofimovich
2020-03-16 13:04 ` Peter Zijlstra
2020-03-16 13:26 ` Jakub Jelinek
2020-03-16 13:42 ` Peter Zijlstra
2020-03-16 17:54 ` Borislav Petkov
2020-03-16 18:03 ` Jakub Jelinek
2020-03-17 14:36 ` Borislav Petkov
2020-03-17 14:39 ` Jakub Jelinek
2020-03-17 14:49 ` Borislav Petkov
2020-03-17 16:35 ` David Laight
2020-03-25 13:31 ` Borislav Petkov
2020-03-26 21:54 ` Sergei Trofimovich
2020-03-26 22:35 ` Borislav Petkov
2020-03-28 8:48 ` [PATCH v2] " Sergei Trofimovich
2020-04-13 14:15 ` [tip: x86/urgent] x86: Fix " tip-bot2 for Sergei Trofimovich
2020-04-13 16:35 ` [PATCH v2] x86: fix " Borislav Petkov
2020-04-14 13:50 ` Michael Matz
2020-04-15 7:48 ` Borislav Petkov
2020-04-15 14:53 ` Michael Matz
2020-04-15 22:19 ` Sergei Trofimovich
2020-04-17 7:57 ` Borislav Petkov
2020-04-17 8:07 ` Jakub Jelinek
2020-04-17 8:42 ` Borislav Petkov
2020-04-17 8:58 ` Jakub Jelinek
2020-04-17 9:09 ` Borislav Petkov
2020-04-17 18:15 ` Nick Desaulniers
2020-04-17 18:22 ` Nick Desaulniers
2020-04-17 19:06 ` Jakub Jelinek
2020-04-17 19:49 ` Nick Desaulniers
2020-04-17 19:53 ` Nick Desaulniers
2020-04-20 14:04 ` Michael Matz
2020-04-22 10:23 ` Borislav Petkov
2020-04-22 11:40 ` Peter Zijlstra
2020-04-22 13:49 ` Borislav Petkov
2020-04-22 13:55 ` Jakub Jelinek
2020-04-22 14:16 ` Martin Liška
2020-04-22 15:06 ` Michael Matz [this message]
2020-04-22 16:53 ` Borislav Petkov
2020-04-22 17:02 ` Jakub Jelinek
2020-04-22 18:47 ` Nick Desaulniers
2020-04-22 18:55 ` Nick Desaulniers
2020-04-22 19:21 ` Borislav Petkov
2020-04-22 21:05 ` Nick Desaulniers
2020-04-22 21:26 ` Borislav Petkov
2020-04-22 22:57 ` Nick Desaulniers
2020-04-23 12:53 ` Borislav Petkov
2020-04-23 16:12 ` [PATCH] x86: Fix early boot crash on gcc-10, next try Borislav Petkov
2020-04-23 17:30 ` Borislav Petkov
2020-04-23 18:02 ` Nick Desaulniers
2020-04-23 18:27 ` Borislav Petkov
2020-04-27 11:37 ` [tip: x86/build] x86/build: Check whether the compiler is sane tip-bot2 for Borislav Petkov
2020-04-23 19:40 ` [PATCH] x86: Fix early boot crash on gcc-10, next try Kees Cook
2020-04-25 1:46 ` Arvind Sankar
2020-04-25 8:57 ` Borislav Petkov
2020-04-25 11:09 ` Jürgen Groß
2020-04-25 15:04 ` Arvind Sankar
2020-04-25 17:31 ` Borislav Petkov
2020-04-25 17:52 ` Borislav Petkov
2020-04-27 17:07 ` David Laight
2020-04-25 18:37 ` Segher Boessenkool
2020-04-25 18:53 ` Borislav Petkov
2020-04-25 19:15 ` Segher Boessenkool
2020-04-25 22:17 ` Borislav Petkov
2020-04-25 22:25 ` Arvind Sankar
2020-04-17 10:38 ` [PATCH v2] x86: fix early boot crash on gcc-10 Peter Zijlstra
2020-04-18 13:12 ` David Laight
2020-04-17 10:41 ` Peter Zijlstra
2020-03-16 18:20 ` [PATCH] " Arvind Sankar
2020-03-16 18:54 ` Arvind Sankar
2020-03-16 19:53 ` Arvind Sankar
2020-03-16 20:08 ` Jakub Jelinek
2020-03-16 20:40 ` Arvind Sankar
2020-03-16 22:12 ` Sergei Trofimovich
2020-03-17 11:46 ` Jakub Jelinek
2020-03-17 18:10 ` Sergei Trofimovich
2020-03-16 18:22 ` Arvind Sankar
2020-03-26 23:16 ` [PATCH v2] " Sergei Trofimovich
2020-04-27 11:37 ` [tip: x86/build] x86: Fix early boot crash on gcc-10, next try tip-bot2 for Borislav Petkov
2020-05-15 11:20 ` [tip: x86/urgent] x86: Fix early boot crash on gcc-10, third try tip-bot2 for Borislav Petkov
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