From: Nick Desaulniers <ndesaulniers@google.com>
To: Borislav Petkov <bp@alien8.de>
Cc: "Michael Matz" <matz@suse.de>, "Jakub Jelinek" <jakub@redhat.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>,
"Peter Zijlstra" <peterz@infradead.org>,
"maintainer:X86 ARCHITECTURE (32-BIT AND 64-BIT)"
<x86@kernel.org>,
clang-built-linux <clang-built-linux@googlegroups.com>,
"Kees Cook" <keescook@chromium.org>,
"Martin Liška" <mliska@suse.cz>,
"Masahiro Yamada" <masahiroy@kernel.org>
Subject: Re: [PATCH] x86: Fix early boot crash on gcc-10, next try
Date: Thu, 23 Apr 2020 11:02:09 -0700 [thread overview]
Message-ID: <CAKwvOdmmuE=o-bGpraR1rJdzDgf2UYvgcx2-S7cdGSFWWkWurA@mail.gmail.com> (raw)
In-Reply-To: <20200423173058.GE26021@zn.tnic>
On Thu, Apr 23, 2020 at 10:31 AM Borislav Petkov <bp@alien8.de> wrote:
>
> On Thu, Apr 23, 2020 at 06:12:24PM +0200, Borislav Petkov wrote:
> > Ok,
> >
> > I have tried to summarize our odyssey so far and here's what I came up
> > with. Just built latest gcc from the git repo and it seems to work.
> >
> > Next I need to come up with a slick way of testing the compiler...
>
> Maybe something like this. Seems to work with both.
>
> ---
> From: Borislav Petkov <bp@suse.de>
> Date: Thu, 23 Apr 2020 19:28:28 +0200
> Subject: [PATCH] Check compiler
>
> Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Tested-by: Nick Desaulniers <ndesaulniers@google.com>
It's too bad that $(CC) isn't exported yet; IIUC we include the arch
specific Makefiles then later export $(CC). If that was the case, we
could just use $(CC) in the shell script, rather than passing it along
as an argument. Oh well.
> ---
> arch/x86/Makefile | 4 ++++
> scripts/x86-check-compiler.sh | 9 +++++++++
> 2 files changed, 13 insertions(+)
> create mode 100755 scripts/x86-check-compiler.sh
>
> diff --git a/arch/x86/Makefile b/arch/x86/Makefile
> index 00e378de8bc0..38d3eec5062e 100644
> --- a/arch/x86/Makefile
> +++ b/arch/x86/Makefile
> @@ -1,6 +1,10 @@
> # SPDX-License-Identifier: GPL-2.0
> # Unified Makefile for i386 and x86_64
>
> +# Check the compiler
> +sane_compiler := $(shell $(srctree)/scripts/x86-check-compiler.sh $(CC))
> +$(if $(sane_compiler),$(error $(CC) check failed. Aborting),)
If I add `echo "hello world"` to the end of
scripts/x86-check-compiler.sh to verify this stops a build, this is
the error message I would observe:
arch/x86/Makefile:6: *** clang check failed. Aborting. Stop.
> +
> # select defconfig based on actual architecture
> ifeq ($(ARCH),x86)
> ifeq ($(shell uname -m),x86_64)
> diff --git a/scripts/x86-check-compiler.sh b/scripts/x86-check-compiler.sh
> new file mode 100755
> index 000000000000..b2b5b54b6939
> --- /dev/null
> +++ b/scripts/x86-check-compiler.sh
> @@ -0,0 +1,9 @@
> +#!/bin/sh
> +# SPDX-License-Identifier: GPL-2.0
> +
> +# Check whether the compiler tail-call optimizes across an asm() statement.
> +# Fail the build if it does.
> +
> +echo "int foo(int a); int bar(int a) { int r = foo(a); asm(\"\"); return r; }" |\
> + $* -O2 -x c -c -S - -o - 2>/dev/null |\
> + grep -E "^[[:blank:]]+jmp[[:blank:]]+.*"
> --
> 2.21.0
>
> --
> Regards/Gruss,
> Boris.
>
> https://people.kernel.org/tglx/notes-about-netiquette
--
Thanks,
~Nick Desaulniers
next prev parent reply other threads:[~2020-04-23 18:02 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
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 [this message]
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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