From: Dave Hansen <dave.hansen@linux.intel.com>
To: Thomas Gleixner <tglx@linutronix.de>, Lars Wendler <wendler.lars@web.de>
Cc: LKML <linux-kernel@vger.kernel.org>,
x86@kernel.org, Borislav Betkov <bp@alien8.de>,
Andy Lutomirski <luto@kernel.org>,
Peter Zijlstra <peterz@infradead.org>,
Greg KH <gregkh@linuxfoundation.org>
Subject: Re: CONFIG_PAGE_TABLE_ISOLATION=y on x86_64 causes gcc to segfault when building x86_32 binaries
Date: Wed, 3 Jan 2018 07:42:08 -0800 [thread overview]
Message-ID: <a5bdc44d-6c65-563f-a9cc-aee1d264d8f1@linux.intel.com> (raw)
In-Reply-To: <alpine.DEB.2.20.1801031620020.1957@nanos>
On 01/03/2018 07:21 AM, Thomas Gleixner wrote:
> On Wed, 3 Jan 2018, Lars Wendler wrote:
>> Am Wed, 3 Jan 2018 13:05:38 +0100 (CET)
>> schrieb Thomas Gleixner <tglx@linutronix.de>:
>>> Also can you please try Linus v4.15-rc6 with PTI enabled so we can see
>>> whether that's a backport issue or a general one?
>> Same problem with 4.15-rc6. So I suppose that means it's a general
>> issue.
> Just a shot in the dark as I just decoded another issue on a AMD CPU. Can
> you please try the patch below?
Hi Lars,
I see the double-faults in your dmesg. Those are usually indicative of
a failed user->kernel CR3 switch on entering the kernel.
Could you run a copy of the x86 selftests? From the kernel tree I
usually do:
cd tools/testing/selftests/x86/
make
for i in *_64 *_32; do ./$i || break; done
See if any of those fail.
I wonder if we screwed up something in the SYSCALL code in
entry_64_compat.S. It's probably been much more lightly tested than all
the other entry code.
I'll see if I can reproduce this.
next prev parent reply other threads:[~2018-01-03 15:42 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <20180103123723.1dd26828@abudhabi.paradoxon.rec>
2018-01-03 11:57 ` CONFIG_PAGE_TABLE_ISOLATION=y on x86_64 causes gcc to segfault when building x86_32 binaries Thomas Gleixner
2018-01-03 12:05 ` Thomas Gleixner
2018-01-03 13:30 ` Lars Wendler
2018-01-03 15:21 ` Thomas Gleixner
2018-01-03 15:42 ` Dave Hansen [this message]
2018-01-03 18:52 ` Thomas Gleixner
2018-01-03 22:12 ` Laura Abbott
2018-01-03 22:14 ` Andy Lutomirski
2018-01-03 22:22 ` Thomas Gleixner
2018-01-03 23:43 ` Andy Lutomirski
2018-01-03 22:27 ` Dave Hansen
2018-01-03 22:25 ` [tip:x86/pti] x86/pti: Switch to kernel CR3 at early in entry_SYSCALL_compat() tip-bot for Thomas Gleixner
2018-01-03 23:46 ` CONFIG_PAGE_TABLE_ISOLATION=y on x86_64 causes gcc to segfault when building x86_32 binaries Lars Wendler
2018-01-04 2:44 ` Boris Ostrovsky
2018-01-03 15:40 ` Borislav Petkov
2018-01-03 23:22 ` Lars Wendler
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