Messages in this thread | | | Subject | Re: CONFIG_PAGE_TABLE_ISOLATION=y on x86_64 causes gcc to segfault when building x86_32 binaries | From | Dave Hansen <> | Date | Wed, 3 Jan 2018 07:42:08 -0800 |
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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.
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