Messages in this thread Patch in this message | | | Date | Wed, 3 Jan 2018 16:21:32 +0100 (CET) | From | Thomas Gleixner <> | Subject | Re: CONFIG_PAGE_TABLE_ISOLATION=y on x86_64 causes gcc to segfault when building x86_32 binaries |
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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?
Thanks,
tglx
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commit 52994c256df36fda9a715697431cba9daecb6b11 Author: Thomas Gleixner <tglx@linutronix.de> Date: Wed Jan 3 15:57:59 2018 +0100
x86/pti: Make sure the user/kernel PTEs match Meelis reported that his K8 Athlon64 emits MCE warnings when PTI is enabled: [Hardware Error]: Error Addr: 0x0000ffff81e000e0 [Hardware Error]: MC1 Error: L1 TLB multimatch. [Hardware Error]: cache level: L1, tx: INSN The address is in the entry area, which is mapped into kernel _AND_ user space. That's special because we switch CR3 while we are executing there. User mapping: 0xffffffff81e00000-0xffffffff82000000 2M ro PSE GLB x pmd Kernel mapping: 0xffffffff81000000-0xffffffff82000000 16M ro PSE x pmd So the K8 is complaining that the TLB entries differ. They differ in the GLB bit. Drop the GLB bit when installing the user shared mapping. Fixes: 6dc72c3cbca0 ("x86/mm/pti: Share entry text PMD") Reported-by: Meelis Roos <mroos@linux.ee> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Tested-by: Meelis Roos <mroos@linux.ee> Cc: Borislav Petkov <bp@alien8.de> Cc: Tom Lendacky <thomas.lendacky@amd.com> Cc: stable@vger.kernel.org Link: https://lkml.kernel.org/r/alpine.DEB.2.20.1801031407180.1957@nanos
diff --git a/arch/x86/mm/pti.c b/arch/x86/mm/pti.c index bce8aea65606..2da28ba97508 100644 --- a/arch/x86/mm/pti.c +++ b/arch/x86/mm/pti.c @@ -367,7 +367,8 @@ static void __init pti_setup_espfix64(void) static void __init pti_clone_entry_text(void) { pti_clone_pmds((unsigned long) __entry_text_start, - (unsigned long) __irqentry_text_end, _PAGE_RW); + (unsigned long) __irqentry_text_end, + _PAGE_RW | _PAGE_GLOBAL); } /*
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