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| author | Thomas Gleixner <tglx@linutronix.de> | 2018-01-03 15:57:59 +0100 |
|---|---|---|
| committer | Thomas Gleixner <tglx@linutronix.de> | 2018-01-03 15:57:59 +0100 |
| commit | 52994c256df36fda9a715697431cba9daecb6b11 (patch) | |
| tree | c446672f16e816c3221f2cfff71cd988dc8c78ae | |
| parent | 694d99d40972f12e59a3696effee8a376b79d7c8 (diff) | |
| download | linux-52994c256df36fda9a715697431cba9daecb6b11.tar.gz | |
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
| -rw-r--r-- | arch/x86/mm/pti.c | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/arch/x86/mm/pti.c b/arch/x86/mm/pti.c index bce8aea6560621..2da28ba9750824 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); } /* |