x86: check PMD in spurious_fault handler

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Impact: fix to prevent hard lockup on bad PMD permissions

If the PMD does not have the correct permissions for a page access,
but the PTE does, the spurious fault handler will mistake the fault
as a lazy TLB transaction. This will result in an infinite loop of:

 fault -> spurious_fault check (pass) -> return to code -> fault

This patch adds a check and a warn on if the PTE passes the permissions
but the PMD does not.

[ Updated: Ingo Molnar suggested using WARN_ONCE with some text ]

Signed-off-by: Steven Rostedt <srostedt@redhat.com>

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This commit is contained in:

Steven Rostedt 2009-02-19 11:46:36 -05:00

parent 07a66d7c53

commit 3c3e5694ad

1 changed files with 12 additions and 1 deletions

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arch/x86/mm/fault.c

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