[PARISC] Purge existing TLB entries in set_pte_at and ptep_set_wrprotect
authorJohn David Anglin <dave.anglin@bell.net>
Tue, 15 Jan 2013 00:45:00 +0000 (19:45 -0500)
committerJames Bottomley <JBottomley@Parallels.com>
Sat, 19 Jan 2013 10:54:45 +0000 (10:54 +0000)
commit7139bc1579901b53db7e898789e916ee2fb52d78
treec5030cb7afe83a347de96757c2a3b5490a9782e8
parent5da1f88b8b727dc3a66c52d4513e871be6d43d19
[PARISC] Purge existing TLB entries in set_pte_at and ptep_set_wrprotect

This patch goes a long way toward fixing the minifail bug, and
it  significantly improves the stability of SMP machines such as
the rp3440.  When write  protecting a page for COW, we need to
purge the existing translation.  Otherwise, the COW break
doesn't occur as expected because the TLB may still have a stale entry
which allows writes.

[jejb: fix up checkpatch errors]
Signed-off-by: John David Anglin <dave.anglin@bell.net>
Cc: stable@vger.kernel.org
Signed-off-by: James Bottomley <JBottomley@Parallels.com>
arch/parisc/include/asm/pgtable.h
arch/parisc/kernel/cache.c