sparc64: Fix huge PMD invalidation.
authorDavid S. Miller <davem@davemloft.net>
Thu, 24 Apr 2014 20:58:02 +0000 (13:58 -0700)
committerDavid S. Miller <davem@davemloft.net>
Sun, 4 May 2014 05:31:52 +0000 (22:31 -0700)
commit51e5ef1bb7ab0e5fa7de4e802da5ab22fe35f0bf
treef8ef5fdc807082bf9d9f75577e764cec96ed13a4
parent5b1e94fa439a3227beefad58c28c17f68287a8e9
sparc64: Fix huge PMD invalidation.

On sparc64 "present" and "valid" are seperate PTE bits, this allows us to
naturally distinguish between the user explicitly asking for PROT_NONE
with mprotect() and other situations.

However we weren't handling this properly in the huge PMD paths.

First of all, the page table walker in the TSB miss path only checks
for _PAGE_PMD_HUGE.  So the generic pmdp_invalidate() would clear
_PAGE_PRESENT but the TLB miss paths would still load it into the TLB
as a valid huge PMD.

Fix this by clearing the valid bit in pmdp_invalidate(), and also
checking the valid bit in USER_PGTABLE_CHECK_PMD_HUGE using "brgez"
since _PAGE_VALID is bit 63 in both the sun4u and sun4v pte layouts.

Signed-off-by: David S. Miller <davem@davemloft.net>
arch/sparc/include/asm/pgtable_64.h
arch/sparc/include/asm/tsb.h
arch/sparc/mm/tlb.c