arm64: mm: Make icache synchronisation logic huge page aware

The __sync_icache_dcache routine will only flush the dcache for the
first page of a compound page, potentially leading to stale icache
data residing further on in a hugetlb page.

This patch addresses this issue by taking into consideration the
order of the page when flushing the dcache.

Reported-by: Mark Brown <broonie@linaro.org>
Tested-by: Mark Brown <broonie@linaro.org>
Signed-off-by: Steve Capper <steve.capper@linaro.org>
Acked-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Cc: <stable@vger.kernel.org> # v3.11+

diff --git a/arch/arm64/mm/flush.c b/arch/arm64/mm/flush.c
index e4193e3..0d64089 100644 (file)
--- a/arch/arm64/mm/flush.c
+++ b/arch/arm64/mm/flush.c
@@ -79,7 +79,8 @@ void __sync_icache_dcache(pte_t pte, unsigned long addr)
                return;
 
        if (!test_and_set_bit(PG_dcache_clean, &page->flags)) {
-               __flush_dcache_area(page_address(page), PAGE_SIZE);
+               __flush_dcache_area(page_address(page),
+                               PAGE_SIZE << compound_order(page));
                __flush_icache_all();
        } else if (icache_is_aivivt()) {
                __flush_icache_all();