From acca4f4d9bd657e8bc7e1665ba5077465138f133 Mon Sep 17 00:00:00 2001 From: Paul Mundt Date: Mon, 10 Nov 2008 20:00:45 +0900 Subject: sh: Handle fixmap TLB eviction more coherently. There was a race in the kmap_coherent() implementation. While we guarded against preemption, there was nothing preventing eviction of the pre-faulted fixmap entry from the UTLB. Under certain workloads this would result in the fixmap entries used for cache colouring being evicted from the UTLB in the midst of a copy_page(). In addition to pre-faulting, we also make sure to preserve the PTEs in the kernel page table and introduce a cached PTE for kmap_coherent() usage. This follows a similar change on MIPS ("[MIPS] Fix aliasing bug in copy_to_user_page / copy_from_user_page"). Reported-by: Hideo Saito Reported-by: CHIKAMA Masaki Tested-by: Yoshihiro Shimoda Signed-off-by: Paul Mundt --- arch/sh/mm/init.c | 12 +++++++++--- 1 file changed, 9 insertions(+), 3 deletions(-) (limited to 'arch/sh/mm/init.c') diff --git a/arch/sh/mm/init.c b/arch/sh/mm/init.c index 4abf00031dae..6cbef8caeb56 100644 --- a/arch/sh/mm/init.c +++ b/arch/sh/mm/init.c @@ -137,6 +137,7 @@ void __init page_table_range_init(unsigned long start, unsigned long end, void __init paging_init(void) { unsigned long max_zone_pfns[MAX_NR_ZONES]; + unsigned long vaddr; int nid; /* We don't need to map the kernel through the TLB, as @@ -148,10 +149,15 @@ void __init paging_init(void) * check for a null value. */ set_TTB(swapper_pg_dir); - /* Populate the relevant portions of swapper_pg_dir so that + /* + * Populate the relevant portions of swapper_pg_dir so that * we can use the fixmap entries without calling kmalloc. - * pte's will be filled in by __set_fixmap(). */ - page_table_range_init(FIXADDR_START, FIXADDR_TOP, swapper_pg_dir); + * pte's will be filled in by __set_fixmap(). + */ + vaddr = __fix_to_virt(__end_of_fixed_addresses - 1) & PMD_MASK; + page_table_range_init(vaddr, 0, swapper_pg_dir); + + kmap_coherent_init(); memset(max_zone_pfns, 0, sizeof(max_zone_pfns)); -- cgit v1.2.2