From 6f60deb47707b879e4e263d700742cf9a3e6901d Mon Sep 17 00:00:00 2001 From: David Hildenbrand Date: Mon, 11 May 2015 17:52:09 +0200 Subject: sched/preempt, mm/kmap: Explicitly disable/enable preemption in kmap_atomic_* The existing code relies on pagefault_disable() implicitly disabling preemption, so that no schedule will happen between kmap_atomic() and kunmap_atomic(). Let's make this explicit, to prepare for pagefault_disable() not touching preemption anymore. [uptream commit 2cb7c9cb426660b5ed58b643d9e7dd5d50ba901f] Signed-off-by: David Hildenbrand --- arch/arm/mm/highmem.c | 3 +++ 1 file changed, 3 insertions(+) (limited to 'arch/arm/mm') diff --git a/arch/arm/mm/highmem.c b/arch/arm/mm/highmem.c index b98895d9fe57..ee8dfa793989 100644 --- a/arch/arm/mm/highmem.c +++ b/arch/arm/mm/highmem.c @@ -59,6 +59,7 @@ void *kmap_atomic(struct page *page) void *kmap; int type; + preempt_disable(); pagefault_disable(); if (!PageHighMem(page)) return page_address(page); @@ -121,6 +122,7 @@ void __kunmap_atomic(void *kvaddr) kunmap_high(pte_page(pkmap_page_table[PKMAP_NR(vaddr)])); } pagefault_enable(); + preempt_enable(); } EXPORT_SYMBOL(__kunmap_atomic); @@ -130,6 +132,7 @@ void *kmap_atomic_pfn(unsigned long pfn) int idx, type; struct page *page = pfn_to_page(pfn); + preempt_disable(); pagefault_disable(); if (!PageHighMem(page)) return page_address(page); -- cgit v1.2.3