| From | Greg Kroah-Hartman <> | Subject | [PATCH 4.4 024/210] sched/preempt, sh: kmap_coherent relies on disabled preemption | Date | Sun, 10 Apr 2016 11:34:05 -0700 |
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4.4-stable review patch. If anyone has any objections, please let me know.
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From: David Hildenbrand <dahi@linux.vnet.ibm.com>
commit b15d53d009558d14c4f394a6d1fa2039c7f45c43 upstream.
kmap_coherent needs disabled preemption to not schedule in the critical section, just like kmap_coherent on mips and kmap_atomic in general.
Fixes: 8222dbe21e79 "sched/preempt, mm/fault: Decouple preemption from the page fault logic" Reported-by: Hans Verkuil <hverkuil@xs4all.nl> Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com> Tested-by: Hans Verkuil <hans.verkuil@cisco.com> Signed-off-by: Rich Felker <dalias@libc.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
--- arch/sh/mm/kmap.c | 2 ++ 1 file changed, 2 insertions(+)
--- a/arch/sh/mm/kmap.c +++ b/arch/sh/mm/kmap.c @@ -36,6 +36,7 @@ void *kmap_coherent(struct page *page, u BUG_ON(!test_bit(PG_dcache_clean, &page->flags)); + preempt_disable(); pagefault_disable(); idx = FIX_CMAP_END - @@ -64,4 +65,5 @@ void kunmap_coherent(void *kvaddr) } pagefault_enable(); + preempt_enable(); }
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