powerpc/mm: Add memory barrier in __hugepte_alloc()

__hugepte_alloc() uses kmem_cache_zalloc() to allocate a zeroed PTE
and proceeds to use the newly allocated PTE. Add a memory barrier to
make sure that the other CPUs see a properly initialized PTE.

Based on a fix suggested by James Dykman.

Reported-by: James Dykman <jdykman@us.ibm.com>
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
Tested-by: James Dykman <jdykman@us.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
This commit is contained in:
Sukadev Bhattiprolu 2016-03-24 02:07:57 -04:00 committed by Michael Ellerman
parent 31278b17a0
commit 0eab46be21

View File

@ -81,6 +81,13 @@ static int __hugepte_alloc(struct mm_struct *mm, hugepd_t *hpdp,
if (! new)
return -ENOMEM;
/*
* Make sure other cpus find the hugepd set only after a
* properly initialized page table is visible to them.
* For more details look for comment in __pte_alloc().
*/
smp_wmb();
spin_lock(&mm->page_table_lock);
#ifdef CONFIG_PPC_FSL_BOOK3E
/*