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Commit 0eab46be authored by Sukadev Bhattiprolu's avatar Sukadev Bhattiprolu Committed by Michael Ellerman
Browse files

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: default avatarJames Dykman <jdykman@us.ibm.com>
Signed-off-by: default avatarAneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: default avatarSukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
Tested-by: default avatarJames Dykman <jdykman@us.ibm.com>
Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
parent 31278b17

arch/powerpc/mm/hugetlbpage.c

+7 −0
Original line number Diff line number Diff line
@@ -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

	/*