Commit 0cfc8a8d authored May 23, 2020 by Mike Rapoport Committed by Linus Torvalds May 23, 2020

sparc32: fix page table traversal in srmmu_nocache_init()



The srmmu_nocache_init() uses __nocache_fix() macro to add an offset to
page table entry to access srmmu_nocache_pool.

But since sparc32 has only three actual page table levels, pgd, p4d and
pud are essentially the same thing and pgd_offset() and p4d_offset() are
no-ops, the __nocache_fix() should be done only at PUD level.

Remove __nocache_fix() for p4d_offset() and pud_offset() and keep it
only for PUD and lower levels.

Fixes: c2bc26f7 ("sparc32: use PUD rather than PGD to get PMD in srmmu_nocache_init()")
Signed-off-by: Mike Rapoport <rppt@linux.ibm.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: Anatoly Pugachev <matorola@gmail.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

parent 423b8baf

arch/sparc/mm/srmmu.c

+2 −2

Original line number	Diff line number	Diff line
		@@ -331,8 +331,8 @@ static void __init srmmu_nocache_init(void)

		while (vaddr < srmmu_nocache_end) {
		pgd = pgd_offset_k(vaddr);
		p4d = p4d_offset(__nocache_fix(pgd), vaddr);
		pud = pud_offset(__nocache_fix(p4d), vaddr);
		p4d = p4d_offset(pgd, vaddr);
		pud = pud_offset(p4d, vaddr);
		pmd = pmd_offset(__nocache_fix(pud), vaddr);
		pte = pte_offset_kernel(__nocache_fix(pmd), vaddr);

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