From 7a8ab31b78ad38a165f379a79db696ebe3c6e21b Mon Sep 17 00:00:00 2001 From: "Jon Medhurst (Tixy)" Date: Wed, 28 Nov 2012 11:17:51 +0000 Subject: [PATCH] ARM: mm: Allow an empty PMD in alloc_init_pte() The Android patch titled "ARM: allow the kernel text section to be made read-only" modifies alloc_init_pte() and adds a BUG_ON to detect the case where a section mapping is being overwritten. However the test doesn't allow for the legitimate case where the PMD is empty, as can happen for kernels built with CONFIG_ARM_LPAE. So extend the test to allow this. Change-Id: I28eeaefd856bae63a5532980e41e0fd4d8922e79 Signed-off-by: Jon Medhurst Signed-off-by: John Stultz --- arch/arm/mm/mmu.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/arm/mm/mmu.c b/arch/arm/mm/mmu.c index cc9c66694f34..394342d0482e 100644 --- a/arch/arm/mm/mmu.c +++ b/arch/arm/mm/mmu.c @@ -627,7 +627,7 @@ static void __init alloc_init_pte(pmd_t *pmd, unsigned long addr, pte_t *pte = start_pte + pte_index(addr); /* If replacing a section mapping, the whole section must be replaced */ - BUG_ON(pmd_bad(*pmd) && ((addr | end) & ~PMD_MASK)); + BUG_ON(!pmd_none(*pmd) && pmd_bad(*pmd) && ((addr | end) & ~PMD_MASK)); do { set_pte_ext(pte, pfn_pte(pfn, __pgprot(type->prot_pte)), 0);