From 33a9c41bf5d8adae9d882513e617c4c645195e71 Mon Sep 17 00:00:00 2001 From: "Kirill A. Shutemov" Date: Thu, 22 Jul 2010 13:20:22 +0100 Subject: ARM: 6255/1: Workaround infinity loop in handling of translation faults On ARM one Linux PGD entry contains two hardware entries (see page tables layout in pgtable.h). We normally guarantee that we always fill both L1 entries. But create_mapping() doesn't follow the rule. It can create inidividual L1 entries, so here we have to call pmd_none() check in do_translation_fault() for the entry really corresponded to address, not for the first of pair. Signed-off-by: Kirill A. Shutemov Signed-off-by: Russell King --- arch/arm/mm/fault.c | 11 ++++++++++- 1 file changed, 10 insertions(+), 1 deletion(-) (limited to 'arch/arm/mm/fault.c') diff --git a/arch/arm/mm/fault.c b/arch/arm/mm/fault.c index 84131c8..564b1c4 100644 --- a/arch/arm/mm/fault.c +++ b/arch/arm/mm/fault.c @@ -413,7 +413,16 @@ do_translation_fault(unsigned long addr, unsigned int fsr, pmd_k = pmd_offset(pgd_k, addr); pmd = pmd_offset(pgd, addr); - if (pmd_none(*pmd_k)) + /* + * On ARM one Linux PGD entry contains two hardware entries (see page + * tables layout in pgtable.h). We normally guarantee that we always + * fill both L1 entries. But create_mapping() doesn't follow the rule. + * It can create inidividual L1 entries, so here we have to call + * pmd_none() check for the entry really corresponded to address, not + * for the first of pair. + */ + index = (addr >> SECTION_SHIFT) & 1; + if (pmd_none(pmd_k[index])) goto bad_area; copy_pmd(pmd, pmd_k); -- cgit v1.1