From: Steve Capper Date: Fri, 19 Apr 2013 14:49:31 +0000 (+0100) Subject: arm64: mm: Correct show_pte behaviour X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=4339e3f389081ea90e230a785bdbe10eccd02b71;p=GitHub%2Fexynos8895%2Fandroid_kernel_samsung_universal8895.git arm64: mm: Correct show_pte behaviour show_pte makes use of the *_none_or_clear_bad style functions. If a pgd, pud or pmd is identified as being bad, it will then be cleared. As show_pte appears to be called from either the user or kernel fault handlers this side effect can lead to unpredictable behaviour; especially as TLB entries are not invalidated. This patch removes the page table sanitisation from show_pte. If a bad pgd, pud or pmd is encountered it is left unmodified. Signed-off-by: Steve Capper Signed-off-by: Catalin Marinas --- diff --git a/arch/arm64/mm/fault.c b/arch/arm64/mm/fault.c index afadae6682ed..52638171d6fd 100644 --- a/arch/arm64/mm/fault.c +++ b/arch/arm64/mm/fault.c @@ -57,16 +57,16 @@ void show_pte(struct mm_struct *mm, unsigned long addr) pmd_t *pmd; pte_t *pte; - if (pgd_none_or_clear_bad(pgd)) + if (pgd_none(*pgd) || pgd_bad(*pgd)) break; pud = pud_offset(pgd, addr); - if (pud_none_or_clear_bad(pud)) + if (pud_none(*pud) || pud_bad(*pud)) break; pmd = pmd_offset(pud, addr); printk(", *pmd=%016llx", pmd_val(*pmd)); - if (pmd_none_or_clear_bad(pmd)) + if (pmd_none(*pmd) || pmd_bad(*pmd)) break; pte = pte_offset_map(pmd, addr);