From b0bfece40b1988aa8e3d910938691dce7859d82d Mon Sep 17 00:00:00 2001 From: Jan Beulich <jbeulich@novell.com> Date: Thu, 7 Dec 2006 02:14:09 +0100 Subject: [PATCH] [PATCH] i386: clear_fixmap() should not use set_pte() While not strictly required with the current code (as the upper half of page table entries generated by __set_fixmap() cannot be non-zero due to the second parameter of this function being 'unsigned long'), the use of set_pte() in __set_fixmap() in the context of clear_fixmap() is still improper with CONFIG_X86_PAE (see the respective comment in include/asm-i386/pgtable-3level.h) and would turn into a bug if that second parameter ever gets changed to a 64-bit type. Signed-off-by: Jan Beulich <jbeulich@novell.com> Signed-off-by: Andi Kleen <ak@suse.de> --- arch/i386/mm/pgtable.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) diff --git a/arch/i386/mm/pgtable.c b/arch/i386/mm/pgtable.c index 10126e3f8174..65b5c0959033 100644 --- a/arch/i386/mm/pgtable.c +++ b/arch/i386/mm/pgtable.c @@ -95,8 +95,11 @@ static void set_pte_pfn(unsigned long vaddr, unsigned long pfn, pgprot_t flags) return; } pte = pte_offset_kernel(pmd, vaddr); - /* <pfn,flags> stored as-is, to permit clearing entries */ - set_pte(pte, pfn_pte(pfn, flags)); + if (pgprot_val(flags)) + /* <pfn,flags> stored as-is, to permit clearing entries */ + set_pte(pte, pfn_pte(pfn, flags)); + else + pte_clear(&init_mm, vaddr, pte); /* * It's enough to flush this one mapping. -- GitLab