[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>
diff --git a/arch/i386/mm/pgtable.c b/arch/i386/mm/pgtable.c
index 10126e3..65b5c09 100644
--- a/arch/i386/mm/pgtable.c
+++ b/arch/i386/mm/pgtable.c
@@ -95,8 +95,11 @@
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.