Commit 2884f110 authored May 28, 2008 by Hugh Dickins Committed by Thomas Gleixner Jun 04, 2008

x86: fix bad pmd ffff810000207xxx(9090909090909090)



OGAWA Hirofumi and Fede have reported rare pmd_ERROR messages:
mm/memory.c:127: bad pmd ffff810000207xxx(9090909090909090).

Initialization's cleanup_highmap was leaving alignment filler
behind in the pmd for MODULES_VADDR: when vmalloc's guard page
would occupy a new page table, it's not allocated, and then
module unload's vfree hits the bad 9090 pmd entry left over.

Signed-off-by: Hugh Dickins <hugh@veritas.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

parent 226e9a93

arch/x86/mm/init_64.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -206,7 +206,7 @@ void __init cleanup_highmap(void)
		pmd_t *last_pmd = pmd + PTRS_PER_PMD;

		for (; pmd < last_pmd; pmd++, vaddr += PMD_SIZE) {
		if (!pmd_present(*pmd))
		if (pmd_none(*pmd))
		continue;
		if (vaddr < (unsigned long) _text \|\| vaddr > end)
		set_pmd(pmd, __pmd(0));

Admin message