From: Ingo Molnar <mingo@elte.hu>
Date: Mon, 3 Mar 2008 08:53:17 +0000 (+0100)
Subject: x86: debug pmd_bad()
X-Git-Tag: v2.6.26-rc1~1154^2~492
X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=9fc34113f6880b215cbea4e7017fc818700384c2;p=linux-2.6

x86: debug pmd_bad()

Signed-off-by: Ingo Molnar <mingo@elte.hu>
---

diff --git a/arch/x86/mm/pgtable_32.c b/arch/x86/mm/pgtable_32.c
index 2f9e9afcb9..76e4f4d262 100644
--- a/arch/x86/mm/pgtable_32.c
+++ b/arch/x86/mm/pgtable_32.c
@@ -381,3 +381,10 @@ void __pmd_free_tlb(struct mmu_gather *tlb, pmd_t *pmd)
 }
 
 #endif
+
+int pmd_bad(pmd_t pmd)
+{
+	WARN_ON_ONCE(pmd_bad_v1(pmd) != pmd_bad_v2(pmd));
+
+	return pmd_bad_v1(pmd);
+}
diff --git a/include/asm-x86/pgtable_32.h b/include/asm-x86/pgtable_32.h
index 997c36c6b4..1e2c0d8395 100644
--- a/include/asm-x86/pgtable_32.h
+++ b/include/asm-x86/pgtable_32.h
@@ -90,7 +90,11 @@ extern unsigned long pg0[];
 /* To avoid harmful races, pmd_none(x) should check only the lower when PAE */
 #define pmd_none(x)	(!(unsigned long)pmd_val(x))
 #define pmd_present(x)	(pmd_val(x) & _PAGE_PRESENT)
-#define	pmd_bad(x)	((pmd_val(x) \
+
+extern int pmd_bad(pmd_t pmd);
+
+#define pmd_bad_v1(x)	((pmd_val(x) & (~PAGE_MASK & ~_PAGE_USER)) != _KERNPG_TABLE)
+#define	pmd_bad_v2(x)	((pmd_val(x) \
 			  & ~(PAGE_MASK | _PAGE_USER | _PAGE_PSE | _PAGE_NX)) \
 			 != _KERNPG_TABLE)