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authorDavid Gibson <david@gibson.dropbear.id.au>2006-03-06 04:51:29 +0300
committerPaul Mackerras <paulus@samba.org>2006-03-17 05:20:40 +0300
commit0f6be7b77ceaea01a35b37fab26f4ea3b01efe14 (patch)
treea8e8cf9dd90f6778fa29879fee40d04a55cd9b4f /include/asm-powerpc
parent23dd64011285010ac291f7dddf6e287bdb43a0ad (diff)
downloadlinux-0f6be7b77ceaea01a35b37fab26f4ea3b01efe14.tar.xz
[PATCH] powerpc: Better pmd_bad() and pud_bad() checks
At present, the powerpc pmd_bad() and pud_bad() macros return false unless the given pmd or pud is zero. This patch makes these tests more thorough, checking if the given pmd or pud looks like a plausible pte page or pmd page pointer respectively. This can result in helpful error messages when messing with the pagetable code. Signed-off-by: David Gibson <dwg@au1.ibm.com> Signed-off-by: Paul Mackerras <paulus@samba.org>
Diffstat (limited to 'include/asm-powerpc')
-rw-r--r--include/asm-powerpc/pgtable.h9
1 files changed, 7 insertions, 2 deletions
diff --git a/include/asm-powerpc/pgtable.h b/include/asm-powerpc/pgtable.h
index e38931379a72..8dc3eb54276f 100644
--- a/include/asm-powerpc/pgtable.h
+++ b/include/asm-powerpc/pgtable.h
@@ -188,9 +188,13 @@ static inline pte_t pfn_pte(unsigned long pfn, pgprot_t pgprot)
#define pte_pfn(x) ((unsigned long)((pte_val(x)>>PTE_RPN_SHIFT)))
#define pte_page(x) pfn_to_page(pte_pfn(x))
+#define PMD_BAD_BITS (PTE_TABLE_SIZE-1)
+#define PUD_BAD_BITS (PMD_TABLE_SIZE-1)
+
#define pmd_set(pmdp, pmdval) (pmd_val(*(pmdp)) = (pmdval))
#define pmd_none(pmd) (!pmd_val(pmd))
-#define pmd_bad(pmd) (pmd_val(pmd) == 0)
+#define pmd_bad(pmd) (!is_kernel_addr(pmd_val(pmd)) \
+ || (pmd_val(pmd) & PMD_BAD_BITS))
#define pmd_present(pmd) (pmd_val(pmd) != 0)
#define pmd_clear(pmdp) (pmd_val(*(pmdp)) = 0)
#define pmd_page_kernel(pmd) (pmd_val(pmd) & ~PMD_MASKED_BITS)
@@ -198,7 +202,8 @@ static inline pte_t pfn_pte(unsigned long pfn, pgprot_t pgprot)
#define pud_set(pudp, pudval) (pud_val(*(pudp)) = (pudval))
#define pud_none(pud) (!pud_val(pud))
-#define pud_bad(pud) ((pud_val(pud)) == 0)
+#define pud_bad(pud) (!is_kernel_addr(pud_val(pud)) \
+ || (pud_val(pud) & PUD_BAD_BITS))
#define pud_present(pud) (pud_val(pud) != 0)
#define pud_clear(pudp) (pud_val(*(pudp)) = 0)
#define pud_page(pud) (pud_val(pud) & ~PUD_MASKED_BITS)