[PATCH] powerpc/kmemleak: Do not scan the DART table

From: Catalin Marinas
Date: Fri Jun 13 2014 - 04:44:21 EST


The DART table allocation is registered to kmemleak via the
memblock_alloc_base() call. However, the DART table is later unmapped
and dart_tablebase VA no longer accessible. This patch tells kmemleak
not to scan this block and avoid an unhandled paging request.

Signed-off-by: Catalin Marinas <catalin.marinas@xxxxxxx>
Cc: Benjamin Herrenschmidt <benh@xxxxxxxxxxxxxxxxxxx>
Cc: Paul Mackerras <paulus@xxxxxxxxx>
---
arch/powerpc/sysdev/dart_iommu.c | 5 +++++
1 file changed, 5 insertions(+)

diff --git a/arch/powerpc/sysdev/dart_iommu.c b/arch/powerpc/sysdev/dart_iommu.c
index 62c47bb76517..9e5353ff6d1b 100644
--- a/arch/powerpc/sysdev/dart_iommu.c
+++ b/arch/powerpc/sysdev/dart_iommu.c
@@ -476,6 +476,11 @@ void __init alloc_dart_table(void)
*/
dart_tablebase = (unsigned long)
__va(memblock_alloc_base(1UL<<24, 1UL<<24, 0x80000000L));
+ /*
+ * The DART space is later unmapped from the kernel linear mapping and
+ * accessing dart_tablebase during kmemleak scanning will fault.
+ */
+ kmemleak_no_scan((void *)dart_tablebase);

printk(KERN_INFO "DART table allocated at: %lx\n", dart_tablebase);
}
--
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