powerpc/kmemleak: Do not scan the DART table

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 <[email protected]>
Cc: Benjamin Herrenschmidt <[email protected]>
Cc: Paul Mackerras <[email protected]>
Signed-off-by: Benjamin Herrenschmidt <[email protected]>

diff --git a/arch/powerpc/sysdev/dart_iommu.c b/arch/powerpc/sysdev/dart_iommu.c
index 62c47bb765178a10fe3aa371ef0c7d5d0c0c6364..9e5353ff6d1bb936fb1b84af74d8f2e6a1dd6da2 100644 (file)
--- 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);
 }