From: Catalin Marinas <catalin.marinas@arm.com>
Date: Fri, 13 Jun 2014 08:44:21 +0000 (+0100)
Subject: powerpc/kmemleak: Do not scan the DART table
X-Git-Tag: v3.16-rc3~24^2~3
X-Git-Url: https://openfabrics.org/gitweb/?a=commitdiff_plain;h=a1d23d5c94256ffa0de510a3d59d6eff551d97ae;p=~emulex%2Finfiniband.git

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 <catalin.marinas@arm.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
---

diff --git a/arch/powerpc/sysdev/dart_iommu.c b/arch/powerpc/sysdev/dart_iommu.c
index 62c47bb7651..9e5353ff6d1 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);
 }