From mboxrd@z Thu Jan 1 00:00:00 1970 From: Joerg Roedel Subject: Re: [RFC PATCH v2] iommu/amd: gray the 'irq_remap_table' object for kmemleak Date: Wed, 25 Nov 2015 16:08:06 +0100 Message-ID: <20151125150806.GG2064@8bytes.org> References: <564EFF6A.2050709@profitbricks.com> <564F051E.9010703@profitbricks.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <564F051E.9010703@profitbricks.com> Sender: linux-kernel-owner@vger.kernel.org To: Michael Wang Cc: iommu@lists.linux-foundation.org, linux-kernel@vger.kernel.org List-Id: iommu@lists.linux-foundation.org On Fri, Nov 20, 2015 at 12:33:50PM +0100, Michael Wang wrote: > The kmemleak testing on 3.18.24 show: > > unreferenced object 0xffff880233ff9010 (size 16): > comm "swapper/0", pid 1, jiffies 4294937440 (age 2010.490s) > hex dump (first 16 bytes): > 0a 0a 00 00 20 00 00 00 00 44 fb 33 02 88 ff ff .... ....D.3.... > backtrace: > [] create_object+0x10d/0x2d0 > [] kmemleak_alloc+0x5b/0xc0 > [] kmem_cache_alloc_trace+0xb9/0x160 > [] get_irq_table+0x151/0x380 > > This is caused by the 'irq_lookup_table' was allocated with > __get_free_pages() which won't create kmemleak object, thus it's > pointers won't be count as referencing 'irq_remap_table' in > kmemleak scan. Isn't it better to allocate the kmemleak object manually instead of ignoring all irq-table pointers? With this patch we might not notice any real leak of irq-tables. Joerg