Messages in this thread | | | Subject | Re: [RFC PATCH v2] iommu/amd: gray the 'irq_remap_table' object for kmemleak | From | Michael Wang <> | Date | Wed, 25 Nov 2015 16:14:58 +0100 |
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On 11/25/2015 04:08 PM, Joerg Roedel wrote: > 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: >> [<ffffffff8118192d>] create_object+0x10d/0x2d0 >> [<ffffffff815c2d4b>] kmemleak_alloc+0x5b/0xc0 >> [<ffffffff8116dd19>] kmem_cache_alloc_trace+0xb9/0x160 >> [<ffffffff814ffe51>] 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.
We've considered that too, but found that the irq-tables is not dynamically alloc/free, they won't be freed once initialized, so there is no leaking for such object :-)
Regards, Michael Wang
> > > > Joerg >
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