Catalin Marinas <catalin.mari...@arm.com> writes: > On Wed, 11 Jul 2018 at 00:40, Benjamin Herrenschmidt > <b...@kernel.crashing.org> wrote: >> On Tue, 2018-07-10 at 17:17 +0200, Paul Menzel wrote: >> > On a the IBM S822LC (8335-GTA) with Ubuntu 18.04 I built Linux master >> > – 4.18-rc4+, commit 092150a2 (Merge branch 'for-linus' >> > of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/hid) – with >> > kmemleak. Several issues are found. >> >> Some of these are completely uninteresting though and look like >> kmemleak bugs to me :-) >> >> > [<00000000bc285bbf>] __pud_alloc+0x80/0x270 >> > [<0000000007135d64>] hash__map_kernel_page+0x30c/0x4d0 >> > [<0000000071677858>] __ioremap_at+0x108/0x140 >> > [<000000000023e921>] __ioremap_caller+0x130/0x180 >> > [<000000009dbc3923>] icp_native_init_one_node+0x5cc/0x760 >> > [<0000000015f3168a>] icp_native_init+0x70/0x13c >> > [<00000000655550ed>] xics_init+0x38/0x1ac >> > [<0000000088dbf9d1>] pnv_init_IRQ+0x30/0x5c >> >> This is the interrupt controller mapping its registers, why on earth >> would that be considered a leak ? kmemleak needs to learn to ignore >> kernel page tables allocations. > > Indeed, that's just a false positive for powerpc. Kmemleak ignores > page allocations and most architectures use __get_free_pages() for the > page table. In this particular case, the powerpc code uses > kmem_cache_alloc() and that's tracked by kmemleak. Since the pgd > stores the __pa(pud), kmemleak doesn't detect this pointer and reports > it as a leak. To work around this, you can pass SLAB_NOLEAKTRACE to > kmem_cache_create() in pgtable_cache_add()
Ah thanks, I didn't know we could do it that way. I did this instead which seems to work: https://git.kernel.org/torvalds/c/a984506c542e cheers
