From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id B2B97E95A8E for ; Mon, 9 Oct 2023 11:20:40 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id F27378D0057; Mon, 9 Oct 2023 07:20:39 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id ED70B8D0031; Mon, 9 Oct 2023 07:20:39 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id DECCC8D0057; Mon, 9 Oct 2023 07:20:39 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0012.hostedemail.com [216.40.44.12]) by kanga.kvack.org (Postfix) with ESMTP id D198B8D0031 for ; Mon, 9 Oct 2023 07:20:39 -0400 (EDT) Received: from smtpin09.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay01.hostedemail.com (Postfix) with ESMTP id AADAA1CA670 for ; 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charset=us-ascii Content-Disposition: inline In-Reply-To: X-Rspamd-Queue-Id: 0784C4001D X-Rspam-User: X-Rspamd-Server: rspam04 X-Stat-Signature: 5fatqi6ca1zpndfycdijpnhbuawp6sg6 X-HE-Tag: 1696850437-507634 X-HE-Meta: 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 qocTB6AM 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 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Mon, Oct 09, 2023 at 10:22:52AM +0200, Vlastimil Babka wrote: > On 10/6/23 18:39, Catalin Marinas wrote: > > Commit b035f5a6d852 ("mm: slab: reduce the kmalloc() minimum alignment > > if DMA bouncing possible") allows architectures with non-coherent DMA to > > define a small ARCH_KMALLOC_MINALIGN (e.g. sizeof(unsigned long long)) > > and this has been enabled on arm64. With KASAN_HW_TAGS enabled, however, > > ARCH_SLAB_MINALIGN becomes 16 on arm64 (arch_slab_minalign() dynamically > > selects it since commit d949a8155d13 ("mm: make minimum slab alignment a > > runtime property")). This can lead to a situation where kmalloc-8 caches > > are attempted to be created with a kmem_caches.size aligned to 16. When > > the cache is mergeable, it can lead to kernel warnings like: > > > > sysfs: cannot create duplicate filename '/kernel/slab/:d-0000016' > > CPU: 0 PID: 1 Comm: swapper/0 Not tainted 6.6.0-rc1-00001-gda98843cd306-dirty #5 > > Hardware name: QEMU QEMU Virtual Machine, BIOS 0.0.0 02/06/2015 > > Call trace: > > dump_backtrace+0x90/0xe8 > > show_stack+0x18/0x24 > > dump_stack_lvl+0x48/0x60 > > dump_stack+0x18/0x24 > > sysfs_warn_dup+0x64/0x80 > > sysfs_create_dir_ns+0xe8/0x108 > > kobject_add_internal+0x98/0x264 > > kobject_init_and_add+0x8c/0xd8 > > sysfs_slab_add+0x12c/0x248 > > slab_sysfs_init+0x98/0x14c > > do_one_initcall+0x6c/0x1b0 > > kernel_init_freeable+0x1c0/0x288 > > kernel_init+0x24/0x1e0 > > ret_from_fork+0x10/0x20 > > kobject: kobject_add_internal failed for :d-0000016 with -EEXIST, don't try to register things with the same name in the same directory. > > SLUB: Unable to add boot slab dma-kmalloc-8 to sysfs > > > > Limit the __kmalloc_minalign() return value (used to create the > > kmalloc-* caches) to arch_slab_minalign() so that kmalloc-8 caches are > > skipped when KASAN_HW_TAGS is enabled (both config and runtime). > > > > Fixes: b035f5a6d852 ("mm: slab: reduce the kmalloc() minimum alignment if DMA bouncing possible") > > Signed-off-by: Catalin Marinas > > Reported-by: Mark Rutland > > Cc: Andrew Morton > > Cc: Vlastimil Babka > > Cc: Peter Collingbourne > > Cc: # 6.5.x > > --- > > > > The previous post was messed up by my git send-email configuration, so > > sending it again. Also cc'ing Vlastimil since he reviewed the previous > > slab changes for ARCH_KMALLOC_MINALIGN. Thanks. > > It also touches only slab files so I can take it via slab tree. Thanks. > > mm/slab_common.c | 7 +++++-- > > 1 file changed, 5 insertions(+), 2 deletions(-) > > > > diff --git a/mm/slab_common.c b/mm/slab_common.c > > index cd71f9581e67..8b45922ed295 100644 > > --- a/mm/slab_common.c > > +++ b/mm/slab_common.c > > @@ -895,10 +895,13 @@ void __init setup_kmalloc_cache_index_table(void) > > > > static unsigned int __kmalloc_minalign(void) > > { > > + unsigned int minalign = dma_get_cache_alignment(); > > + > > if (IS_ENABLED(CONFIG_DMA_BOUNCE_UNALIGNED_KMALLOC) && > > is_swiotlb_allocated()) > > - return ARCH_KMALLOC_MINALIGN; > > - return dma_get_cache_alignment(); > > + minalign = ARCH_KMALLOC_MINALIGN; > > + > > + return ALIGN(minalign, arch_slab_minalign()); > > Could it be max() instead of ALIGN()? It would be more obvious, at least to > me :) Yeah, max() would do since they are all a power of two. Do you want me to repost? -- Catalin