From nobody Mon Feb 9 23:42:49 2026 Received: from smtp-out2.suse.de (smtp-out2.suse.de [195.135.223.131]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 5358076907 for ; Tue, 20 Feb 2024 16:58:47 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=195.135.223.131 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1708448329; cv=none; b=M0hTwUImmOUAAZ0aLwv1YBq7jJY9pWzLX7Gm62oBmJdz7CLmSOIFizo9/Xu92joRWXORXUj5OFBY6vGmTI5SKC7/95Nx1Au/ttnENBuOu4B9lAGZFtX6rZ46Zpj1KWg0DPURiJC0V00HBuNw4yEdDwIFL5elzYz6XgnLiy5UFbY= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1708448329; c=relaxed/simple; bh=8dSL5GfjNj31WZBzU1RArK2AdDIYjJIAED64yK7aPeY=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:References: In-Reply-To:To:Cc; b=r7OsfIc3nOYVJybjtR46mboT3r4FWCSDZKuOw68iSqxXEix4zSS4wKBqyYxK1Mx+bDB5vhIn1BPQ+EcNDM+MX2APfgVDCJwJbmFqzX/0yovXJ65llPA28ey6Idl73HUBDRE5cdK59s5MCWyEHgghqtNE/pGe5QrDJ94vmq6OtE0= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=suse.cz; spf=pass smtp.mailfrom=suse.cz; arc=none smtp.client-ip=195.135.223.131 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=suse.cz Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=suse.cz Received: from imap1.dmz-prg2.suse.org (imap1.dmz-prg2.suse.org [IPv6:2a07:de40:b281:104:10:150:64:97]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) by smtp-out2.suse.de (Postfix) with ESMTPS id 7BAC91F8AC; Tue, 20 Feb 2024 16:58:45 +0000 (UTC) Received: from imap1.dmz-prg2.suse.org (localhost [127.0.0.1]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) by imap1.dmz-prg2.suse.org (Postfix) with ESMTPS id 578FD139D0; Tue, 20 Feb 2024 16:58:45 +0000 (UTC) Received: from dovecot-director2.suse.de ([2a07:de40:b281:106:10:150:64:167]) by imap1.dmz-prg2.suse.org with ESMTPSA id CEsVFUXa1GVKXQAAD6G6ig (envelope-from ); Tue, 20 Feb 2024 16:58:45 +0000 From: Vlastimil Babka Date: Tue, 20 Feb 2024 17:58:27 +0100 Subject: [PATCH 3/3] mm, slab, kasan: replace kasan_never_merge() with SLAB_NO_MERGE Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable Message-Id: <20240220-slab-cleanup-flags-v1-3-e657e373944a@suse.cz> References: <20240220-slab-cleanup-flags-v1-0-e657e373944a@suse.cz> In-Reply-To: <20240220-slab-cleanup-flags-v1-0-e657e373944a@suse.cz> To: Christoph Lameter , Pekka Enberg , David Rientjes , Joonsoo Kim , Andrew Morton , Roman Gushchin , Hyeonggon Yoo <42.hyeyoo@gmail.com>, Andrey Ryabinin , Alexander Potapenko , Andrey Konovalov , Dmitry Vyukov , Vincenzo Frascino Cc: Zheng Yejian , Xiongwei Song , Chengming Zhou , linux-mm@kvack.org, linux-kernel@vger.kernel.org, kasan-dev@googlegroups.com, Vlastimil Babka X-Mailer: b4 0.13.0 X-Developer-Signature: v=1; a=openpgp-sha256; l=3299; i=vbabka@suse.cz; h=from:subject:message-id; bh=8dSL5GfjNj31WZBzU1RArK2AdDIYjJIAED64yK7aPeY=; b=owEBbQGS/pANAwAIAbvgsHXSRYiaAcsmYgBl1NpC+Ron5uAKKATthXFJII/xHLgqduJBWbRQt JULEgGEAwCJATMEAAEIAB0WIQR7u8hBFZkjSJZITfG74LB10kWImgUCZdTaQgAKCRC74LB10kWI mt6zB/9ix1+cbRLwfxeQ4PhmyOPOXIy8AuaLRA62hsETFxjPOeumiQBXsvdbnzwsuTrbTPtKCkZ d9K8yRw2rpCG80loeAT/9uGKYzkw3j1XJrIDpXnpsp8/Jtb8zF38E0za2jDekAKVKziUs+xQQ1c VGAgxP7oyKW/Scrkzja41qVLuoQIjHK0k+XLXLFgkgs+iCPInGvRs4Nw50YuoG4okbZHICuchYX EJ07EGSqae4vCKCv3jipCwptC1gLJZ1gNSnfYu6Xla4IZmsWsXnVgCegTbcY8e9LdmySCBYecUL 5FttxJXT+6E5QTHUN3Tw59fKT1yFq1PkGQFvhgv0TDslB5er X-Developer-Key: i=vbabka@suse.cz; a=openpgp; fpr=A940D434992C2E8E99103D50224FA7E7CC82A664 X-Spam-Level: Authentication-Results: smtp-out2.suse.de; none X-Rspamd-Server: rspamd2.dmz-prg2.suse.org X-Spamd-Result: default: False [-4.00 / 50.00]; TAGGED_RCPT(0.00)[]; REPLY(-4.00)[] X-Spam-Score: -4.00 X-Rspamd-Queue-Id: 7BAC91F8AC X-Spam-Flag: NO The SLAB_KASAN flag prevents merging of caches in some configurations, which is handled in a rather complicated way via kasan_never_merge(). Since we now have a generic SLAB_NO_MERGE flag, we can instead use it for KASAN caches in addition to SLAB_KASAN in those configurations, and simplify the SLAB_NEVER_MERGE handling. Signed-off-by: Vlastimil Babka Reviewed-by: Andrey Konovalov Reviewed-by: Chengming Zhou --- include/linux/kasan.h | 6 ------ mm/kasan/generic.c | 16 ++++------------ mm/slab_common.c | 2 +- 3 files changed, 5 insertions(+), 19 deletions(-) diff --git a/include/linux/kasan.h b/include/linux/kasan.h index dbb06d789e74..70d6a8f6e25d 100644 --- a/include/linux/kasan.h +++ b/include/linux/kasan.h @@ -429,7 +429,6 @@ struct kasan_cache { }; =20 size_t kasan_metadata_size(struct kmem_cache *cache, bool in_object); -slab_flags_t kasan_never_merge(void); void kasan_cache_create(struct kmem_cache *cache, unsigned int *size, slab_flags_t *flags); =20 @@ -446,11 +445,6 @@ static inline size_t kasan_metadata_size(struct kmem_c= ache *cache, { return 0; } -/* And thus nothing prevents cache merging. */ -static inline slab_flags_t kasan_never_merge(void) -{ - return 0; -} /* And no cache-related metadata initialization is required. */ static inline void kasan_cache_create(struct kmem_cache *cache, unsigned int *size, diff --git a/mm/kasan/generic.c b/mm/kasan/generic.c index df6627f62402..d8b78d273b9f 100644 --- a/mm/kasan/generic.c +++ b/mm/kasan/generic.c @@ -334,14 +334,6 @@ DEFINE_ASAN_SET_SHADOW(f3); DEFINE_ASAN_SET_SHADOW(f5); DEFINE_ASAN_SET_SHADOW(f8); =20 -/* Only allow cache merging when no per-object metadata is present. */ -slab_flags_t kasan_never_merge(void) -{ - if (!kasan_requires_meta()) - return 0; - return SLAB_KASAN; -} - /* * Adaptive redzone policy taken from the userspace AddressSanitizer runti= me. * For larger allocations larger redzones are used. @@ -372,13 +364,13 @@ void kasan_cache_create(struct kmem_cache *cache, uns= igned int *size, /* * SLAB_KASAN is used to mark caches that are sanitized by KASAN * and that thus have per-object metadata. - * Currently this flag is used in two places: + * Currently this flag is used in one place: * 1. In slab_ksize() to account for per-object metadata when * calculating the size of the accessible memory within the object. - * 2. In slab_common.c via kasan_never_merge() to prevent merging of - * caches with per-object metadata. + * Additionally, we use SLAB_NO_MERGE to prevent merging of caches + * with per-object metadata. */ - *flags |=3D SLAB_KASAN; + *flags |=3D SLAB_KASAN | SLAB_NO_MERGE; =20 ok_size =3D *size; =20 diff --git a/mm/slab_common.c b/mm/slab_common.c index 238293b1dbe1..7cfa2f1ce655 100644 --- a/mm/slab_common.c +++ b/mm/slab_common.c @@ -50,7 +50,7 @@ static DECLARE_WORK(slab_caches_to_rcu_destroy_work, */ #define SLAB_NEVER_MERGE (SLAB_RED_ZONE | SLAB_POISON | SLAB_STORE_USER | \ SLAB_TRACE | SLAB_TYPESAFE_BY_RCU | SLAB_NOLEAKTRACE | \ - SLAB_FAILSLAB | SLAB_NO_MERGE | kasan_never_merge()) + SLAB_FAILSLAB | SLAB_NO_MERGE) =20 #define SLAB_MERGE_SAME (SLAB_RECLAIM_ACCOUNT | SLAB_CACHE_DMA | \ SLAB_CACHE_DMA32 | SLAB_ACCOUNT) --=20 2.43.1