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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id EB238EFD207 for ; Wed, 25 Feb 2026 08:14:59 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:Content-Transfer-Encoding: Content-type:MIME-Version:References:In-Reply-To:Message-ID:Date:Subject:Cc: To:From:Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=1+o8INxubcV2x/Jl5UdObmj+gfJwsgp0C09vqymuwDM=; b=L4591f/KmhaBnkxj7TSzwiWqSR wF9jcm0bQ88K2GpjSXBKJTFMAVEReBRVcNO47uvTLsn4KCYc3k3BZER0N2MtV4+YD6dP63r3q404+ mHfP+OntN4E3822h3GGovi51K3+xk9n8Z2DYmHDeK4k9bbHhAfA0tn2LwlQ5nTGcKsvzHXcz1weUr 7QhIx/jvO19RzfAIY3Bbg9aBQ3BH53fSLWtZ6a4crSX5hzRjDdLeXP+1BwrF7Wqug6bO8ejoKVsUx 1JpbpvxuBKiW8fOHOaES1vleKK39TDvrGC/LL25Gez2CHXwXsnF2OTNP7RpxzBSXhOYHBc0Ln/pBD CnA+4dxA==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux)) id 1vvA2t-00000003UK5-1Pkm; Wed, 25 Feb 2026 08:14:59 +0000 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]) by bombadil.infradead.org with esmtps (Exim 4.98.2 #2 (Red Hat Linux)) id 1vvA2q-00000003UHh-4AFx for linux-um@lists.infradead.org; Wed, 25 Feb 2026 08:14:58 +0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1772007296; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=1+o8INxubcV2x/Jl5UdObmj+gfJwsgp0C09vqymuwDM=; b=YfaD0xozfdQUlUgrC4uUT6noXJAq0SZ6rOFQjfM0QaL68C7gt388Hjjodxr2tm68pe82YC RmCkZK1oUI98e/fTXd/LA+LiabhMSdGdcdLgq3yG5l8pTa7Vsp1cTn8LkiS4rBwufjqeyV z1FhxYhA602EaqiYvliwPtHDQOnIP1A= Received: from mx-prod-mc-05.mail-002.prod.us-west-2.aws.redhat.com (ec2-54-186-198-63.us-west-2.compute.amazonaws.com [54.186.198.63]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-556-nQ4DDfqXPK2cnN4hGIJDvA-1; Wed, 25 Feb 2026 03:14:51 -0500 X-MC-Unique: nQ4DDfqXPK2cnN4hGIJDvA-1 X-Mimecast-MFC-AGG-ID: nQ4DDfqXPK2cnN4hGIJDvA_1772007289 Received: from mx-prod-int-08.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-08.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.111]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mx-prod-mc-05.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id A0E82195609D; Wed, 25 Feb 2026 08:14:48 +0000 (UTC) Received: from MiWiFi-R3L-srv.redhat.com (unknown [10.72.112.55]) by mx-prod-int-08.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTP id DE8351800351; Wed, 25 Feb 2026 08:14:38 +0000 (UTC) From: Baoquan He To: kasan-dev@googlegroups.com Cc: linux-mm@kvack.org, andreyknvl@gmail.com, ryabinin.a.a@gmail.com, glider@google.com, dvyukov@google.com, linux-kernel@vger.kernel.org, linux-um@lists.infradead.org, linux-arm-kernel@lists.infradead.org, loongarch@lists.linux.dev, linuxppc-dev@lists.ozlabs.org, linux-riscv@lists.infradead.org, x86@kernel.org, chris@zankel.net, jcmvbkbc@gmail.com, linux-s390@vger.kernel.org, hca@linux.ibm.com, Baoquan He Subject: [PATCH v5 01/15] mm/kasan: add conditional checks in functions to return directly if kasan is disabled Date: Wed, 25 Feb 2026 16:13:58 +0800 Message-ID: <20260225081412.76502-2-bhe@redhat.com> In-Reply-To: <20260225081412.76502-1-bhe@redhat.com> References: <20260225081412.76502-1-bhe@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.4.1 on 10.30.177.111 X-Mimecast-MFC-PROC-ID: S4dq2k3lysi6cFfy2ifNRxULpWlc8z8cHYSAypbc0CM_1772007289 X-Mimecast-Originator: redhat.com Content-type: text/plain Content-Transfer-Encoding: 8bit X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20260225_001457_093982_E4D128CC X-CRM114-Status: GOOD ( 18.25 ) X-BeenThere: linux-um@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-um" Errors-To: linux-um-bounces+linux-um=archiver.kernel.org@lists.infradead.org The current codes only check if kasan is disabled for hw_tags mode. Here add the conditional checks for functional functions of generic mode and sw_tags mode. And also add a helper __kasan_cache_shrink() in mm/kasan/generic.c so that the conditional check is done in include/linux/kasan.h. This is prepared for later adding kernel parameter kasan=on|off for all three kasan modes. Signed-off-by: Baoquan He --- include/linux/kasan.h | 7 ++++++- mm/kasan/generic.c | 16 ++++++++++++++-- mm/kasan/init.c | 6 ++++++ mm/kasan/quarantine.c | 3 +++ mm/kasan/report.c | 4 +++- mm/kasan/shadow.c | 11 ++++++++++- mm/kasan/sw_tags.c | 3 +++ 7 files changed, 45 insertions(+), 5 deletions(-) diff --git a/include/linux/kasan.h b/include/linux/kasan.h index 338a1921a50a..a9b8d58d8699 100644 --- a/include/linux/kasan.h +++ b/include/linux/kasan.h @@ -492,7 +492,12 @@ size_t kasan_metadata_size(struct kmem_cache *cache, bool in_object); void kasan_cache_create(struct kmem_cache *cache, unsigned int *size, slab_flags_t *flags); -void kasan_cache_shrink(struct kmem_cache *cache); +void __kasan_cache_shrink(struct kmem_cache *cache); +static inline void kasan_cache_shrink(struct kmem_cache *cache) +{ + if (kasan_enabled()) + __kasan_cache_shrink(cache); +} void kasan_cache_shutdown(struct kmem_cache *cache); void kasan_record_aux_stack(void *ptr); diff --git a/mm/kasan/generic.c b/mm/kasan/generic.c index 2b8e73f5f6a7..25850e7c2e00 100644 --- a/mm/kasan/generic.c +++ b/mm/kasan/generic.c @@ -212,14 +212,14 @@ bool kasan_byte_accessible(const void *addr) return shadow_byte >= 0 && shadow_byte < KASAN_GRANULE_SIZE; } -void kasan_cache_shrink(struct kmem_cache *cache) +void __kasan_cache_shrink(struct kmem_cache *cache) { kasan_quarantine_remove_cache(cache); } void kasan_cache_shutdown(struct kmem_cache *cache) { - if (!__kmem_cache_empty(cache)) + if (kasan_enabled() && !__kmem_cache_empty(cache)) kasan_quarantine_remove_cache(cache); } @@ -239,6 +239,9 @@ void __asan_register_globals(void *ptr, ssize_t size) int i; struct kasan_global *globals = ptr; + if (!kasan_enabled()) + return; + for (i = 0; i < size; i++) register_global(&globals[i]); } @@ -369,6 +372,9 @@ void kasan_cache_create(struct kmem_cache *cache, unsigned int *size, unsigned int rem_free_meta_size; unsigned int orig_alloc_meta_offset; + if (!kasan_enabled()) + return; + if (!kasan_requires_meta()) return; @@ -518,6 +524,9 @@ size_t kasan_metadata_size(struct kmem_cache *cache, bool in_object) { struct kasan_cache *info = &cache->kasan_info; + if (!kasan_enabled()) + return 0; + if (!kasan_requires_meta()) return 0; @@ -543,6 +552,9 @@ void kasan_record_aux_stack(void *addr) struct kasan_alloc_meta *alloc_meta; void *object; + if (!kasan_enabled()) + return; + if (is_kfence_address(addr) || !slab) return; diff --git a/mm/kasan/init.c b/mm/kasan/init.c index f084e7a5df1e..c78d77ed47bc 100644 --- a/mm/kasan/init.c +++ b/mm/kasan/init.c @@ -447,6 +447,9 @@ void kasan_remove_zero_shadow(void *start, unsigned long size) unsigned long addr, end, next; pgd_t *pgd; + if (!kasan_enabled()) + return; + addr = (unsigned long)kasan_mem_to_shadow(start); end = addr + (size >> KASAN_SHADOW_SCALE_SHIFT); @@ -482,6 +485,9 @@ int kasan_add_zero_shadow(void *start, unsigned long size) int ret; void *shadow_start, *shadow_end; + if (!kasan_enabled()) + return 0; + shadow_start = kasan_mem_to_shadow(start); shadow_end = shadow_start + (size >> KASAN_SHADOW_SCALE_SHIFT); diff --git a/mm/kasan/quarantine.c b/mm/kasan/quarantine.c index 6958aa713c67..a6dc2c3d8a15 100644 --- a/mm/kasan/quarantine.c +++ b/mm/kasan/quarantine.c @@ -405,6 +405,9 @@ static int __init kasan_cpu_quarantine_init(void) { int ret = 0; + if (!kasan_enabled()) + return 0; + ret = cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, "mm/kasan:online", kasan_cpu_online, kasan_cpu_offline); if (ret < 0) diff --git a/mm/kasan/report.c b/mm/kasan/report.c index 27efb78eb32d..1a39b3f62c57 100644 --- a/mm/kasan/report.c +++ b/mm/kasan/report.c @@ -576,7 +576,9 @@ bool kasan_report(const void *addr, size_t size, bool is_write, unsigned long irq_flags; struct kasan_report_info info; - if (unlikely(report_suppressed_sw()) || unlikely(!report_enabled())) { + if (unlikely(report_suppressed_sw()) || + unlikely(!report_enabled()) || + !kasan_enabled()) { ret = false; goto out; } diff --git a/mm/kasan/shadow.c b/mm/kasan/shadow.c index d286e0a04543..87f517b76d6e 100644 --- a/mm/kasan/shadow.c +++ b/mm/kasan/shadow.c @@ -164,6 +164,8 @@ void kasan_unpoison(const void *addr, size_t size, bool init) { u8 tag = get_tag(addr); + if (!kasan_enabled()) + return; /* * Perform shadow offset calculation based on untagged address, as * some of the callers (e.g. kasan_unpoison_new_object) pass tagged @@ -277,7 +279,8 @@ static int __meminit kasan_mem_notifier(struct notifier_block *nb, static int __init kasan_memhotplug_init(void) { - hotplug_memory_notifier(kasan_mem_notifier, DEFAULT_CALLBACK_PRI); + if (kasan_enabled()) + hotplug_memory_notifier(kasan_mem_notifier, DEFAULT_CALLBACK_PRI); return 0; } @@ -660,6 +663,9 @@ int kasan_alloc_module_shadow(void *addr, size_t size, gfp_t gfp_mask) size_t shadow_size; unsigned long shadow_start; + if (!kasan_enabled()) + return 0; + shadow_start = (unsigned long)kasan_mem_to_shadow(addr); scaled_size = (size + KASAN_GRANULE_SIZE - 1) >> KASAN_SHADOW_SCALE_SHIFT; @@ -696,6 +702,9 @@ int kasan_alloc_module_shadow(void *addr, size_t size, gfp_t gfp_mask) void kasan_free_module_shadow(const struct vm_struct *vm) { + if (!kasan_enabled()) + return; + if (IS_ENABLED(CONFIG_UML)) return; diff --git a/mm/kasan/sw_tags.c b/mm/kasan/sw_tags.c index c75741a74602..6c1caec4261a 100644 --- a/mm/kasan/sw_tags.c +++ b/mm/kasan/sw_tags.c @@ -79,6 +79,9 @@ bool kasan_check_range(const void *addr, size_t size, bool write, u8 *shadow_first, *shadow_last, *shadow; void *untagged_addr; + if (!kasan_enabled()) + return true; + if (unlikely(size == 0)) return true; -- 2.52.0