From nobody Sun Dec 14 18:14:37 2025 Received: from mail-10630.protonmail.ch (mail-10630.protonmail.ch [79.135.106.30]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 3AC992E6CD7; Wed, 29 Oct 2025 19:06:43 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=79.135.106.30 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1761764805; cv=none; b=JfrsolimaBydeCcND1nXmdlrGPCxc+FDZbCI93SvJ07WSrTHRGh5E3Dko6ZYESbiXy4FlBbbjVhY6mZdq2NPApnSCrhO5k/gnbJpKPg/V8F2sR+2b+WXJ+C2Ebf+vbmVzhY6bKQfe4fLLJrV0Ub0MdYwo9+5bhwp1YREvSV+iI0= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1761764805; c=relaxed/simple; bh=wwyHZ2RK4+tdqguT8sq3N+QdyLYVm5hVSL8mWJX3/AE=; h=Date:To:From:Cc:Subject:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=tSTyYez9YGV+AcFwg0mC0a+CsZuQFDMw1gRnhVekVl9iG2r1WZ/E1Nx8JbtR01JSYD8wILmzKNzXjygXjFK1JVwHelMMFFsaouduuSnld4jNuGVEUq6ysxXuZui9BCkAqkPBCMfYHZB9N21KwxIVKi1zwfUwhkdtDb3f3z5jaTE= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=pm.me; spf=pass smtp.mailfrom=pm.me; dkim=pass (2048-bit key) header.d=pm.me header.i=@pm.me header.b=pGVXX/VY; arc=none smtp.client-ip=79.135.106.30 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=pm.me Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=pm.me Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=pm.me header.i=@pm.me header.b="pGVXX/VY" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=pm.me; s=protonmail3; t=1761764801; x=1762024001; bh=RT/zPmq8dzuzMSpg5XGcznppBgYR4y/21vyg9rTeyzk=; h=Date:To:From:Cc:Subject:Message-ID:In-Reply-To:References: Feedback-ID:From:To:Cc:Date:Subject:Reply-To:Feedback-ID: Message-ID:BIMI-Selector; b=pGVXX/VYTWR44Wl1sG/O8IDygFTtrJhNXjWeLezoqqGkYg93K5hXzT1PokJx6a62h GV+r67xFAM4zXxfmJpWSg+F64ywdK83enI1wzWnczmBMFY5OzsI3s9yvN7mT2Td4Dh 7TyK6Vznu89HYA6GkMLZywdeGiiHscMs/4E8pcQkBgwWwHkh9pWdFp7Rt9jF1HxtdQ OMd4mrpIp0uXdoWQ5BDxmbbqnKomkHfV2zzEFu4RrOwaqx4IsoSWQ1IqwNNbeC3qV0 veI/fsLyEWuW5i6UByGv6InudSQ9k9UBxjAaTuvbgfCVVQPibgB5z0JnNq7hhrFh2B fHc1Ge225l1xQ== Date: Wed, 29 Oct 2025 19:06:33 +0000 To: xin@zytor.com, peterz@infradead.org, kaleshsingh@google.com, kbingham@kernel.org, akpm@linux-foundation.org, nathan@kernel.org, ryabinin.a.a@gmail.com, dave.hansen@linux.intel.com, bp@alien8.de, morbo@google.com, jeremy.linton@arm.com, smostafa@google.com, kees@kernel.org, baohua@kernel.org, vbabka@suse.cz, justinstitt@google.com, wangkefeng.wang@huawei.com, leitao@debian.org, jan.kiszka@siemens.com, fujita.tomonori@gmail.com, hpa@zytor.com, urezki@gmail.com, ubizjak@gmail.com, ada.coupriediaz@arm.com, nick.desaulniers+lkml@gmail.com, ojeda@kernel.org, brgerst@gmail.com, elver@google.com, pankaj.gupta@amd.com, glider@google.com, mark.rutland@arm.com, trintaeoitogc@gmail.com, jpoimboe@kernel.org, thuth@redhat.com, pasha.tatashin@soleen.com, dvyukov@google.com, jhubbard@nvidia.com, catalin.marinas@arm.com, yeoreum.yun@arm.com, mhocko@suse.com, lorenzo.stoakes@oracle.com, samuel.holland@sifive.com, vincenzo.frascino@arm.com, bigeasy@linutronix.de, surenb@google.com, ardb@kernel.org, Liam.Howlett@oracle.com, nicolas.schier@linux.dev, ziy@nvidia.com, kas@kernel.org, tglx@linutronix.de, mingo@redhat.com, broonie@kernel.org, corbet@lwn.net, andreyknvl@gmail.com, maciej.wieczor-retman@intel.com, david@redhat.com, maz@kernel.org, rppt@kernel.org, will@kernel.org, luto@kernel.org From: Maciej Wieczor-Retman Cc: kasan-dev@googlegroups.com, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, x86@kernel.org, linux-kbuild@vger.kernel.org, linux-mm@kvack.org, llvm@lists.linux.dev, linux-doc@vger.kernel.org, m.wieczorretman@pm.me Subject: [PATCH v6 04/18] kasan: sw_tags: Support tag widths less than 8 bits Message-ID: <8319582016f3e433bf7cd1c88ce7858c4a3c60fa.1761763681.git.m.wieczorretman@pm.me> In-Reply-To: References: Feedback-ID: 164464600:user:proton X-Pm-Message-ID: 5f5d346b6b1d7504801ff3b4ec51dbe636e94b26 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" From: Samuel Holland Allow architectures to override KASAN_TAG_KERNEL in asm/kasan.h. This is needed on RISC-V, which supports 57-bit virtual addresses and 7-bit pointer tags. For consistency, move the arm64 MTE definition of KASAN_TAG_MIN to asm/kasan.h, since it is also architecture-dependent; RISC-V's equivalent extension is expected to support 7-bit hardware memory tags. Reviewed-by: Andrey Konovalov Signed-off-by: Samuel Holland Signed-off-by: Maciej Wieczor-Retman --- arch/arm64/include/asm/kasan.h | 6 ++++-- arch/arm64/include/asm/uaccess.h | 1 + include/linux/kasan-tags.h | 13 ++++++++----- 3 files changed, 13 insertions(+), 7 deletions(-) diff --git a/arch/arm64/include/asm/kasan.h b/arch/arm64/include/asm/kasan.h index e1b57c13f8a4..4ab419df8b93 100644 --- a/arch/arm64/include/asm/kasan.h +++ b/arch/arm64/include/asm/kasan.h @@ -6,8 +6,10 @@ =20 #include #include -#include -#include + +#ifdef CONFIG_KASAN_HW_TAGS +#define KASAN_TAG_MIN 0xF0 /* minimum value for random tags */ +#endif =20 #define arch_kasan_set_tag(addr, tag) __tag_set(addr, tag) #define arch_kasan_reset_tag(addr) __tag_reset(addr) diff --git a/arch/arm64/include/asm/uaccess.h b/arch/arm64/include/asm/uacc= ess.h index 1aa4ecb73429..8f700a7dd2cd 100644 --- a/arch/arm64/include/asm/uaccess.h +++ b/arch/arm64/include/asm/uaccess.h @@ -22,6 +22,7 @@ #include #include #include +#include #include #include #include diff --git a/include/linux/kasan-tags.h b/include/linux/kasan-tags.h index 4f85f562512c..e07c896f95d3 100644 --- a/include/linux/kasan-tags.h +++ b/include/linux/kasan-tags.h @@ -2,13 +2,16 @@ #ifndef _LINUX_KASAN_TAGS_H #define _LINUX_KASAN_TAGS_H =20 +#include + +#ifndef KASAN_TAG_KERNEL #define KASAN_TAG_KERNEL 0xFF /* native kernel pointers tag */ -#define KASAN_TAG_INVALID 0xFE /* inaccessible memory tag */ -#define KASAN_TAG_MAX 0xFD /* maximum value for random tags */ +#endif + +#define KASAN_TAG_INVALID (KASAN_TAG_KERNEL - 1) /* inaccessible memory ta= g */ +#define KASAN_TAG_MAX (KASAN_TAG_KERNEL - 2) /* maximum value for random = tags */ =20 -#ifdef CONFIG_KASAN_HW_TAGS -#define KASAN_TAG_MIN 0xF0 /* minimum value for random tags */ -#else +#ifndef KASAN_TAG_MIN #define KASAN_TAG_MIN 0x00 /* minimum value for random tags */ #endif =20 --=20 2.51.0