From nobody Sun Dec 14 18:13:22 2025 Received: from mail-24417.protonmail.ch (mail-24417.protonmail.ch [109.224.244.17]) (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 9B052357A4C for ; Wed, 29 Oct 2025 19:07:12 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=109.224.244.17 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1761764834; cv=none; b=nBaXmSrkJMTXNv3dT/+W/OQmAuypjtq63iXFaYvjyszQFj1Gez045DdX7DTWi1bfc3QludOTDeiYbFXBrW8L0mbu9VAEJB6yZ0aCjpq2X5aEpwLOGmQ/q+RTQjsI7SSOjhhZ2L6XATrfS6f+o7rA/cuVfcth4HMW1bAKluAtBxE= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1761764834; c=relaxed/simple; bh=uGCpeSXg/TwzqC/G0Sv5pR2uEf/a3YnL7Q02GxMvD18=; h=Date:To:From:Cc:Subject:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=QkU4SyspV2ER8EkuImi6SWerB17O5oh2RcIVNixwf2mGIlbbR9ndJBQQ5+G3PWDNqO/mFIE4gKnj4JQwqtTz3i6OIAALAF+PvlJhqFLpi+BLkGOZlQGIp8DFD6bdfOx2HTQpb4MMGw/e+Ews2cIgwCWHeOHJsplJzMf6D9wWQNs= 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=OLK+mYTZ; arc=none smtp.client-ip=109.224.244.17 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="OLK+mYTZ" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=pm.me; s=protonmail3; t=1761764830; x=1762024030; bh=V+GI3JCHWjOQcFbXmMHTXI5iGSfAXcKKoBJ+NaZcg5c=; 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=OLK+mYTZss2HUSw9NfQJFmBZXPQpGyO18z4fzmKhditcec3bCsPrPoXyhQ2UsC2Ra rAl5/2CYQI+Y1mMVRPqPEuOOiBjJHK544HtwILnNJT5/FKFU/v2pjnyIqXshlSmKEc VadPr3Md0c5XXKXtYdnRBxE4zYRMSH50w+hN92Mg8Mv8P2KQAGZRBKBKqEStGqf0BM /anLMmHFeqGGLt/rMS4Jqu4Xq1dszXRzP7qoEacCQwdD5XaLd82s2oXhsRREEJrf5B 3rkW2LUFOlJ4uHEyTIgUZpV2j3EWms0GxjcIoQ0nALLhlo0Hqiht1iraRW9TnRf3oG iDVK81uAmCuwA== Date: Wed, 29 Oct 2025 19:07:05 +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 06/18] x86/kasan: Add arch specific kasan functions Message-ID: <5be986faa12ed1176889c3ba25852c42674305f4.1761763681.git.m.wieczorretman@pm.me> In-Reply-To: References: Feedback-ID: 164464600:user:proton X-Pm-Message-ID: 78312123e49b3e9b61a0495ac0e750673eadf38b 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: Maciej Wieczor-Retman KASAN's software tag-based mode needs multiple macros/functions to handle tag and pointer interactions - to set, retrieve and reset tags from the top bits of a pointer. Mimic functions currently used by arm64 but change the tag's position to bits [60:57] in the pointer. Signed-off-by: Maciej Wieczor-Retman Acked-by: Andrey Konovalov --- Changelog v6: - Remove empty line after ifdef CONFIG_KASAN_SW_TAGS - Add ifdef 64 bit to avoid problems in vdso32. - Add Andrey's Acked-by tag. Changelog v4: - Rewrite __tag_set() without pointless casts and make it more readable. Changelog v3: - Reorder functions so that __tag_*() etc are above the arch_kasan_*() ones. - Remove CONFIG_KASAN condition from __tag_set() arch/x86/include/asm/kasan.h | 42 ++++++++++++++++++++++++++++++++++-- 1 file changed, 40 insertions(+), 2 deletions(-) diff --git a/arch/x86/include/asm/kasan.h b/arch/x86/include/asm/kasan.h index d7e33c7f096b..396071832d02 100644 --- a/arch/x86/include/asm/kasan.h +++ b/arch/x86/include/asm/kasan.h @@ -3,6 +3,8 @@ #define _ASM_X86_KASAN_H =20 #include +#include +#include #define KASAN_SHADOW_OFFSET _AC(CONFIG_KASAN_SHADOW_OFFSET, UL) #define KASAN_SHADOW_SCALE_SHIFT 3 =20 @@ -24,8 +26,43 @@ KASAN_SHADOW_SCALE_SHIFT))) =20 #ifndef __ASSEMBLER__ +#include +#include +#include + +#ifdef CONFIG_KASAN_SW_TAGS +#define __tag_shifted(tag) FIELD_PREP(GENMASK_ULL(60, 57), tag) +#define __tag_reset(addr) (sign_extend64((u64)(addr), 56)) +#define __tag_get(addr) ((u8)FIELD_GET(GENMASK_ULL(60, 57), (u64)addr)) +#else +#define __tag_shifted(tag) 0UL +#define __tag_reset(addr) (addr) +#define __tag_get(addr) 0 +#endif /* CONFIG_KASAN_SW_TAGS */ + +#ifdef CONFIG_64BIT +static inline void *__tag_set(const void *__addr, u8 tag) +{ + u64 addr =3D (u64)__addr; + + addr &=3D ~__tag_shifted(KASAN_TAG_MASK); + addr |=3D __tag_shifted(tag); + + return (void *)addr; +} +#else +static inline void *__tag_set(void *__addr, u8 tag) +{ + return __addr; +} +#endif + +#define arch_kasan_set_tag(addr, tag) __tag_set(addr, tag) +#define arch_kasan_reset_tag(addr) __tag_reset(addr) +#define arch_kasan_get_tag(addr) __tag_get(addr) =20 #ifdef CONFIG_KASAN + void __init kasan_early_init(void); void __init kasan_init(void); void __init kasan_populate_shadow_for_vaddr(void *va, size_t size, int nid= ); @@ -34,8 +71,9 @@ static inline void kasan_early_init(void) { } static inline void kasan_init(void) { } static inline void kasan_populate_shadow_for_vaddr(void *va, size_t size, int nid) { } -#endif =20 -#endif +#endif /* CONFIG_KASAN */ + +#endif /* __ASSEMBLER__ */ =20 #endif --=20 2.51.0