From nobody Mon Oct 20 09:37:09 2025 Received: from mail-pl1-f171.google.com (mail-pl1-f171.google.com [209.85.214.171]) (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 0429C212FB0 for ; Wed, 4 Jun 2025 17:16:38 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.214.171 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1749057400; cv=none; b=GHCKY7UzmDSrl8jemhtaUCFztZktl/JoxnQ8M1uAulqAGWKDEcU4Gs8k8IkZkWIRxjGufaloHE+89YXIoxCUcKNn7vO6pvnR9PjyW7eMwHHHLTQluTRowmMXn5ox3tUfJtxPtJlGTalRh9UgGihIXG0YWgW+UpD2S4/2X0jjdf4= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1749057400; c=relaxed/simple; bh=sfs/voBRgEO0N2IxC4EipgroXAUwYP7ftsvLbUORtCw=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:References: In-Reply-To:To:Cc; b=F/74ZHOz4SDVr1dWVTeM7YYRMR1n/a86UApsCXBOQkTu5jE4f/ZD0jQOz6A6qoQXuCW03/C+RhcaP9EhyM4usDZWEjEYd0PsKhbwk8E4A5oMT9egdMGN1XFKgXXY/sVdsHojss7AkoaB/Djrk/rX52rV0/OmEl5sI+h9L1zFV4g= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=rivosinc.com; spf=pass smtp.mailfrom=rivosinc.com; dkim=pass (2048-bit key) header.d=rivosinc-com.20230601.gappssmtp.com header.i=@rivosinc-com.20230601.gappssmtp.com header.b=Tg/7NlgR; arc=none smtp.client-ip=209.85.214.171 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=rivosinc.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=rivosinc.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=rivosinc-com.20230601.gappssmtp.com header.i=@rivosinc-com.20230601.gappssmtp.com header.b="Tg/7NlgR" Received: by mail-pl1-f171.google.com with SMTP id d9443c01a7336-234d366e5f2so897265ad.1 for ; Wed, 04 Jun 2025 10:16:38 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=rivosinc-com.20230601.gappssmtp.com; s=20230601; t=1749057398; x=1749662198; darn=vger.kernel.org; h=cc:to:in-reply-to:references:message-id:content-transfer-encoding :mime-version:subject:date:from:from:to:cc:subject:date:message-id :reply-to; bh=RWhABZTC7HgMOVZUdFo2P0cmdg9cGlaFRd3WQ+8L7gE=; b=Tg/7NlgROD1tWblZMmMRK0vAHPpTgvb0aSzjnTE80f7xZObh0ut1lgIIMa4jLMj/hq X3Bv82f7ydU30tSttR9NUxsYQssAvX6MP+00sf8px+aVEN5QhalnkCZRhHevs19TrWOa /RUu6CFBds3CznmXTUc2hc07/MMYqJHlfNDzipfLMp6BcFh3NQiPytfMm+DcruXVVCr1 9zeptFYKAIe+hx6Wyc+zdDBgvtuhZtfhydQuJJudafkar+IEVR3IeB+u+BEWD0N0f24u RxzQ0d8evm2MB/yIuibSf9S8Yv5MeuFBHeVjvN+xKsgQgrSJybw6Qk2Qo6n8Nn+Es+48 S4yQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1749057398; x=1749662198; h=cc:to:in-reply-to:references:message-id:content-transfer-encoding :mime-version:subject:date:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=RWhABZTC7HgMOVZUdFo2P0cmdg9cGlaFRd3WQ+8L7gE=; b=JNkR2n/0jX3RBMlioLXD7sA81iBAD2cy/9QJf+8D9auojmXCywG/+Fmizo9bRtP57Q czdGx/tHlb8I22gZ9vOzSinz9pAGQcFHDfquyuEpZ3PSXZs7B+EXTuqw2F/Ytx5GKB+/ dnKj0scqkBijr5khe/1FC5YfAsDGIer9QLVZUXk8kA85M/Gz0HiHq+sCvbE9C8LtxeCH 32Mv063U8Tr8sIhcIOXsbiv3dFSj76b8S5ig+UvQY3HWCnNi45P2AYM55dqNkuGIXRAR uGUWOnyBY9vx6FfjuV/ov7XsRbVlN7AWDNMiV5QIitsi1plonwAwUt9Mg2C7Lige6Buh zeJA== X-Gm-Message-State: AOJu0Yyc8aulxKPaA6rbbg7Voy9OwjGdac2DbvgAUYZ8CtqPdgNoWJG0 qgF0RWeMVv5d5a6ma5n6dO9z6i9viAwvPetwjZjcLXXqwiS47AvRsJ2UG5vUOhcAbI4= X-Gm-Gg: ASbGncvxHoJIlOPpI97Hdo0ldMIG6Wrt8J63gpVz/eP/BEh+R9f4BK8rxSrETBvvvg3 00cDhdaWG2dmla6RpyCOSF/brDoMyvyaq1o1Fj5YUDEzIC6XAs1TdlA33DjMOPTWmzFqFVJ1Mhw o9ZefmB7DaGh04XHg253R3zaeaY6+YsnPdXQsqj+q2nQkQfIDEOgyAk5Lbtgv1d/Wo19c4uOOjK cjlWeMFUHBtudSer6baASiQN1nHk2/wdVWqrpnZKvkrfdfl28JoYdszw3bp7mYYfq+/RJhCDIWO pSZOqaZQ/4pD+JuvrgcFYHdHLvxVLlElaeF7k5ybh9WC+xy5lDHYdftDsAVhcw== X-Google-Smtp-Source: AGHT+IESzgVoI6jsn8EBaGsznchFbfhdmr9dOihFSf5lgEfKGzXoOOTnsQHJIuLLab2X/wZNB3LJLg== X-Received: by 2002:a17:903:3d0b:b0:234:a033:b6f6 with SMTP id d9443c01a7336-235e11cb901mr49065825ad.31.1749057398132; Wed, 04 Jun 2025 10:16:38 -0700 (PDT) Received: from debug.ba.rivosinc.com ([64.71.180.162]) by smtp.gmail.com with ESMTPSA id 98e67ed59e1d1-3124e2e9c9fsm9178972a91.30.2025.06.04.10.16.35 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 04 Jun 2025 10:16:37 -0700 (PDT) From: Deepak Gupta Date: Wed, 04 Jun 2025 10:15:32 -0700 Subject: [PATCH v17 08/27] riscv/mm: teach pte_mkwrite to manufacture shadow stack PTEs 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: <20250604-v5_user_cfi_series-v17-8-4565c2cf869f@rivosinc.com> References: <20250604-v5_user_cfi_series-v17-0-4565c2cf869f@rivosinc.com> In-Reply-To: <20250604-v5_user_cfi_series-v17-0-4565c2cf869f@rivosinc.com> To: Thomas Gleixner , Ingo Molnar , Borislav Petkov , Dave Hansen , x86@kernel.org, "H. Peter Anvin" , Andrew Morton , "Liam R. Howlett" , Vlastimil Babka , Lorenzo Stoakes , Paul Walmsley , Palmer Dabbelt , Albert Ou , Conor Dooley , Rob Herring , Krzysztof Kozlowski , Arnd Bergmann , Christian Brauner , Peter Zijlstra , Oleg Nesterov , Eric Biederman , Kees Cook , Jonathan Corbet , Shuah Khan , Jann Horn , Conor Dooley , Miguel Ojeda , Alex Gaynor , Boqun Feng , Gary Guo , =?utf-8?q?Bj=C3=B6rn_Roy_Baron?= , Benno Lossin , Andreas Hindborg , Alice Ryhl , Trevor Gross Cc: linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-mm@kvack.org, linux-riscv@lists.infradead.org, devicetree@vger.kernel.org, linux-arch@vger.kernel.org, linux-doc@vger.kernel.org, linux-kselftest@vger.kernel.org, alistair.francis@wdc.com, richard.henderson@linaro.org, jim.shu@sifive.com, andybnac@gmail.com, kito.cheng@sifive.com, charlie@rivosinc.com, atishp@rivosinc.com, evan@rivosinc.com, cleger@rivosinc.com, alexghiti@rivosinc.com, samitolvanen@google.com, broonie@kernel.org, rick.p.edgecombe@intel.com, rust-for-linux@vger.kernel.org, Zong Li , Deepak Gupta X-Mailer: b4 0.13.0 pte_mkwrite creates PTEs with WRITE encodings for underlying arch. Underlying arch can have two types of writeable mappings. One that can be written using regular store instructions. Another one that can only be written using specialized store instructions (like shadow stack stores). pte_mkwrite can select write PTE encoding based on VMA range (i.e. VM_SHADOW_STACK) Reviewed-by: Alexandre Ghiti Reviewed-by: Zong Li Signed-off-by: Deepak Gupta --- arch/riscv/include/asm/pgtable.h | 7 +++++++ arch/riscv/mm/pgtable.c | 16 ++++++++++++++++ 2 files changed, 23 insertions(+) diff --git a/arch/riscv/include/asm/pgtable.h b/arch/riscv/include/asm/pgta= ble.h index f21c888f59eb..60d4821627d2 100644 --- a/arch/riscv/include/asm/pgtable.h +++ b/arch/riscv/include/asm/pgtable.h @@ -428,6 +428,10 @@ static inline pte_t pte_wrprotect(pte_t pte) =20 /* static inline pte_t pte_mkread(pte_t pte) */ =20 +struct vm_area_struct; +pte_t pte_mkwrite(pte_t pte, struct vm_area_struct *vma); +#define pte_mkwrite pte_mkwrite + static inline pte_t pte_mkwrite_novma(pte_t pte) { return __pte(pte_val(pte) | _PAGE_WRITE); @@ -778,6 +782,9 @@ static inline pmd_t pmd_mkyoung(pmd_t pmd) return pte_pmd(pte_mkyoung(pmd_pte(pmd))); } =20 +pmd_t pmd_mkwrite(pmd_t pmd, struct vm_area_struct *vma); +#define pmd_mkwrite pmd_mkwrite + static inline pmd_t pmd_mkwrite_novma(pmd_t pmd) { return pte_pmd(pte_mkwrite_novma(pmd_pte(pmd))); diff --git a/arch/riscv/mm/pgtable.c b/arch/riscv/mm/pgtable.c index 4ae67324f992..0bedf6523108 100644 --- a/arch/riscv/mm/pgtable.c +++ b/arch/riscv/mm/pgtable.c @@ -155,3 +155,19 @@ pmd_t pmdp_collapse_flush(struct vm_area_struct *vma, return pmd; } #endif /* CONFIG_TRANSPARENT_HUGEPAGE */ + +pte_t pte_mkwrite(pte_t pte, struct vm_area_struct *vma) +{ + if (vma->vm_flags & VM_SHADOW_STACK) + return pte_mkwrite_shstk(pte); + + return pte_mkwrite_novma(pte); +} + +pmd_t pmd_mkwrite(pmd_t pmd, struct vm_area_struct *vma) +{ + if (vma->vm_flags & VM_SHADOW_STACK) + return pmd_mkwrite_shstk(pmd); + + return pmd_mkwrite_novma(pmd); +} --=20 2.43.0