From patchwork Fri Mar 14 21:39:25 2025 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Deepak Gupta X-Patchwork-Id: 14017493 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 kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id 8131BC28B30 for ; Fri, 14 Mar 2025 21:39:47 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 4F734280015; Fri, 14 Mar 2025 17:39:45 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 42C11280004; Fri, 14 Mar 2025 17:39:45 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 20B53280015; Fri, 14 Mar 2025 17:39:45 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0016.hostedemail.com [216.40.44.16]) by kanga.kvack.org (Postfix) with ESMTP id F278B280004 for ; Fri, 14 Mar 2025 17:39:44 -0400 (EDT) Received: from smtpin28.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay08.hostedemail.com (Postfix) with ESMTP id E8DD0141539 for ; Fri, 14 Mar 2025 21:39:45 +0000 (UTC) X-FDA: 83221473930.28.4B79E02 Received: from mail-pl1-f180.google.com (mail-pl1-f180.google.com [209.85.214.180]) by imf06.hostedemail.com (Postfix) with ESMTP id 07828180006 for ; Fri, 14 Mar 2025 21:39:43 +0000 (UTC) Authentication-Results: imf06.hostedemail.com; dkim=pass header.d=rivosinc-com.20230601.gappssmtp.com header.s=20230601 header.b=GQMtMIha; spf=pass (imf06.hostedemail.com: domain of debug@rivosinc.com designates 209.85.214.180 as permitted sender) smtp.mailfrom=debug@rivosinc.com; dmarc=none ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1741988384; h=from:from:sender: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:dkim-signature; bh=gQxyFEGdxJnYf6tF0dDNzkrR4Tdl8J2Aoq3Zv3gQ3iw=; b=fcR2AqU0dkbFouuJq1Juh5gLjW4UuBeaxpwOoOcPkT6lXG53FvfAzC/bIw1aD7+0UEXUE+ q1mQZBeFmNyOWyzPzdsx38q1SsK4dNj+JN+U2E4NUPVaUijjJhraIWoKFgLXHN5eg0v0p9 opHQgKT33TW/QxIfhJPo6Vhrtu2nDGE= ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1741988384; a=rsa-sha256; cv=none; b=aYADMMhcdo6t6NW/TFY71rZb8DG3PGg3vsR+lD4FF8T1dfS9N/BuUb7+tfwYnQRGdspnW2 twyRYObV21GJpJ/NP6gdkLOaFcjjJaiQbdzed9RTIJXck3EmYxxsvF2+UDJaAXE4rYkvJZ 8ZJD04ckRGQpZ2pzKwPsoUm9aKQpBzo= ARC-Authentication-Results: i=1; imf06.hostedemail.com; dkim=pass header.d=rivosinc-com.20230601.gappssmtp.com header.s=20230601 header.b=GQMtMIha; spf=pass (imf06.hostedemail.com: domain of debug@rivosinc.com designates 209.85.214.180 as permitted sender) smtp.mailfrom=debug@rivosinc.com; dmarc=none Received: by mail-pl1-f180.google.com with SMTP id d9443c01a7336-2241053582dso61484165ad.1 for ; Fri, 14 Mar 2025 14:39:43 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=rivosinc-com.20230601.gappssmtp.com; s=20230601; t=1741988383; x=1742593183; darn=kvack.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=gQxyFEGdxJnYf6tF0dDNzkrR4Tdl8J2Aoq3Zv3gQ3iw=; b=GQMtMIha9WQAOYIDPYQJtbEWWbER/Hd7Vc/2J8FIJMZJqS9i6S8ADUeST36+UsErkF hRBG7s5IqDmEJUdqh6G+6tG0xbuS9Re1zZWfD170YltU+rAzy6oONqTgU5FDTAqcdvwz YUvyD6FfO5n4jMeMi/Yo37KjvB4hsHaWCKcrf1vK38C3V4vDmsQhPqAcIv7xsKJSQ0yY /GFQp28LniXa1RqazNM5MwmJDFAkWYsFVhw6eYGLKa/AwvYuR4ZPjlfzclVpV88laVmt 2l0KNpFAbFACCa9rDtlF0YZkUm4P7Ch+UnRsHnLyJKlwGc1OmZ6oeFCWyc5jyzSTNFno IPYA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1741988383; x=1742593183; 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=gQxyFEGdxJnYf6tF0dDNzkrR4Tdl8J2Aoq3Zv3gQ3iw=; b=Q/gOMH12cennuicMl/puNMArVQQMIlJneOZtvMdEIm/QDKPH1JlxDNA5EC0ETfp+nr TK7dGqkFIQQ6Dh4WpOWgZlb96wyo5PMfFRi+XSTNVKDnIQGLrWy3IwDlulMTGMEunZeV SrSqYvWwoJyVZcJSC0ySzUEdWLX7bNlOs9heGQItlRVdzLRAUz3Oe+cXNYQbB3TVie8h gslSU9SNM5uFLmh8ZuOx8pH7wveT2vkaLpwSf6nw4T1uwSFUTguDc+9p2nNf38PHHsje kwWoLB/epKlc5l9mkHsX7xPzth8+8hRQ/Fzz/suF+XLgFq6q71zvxR4V1FpD02oUcp+o E8PA== X-Forwarded-Encrypted: i=1; AJvYcCU2SpN2+EGJKSKUiEWRDEkEsgGLEb6AQe0XpzsDeHeXBMj3mcXJbw1qQgnIN5dDj2zQ/NDdwOwEkA==@kvack.org X-Gm-Message-State: AOJu0YzqLgL23EKHfZ1hW7brHSYa45mj/Lk2P+ehrLk0NuVi3CKGIGv4 gtyWSJsvhU77g8p+4L1SUjFkQbQM5rEAB8ACvue2xOF0BRS1o7qTordGRZwW53I= X-Gm-Gg: ASbGncs/zYQGqS0bC0OGQo6hzPoFbiGIf/ekUaibqcD88zjJWQ+BfUgo/gPSdu6O0Hi zVcyXlNZmR2DnleqB/pxh0zF5+4uFfsx1G3X/b/PPfduzrguX+6INb62t9QxtpNgicOl/D4/jno /aQrsPwyVVUWqVbdTeLQi0kqMHiUbJ1HrPWuuBqEvdb668tAnCKZO23n6sRPVXBz3OlCD3ghsU/ LU2HUN5jEyWf+fkbXQqtPDnXIpFVkoETpQK0bW43vg4HCKjIVHhhQozUxVNJieyeIiQFTHq5AAt /PFJ3Vw0VZ58DuwqfvA94n2wKsL7ZnyywAF9vglIaXF6euITTOg2Q8w= X-Google-Smtp-Source: AGHT+IG1XKNpuQB9eoNKiKGV8OaMyZRapBWvcssowC/o6htzWDndePZH0CVmNsc5LDFT4JSdbgFB4Q== X-Received: by 2002:a17:902:f693:b0:21d:3bd7:afdd with SMTP id d9443c01a7336-225e0868050mr56743905ad.0.1741988382861; Fri, 14 Mar 2025 14:39:42 -0700 (PDT) Received: from debug.ba.rivosinc.com ([64.71.180.162]) by smtp.gmail.com with ESMTPSA id d9443c01a7336-225c68a6e09sm33368855ad.55.2025.03.14.14.39.40 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 14 Mar 2025 14:39:42 -0700 (PDT) From: Deepak Gupta Date: Fri, 14 Mar 2025 14:39:25 -0700 Subject: [PATCH v12 06/28] riscv/mm : ensure PROT_WRITE leads to VM_READ | VM_WRITE MIME-Version: 1.0 Message-Id: <20250314-v5_user_cfi_series-v12-6-e51202b53138@rivosinc.com> References: <20250314-v5_user_cfi_series-v12-0-e51202b53138@rivosinc.com> In-Reply-To: <20250314-v5_user_cfi_series-v12-0-e51202b53138@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 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, Zong Li , Deepak Gupta X-Mailer: b4 0.14.0 X-Rspam-User: X-Rspamd-Server: rspam02 X-Rspamd-Queue-Id: 07828180006 X-Stat-Signature: zhcowxgyeg6npwo8sy7bwkwgkgm4do3c X-HE-Tag: 1741988383-593814 X-HE-Meta: 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 trE1iebG 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 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: `arch_calc_vm_prot_bits` is implemented on risc-v to return VM_READ | VM_WRITE if PROT_WRITE is specified. Similarly `riscv_sys_mmap` is updated to convert all incoming PROT_WRITE to (PROT_WRITE | PROT_READ). This is to make sure that any existing apps using PROT_WRITE still work. Earlier `protection_map[VM_WRITE]` used to pick read-write PTE encodings. Now `protection_map[VM_WRITE]` will always pick PAGE_SHADOWSTACK PTE encodings for shadow stack. Above changes ensure that existing apps continue to work because underneath kernel will be picking `protection_map[VM_WRITE|VM_READ]` PTE encodings. Reviewed-by: Zong Li Signed-off-by: Deepak Gupta --- arch/riscv/include/asm/mman.h | 25 +++++++++++++++++++++++++ arch/riscv/include/asm/pgtable.h | 1 + arch/riscv/kernel/sys_riscv.c | 10 ++++++++++ arch/riscv/mm/init.c | 2 +- 4 files changed, 37 insertions(+), 1 deletion(-) diff --git a/arch/riscv/include/asm/mman.h b/arch/riscv/include/asm/mman.h new file mode 100644 index 000000000000..392c9c2d2e78 --- /dev/null +++ b/arch/riscv/include/asm/mman.h @@ -0,0 +1,25 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef __ASM_MMAN_H__ +#define __ASM_MMAN_H__ + +#include +#include +#include + +static inline unsigned long arch_calc_vm_prot_bits(unsigned long prot, + unsigned long pkey __always_unused) +{ + unsigned long ret = 0; + + /* + * If PROT_WRITE was specified, force it to VM_READ | VM_WRITE. + * Only VM_WRITE means shadow stack. + */ + if (prot & PROT_WRITE) + ret = (VM_READ | VM_WRITE); + return ret; +} + +#define arch_calc_vm_prot_bits(prot, pkey) arch_calc_vm_prot_bits(prot, pkey) + +#endif /* ! __ASM_MMAN_H__ */ diff --git a/arch/riscv/include/asm/pgtable.h b/arch/riscv/include/asm/pgtable.h index 050fdc49b5ad..8c528cd7347a 100644 --- a/arch/riscv/include/asm/pgtable.h +++ b/arch/riscv/include/asm/pgtable.h @@ -178,6 +178,7 @@ extern struct pt_alloc_ops pt_ops __meminitdata; #define PAGE_READ_EXEC __pgprot(_PAGE_BASE | _PAGE_READ | _PAGE_EXEC) #define PAGE_WRITE_EXEC __pgprot(_PAGE_BASE | _PAGE_READ | \ _PAGE_EXEC | _PAGE_WRITE) +#define PAGE_SHADOWSTACK __pgprot(_PAGE_BASE | _PAGE_WRITE) #define PAGE_COPY PAGE_READ #define PAGE_COPY_EXEC PAGE_READ_EXEC diff --git a/arch/riscv/kernel/sys_riscv.c b/arch/riscv/kernel/sys_riscv.c index d77afe05578f..43a448bf254b 100644 --- a/arch/riscv/kernel/sys_riscv.c +++ b/arch/riscv/kernel/sys_riscv.c @@ -7,6 +7,7 @@ #include #include +#include static long riscv_sys_mmap(unsigned long addr, unsigned long len, unsigned long prot, unsigned long flags, @@ -16,6 +17,15 @@ static long riscv_sys_mmap(unsigned long addr, unsigned long len, if (unlikely(offset & (~PAGE_MASK >> page_shift_offset))) return -EINVAL; + /* + * If PROT_WRITE is specified then extend that to PROT_READ + * protection_map[VM_WRITE] is now going to select shadow stack encodings. + * So specifying PROT_WRITE actually should select protection_map [VM_WRITE | VM_READ] + * If user wants to create shadow stack then they should use `map_shadow_stack` syscall. + */ + if (unlikely((prot & PROT_WRITE) && !(prot & PROT_READ))) + prot |= PROT_READ; + return ksys_mmap_pgoff(addr, len, prot, flags, fd, offset >> (PAGE_SHIFT - page_shift_offset)); } diff --git a/arch/riscv/mm/init.c b/arch/riscv/mm/init.c index 15b2eda4c364..9d6661638d0b 100644 --- a/arch/riscv/mm/init.c +++ b/arch/riscv/mm/init.c @@ -342,7 +342,7 @@ pgd_t early_pg_dir[PTRS_PER_PGD] __initdata __aligned(PAGE_SIZE); static const pgprot_t protection_map[16] = { [VM_NONE] = PAGE_NONE, [VM_READ] = PAGE_READ, - [VM_WRITE] = PAGE_COPY, + [VM_WRITE] = PAGE_SHADOWSTACK, [VM_WRITE | VM_READ] = PAGE_COPY, [VM_EXEC] = PAGE_EXEC, [VM_EXEC | VM_READ] = PAGE_READ_EXEC,