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AJvYcCU7lGWPmInPSfrzs3S95mNdrPGoyo6h/6wmtKp2yl3pxSB6hepCpxEqjlPvetLKl5cZcAyaNww0/Dinf2fDNonDz8s6KP90DAuxW9wH X-Gm-Message-State: AOJu0Ywa0Cl9R46ErbYX/5QBMzdWlBhbcen7Mww7kQrzJZqcz/dQ5urV 7CEta8F9ls4qB6Zk5prpomqg2rNF6WtbOBo8a4vFAaaYtML1xMmnG1rbAOVPcjI= X-Google-Smtp-Source: AGHT+IHkNGwGYsa0lxSVV6I7rhUYi4wQsB/IhRzR2mYXyandS5eg+YGt4M7UftNEIAsc9qZb2HdgcA== X-Received: by 2002:a05:6808:3385:b0:3c3:ebba:2cdc with SMTP id ce5-20020a056808338500b003c3ebba2cdcmr1352197oib.17.1711687582182; Thu, 28 Mar 2024 21:46:22 -0700 (PDT) Received: from debug.ba.rivosinc.com ([64.71.180.162]) by smtp.gmail.com with ESMTPSA id i18-20020aa78b52000000b006ea7e972947sm2217120pfd.130.2024.03.28.21.46.19 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 28 Mar 2024 21:46:21 -0700 (PDT) From: Deepak Gupta To: paul.walmsley@sifive.com, rick.p.edgecombe@intel.com, broonie@kernel.org, Szabolcs.Nagy@arm.com, kito.cheng@sifive.com, keescook@chromium.org, ajones@ventanamicro.com, conor.dooley@microchip.com, cleger@rivosinc.com, atishp@atishpatra.org, alex@ghiti.fr, bjorn@rivosinc.com, alexghiti@rivosinc.com, samuel.holland@sifive.com, palmer@sifive.com, conor@kernel.org, linux-doc@vger.kernel.org, linux-riscv@lists.infradead.org, linux-kernel@vger.kernel.org, devicetree@vger.kernel.org, linux-mm@kvack.org, linux-arch@vger.kernel.org, linux-kselftest@vger.kernel.org Cc: corbet@lwn.net, tech-j-ext@lists.risc-v.org, palmer@dabbelt.com, aou@eecs.berkeley.edu, robh+dt@kernel.org, krzysztof.kozlowski+dt@linaro.org, oleg@redhat.com, akpm@linux-foundation.org, arnd@arndb.de, ebiederm@xmission.com, Liam.Howlett@oracle.com, vbabka@suse.cz, lstoakes@gmail.com, shuah@kernel.org, brauner@kernel.org, debug@rivosinc.com, andy.chiu@sifive.com, jerry.shih@sifive.com, hankuan.chen@sifive.com, greentime.hu@sifive.com, evan@rivosinc.com, xiao.w.wang@intel.com, charlie@rivosinc.com, apatel@ventanamicro.com, mchitale@ventanamicro.com, dbarboza@ventanamicro.com, sameo@rivosinc.com, shikemeng@huaweicloud.com, willy@infradead.org, vincent.chen@sifive.com, guoren@kernel.org, samitolvanen@google.com, songshuaishuai@tinylab.org, gerg@kernel.org, heiko@sntech.de, bhe@redhat.com, jeeheng.sia@starfivetech.com, cyy@cyyself.name, maskray@google.com, ancientmodern4@gmail.com, mathis.salmen@matsal.de, cuiyunhui@bytedance.com, bgray@linux.ibm.com, mpe@ellerman.id.au, baruch@tkos.co.il, alx@kernel.org, david@redhat.com, catalin.marinas@arm.com, revest@chromium.org, josh@joshtriplett.org, shr@devkernel.io, deller@gmx.de, omosnace@redhat.com, ojeda@kernel.org, jhubbard@nvidia.com Subject: [PATCH v2 11/27] riscv mmu: teach pte_mkwrite to manufacture shadow stack PTEs Date: Thu, 28 Mar 2024 21:44:43 -0700 Message-Id: <20240329044459.3990638-12-debug@rivosinc.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20240329044459.3990638-1-debug@rivosinc.com> References: <20240329044459.3990638-1-debug@rivosinc.com> 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" pte_mkwrite creates PTEs with WRITE encodings for underlying arch. Underlyi= ng 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 spec= ialized store instructions (like shadow stack stores). pte_mkwrite can select write= PTE encoding based on VMA range. On riscv, presence of only VM_WRITE in vma->vm_flags means it's a shadow st= ack. Signed-off-by: Deepak Gupta rebase with a30f0ca0fa31cdb2ac3d24b7b5be9e3ae75f4175 Implementation of pte_mkwrite and pmd_mkwrite on riscv Signed-off-by: Deepak Gupta --- arch/riscv/include/asm/pgtable.h | 7 +++++++ arch/riscv/mm/pgtable.c | 21 +++++++++++++++++++++ 2 files changed, 28 insertions(+) diff --git a/arch/riscv/include/asm/pgtable.h b/arch/riscv/include/asm/pgta= ble.h index 6362407f1e83..9b837239d3e8 100644 --- a/arch/riscv/include/asm/pgtable.h +++ b/arch/riscv/include/asm/pgtable.h @@ -403,6 +403,10 @@ 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); @@ -694,6 +698,9 @@ 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 ef887efcb679..933c5f23ef73 100644 --- a/arch/riscv/mm/pgtable.c +++ b/arch/riscv/mm/pgtable.c @@ -142,3 +142,24 @@ 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 (arch_is_shadow_stack(vma->vm_flags)) + return pte_mkwrite_shstk(pte); + + pte =3D pte_mkwrite_novma(pte); + + return pte; +} + +pmd_t pmd_mkwrite(pmd_t pmd, struct vm_area_struct *vma) +{ + if (arch_is_shadow_stack(vma->vm_flags)) + return pmd_mkwrite_shstk(pmd); + + pmd =3D pmd_mkwrite_novma(pmd); + + return pmd; +} + --=20 2.43.2