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Howlett" , Vlastimil Babka , Mike Rapoport , Suren Baghdasaryan , Michal Hocko , Axel Rasmussen , Yuanchu Xie , Chunyan Zhang Subject: [PATCH V10 5/5] riscv: mm: Add uffd write-protect support Date: Tue, 9 Sep 2025 17:56:11 +0800 Message-Id: <20250909095611.803898-6-zhangchunyan@iscas.ac.cn> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20250909095611.803898-1-zhangchunyan@iscas.ac.cn> References: <20250909095611.803898-1-zhangchunyan@iscas.ac.cn> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-CM-TRANSID:qwCowADHHqHO+b9oWh7qAQ--.61766S7 X-Coremail-Antispam: 1UD129KBjvJXoWxZF4UZw1rtw17Kr1DuF4kJFb_yoWruFWfpr s5GayrurWDJFn2yayftr4FgrWrZw4fWa4DWr93Ca1kJFy7K3yDXr95Kry3try8XFWvv347 WFWrKr1rCw47JrDanT9S1TB71UUUUU7qnTZGkaVYY2UrUUUUjbIjqfuFe4nvWSU5nxnvy2 9KBjDU0xBIdaVrnRJUUUQjb7Iv0xC_Cr1lb4IE77IF4wAFF20E14v26rWj6s0DM7CY07I2 0VC2zVCF04k26cxKx2IYs7xG6rWj6s0DM7CIcVAFz4kK6r1j6r18M28IrcIa0xkI8VA2jI 8067AKxVWUAVCq3wA2048vs2IY020Ec7CjxVAFwI0_Xr0E3s1l8cAvFVAK0II2c7xJM28C jxkF64kEwVA0rcxSw2x7M28EF7xvwVC0I7IYx2IY67AKxVW8JVW5JwA2z4x0Y4vE2Ix0cI 8IcVCY1x0267AKxVW8Jr0_Cr1UM28EF7xvwVC2z280aVAFwI0_Cr1j6rxdM28EF7xvwVC2 z280aVCY1x0267AKxVW0oVCq3wAS0I0E0xvYzxvE52x082IY62kv0487Mc02F40EFcxC0V AKzVAqx4xG6I80ewAv7VC0I7IYx2IY67AKxVWUGVWUXwAv7VC2z280aVAFwI0_Gr0_Cr1l Ox8S6xCaFVCjc4AY6r1j6r4UM4x0Y48IcxkI7VAKI48JM4IIrI8v6xkF7I0E8cxan2IY04 v7MxkF7I0En4kS14v26r4a6rW5MxkIecxEwVAFwVW8uwCF04k20xvY0x0EwIxGrwCFx2Iq xVCFs4IE7xkEbVWUJVW8JwC20s026c02F40E14v26r1j6r18MI8I3I0E7480Y4vE14v26r 106r1rMI8E67AF67kF1VAFwI0_GFv_WrylIxkGc2Ij64vIr41lIxAIcVC0I7IYx2IY67AK xVWUCVW8JwCI42IY6xIIjxv20xvEc7CjxVAFwI0_Gr1j6F4UJwCI42IY6xAIw20EY4v20x vaj40_Jr0_JF4lIxAIcVC2z280aVAFwI0_Jr0_Gr1lIxAIcVC2z280aVCY1x0267AKxVW8 Jr0_Cr1UYxBIdaVFxhVjvjDU0xZFpf9x07j93kZUUUUU= X-Originating-IP: [210.73.43.101] X-CM-SenderInfo: x2kd0wxfkx051dq6x2xfdvhtffof0/1tbiDAcAB2i-53NJfAAAs6 X-Rspamd-Server: rspam12 X-Rspamd-Queue-Id: 1B924C000D X-Stat-Signature: 46kqjswtks998a319mg65dntkew17q8g X-Rspam-User: X-HE-Tag: 1757411829-846160 X-HE-Meta: U2FsdGVkX18BkyLUm+pd4eflaF533GQ13q0qvzYfaeFhRApflvq6fAQ3Hl7AshmRLw45zwPyxO/Vlui6ulODPZwpqUAVbBgTC/LS/S2Ij1whAOBy0pHCFgE9g1kaXsE9AqqEL+I/tn4gOE1TteHHh8HIZMI5GvdeE5PAOys3V4ildRNJy7DDvFRrOvyaqzhTm3ZJkTDY9hzbtm9cZa+WV/VwZQj7MNAqRzt3GuK4Tc0QsIDzcZUWSdXP92Wd70dteGIdys+RuYKXZ7XStc59DCYqjj0Q4DdUJ+wUHZw+/K1T7EvDgE4p/d/r25LE8rJOP8EcqPRWX2iOLHQF8Spfvh7JLhGQDsQVHgf6A9d0cM9epsQQ5UPz+zEDlfBNtMt36rqpNJDQHwafcRQEootwV5El+e9uQiTuGucRtzT1uWo5F2h/3tZNfctkbfHd9YjzGMhecN9mcX2Htj0LOV8ouNv3r61FqGic6vLu6h9wbb9lMGKEdOXloawrEmoEwX12uyU0VbOlYjUAT/4LMolG6rvI91Rvga7pGpBMJn1WPikjdLVcvaJKR4GASz7tPjdjHP0JNeWafhOE31mIrGXA/peXfLQMQr4QVOpzY6rH2kEMRBBvWiePFVesLx2EO707EHNbRhfmCE7kntIR+85pHaocUbaOy6MtLU8rszxYFI+LfsXZWIw0LR5vXHBo/uHX3JfxVrzv205yEvK73Ugo7xghTb1T8UA2Zgdno3kpD7U1fC/YCpDgLMAFFb4E23ue8KMa19YZRys19F6/vFY5y4UfMh+FuDLUOXFutAJy8NqmBhjQD3MXgmQtfcoz5DVow8CJGZSPi+9dRUGTt0BZNn9ieg7rMcPSfgT5p9SFNoaxkGYrG8CYvnuOzopG31RvnbG3S5W/JSAG6ooR8hihC6e+PYnEPErptcvXTiihYQK7Ijehb9iBfIkHyDDOxodPlBHxGOONjwcmpKoxQE2 s5KL2icR 9Qm1+M6VURrV6+mtFqHcSD3lztJ/POpiM4jfTwuyrEbkQ39RJW5J4BJRcaOit/Xn4bTzYbd3na7KDvx3+iLrt1+iAfDpw3XHbZ1LIff298MXVpOA+oxPNwqrcRMHhX+AQ83BS0gqKOEwKWpkIcVPdibQjCI4kbxa0kIUuCobtjeWziYVW67OQkhQZ+cdbk9jX91aE 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: The Svrsw60t59b extension allows to free the PTE reserved bits 60 and 59 for software, this patch uses bit 60 for uffd-wp tracking Additionally for tracking the uffd-wp state as a PTE swap bit, we borrow bit 4 which is not involved into swap entry computation. Signed-off-by: Chunyan Zhang --- arch/riscv/Kconfig | 1 + arch/riscv/include/asm/pgtable-bits.h | 18 +++++++ arch/riscv/include/asm/pgtable.h | 67 +++++++++++++++++++++++++++ 3 files changed, 86 insertions(+) diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig index 53b73e4bdf3f..f928768bb14a 100644 --- a/arch/riscv/Kconfig +++ b/arch/riscv/Kconfig @@ -147,6 +147,7 @@ config RISCV select HAVE_ARCH_TRANSPARENT_HUGEPAGE if 64BIT && MMU select HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD if 64BIT && MMU select HAVE_ARCH_USERFAULTFD_MINOR if 64BIT && USERFAULTFD + select HAVE_ARCH_USERFAULTFD_WP if 64BIT && MMU && USERFAULTFD && RISCV_ISA_SVRSW60T59B select HAVE_ARCH_VMAP_STACK if MMU && 64BIT select HAVE_ASM_MODVERSIONS select HAVE_CONTEXT_TRACKING_USER diff --git a/arch/riscv/include/asm/pgtable-bits.h b/arch/riscv/include/asm/pgtable-bits.h index 8ffe81bf66d2..894b2a24fc49 100644 --- a/arch/riscv/include/asm/pgtable-bits.h +++ b/arch/riscv/include/asm/pgtable-bits.h @@ -38,6 +38,24 @@ #define _PAGE_SWP_SOFT_DIRTY 0 #endif /* CONFIG_MEM_SOFT_DIRTY */ +#ifdef CONFIG_HAVE_ARCH_USERFAULTFD_WP + +/* ext_svrsw60t59b: Bit(60) for uffd-wp tracking */ +#define _PAGE_UFFD_WP \ + ((riscv_has_extension_unlikely(RISCV_ISA_EXT_SVRSW60T59B)) ? \ + (1UL << 60) : 0) +/* + * Bit 4 is not involved into swap entry computation, so we + * can borrow it for swap page uffd-wp tracking. + */ +#define _PAGE_SWP_UFFD_WP \ + ((riscv_has_extension_unlikely(RISCV_ISA_EXT_SVRSW60T59B)) ? \ + _PAGE_USER : 0) +#else +#define _PAGE_UFFD_WP 0 +#define _PAGE_SWP_UFFD_WP 0 +#endif + #define _PAGE_TABLE _PAGE_PRESENT /* diff --git a/arch/riscv/include/asm/pgtable.h b/arch/riscv/include/asm/pgtable.h index b2d00d129d81..94cc97d3dbff 100644 --- a/arch/riscv/include/asm/pgtable.h +++ b/arch/riscv/include/asm/pgtable.h @@ -416,6 +416,40 @@ static inline pte_t pte_wrprotect(pte_t pte) return __pte(pte_val(pte) & ~(_PAGE_WRITE)); } +#ifdef CONFIG_HAVE_ARCH_USERFAULTFD_WP +#define pte_uffd_wp_available() riscv_has_extension_unlikely(RISCV_ISA_EXT_SVRSW60T59B) + +static inline bool pte_uffd_wp(pte_t pte) +{ + return !!(pte_val(pte) & _PAGE_UFFD_WP); +} + +static inline pte_t pte_mkuffd_wp(pte_t pte) +{ + return pte_wrprotect(__pte(pte_val(pte) | _PAGE_UFFD_WP)); +} + +static inline pte_t pte_clear_uffd_wp(pte_t pte) +{ + return __pte(pte_val(pte) & ~(_PAGE_UFFD_WP)); +} + +static inline bool pte_swp_uffd_wp(pte_t pte) +{ + return !!(pte_val(pte) & _PAGE_SWP_UFFD_WP); +} + +static inline pte_t pte_swp_mkuffd_wp(pte_t pte) +{ + return __pte(pte_val(pte) | _PAGE_SWP_UFFD_WP); +} + +static inline pte_t pte_swp_clear_uffd_wp(pte_t pte) +{ + return __pte(pte_val(pte) & ~(_PAGE_SWP_UFFD_WP)); +} +#endif /* CONFIG_HAVE_ARCH_USERFAULTFD_WP */ + /* static inline pte_t pte_mkread(pte_t pte) */ static inline pte_t pte_mkwrite_novma(pte_t pte) @@ -836,6 +870,38 @@ static inline pud_t pud_mkspecial(pud_t pud) } #endif +#ifdef CONFIG_HAVE_ARCH_USERFAULTFD_WP +static inline bool pmd_uffd_wp(pmd_t pmd) +{ + return pte_uffd_wp(pmd_pte(pmd)); +} + +static inline pmd_t pmd_mkuffd_wp(pmd_t pmd) +{ + return pte_pmd(pte_mkuffd_wp(pmd_pte(pmd))); +} + +static inline pmd_t pmd_clear_uffd_wp(pmd_t pmd) +{ + return pte_pmd(pte_clear_uffd_wp(pmd_pte(pmd))); +} + +static inline bool pmd_swp_uffd_wp(pmd_t pmd) +{ + return pte_swp_uffd_wp(pmd_pte(pmd)); +} + +static inline pmd_t pmd_swp_mkuffd_wp(pmd_t pmd) +{ + return pte_pmd(pte_swp_mkuffd_wp(pmd_pte(pmd))); +} + +static inline pmd_t pmd_swp_clear_uffd_wp(pmd_t pmd) +{ + return pte_pmd(pte_swp_clear_uffd_wp(pmd_pte(pmd))); +} +#endif /* CONFIG_HAVE_ARCH_USERFAULTFD_WP */ + #ifdef CONFIG_HAVE_ARCH_SOFT_DIRTY static inline bool pmd_soft_dirty(pmd_t pmd) { @@ -1053,6 +1119,7 @@ static inline pud_t pud_modify(pud_t pud, pgprot_t newprot) * bit 0: _PAGE_PRESENT (zero) * bit 1 to 2: (zero) * bit 3: _PAGE_SWP_SOFT_DIRTY + * bit 4: _PAGE_SWP_UFFD_WP * bit 5: _PAGE_PROT_NONE (zero) * bit 6: exclusive marker * bits 7 to 11: swap type -- 2.34.1