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charset=UTF-8 Content-Transfer-Encoding: 7bit X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On 9/9/26 06:00, Anshuman Khandual wrote: > The page table entry print helpers and related macros which are defined in > will not be accessible in platform which > is basically caused by cycling dependency. > > Move __check_safe_pte_update() inside arch/arm64/mm/mmu.c as a preparation > for subsequent usage of the afore mentioned generic MM helpers. While here > drop IS_ENABLED(CONFIG_DEBUG_VM), although wrap __check_safe_pte_update() > inside #ifdef CONFIG_DEBUG_VM that preserves the current code optimization > which is achieved via the static inline functions. > > This does not cause any functional change. > > Cc: Catalin Marinas > Cc: Will Deacon > Cc: linux-arm-kernel@lists.infradead.org > Cc: linux-kernel@vger.kernel.org > Signed-off-by: Anshuman Khandual > --- > Changes in V2: > > - Moved __check_safe_pte_update() inside #ifdef CONFIG_DEBUG_VM > - Added empty stub for __check_safe_pte_update() when !CONFIG_DEBUG_VM > - Dropped IS_ENABLED(CONFIG_DEBUG_VM) from __check_safe_pte_update() > > arch/arm64/include/asm/pgtable.h | 49 ++++---------------------------- > arch/arm64/mm/mmu.c | 44 ++++++++++++++++++++++++++++ > 2 files changed, 49 insertions(+), 44 deletions(-) > > diff --git a/arch/arm64/include/asm/pgtable.h b/arch/arm64/include/asm/pgtable.h > index e89ec5f4787b..281a512f1fc6 100644 > --- a/arch/arm64/include/asm/pgtable.h > +++ b/arch/arm64/include/asm/pgtable.h > @@ -387,52 +387,13 @@ static inline pte_t __ptep_get(pte_t *ptep) > extern void __sync_icache_dcache(pte_t pteval); > bool pgattr_change_is_safe(pteval_t old, pteval_t new); > > -/* > - * PTE bits configuration in the presence of hardware Dirty Bit Management > - * (PTE_WRITE == PTE_DBM): > - * > - * Dirty Writable | PTE_RDONLY PTE_WRITE PTE_DIRTY (sw) > - * 0 0 | 1 0 0 > - * 0 1 | 1 1 0 > - * 1 0 | 1 0 1 > - * 1 1 | 0 1 x > - * > - * When hardware DBM is not present, the software PTE_DIRTY bit is updated via > - * the page fault mechanism. Checking the dirty status of a pte becomes: > - * > - * PTE_DIRTY || (PTE_WRITE && !PTE_RDONLY) > - */ > - > -static inline void __check_safe_pte_update(struct mm_struct *mm, pte_t *ptep, > - pte_t pte) > +#ifdef CONFIG_DEBUG_VM > +void __check_safe_pte_update(struct mm_struct *mm, pte_t *ptep, pte_t pte); > +#else > +static inline void __check_safe_pte_update(struct mm_struct *mm, pte_t *ptep, pte_t pte) > { > - pte_t old_pte; > - > - if (!IS_ENABLED(CONFIG_DEBUG_VM)) > - return; > - > - old_pte = __ptep_get(ptep); > - > - if (!pte_valid(old_pte) || !pte_valid(pte)) > - return; > - if (mm != current->active_mm && atomic_read(&mm->mm_users) <= 1) > - return; > - > - /* > - * Check for potential race with hardware updates of the pte > - * (__ptep_set_access_flags safely changes valid ptes without going > - * through an invalid entry). > - */ > - VM_WARN_ONCE(!pte_young(pte), > - "%s: racy access flag clearing: 0x%016llx -> 0x%016llx", > - __func__, pte_val(old_pte), pte_val(pte)); > - VM_WARN_ONCE(pte_write(old_pte) && !pte_dirty(pte), > - "%s: racy dirty state clearing: 0x%016llx -> 0x%016llx", > - __func__, pte_val(old_pte), pte_val(pte)); > - VM_WARN_ONCE(!pgattr_change_is_safe(pte_val(old_pte), pte_val(pte)), > - "%s: unsafe attribute change: 0x%016llx -> 0x%016llx", > - __func__, pte_val(old_pte), pte_val(pte)); > } > +#endif [...] > +#ifdef CONFIG_DEBUG_VM > +void __check_safe_pte_update(struct mm_struct *mm, pte_t *ptep, pte_t pte) > +{ > + pte_t old_pte; > + > + old_pte = __ptep_get(ptep); > + > + if (!pte_valid(old_pte) || !pte_valid(pte)) > + return; > + if (mm != current->active_mm && atomic_read(&mm->mm_users) <= 1) > + return; > + > + /* > + * Check for potential race with hardware updates of the pte > + * (__ptep_set_access_flags safely changes valid ptes without going > + * through an invalid entry). > + */ > + VM_WARN_ONCE(!pte_young(pte), > + "%s: racy access flag clearing: 0x%016llx -> 0x%016llx", > + __func__, pte_val(old_pte), pte_val(pte)); > + VM_WARN_ONCE(pte_write(old_pte) && !pte_dirty(pte), > + "%s: racy dirty state clearing: 0x%016llx -> 0x%016llx", > + __func__, pte_val(old_pte), pte_val(pte)); > + VM_WARN_ONCE(!pgattr_change_is_safe(pte_val(old_pte), pte_val(pte)), > + "%s: unsafe attribute change: 0x%016llx -> 0x%016llx", > + __func__, pte_val(old_pte), pte_val(pte)); > +} > +#endif #endif /* CONFIG_DEBUG_VM */ Might be helpful here. Consider the same in the case above Reviewed-by: David Hildenbrand (Arm) -- Cheers, David