gup_can_follow_protnone() is defined in include/linux/mm.h but only used by mm/gup.c.
First, there is no reason to have it in already gigantic header. Next, the upcoming refactoring of userfaultfd flags will make gup_can_follow_protnone() depend on userfaultfd_k.h which would cause a cyclic header dependency. Move gup_can_follow_protnone() to mm/gup.c. No functional change. Assisted-by: copilot:claude-opus-5 Signed-off-by: Mike Rapoport (Microsoft) <[email protected]> --- include/linux/mm.h | 38 -------------------------------------- mm/gup.c | 38 ++++++++++++++++++++++++++++++++++++++ 2 files changed, 38 insertions(+), 38 deletions(-) diff --git a/include/linux/mm.h b/include/linux/mm.h index 0829e0d3b2d1..4daf9cd6ae8e 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -4860,44 +4860,6 @@ static inline int vm_fault_to_errno(vm_fault_t vm_fault, int foll_flags) return 0; } -/* - * Indicates whether GUP can follow a PROT_NONE mapped page, or whether - * a (NUMA hinting or userfaultfd RWP) fault is required. - */ -static inline bool gup_can_follow_protnone(const struct vm_area_struct *vma, - unsigned int flags) -{ - /* - * VM_UFFD_RWP uses protnone as an access-tracking marker, not for - * NUMA hinting. GUP must always take a fault so the access is - * delivered to userfaultfd, regardless of FOLL_HONOR_NUMA_FAULT. - * - * Only do so while the VMA is accessible. If it has been made - * inaccessible (e.g. mprotect(PROT_NONE)), fall through to the guard - * below: forcing a fault there would loop, as handle_mm_fault() makes - * no progress on protnone in an inaccessible VMA, and the access is - * denied regardless of RWP anyway. - */ - if (vma_test_single_mask(vma, VMA_UFFD_RWP) && vma_is_accessible(vma)) - return false; - - /* - * If callers don't want to honor NUMA hinting faults, no need to - * determine if we would actually have to trigger a NUMA hinting fault. - */ - if (!(flags & FOLL_HONOR_NUMA_FAULT)) - return true; - - /* - * NUMA hinting faults don't apply in inaccessible (PROT_NONE) VMAs. - * - * Requiring a fault here even for inaccessible VMAs would mean that - * FOLL_FORCE cannot make any progress, because handle_mm_fault() - * refuses to process NUMA hinting faults in inaccessible VMAs. - */ - return !vma_is_accessible(vma); -} - typedef int (*pte_fn_t)(pte_t *pte, unsigned long addr, void *data); extern int apply_to_page_range(struct mm_struct *mm, unsigned long address, unsigned long size, pte_fn_t fn, void *data); diff --git a/mm/gup.c b/mm/gup.c index eb898ea1ee22..500e2aa99e48 100644 --- a/mm/gup.c +++ b/mm/gup.c @@ -633,6 +633,44 @@ static struct page *no_page_table(struct vm_area_struct *vma, return NULL; } +/* + * Indicates whether GUP can follow a PROT_NONE mapped page, or whether + * a (NUMA hinting or userfaultfd RWP) fault is required. + */ +static inline bool gup_can_follow_protnone(const struct vm_area_struct *vma, + unsigned int flags) +{ + /* + * VM_UFFD_RWP uses protnone as an access-tracking marker, not for + * NUMA hinting. GUP must always take a fault so the access is + * delivered to userfaultfd, regardless of FOLL_HONOR_NUMA_FAULT. + * + * Only do so while the VMA is accessible. If it has been made + * inaccessible (e.g. mprotect(PROT_NONE)), fall through to the guard + * below: forcing a fault there would loop, as handle_mm_fault() makes + * no progress on protnone in an inaccessible VMA, and the access is + * denied regardless of RWP anyway. + */ + if (vma_test_single_mask(vma, VMA_UFFD_RWP) && vma_is_accessible(vma)) + return false; + + /* + * If callers don't want to honor NUMA hinting faults, no need to + * determine if we would actually have to trigger a NUMA hinting fault. + */ + if (!(flags & FOLL_HONOR_NUMA_FAULT)) + return true; + + /* + * NUMA hinting faults don't apply in inaccessible (PROT_NONE) VMAs. + * + * Requiring a fault here even for inaccessible VMAs would mean that + * FOLL_FORCE cannot make any progress, because handle_mm_fault() + * refuses to process NUMA hinting faults in inaccessible VMAs. + */ + return !vma_is_accessible(vma); +} + #ifdef CONFIG_PGTABLE_HAS_HUGE_LEAVES /* FOLL_FORCE can write to even unwritable PUDs in COW mappings. */ static inline bool can_follow_write_pud(pud_t pud, struct page *page, -- 2.53.0
