From b62b633e048bbddef90b2e55d2e33823187b425f Mon Sep 17 00:00:00 2001 From: "Liam R. Howlett" Date: Fri, 20 Jan 2023 11:26:08 -0500 Subject: [PATCH] mm: expand vma iterator interface Add wrappers for the maple tree to the vma iterator. This will provide type safety at compile time. Link: https://lkml.kernel.org/r/20230120162650.984577-8-Liam.Howlett@oracle.com Signed-off-by: Liam R. Howlett Signed-off-by: Andrew Morton --- include/linux/mm.h | 46 ++++++++++++++++++++++++++--- include/linux/mm_types.h | 4 +-- mm/internal.h | 64 ++++++++++++++++++++++++++++++++++++++++ mm/mmap.c | 18 +++++++++++ 4 files changed, 125 insertions(+), 7 deletions(-) diff --git a/include/linux/mm.h b/include/linux/mm.h index c9db257f09b3..b977a90d9829 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -670,16 +670,16 @@ static inline bool vma_is_accessible(struct vm_area_struct *vma) static inline struct vm_area_struct *vma_find(struct vma_iterator *vmi, unsigned long max) { - return mas_find(&vmi->mas, max); + return mas_find(&vmi->mas, max - 1); } static inline struct vm_area_struct *vma_next(struct vma_iterator *vmi) { /* - * Uses vma_find() to get the first VMA when the iterator starts. + * Uses mas_find() to get the first VMA when the iterator starts. * Calling mas_next() could skip the first entry. */ - return vma_find(vmi, ULONG_MAX); + return mas_find(&vmi->mas, ULONG_MAX); } static inline struct vm_area_struct *vma_prev(struct vma_iterator *vmi) @@ -692,12 +692,50 @@ static inline unsigned long vma_iter_addr(struct vma_iterator *vmi) return vmi->mas.index; } +static inline unsigned long vma_iter_end(struct vma_iterator *vmi) +{ + return vmi->mas.last + 1; +} +static inline int vma_iter_bulk_alloc(struct vma_iterator *vmi, + unsigned long count) +{ + return mas_expected_entries(&vmi->mas, count); +} + +/* Free any unused preallocations */ +static inline void vma_iter_free(struct vma_iterator *vmi) +{ + mas_destroy(&vmi->mas); +} + +static inline int vma_iter_bulk_store(struct vma_iterator *vmi, + struct vm_area_struct *vma) +{ + vmi->mas.index = vma->vm_start; + vmi->mas.last = vma->vm_end - 1; + mas_store(&vmi->mas, vma); + if (unlikely(mas_is_err(&vmi->mas))) + return -ENOMEM; + + return 0; +} + +static inline void vma_iter_invalidate(struct vma_iterator *vmi) +{ + mas_pause(&vmi->mas); +} + +static inline void vma_iter_set(struct vma_iterator *vmi, unsigned long addr) +{ + mas_set(&vmi->mas, addr); +} + #define for_each_vma(__vmi, __vma) \ while (((__vma) = vma_next(&(__vmi))) != NULL) /* The MM code likes to work with exclusive end addresses */ #define for_each_vma_range(__vmi, __vma, __end) \ - while (((__vma) = vma_find(&(__vmi), (__end) - 1)) != NULL) + while (((__vma) = vma_find(&(__vmi), (__end))) != NULL) #ifdef CONFIG_SHMEM /* diff --git a/include/linux/mm_types.h b/include/linux/mm_types.h index 452920467223..5ca11c6c46e8 100644 --- a/include/linux/mm_types.h +++ b/include/linux/mm_types.h @@ -849,9 +849,7 @@ struct vma_iterator { static inline void vma_iter_init(struct vma_iterator *vmi, struct mm_struct *mm, unsigned long addr) { - vmi->mas.tree = &mm->mm_mt; - vmi->mas.index = addr; - vmi->mas.node = MAS_START; + mas_init(&vmi->mas, &mm->mm_mt, addr); } struct mmu_gather; diff --git a/mm/internal.h b/mm/internal.h index 2d1b9fa8083e..ffd65248f266 100644 --- a/mm/internal.h +++ b/mm/internal.h @@ -877,4 +877,68 @@ static inline bool vma_soft_dirty_enabled(struct vm_area_struct *vma) return !(vma->vm_flags & VM_SOFTDIRTY); } +/* + * VMA Iterator functions shared between nommu and mmap + */ +static inline int vma_iter_prealloc(struct vma_iterator *vmi) +{ + return mas_preallocate(&vmi->mas, GFP_KERNEL); +} + +static inline void vma_iter_clear(struct vma_iterator *vmi, + unsigned long start, unsigned long end) +{ + mas_set_range(&vmi->mas, start, end - 1); + mas_store_prealloc(&vmi->mas, NULL); +} + +static inline struct vm_area_struct *vma_iter_load(struct vma_iterator *vmi) +{ + return mas_walk(&vmi->mas); +} + +/* Store a VMA with preallocated memory */ +static inline void vma_iter_store(struct vma_iterator *vmi, + struct vm_area_struct *vma) +{ + +#if defined(CONFIG_DEBUG_VM_MAPLE_TREE) + if (WARN_ON(vmi->mas.node != MAS_START && vmi->mas.index > vma->vm_start)) { + printk("%lu > %lu\n", vmi->mas.index, vma->vm_start); + printk("store of vma %lu-%lu", vma->vm_start, vma->vm_end); + printk("into slot %lu-%lu", vmi->mas.index, vmi->mas.last); + mt_dump(vmi->mas.tree); + } + if (WARN_ON(vmi->mas.node != MAS_START && vmi->mas.last < vma->vm_start)) { + printk("%lu < %lu\n", vmi->mas.last, vma->vm_start); + printk("store of vma %lu-%lu", vma->vm_start, vma->vm_end); + printk("into slot %lu-%lu", vmi->mas.index, vmi->mas.last); + mt_dump(vmi->mas.tree); + } +#endif + + if (vmi->mas.node != MAS_START && + ((vmi->mas.index > vma->vm_start) || (vmi->mas.last < vma->vm_start))) + vma_iter_invalidate(vmi); + + vmi->mas.index = vma->vm_start; + vmi->mas.last = vma->vm_end - 1; + mas_store_prealloc(&vmi->mas, vma); +} + +static inline int vma_iter_store_gfp(struct vma_iterator *vmi, + struct vm_area_struct *vma, gfp_t gfp) +{ + if (vmi->mas.node != MAS_START && + ((vmi->mas.index > vma->vm_start) || (vmi->mas.last < vma->vm_start))) + vma_iter_invalidate(vmi); + + vmi->mas.index = vma->vm_start; + vmi->mas.last = vma->vm_end - 1; + mas_store_gfp(&vmi->mas, vma, gfp); + if (unlikely(mas_is_err(&vmi->mas))) + return -ENOMEM; + + return 0; +} #endif /* __MM_INTERNAL_H */ diff --git a/mm/mmap.c b/mm/mmap.c index ffc0815cd7fb..db70f3e2181e 100644 --- a/mm/mmap.c +++ b/mm/mmap.c @@ -144,6 +144,24 @@ static void remove_vma(struct vm_area_struct *vma) vm_area_free(vma); } +static inline struct vm_area_struct *vma_prev_limit(struct vma_iterator *vmi, + unsigned long min) +{ + return mas_prev(&vmi->mas, min); +} + +static inline int vma_iter_clear_gfp(struct vma_iterator *vmi, + unsigned long start, unsigned long end, gfp_t gfp) +{ + vmi->mas.index = start; + vmi->mas.last = end - 1; + mas_store_gfp(&vmi->mas, NULL, gfp); + if (unlikely(mas_is_err(&vmi->mas))) + return -ENOMEM; + + return 0; +} + /* * check_brk_limits() - Use platform specific check of range & verify mlock * limits. -- 2.39.5