diff --git a/include/linux/mm.h b/include/linux/mm.h index 87feaa5a2b78..df78847f5f07 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -4393,6 +4393,65 @@ static inline pgoff_t vma_last_pgoff(const struct vm_area_struct *vma) return vma_end_pgoff(vma) - 1; } +/** + * vma_start_anon_pgoff() - Get the anonymous page offset of the start of @vma + * @vma: The VMA whose anonymous page offset is required. + * + * If unfaulted, then this is vma->vm_start >> PAGE_SHIFT, if faulted then the + * anonymous page offset at the time of first fault. + * + * If the VMA is anonymous, this returns the same value as vma_start_pgoff(). + * + * This value is used for tracking MAP_PRIVATE file-backed mappings by their + * anonymous page offset. + * + * Returns: The anonymous page offset of the start of @vma. + */ +static inline pgoff_t vma_start_anon_pgoff(const struct vm_area_struct *vma) +{ + pgoff_t pgoff = 0; + +#ifdef CONFIG_64BIT + pgoff += vma->__vm_anon_pgoff_hi; + pgoff <<= 32; +#endif + pgoff += vma->__vm_anon_pgoff_lo; + return pgoff; +} + +/** + * vma_end_anon_pgoff() - Get the anonymous page offset of the exclusive end of + * @vma. + * @vma: The VMA whose end anonymous page offset is required. + * + * This returns the anonymous exclusive end page offset of @vma, which is useful + * for expressing page offset ranges. + * + * See the description of vma_start_anon_pgoff() for a description of VMA + * anonymous page offsets. + * + * Returns: The exclusive end anonymous page offset of @vma. + */ +static inline pgoff_t vma_end_anon_pgoff(const struct vm_area_struct *vma) +{ + return vma_start_anon_pgoff(vma) + vma_pages(vma); +} + +/** + * vma_last_anon_pgoff() - Get the anonymous page offset of the last page in + * @vma. + * @vma: The VMA whose last anonymous page offset is required. + * + * See the description of vma_start_anon_pgoff() for a description of VMA + * anonymous page offsets. + * + * Returns: The last anonymous page offset of @vma. + */ +static inline pgoff_t vma_last_anon_pgoff(const struct vm_area_struct *vma) +{ + return vma_end_anon_pgoff(vma) - 1; +} + static inline unsigned long vma_desc_size(const struct vm_area_desc *desc) { return desc->end - desc->start; diff --git a/include/linux/mm_types.h b/include/linux/mm_types.h index 939b5ea8c9e0..ebf0d912be7d 100644 --- a/include/linux/mm_types.h +++ b/include/linux/mm_types.h @@ -967,6 +967,11 @@ struct vm_area_struct { */ unsigned int vm_lock_seq; #endif + /* + * Low 32-bits of anonymous page offset. + * See vma_start_anon_pgoff() comment for details. + */ + unsigned int __vm_anon_pgoff_lo; /* * A file's MAP_PRIVATE vma can be in both i_mmap tree and anon_vma * list, after a COW of one of the file pages. A MAP_SHARED vma @@ -1041,6 +1046,13 @@ struct vm_area_struct { #ifdef CONFIG_DEBUG_LOCK_ALLOC struct lockdep_map vmlock_dep_map; #endif +#endif +#ifdef CONFIG_64BIT + /* + * High 32-bits of anonymous page offset. + * See vma_start_anon_pgoff() comment for details. + */ + unsigned int __vm_anon_pgoff_hi; #endif /* * For areas with an address space and backing store, diff --git a/mm/vma.h b/mm/vma.h index 0bc7d521e976..54ed7c744e3b 100644 --- a/mm/vma.h +++ b/mm/vma.h @@ -283,6 +283,20 @@ static inline void vma_set_pgoff(struct vm_area_struct *vma, pgoff_t pgoff) vma->vm_pgoff = pgoff; } +static inline void __vma_set_anon_pgoff(struct vm_area_struct *vma, pgoff_t pgoff) +{ +#ifdef CONFIG_64BIT + vma->__vm_anon_pgoff_hi = pgoff >> 32; +#endif + vma->__vm_anon_pgoff_lo = pgoff & GENMASK(31, 0); +} + +static inline void vma_set_anon_pgoff(struct vm_area_struct *vma, pgoff_t pgoff) +{ + vma_assert_can_modify(vma); + __vma_set_anon_pgoff(vma, pgoff); +} + static inline void vma_add_pgoff(struct vm_area_struct *vma, pgoff_t delta) { vma_assert_can_modify(vma); diff --git a/mm/vma_init.c b/mm/vma_init.c index 715feee283f0..baa7e82f47e3 100644 --- a/mm/vma_init.c +++ b/mm/vma_init.c @@ -51,6 +51,7 @@ static void vm_area_init_from(const struct vm_area_struct *src, dest->vm_end = src->vm_end; dest->anon_vma = src->anon_vma; dest->vm_pgoff = vma_start_pgoff(src); + __vma_set_anon_pgoff(dest, vma_start_anon_pgoff(src)); dest->vm_file = src->vm_file; dest->vm_private_data = src->vm_private_data; vm_flags_init(dest, src->vm_flags); diff --git a/tools/testing/vma/include/dup.h b/tools/testing/vma/include/dup.h index cdeb53bbdd1b..17f94e5de569 100644 --- a/tools/testing/vma/include/dup.h +++ b/tools/testing/vma/include/dup.h @@ -577,6 +577,7 @@ struct vm_area_struct { */ unsigned int vm_lock_seq; #endif + unsigned int __vm_anon_pgoff_lo; /* * A file's MAP_PRIVATE vma can be in both i_mmap tree and anon_vma @@ -612,6 +613,9 @@ struct vm_area_struct { #ifdef CONFIG_PER_VMA_LOCK /* Unstable RCU readers are allowed to read this. */ refcount_t vm_refcnt; +#endif +#ifdef CONFIG_64BIT + unsigned int __vm_anon_pgoff_hi; #endif /* * For areas with an address space and backing store, @@ -1320,6 +1324,28 @@ static inline pgoff_t vma_end_pgoff(const struct vm_area_struct *vma) return vma_start_pgoff(vma) + vma_pages(vma); } +static inline pgoff_t vma_start_anon_pgoff(const struct vm_area_struct *vma) +{ + pgoff_t pgoff = 0; + +#ifdef CONFIG_64BIT + pgoff += vma->__vm_anon_pgoff_hi; + pgoff <<= 32; +#endif + pgoff += vma->__vm_anon_pgoff_lo; + return pgoff; +} + +static inline pgoff_t vma_end_anon_pgoff(const struct vm_area_struct *vma) +{ + return vma_start_anon_pgoff(vma) + vma_pages(vma); +} + +static inline pgoff_t vma_last_anon_pgoff(const struct vm_area_struct *vma) +{ + return vma_end_anon_pgoff(vma) - 1; +} + static inline int vfs_mmap_prepare(struct file *file, struct vm_area_desc *desc) { return file->f_op->mmap_prepare(desc);