From: "Liam R. Howlett" <Liam.Howlett@xxxxxxxxxx> Using the maple tree interface mt_find() will handle the RCU locking and will start searching at the address up to the limit, ULONG_MAX in this case. Add kernel documentation to this API. Link: https://lkml.kernel.org/r/20220504010716.661115-13-Liam.Howlett@xxxxxxxxxx Link: https://lkml.kernel.org/r/20220621204632.3370049-12-Liam.Howlett@xxxxxxxxxx Signed-off-by: Liam R. Howlett <Liam.Howlett@xxxxxxxxxx> Acked-by: Vlastimil Babka <vbabka@xxxxxxx> Reviewed-by: David Hildenbrand <david@xxxxxxxxxx> Cc: Catalin Marinas <catalin.marinas@xxxxxxx> Cc: David Howells <dhowells@xxxxxxxxxx> Cc: "Matthew Wilcox (Oracle)" <willy@xxxxxxxxxxxxx> Cc: SeongJae Park <sj@xxxxxxxxxx> Cc: Will Deacon <will@xxxxxxxxxx> Cc: Davidlohr Bueso <dave@xxxxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- mm/mmap.c | 28 ++++++++++------------------ 1 file changed, 10 insertions(+), 18 deletions(-) diff --git a/mm/mmap.c b/mm/mmap.c index 1ba4074c75cf..96ff32ff97cd 100644 --- a/mm/mmap.c +++ b/mm/mmap.c @@ -2494,11 +2494,18 @@ get_unmapped_area(struct file *file, unsigned long addr, unsigned long len, EXPORT_SYMBOL(get_unmapped_area); -/* Look up the first VMA which satisfies addr < vm_end, NULL if none. */ +/** + * find_vma() - Find the VMA for a given address, or the next VMA. + * @mm: The mm_struct to check + * @addr: The address + * + * Returns: The VMA associated with addr, or the next VMA. + * May return %NULL in the case of no VMA at addr or above. + */ struct vm_area_struct *find_vma(struct mm_struct *mm, unsigned long addr) { - struct rb_node *rb_node; struct vm_area_struct *vma; + unsigned long index = addr; mmap_assert_locked(mm); /* Check the cache first. */ @@ -2506,22 +2513,7 @@ struct vm_area_struct *find_vma(struct mm_struct *mm, unsigned long addr) if (likely(vma)) return vma; - rb_node = mm->mm_rb.rb_node; - - while (rb_node) { - struct vm_area_struct *tmp; - - tmp = rb_entry(rb_node, struct vm_area_struct, vm_rb); - - if (tmp->vm_end > addr) { - vma = tmp; - if (tmp->vm_start <= addr) - break; - rb_node = rb_node->rb_left; - } else - rb_node = rb_node->rb_right; - } - + vma = mt_find(&mm->mm_mt, &index, ULONG_MAX); if (vma) vmacache_update(addr, vma); return vma; -- 2.35.1
