From: "Liam R. Howlett" <Liam.Howlett@xxxxxxxxxx> Move find_vma_intersection() to mmap.c and change implementation to maple tree. When searching for a vma within a range, it is easier to use the maple tree interface. Exported find_vma_intersection() for kvm module. Link: https://lkml.kernel.org/r/20220504011345.662299-8-Liam.Howlett@xxxxxxxxxx Link: https://lkml.kernel.org/r/20220621204632.3370049-24-Liam.Howlett@xxxxxxxxxx Signed-off-by: Liam R. Howlett <Liam.Howlett@xxxxxxxxxx> Cc: Catalin Marinas <catalin.marinas@xxxxxxx> Cc: David Howells <dhowells@xxxxxxxxxx> Cc: "Matthew Wilcox (Oracle)" <willy@xxxxxxxxxxxxx> Cc: SeongJae Park <sj@xxxxxxxxxx> Cc: Vlastimil Babka <vbabka@xxxxxxx> Cc: Will Deacon <will@xxxxxxxxxx> Cc: Davidlohr Bueso <dave@xxxxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- include/linux/mm.h | 22 ++++------------------ mm/mmap.c | 29 +++++++++++++++++++++++++++++ mm/nommu.c | 11 +++++++++++ 3 files changed, 44 insertions(+), 18 deletions(-) diff --git a/include/linux/mm.h b/include/linux/mm.h index 8207fbc6ed87..55b4b53895e8 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -2792,26 +2792,12 @@ extern struct vm_area_struct * find_vma(struct mm_struct * mm, unsigned long add extern struct vm_area_struct * find_vma_prev(struct mm_struct * mm, unsigned long addr, struct vm_area_struct **pprev); -/** - * find_vma_intersection() - Look up the first VMA which intersects the interval - * @mm: The process address space. - * @start_addr: The inclusive start user address. - * @end_addr: The exclusive end user address. - * - * Returns: The first VMA within the provided range, %NULL otherwise. Assumes - * start_addr < end_addr. +/* + * Look up the first VMA which intersects the interval [start_addr, end_addr) + * NULL if none. Assume start_addr < end_addr. */ -static inline struct vm_area_struct *find_vma_intersection(struct mm_struct *mm, - unsigned long start_addr, - unsigned long end_addr) -{ - struct vm_area_struct *vma = find_vma(mm, start_addr); - - if (vma && end_addr <= vma->vm_start) - vma = NULL; - return vma; -} + unsigned long start_addr, unsigned long end_addr); /** * vma_lookup() - Find a VMA at a specific address diff --git a/mm/mmap.c b/mm/mmap.c index 7570e008ef52..378275cc390b 100644 --- a/mm/mmap.c +++ b/mm/mmap.c @@ -2110,6 +2110,35 @@ get_unmapped_area(struct file *file, unsigned long addr, unsigned long len, EXPORT_SYMBOL(get_unmapped_area); +/** + * find_vma_intersection() - Look up the first VMA which intersects the interval + * @mm: The process address space. + * @start_addr: The inclusive start user address. + * @end_addr: The exclusive end user address. + * + * Returns: The first VMA within the provided range, %NULL otherwise. Assumes + * start_addr < end_addr. + */ +struct vm_area_struct *find_vma_intersection(struct mm_struct *mm, + unsigned long start_addr, + unsigned long end_addr) +{ + struct vm_area_struct *vma; + unsigned long index = start_addr; + + mmap_assert_locked(mm); + /* Check the cache first. */ + vma = vmacache_find(mm, start_addr); + if (likely(vma)) + return vma; + + vma = mt_find(&mm->mm_mt, &index, end_addr - 1); + if (vma) + vmacache_update(start_addr, vma); + return vma; +} +EXPORT_SYMBOL(find_vma_intersection); + /** * find_vma() - Find the VMA for a given address, or the next VMA. * @mm: The mm_struct to check diff --git a/mm/nommu.c b/mm/nommu.c index f2031f865dbb..b098c0251137 100644 --- a/mm/nommu.c +++ b/mm/nommu.c @@ -642,6 +642,17 @@ static void delete_vma(struct mm_struct *mm, struct vm_area_struct *vma) vm_area_free(vma); } +struct vm_area_struct *find_vma_intersection(struct mm_struct *mm, + unsigned long start_addr, + unsigned long end_addr) +{ + unsigned long index = start_addr; + + mmap_assert_locked(mm); + return mt_find(&mm->mm_mt, &index, end_addr - 1); +} +EXPORT_SYMBOL(find_vma_intersection); + /* * look up the first VMA in which addr resides, NULL if none * - should be called with mm->mmap_lock at least held readlocked -- 2.35.1
