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authorLiam R. Howlett <Liam.Howlett@Oracle.com>2022-09-06 19:48:50 +0000
committerAndrew Morton <akpm@linux-foundation.org>2022-09-26 19:46:17 -0700
commitabdba2dda0c477ca708a939b02f9b2e74666ed2d (patch)
treec634443af9c5026c42d8b3effb20de631bbb38d0 /mm/mmap.c
parent2e7ce7d354f2fae4c9becb8af799cbedf4f71665 (diff)
mm: use maple tree operations for find_vma_intersection()
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/20220906194824.2110408-24-Liam.Howlett@oracle.com Signed-off-by: Liam R. Howlett <Liam.Howlett@Oracle.com> Tested-by: Yu Zhao <yuzhao@google.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: David Hildenbrand <david@redhat.com> Cc: David Howells <dhowells@redhat.com> Cc: Davidlohr Bueso <dave@stgolabs.net> Cc: "Matthew Wilcox (Oracle)" <willy@infradead.org> Cc: SeongJae Park <sj@kernel.org> Cc: Sven Schnelle <svens@linux.ibm.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Will Deacon <will@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Diffstat (limited to 'mm/mmap.c')
-rw-r--r--mm/mmap.c29
1 files changed, 29 insertions, 0 deletions
diff --git a/mm/mmap.c b/mm/mmap.c
index 0baa2ca5b0bf..699af34c3573 100644
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -2062,6 +2062,35 @@ 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
* @addr: The address