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Date: Tue, 5 Oct 2021 01:31:16 +0000
From: Liam Howlett <liam.howlett@...cle.com>
To: "maple-tree@...ts.infradead.org" <maple-tree@...ts.infradead.org>,
"linux-mm@...ck.org" <linux-mm@...ck.org>,
"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
Andrew Morton <akpm@...ux-foundation.org>,
David Hildenbrand <david@...hat.com>,
Douglas Gilbert <dgilbert@...erlog.com>
CC: Song Liu <songliubraving@...com>,
Davidlohr Bueso <dave@...olabs.net>,
"Paul E . McKenney" <paulmck@...nel.org>,
Matthew Wilcox <willy@...radead.org>,
David Rientjes <rientjes@...gle.com>,
Axel Rasmussen <axelrasmussen@...gle.com>,
Suren Baghdasaryan <surenb@...gle.com>,
Vlastimil Babka <vbabka@...e.cz>,
Rik van Riel <riel@...riel.com>,
Peter Zijlstra <peterz@...radead.org>
Subject: [PATCH v3 66/66] mm/mmap: Drop range_has_overlap() function
From: "Liam R. Howlett" <Liam.Howlett@...cle.com>
Since there is no longer a linked list, the range_has_overlap() function
is identical to the find_vma_intersection() function. There is only one
place that actually needs the previous vma, so just use vma_prev() in
that one case.
Signed-off-by: Liam R. Howlett <Liam.Howlett@...cle.com>
---
mm/mmap.c | 49 +++++++++++--------------------------------------
1 file changed, 11 insertions(+), 38 deletions(-)
diff --git a/mm/mmap.c b/mm/mmap.c
index 51620d545021..39929b20ef9f 100644
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -433,30 +433,6 @@ anon_vma_interval_tree_post_update_vma(struct vm_area_struct *vma)
anon_vma_interval_tree_insert(avc, &avc->anon_vma->rb_root);
}
-/*
- * range_has_overlap() - Check the @start - @end range for overlapping VMAs and
- * sets up a pointer to the previous VMA
- * @mm: the mm struct
- * @start: the start address of the range
- * @end: the end address of the range
- * @pprev: the pointer to the pointer of the previous VMA
- *
- * Returns: True if there is an overlapping VMA, false otherwise
- */
-static inline
-bool range_has_overlap(struct mm_struct *mm, unsigned long start,
- unsigned long end, struct vm_area_struct **pprev)
-{
- struct vm_area_struct *existing;
-
- MA_STATE(mas, &mm->mm_mt, start, start);
- rcu_read_lock();
- existing = mas_find(&mas, end - 1);
- *pprev = mas_prev(&mas, 0);
- rcu_read_unlock();
- return existing ? true : false;
-}
-
/*
* count_vma_pages_range() - Count the number of pages in a range.
* @mas: The maple state
@@ -554,7 +530,7 @@ void vma_mt_store(struct mm_struct *mm, struct vm_area_struct *vma)
* Must not hold the maple tree lock.
*/
static void vma_mas_link(struct mm_struct *mm, struct vm_area_struct *vma,
- struct ma_state *mas, struct vm_area_struct *prev)
+ struct ma_state *mas)
{
struct address_space *mapping = NULL;
@@ -574,8 +550,7 @@ static void vma_mas_link(struct mm_struct *mm, struct vm_area_struct *vma,
mm->map_count++;
}
-static void vma_link(struct mm_struct *mm, struct vm_area_struct *vma,
- struct vm_area_struct *prev)
+static void vma_link(struct mm_struct *mm, struct vm_area_struct *vma)
{
struct address_space *mapping = NULL;
@@ -600,8 +575,6 @@ static void vma_link(struct mm_struct *mm, struct vm_area_struct *vma,
*/
static void __insert_vm_struct(struct mm_struct *mm, struct vm_area_struct *vma)
{
- struct vm_area_struct *prev;
-
vma_mt_store(mm, vma);
mm->map_count++;
}
@@ -2760,7 +2733,7 @@ unsigned long mmap_region(struct file *file, unsigned long addr,
goto free_vma;
}
- vma_mas_link(mm, vma, &mas, prev);
+ vma_mas_link(mm, vma, &mas);
/* Once vma denies write, undo our temporary denial count */
unmap_writable:
if (file && vm_flags & VM_SHARED)
@@ -3137,7 +3110,7 @@ static int do_brk_flags(struct ma_state *mas, struct ma_state *ma_prev,
vma->vm_pgoff = addr >> PAGE_SHIFT;
vma->vm_flags = flags;
vma->vm_page_prot = vm_get_page_prot(flags);
- vma_mas_link(mm, vma, mas, NULL);
+ vma_mas_link(mm, vma, mas);
*brkvma = vma;
out:
perf_event_mmap(vma);
@@ -3289,9 +3262,7 @@ void exit_mmap(struct mm_struct *mm)
*/
int insert_vm_struct(struct mm_struct *mm, struct vm_area_struct *vma)
{
- struct vm_area_struct *prev;
-
- if (range_has_overlap(mm, vma->vm_start, vma->vm_end, &prev))
+ if (find_vma_intersection(mm, vma->vm_start, vma->vm_end))
return -ENOMEM;
if ((vma->vm_flags & VM_ACCOUNT) &&
@@ -3315,7 +3286,7 @@ int insert_vm_struct(struct mm_struct *mm, struct vm_area_struct *vma)
vma->vm_pgoff = vma->vm_start >> PAGE_SHIFT;
}
- vma_link(mm, vma, prev);
+ vma_link(mm, vma);
return 0;
}
@@ -3330,7 +3301,8 @@ struct vm_area_struct *copy_vma(struct vm_area_struct **vmap,
struct vm_area_struct *vma = *vmap;
unsigned long vma_start = vma->vm_start;
struct mm_struct *mm = vma->vm_mm;
- struct vm_area_struct *new_vma, *prev;
+ struct vm_area_struct *new_vma;
+ struct vm_area_struct *prev;
bool faulted_in_anon_vma = true;
validate_mm_mt(mm);
@@ -3343,9 +3315,10 @@ struct vm_area_struct *copy_vma(struct vm_area_struct **vmap,
faulted_in_anon_vma = false;
}
- if (range_has_overlap(mm, addr, addr + len, &prev))
+ if (find_vma_intersection(mm, addr, addr + len))
return NULL; /* should never get here */
+ prev = vma_prev(mm, vma);
new_vma = vma_merge(mm, prev, addr, addr + len, vma->vm_flags,
vma->anon_vma, vma->vm_file, pgoff, vma_policy(vma),
vma->vm_userfaultfd_ctx);
@@ -3386,7 +3359,7 @@ struct vm_area_struct *copy_vma(struct vm_area_struct **vmap,
get_file(new_vma->vm_file);
if (new_vma->vm_ops && new_vma->vm_ops->open)
new_vma->vm_ops->open(new_vma);
- vma_link(mm, new_vma, prev);
+ vma_link(mm, new_vma);
*need_rmap_locks = false;
}
validate_mm_mt(mm);
--
2.30.2
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