From: "Liam R. Howlett" <Liam.Howlett@Oracle.com>
To: maple-tree@lists.infradead.org, linux-mm@kvack.org,
linux-kernel@vger.kernel.org
Cc: Andrew Morton <akpm@google.com>, Song Liu <songliubraving@fb.com>,
Davidlohr Bueso <dave@stgolabs.net>,
"Paul E . McKenney" <paulmck@kernel.org>,
Matthew Wilcox <willy@infradead.org>,
Jerome Glisse <jglisse@redhat.com>,
David Rientjes <rientjes@google.com>,
Axel Rasmussen <axelrasmussen@google.com>,
Suren Baghdasaryan <surenb@google.com>,
Vlastimil Babka <vbabka@suse.cz>
Subject: [PATCH 23/28] mm/mmap: Add do_mas_munmap() and wraper for __do_munmap()
Date: Thu, 10 Dec 2020 12:03:57 -0500 [thread overview]
Message-ID: <20201210170402.3468568-24-Liam.Howlett@Oracle.com> (raw)
In-Reply-To: <20201210170402.3468568-1-Liam.Howlett@Oracle.com>
To avoid extra tree work, it is necessary to support passing in a maple state
to key functions. Start this work with __do_munmap().
Signed-off-by: Liam R. Howlett <Liam.Howlett@Oracle.com>
---
mm/mmap.c | 102 ++++++++++++++++++++++++++++++++++++++----------------
1 file changed, 72 insertions(+), 30 deletions(-)
diff --git a/mm/mmap.c b/mm/mmap.c
index b501388c73ebd..4ef32ed2c34dc 100644
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -2422,34 +2422,24 @@ static inline int unlock_range(struct vm_area_struct *start,
return count;
}
-/* Munmap is split into 2 main parts -- this part which finds
- * what needs doing, and the areas themselves, which do the
- * work. This now handles partial unmappings.
- * Jeremy Fitzhardinge <jeremy@goop.org>
+
+/* do_mas_align_munmap() - munmap the aligned region from @start to @end.
+ *
+ * @mas: The maple_state, ideally set up to alter the correct tree location.
+ * @vma: The starting vm_area_struct
+ * @mm: The mm_struct
+ * @start: The aligned start address to munmap.
+ * @end: The aligned end address to munmap.
+ * @uf: The userfaultfd list_head
+ * @downgrade: Set to true to attempt a downwrite of the mmap_sem
+ *
+ *
*/
-int __do_munmap(struct mm_struct *mm, unsigned long start, size_t len,
- struct list_head *uf, bool downgrade)
+int do_mas_align_munmap(struct ma_state *mas, struct vm_area_struct *vma,
+ struct mm_struct *mm, unsigned long start,
+ unsigned long end, struct list_head *uf, bool downgrade)
{
- unsigned long end;
- struct vm_area_struct *vma, *prev, *last;
- MA_STATE(mas, &mm->mm_mt, start, start);
-
- if ((offset_in_page(start)) || start > TASK_SIZE || len > TASK_SIZE-start)
- return -EINVAL;
-
- end = start + PAGE_ALIGN(len);
- if (end == start)
- return -EINVAL;
-
- /* arch_unmap() might do unmaps itself. */
- arch_unmap(mm, start, end);
-
- /* Find the first overlapping VMA */
- vma = mas_find(&mas, end - 1);
- if (!vma)
- return 0;
-
- mas.last = end - 1;
+ struct vm_area_struct *prev, *last;
/* we have start < vma->vm_end */
/*
@@ -2474,8 +2464,8 @@ int __do_munmap(struct mm_struct *mm, unsigned long start, size_t len,
return error;
prev = vma;
vma = vma_next(mm, prev);
- mas.index = start;
- mas_reset(&mas);
+ mas->index = start;
+ mas_reset(mas);
} else {
prev = vma->vm_prev;
}
@@ -2491,7 +2481,7 @@ int __do_munmap(struct mm_struct *mm, unsigned long start, size_t len,
if (error)
return error;
vma = vma_next(mm, prev);
- mas_reset(&mas);
+ mas_reset(mas);
}
@@ -2518,7 +2508,7 @@ int __do_munmap(struct mm_struct *mm, unsigned long start, size_t len,
*/
mm->map_count -= unlock_range(vma, &last, end);
/* Drop removed area from the tree */
- mas_store_gfp(&mas, NULL, GFP_KERNEL);
+ mas_store_gfp(mas, NULL, GFP_KERNEL);
/* Detach vmas from the MM linked list */
vma->vm_prev = NULL;
@@ -2555,6 +2545,58 @@ int __do_munmap(struct mm_struct *mm, unsigned long start, size_t len,
return downgrade ? 1 : 0;
}
+int __do_munmap(struct mm_struct *mm, unsigned long start, size_t len,
+ struct list_head *uf, bool downgrade)
+{
+ MA_STATE(mas, &mm->mm_mt, start, start);
+ return do_mas_munmap(&mas, mm, start, len, uf, downgrade);
+}
+
+/*
+ * do_mas_munmap() - munmap a given range.
+ * @mas: The maple state
+ * @mm: The mm_struct
+ * @start: The start address to munmap
+ * @len: The length of the range to munmap
+ * @uf: The userfaultfd list_head
+ * @downgrade: set to true if the user wants to attempt to write_downgrade the
+ * mmap_sem
+ *
+ * This function takes a @mas that is in the correct state to remove the
+ * mapping(s). The @len will be aligned and any arch_unmap work will be
+ * preformed.
+ */
+int do_mas_munmap(struct ma_state *mas, struct mm_struct *mm,
+ unsigned long start, size_t len, struct list_head *uf,
+ bool downgrade)
+{
+ unsigned long end;
+ struct vm_area_struct *vma;
+
+ if ((offset_in_page(start)) || start > TASK_SIZE || len > TASK_SIZE-start)
+ return -EINVAL;
+
+ end = start + PAGE_ALIGN(len);
+ if (end == start)
+ return -EINVAL;
+
+ /* arch_unmap() might do unmaps itself. */
+ arch_unmap(mm, start, end);
+
+ /* Find the first overlapping VMA */
+ vma = mas_find(mas, end - 1);
+ if (!vma)
+ return 0;
+
+ mas->last = end - 1;
+ return do_mas_align_munmap(mas, vma, mm, start, end, uf, downgrade);
+}
+/* do_munmap() - Wrapper function for non-maple tree aware do_munmap() calls.
+ * @mm: The mm_struct
+ * @start: The start address to munmap
+ * @len: The length to be munmapped.
+ * @uf: The userfaultfd list_head
+ */
int do_munmap(struct mm_struct *mm, unsigned long start, size_t len,
struct list_head *uf)
{
--
2.28.0
next prev parent reply other threads:[~2020-12-10 17:05 UTC|newest]
Thread overview: 31+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-12-10 17:03 [PATCH 00/28] RFC mm: Introducing the Maple Tree Liam R. Howlett
2020-12-10 17:03 ` [PATCH 01/28] radix tree test suite: Enhancements for " Liam R. Howlett
2020-12-10 17:03 ` [PATCH 02/28] radix tree test suite: Add support for fallthrough attribute Liam R. Howlett
2020-12-10 17:03 ` [PATCH 03/28] radix tree test suite: Add support for kmem_cache_free_bulk Liam R. Howlett
2020-12-10 17:03 ` [PATCH 04/28] radix tree test suite: Add keme_cache_alloc_bulk() support Liam R. Howlett
2020-12-10 17:03 ` [PATCH 05/28] Maple Tree: Add new data structure Liam R. Howlett
2020-12-10 17:03 ` [PATCH 06/28] mm: Start tracking VMAs with maple tree Liam R. Howlett
2020-12-11 19:30 ` kernel test robot
2020-12-10 17:03 ` [PATCH 07/28] mm/mmap: Introduce unlock_range() for code cleanup Liam R. Howlett
2020-12-10 17:03 ` [PATCH 08/28] mm/mmap: Change find_vma() to use the maple tree Liam R. Howlett
2020-12-10 17:03 ` [PATCH 09/28] mm/mmap: Change find_vma_prev() to use " Liam R. Howlett
2020-12-10 17:03 ` [PATCH 10/28] mm/mmap: Change unmapped_area and unmapped_area_topdown " Liam R. Howlett
2020-12-10 17:03 ` [PATCH 11/28] kernel/fork: Convert dup_mmap " Liam R. Howlett
2020-12-10 17:03 ` [PATCH 12/28] mm: Remove rb tree Liam R. Howlett
2020-12-10 17:03 ` [PATCH 13/28] mm/gup: Expose mm_populate_vma() for use when the vma is known Liam R. Howlett
2020-12-10 21:03 ` kernel test robot
2020-12-10 17:03 ` [PATCH 14/28] mm/mmap: Change do_brk_flags() to expand existing VMA and add do_brk_munmap() Liam R. Howlett
2020-12-10 17:03 ` [PATCH 15/28] mm/mmap: Change vm_brk_flags() to use mm_populate_vma() Liam R. Howlett
2020-12-10 17:03 ` [PATCH 16/28] mm: Move find_vma_intersection to mmap.c and change implementation to maple tree Liam R. Howlett
2020-12-10 17:03 ` [PATCH 17/28] mm/mmap: Change mmap_region to use maple tree state Liam R. Howlett
2020-12-10 17:03 ` [PATCH 18/28] mm/mmap: Drop munmap_vma_range() Liam R. Howlett
2020-12-10 17:03 ` [PATCH 19/28] mm: Remove vmacache Liam R. Howlett
2020-12-10 17:03 ` [PATCH 20/28] mm/mmap: Change __do_munmap() to avoid unnecessary lookups Liam R. Howlett
2020-12-10 17:03 ` [PATCH 21/28] mm/mmap: Change __do_munmap() to use a ma_state Liam R. Howlett
2020-12-10 17:03 ` [PATCH 22/28] mm/mmap: Move mmap_region() below do_munmap() Liam R. Howlett
2020-12-10 17:03 ` Liam R. Howlett [this message]
2020-12-10 17:03 ` [PATCH 24/28] mmap: Use find_vma_intersection in do_mmap() for overlap Liam R. Howlett
2020-12-10 17:03 ` [PATCH 25/28] mmap: Remove __do_munmap() in favour of do_mas_munmap() Liam R. Howlett
2020-12-10 17:04 ` [PATCH 26/28] mm/mmap: Change do_brk_munmap() to use do_mas_align_munmap() Liam R. Howlett
2020-12-10 17:04 ` [PATCH 27/28] mmap: Update count_vma_pages_range() to only use one ma_state Liam R. Howlett
2020-12-10 17:04 ` [PATCH 28/28] mmap: make remove_vma_list() inline Liam R. Howlett
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