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From: Liam Howlett <liam.howlett@oracle.com>
To: "maple-tree@lists.infradead.org" <maple-tree@lists.infradead.org>,
	"linux-mm@kvack.org" <linux-mm@kvack.org>,
	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
	Andrew Morton <akpm@linux-foundation.org>
Cc: Liam Howlett <liam.howlett@oracle.com>,
	Liam Howlett <liam.howlett@oracle.com>
Subject: [PATCH 06/43] mm/mmap: convert brk to use vma iterator
Date: Tue, 29 Nov 2022 16:44:21 +0000	[thread overview]
Message-ID: <20221129164352.3374638-7-Liam.Howlett@oracle.com> (raw)
In-Reply-To: <20221129164352.3374638-1-Liam.Howlett@oracle.com>

From: "Liam R. Howlett" <Liam.Howlett@Oracle.com>

Use the vma iterator API for the brk() system call.  This will provide
type safety at compile time.

Signed-off-by: Liam R. Howlett <Liam.Howlett@oracle.com>
---
 mm/mmap.c | 47 +++++++++++++++++++++++------------------------
 1 file changed, 23 insertions(+), 24 deletions(-)

diff --git a/mm/mmap.c b/mm/mmap.c
index 8f24021ef5b5..054dd3e8e1a4 100644
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -236,10 +236,10 @@ static int check_brk_limits(unsigned long addr, unsigned long len)
 
 	return mlock_future_check(current->mm, current->mm->def_flags, len);
 }
-static int do_brk_munmap(struct ma_state *mas, struct vm_area_struct *vma,
+static int do_brk_munmap(struct vma_iterator *vmi, struct vm_area_struct *vma,
 			 unsigned long newbrk, unsigned long oldbrk,
 			 struct list_head *uf);
-static int do_brk_flags(struct ma_state *mas, struct vm_area_struct *brkvma,
+static int do_brk_flags(struct vma_iterator *vmi, struct vm_area_struct *brkvma,
 		unsigned long addr, unsigned long request, unsigned long flags);
 SYSCALL_DEFINE1(brk, unsigned long, brk)
 {
@@ -250,7 +250,7 @@ SYSCALL_DEFINE1(brk, unsigned long, brk)
 	bool populate;
 	bool downgraded = false;
 	LIST_HEAD(uf);
-	MA_STATE(mas, &mm->mm_mt, 0, 0);
+	struct vma_iterator vmi;
 
 	if (mmap_write_lock_killable(mm))
 		return -EINTR;
@@ -298,8 +298,8 @@ SYSCALL_DEFINE1(brk, unsigned long, brk)
 		int ret;
 
 		/* Search one past newbrk */
-		mas_set(&mas, newbrk);
-		brkvma = mas_find(&mas, oldbrk);
+		vma_iter_init(&vmi, mm, newbrk);
+		brkvma = vma_find(&vmi, oldbrk);
 		BUG_ON(brkvma == NULL);
 		if (brkvma->vm_start >= oldbrk)
 			goto out; /* mapping intersects with an existing non-brk vma. */
@@ -309,7 +309,7 @@ SYSCALL_DEFINE1(brk, unsigned long, brk)
 		 * before calling do_brk_munmap().
 		 */
 		mm->brk = brk;
-		ret = do_brk_munmap(&mas, brkvma, newbrk, oldbrk, &uf);
+		ret = do_brk_munmap(&vmi, brkvma, newbrk, oldbrk, &uf);
 		if (ret == 1)  {
 			downgraded = true;
 			goto success;
@@ -327,14 +327,14 @@ SYSCALL_DEFINE1(brk, unsigned long, brk)
 	 * Only check if the next VMA is within the stack_guard_gap of the
 	 * expansion area
 	 */
-	mas_set(&mas, oldbrk);
-	next = mas_find(&mas, newbrk - 1 + PAGE_SIZE + stack_guard_gap);
+	vma_iter_init(&vmi, mm, oldbrk);
+	next = vma_find(&vmi, newbrk + PAGE_SIZE + stack_guard_gap);
 	if (next && newbrk + PAGE_SIZE > vm_start_gap(next))
 		goto out;
 
-	brkvma = mas_prev(&mas, mm->start_brk);
+	brkvma = vma_prev_limit(&vmi, mm->start_brk);
 	/* Ok, looks good - let it rip. */
-	if (do_brk_flags(&mas, brkvma, oldbrk, newbrk - oldbrk, 0) < 0)
+	if (do_brk_flags(&vmi, brkvma, oldbrk, newbrk - oldbrk, 0) < 0)
 		goto out;
 
 	mm->brk = brk;
@@ -2964,7 +2964,7 @@ SYSCALL_DEFINE5(remap_file_pages, unsigned long, start, unsigned long, size,
 
 /*
  * brk_munmap() - Unmap a parital vma.
- * @mas: The maple tree state.
+ * @vmi: The vma iterator
  * @vma: The vma to be modified
  * @newbrk: the start of the address to unmap
  * @oldbrk: The end of the address to unmap
@@ -2974,7 +2974,7 @@ SYSCALL_DEFINE5(remap_file_pages, unsigned long, start, unsigned long, size,
  * unmaps a partial VMA mapping.  Does not handle alignment, downgrades lock if
  * possible.
  */
-static int do_brk_munmap(struct ma_state *mas, struct vm_area_struct *vma,
+static int do_brk_munmap(struct vma_iterator *vmi, struct vm_area_struct *vma,
 			 unsigned long newbrk, unsigned long oldbrk,
 			 struct list_head *uf)
 {
@@ -2982,14 +2982,14 @@ static int do_brk_munmap(struct ma_state *mas, struct vm_area_struct *vma,
 	int ret;
 
 	arch_unmap(mm, newbrk, oldbrk);
-	ret = do_mas_align_munmap(mas, vma, mm, newbrk, oldbrk, uf, true);
+	ret = do_mas_align_munmap(&vmi->mas, vma, mm, newbrk, oldbrk, uf, true);
 	validate_mm_mt(mm);
 	return ret;
 }
 
 /*
  * do_brk_flags() - Increase the brk vma if the flags match.
- * @mas: The maple tree state.
+ * @vmi: The vma iterator
  * @addr: The start address
  * @len: The length of the increase
  * @vma: The vma,
@@ -2999,7 +2999,7 @@ static int do_brk_munmap(struct ma_state *mas, struct vm_area_struct *vma,
  * do not match then create a new anonymous VMA.  Eventually we may be able to
  * do some brk-specific accounting here.
  */
-static int do_brk_flags(struct ma_state *mas, struct vm_area_struct *vma,
+static int do_brk_flags(struct vma_iterator *vmi, struct vm_area_struct *vma,
 		unsigned long addr, unsigned long len, unsigned long flags)
 {
 	struct mm_struct *mm = current->mm;
@@ -3026,8 +3026,7 @@ static int do_brk_flags(struct ma_state *mas, struct vm_area_struct *vma,
 	if (vma &&
 	    (!vma->anon_vma || list_is_singular(&vma->anon_vma_chain)) &&
 	    ((vma->vm_flags & ~VM_SOFTDIRTY) == flags)) {
-		mas_set_range(mas, vma->vm_start, addr + len - 1);
-		if (mas_preallocate(mas, vma, GFP_KERNEL))
+		if (vma_iter_prealloc(vmi, vma))
 			return -ENOMEM;
 
 		vma_adjust_trans_huge(vma, vma->vm_start, addr + len, 0);
@@ -3037,7 +3036,7 @@ static int do_brk_flags(struct ma_state *mas, struct vm_area_struct *vma,
 		}
 		vma->vm_end = addr + len;
 		vma->vm_flags |= VM_SOFTDIRTY;
-		mas_store_prealloc(mas, vma);
+		vma_iter_store(vmi, vma);
 
 		if (vma->anon_vma) {
 			anon_vma_interval_tree_post_update_vma(vma);
@@ -3058,8 +3057,8 @@ static int do_brk_flags(struct ma_state *mas, struct vm_area_struct *vma,
 	vma->vm_pgoff = addr >> PAGE_SHIFT;
 	vma->vm_flags = flags;
 	vma->vm_page_prot = vm_get_page_prot(flags);
-	mas_set_range(mas, vma->vm_start, addr + len - 1);
-	if (mas_store_gfp(mas, vma, GFP_KERNEL))
+	mas_set_range(&vmi->mas, vma->vm_start, vma->vm_end - 1);
+	if (vma_iter_store_gfp(vmi, vma, GFP_KERNEL))
 		goto mas_store_fail;
 
 	mm->map_count++;
@@ -3088,7 +3087,7 @@ int vm_brk_flags(unsigned long addr, unsigned long request, unsigned long flags)
 	int ret;
 	bool populate;
 	LIST_HEAD(uf);
-	MA_STATE(mas, &mm->mm_mt, addr, addr);
+	VMA_ITERATOR(vmi, mm, addr);
 
 	len = PAGE_ALIGN(request);
 	if (len < request)
@@ -3107,17 +3106,17 @@ int vm_brk_flags(unsigned long addr, unsigned long request, unsigned long flags)
 	if (ret)
 		goto limits_failed;
 
-	ret = do_mas_munmap(&mas, mm, addr, len, &uf, 0);
+	ret = do_mas_munmap(&vmi.mas, mm, addr, len, &uf, 0);
 	if (ret)
 		goto munmap_failed;
 
-	vma = mas_prev(&mas, 0);
+	vma = vma_prev(&vmi);
 	if (!vma || vma->vm_end != addr || vma_policy(vma) ||
 	    !can_vma_merge_after(vma, flags, NULL, NULL,
 				 addr >> PAGE_SHIFT, NULL_VM_UFFD_CTX, NULL))
 		vma = NULL;
 
-	ret = do_brk_flags(&mas, vma, addr, len, flags);
+	ret = do_brk_flags(&vmi, vma, addr, len, flags);
 	populate = ((mm->def_flags & VM_LOCKED) != 0);
 	mmap_write_unlock(mm);
 	userfaultfd_unmap_complete(mm, &uf);
-- 
2.35.1


  parent reply	other threads:[~2022-11-29 16:44 UTC|newest]

Thread overview: 49+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-11-29 16:44 [PATCH 00/43] VMA type safety through VMA iterator Liam Howlett
2022-11-29 16:44 ` [PATCH 03/43] maple_tree: Reduce user error potential Liam Howlett
2022-11-29 16:44 ` [PATCH 02/43] maple_tree: Fix potential rcu issue Liam Howlett
2022-11-29 16:44 ` [PATCH 01/43] maple_tree: Add mas_init() function Liam Howlett
2022-11-29 16:44 ` [PATCH 05/43] mm: Expand vma iterator interface Liam Howlett
2022-11-30 16:35   ` kernel test robot
2022-12-13 21:04     ` Liam Howlett
2022-11-29 16:44 ` Liam Howlett [this message]
2022-11-29 16:44 ` [PATCH 04/43] test_maple_tree: Test modifications while iterating Liam Howlett
2022-11-29 16:44 ` [PATCH 08/43] mmap: Convert vma_link() vma iterator Liam Howlett
2022-11-29 16:44 ` [PATCH 07/43] kernel/fork: Convert forking to using the vmi iterator Liam Howlett
2022-11-29 16:44 ` [PATCH 09/43] mm/mmap: Remove preallocation from do_mas_align_munmap() Liam Howlett
2022-11-29 16:44 ` [PATCH 10/43] mmap: Change do_mas_munmap and do_mas_aligned_munmap() to use vma iterator Liam Howlett
2022-11-29 16:44 ` [PATCH 11/43] mmap: Convert vma_expand() " Liam Howlett
2022-11-29 16:44 ` [PATCH 13/43] ipc/shm: Use the vma iterator for munmap calls Liam Howlett
2022-11-29 16:44 ` [PATCH 12/43] mm: Add temporary vma iterator versions of vma_merge(), split_vma(), and __split_vma() Liam Howlett
2022-11-29 16:44 ` [PATCH 15/43] mm: Change mprotect_fixup to vma iterator Liam Howlett
2022-11-29 16:44 ` [PATCH 14/43] userfaultfd: Use " Liam Howlett
2022-11-29 16:44 ` [PATCH 16/43] mlock: Convert mlock to " Liam Howlett
2022-11-29 16:44 ` [PATCH 17/43] coredump: Convert " Liam Howlett
2022-11-29 16:44 ` [PATCH 18/43] mempolicy: " Liam Howlett
2022-11-29 16:44 ` [PATCH 19/43] task_mmu: " Liam Howlett
2022-11-29 16:44 ` [PATCH 21/43] madvise: Use vmi iterator for __split_vma() and vma_merge() Liam Howlett
2022-11-29 16:44 ` [PATCH 20/43] sched: Convert to vma iterator Liam Howlett
2022-11-29 16:44 ` [PATCH 23/43] mmap: Use vmi version of vma_merge() Liam Howlett
2022-11-29 16:44 ` [PATCH 22/43] mmap: Pass through vmi iterator to __split_vma() Liam Howlett
2022-11-29 16:44 ` [PATCH 24/43] mm/mremap: Use vmi version of vma_merge() Liam Howlett
2022-11-29 16:44 ` [PATCH 25/43] mm: Switch vma_merge(), split_vma(), and __split_vma to vma iterator Liam Howlett
2022-11-29 16:44 ` [PATCH 27/43] mm: Pass through vma iterator to __vma_adjust() Liam Howlett
2022-11-29 16:44 ` [PATCH 26/43] mmap: Convert __vma_adjust() to use vma iterator Liam Howlett
2022-12-01 19:53   ` kernel test robot
2022-12-13 21:05     ` Liam Howlett
2022-11-29 16:44 ` [PATCH 30/43] mm: Pass vma iterator through to __vma_adjust() Liam Howlett
2022-11-29 16:44 ` [PATCH 29/43] mm: Remove unnecessary write to vma iterator in __vma_adjust() Liam Howlett
2022-11-29 16:44 ` [PATCH 28/43] madvise: Use split_vma() instead of __split_vma() Liam Howlett
2022-11-29 16:44 ` [PATCH 31/43] mm: Add vma iterator to vma_adjust() arguments Liam Howlett
2022-11-29 16:44 ` [PATCH 32/43] mmap: Clean up mmap_region() unrolling Liam Howlett
2022-11-29 16:44 ` [PATCH 33/43] mm: Change munmap splitting order and move_vma() Liam Howlett
2022-11-29 16:44 ` [PATCH 36/43] mm/mmap: Use vma_prepare() and vma_complete() in vma_expand() Liam Howlett
2022-11-29 16:44 ` [PATCH 35/43] mm/mmap: Refactor locking out of __vma_adjust() Liam Howlett
2022-11-29 16:44 ` [PATCH 34/43] mm/mmap: move anon_vma setting in __vma_adjust() Liam Howlett
2022-11-29 16:44 ` [PATCH 39/43] mm/mmap: Don't use __vma_adjust() in shift_arg_pages() Liam Howlett
2022-11-29 16:44 ` [PATCH 38/43] mm: Don't use __vma_adjust() in __split_vma() Liam Howlett
2022-11-29 16:44 ` [PATCH 37/43] mm/mmap: Introduce init_vma_prep() and init_multi_vma_prep() Liam Howlett
2022-11-29 16:44 ` [PATCH 42/43] mm/mmap: Remove __vma_adjust() Liam Howlett
2022-11-29 16:44 ` [PATCH 41/43] mm/mmap: Convert do_brk_flags() to use vma_prepare() and vma_complete() Liam Howlett
2022-11-29 16:44 ` [PATCH 40/43] mm/mmap: Introduce dup_vma_anon() helper Liam Howlett
2022-11-29 16:44 ` [PATCH 43/43] vma_merge: Set vma iterator to correct position Liam Howlett
2022-11-30  0:46 ` [PATCH 00/43] VMA type safety through VMA iterator Liam Howlett

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