From: Liam R. Howlett <Liam.Howlett@Oracle.com>
Date: Thu, 23 Jul 2020 19:41:56 +0000 (-0400)
Subject: mm/mmap: Add inline munmap_vma_range() for code readability
X-Git-Tag: howlett/maple/20200727~9
X-Git-Url: https://www.infradead.org/git/?a=commitdiff_plain;h=588e68d4bb60fe2ddb4358edc82e90d9af191027;p=users%2Fjedix%2Flinux-maple.git

mm/mmap: Add inline munmap_vma_range() for code readability

Signed-off-by: Liam R. Howlett <Liam.Howlett@Oracle.com>
---

diff --git a/mm/mmap.c b/mm/mmap.c
index 4f55bda990a3..7c442fd04c18 100644
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -579,6 +579,32 @@ static inline struct vm_area_struct *next_vma_or_first(struct mm_struct *mm,
 
 	return vma->vm_next;
 }
+
+/* Private
+ * munmap_vma_range() - Find all the vm_area_struct that overlap from @start to
+ * @end and munmap them.  Set @pprev to the previous vm_area_struct.
+ *
+ * @mm: The mm struct
+ * @start: The start address.
+ * @len: The length of the range.
+ * @pprev: pointer to the pointer that will be set to previous vm_area_struct
+ * @rb_link - the rb_node
+ * @rb_parent - the parent rb_node
+ *
+ * Returns: -ENOMEM on munmap failure or 0 on success.
+ */
+static inline int
+munmap_vma_range(struct mm_struct *mm, unsigned long start, unsigned long len,
+		 struct vm_area_struct **pprev, struct rb_node ***rb_link,
+		 struct rb_node **rb_parent, struct list_head *uf)
+{
+
+	while (find_vma_links(mm, start, start + len, pprev, rb_link, rb_parent))
+		if (do_munmap(mm, start, len, uf))
+			return -ENOMEM;
+
+	return 0;
+}
 static unsigned long count_vma_pages_range(struct mm_struct *mm,
 		unsigned long addr, unsigned long end)
 {
@@ -1725,13 +1751,9 @@ unsigned long mmap_region(struct file *file, unsigned long addr,
 			return -ENOMEM;
 	}
 
-	/* Clear old maps */
-	while (find_vma_links(mm, addr, addr + len, &prev, &rb_link,
-			      &rb_parent)) {
-		if (do_munmap(mm, addr, len, uf))
-			return -ENOMEM;
-	}
-
+	/* Clear old maps, set up prev, rb_link, rb_parent, and uf */
+	if (munmap_vma_range(mm, addr, len, &prev, &rb_link, &rb_parent, uf))
+		return -ENOMEM;
 	/*
 	 * Private writable mapping: check memory availability
 	 */
@@ -3025,14 +3047,9 @@ static int do_brk_flags(unsigned long addr, unsigned long len, unsigned long fla
 	if (error)
 		return error;
 
-	/*
-	 * Clear old maps.  this also does some error checking for us
-	 */
-	while (find_vma_links(mm, addr, addr + len, &prev, &rb_link,
-			      &rb_parent)) {
-		if (do_munmap(mm, addr, len, uf))
-			return -ENOMEM;
-	}
+	/* Clear old maps, set up prev, rb_link, rb_parent, and uf */
+	if (munmap_vma_range(mm, addr, len, &prev, &rb_link, &rb_parent, uf))
+		return -ENOMEM;
 
 	/* Check against address space limits *after* clearing old maps... */
 	if (!may_expand_vm(mm, flags, len >> PAGE_SHIFT))