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-rw-r--r--mm/mmap.c51
1 files changed, 27 insertions, 24 deletions
diff --git a/mm/mmap.c b/mm/mmap.c
index 6f3766b..a7bf6a3 100644
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -451,9 +451,8 @@ static void vma_link(struct mm_struct *mm, struct vm_area_struct *vma,
}
/*
- * Helper for vma_adjust in the split_vma insert case:
- * insert vm structure into list and rbtree and anon_vma,
- * but it has already been inserted into prio_tree earlier.
+ * Helper for vma_adjust() in the split_vma insert case: insert a vma into the
+ * mm's list and rbtree. It has already been inserted into the prio_tree.
*/
static void __insert_vm_struct(struct mm_struct *mm, struct vm_area_struct *vma)
{
@@ -1112,9 +1111,9 @@ SYSCALL_DEFINE6(mmap_pgoff, unsigned long, addr, unsigned long, len,
* A dummy user value is used because we are not locking
* memory so no accounting is necessary
*/
- len = ALIGN(len, huge_page_size(&default_hstate));
- file = hugetlb_file_setup(HUGETLB_ANON_FILE, len, VM_NORESERVE,
- &user, HUGETLB_ANONHUGE_INODE);
+ file = hugetlb_file_setup(HUGETLB_ANON_FILE, addr, len,
+ VM_NORESERVE, &user,
+ HUGETLB_ANONHUGE_INODE);
if (IS_ERR(file))
return PTR_ERR(file);
}
@@ -1439,10 +1438,8 @@ void arch_unmap_area(struct mm_struct *mm, unsigned long addr)
/*
* Is this a new hole at the lowest possible address?
*/
- if (addr >= TASK_UNMAPPED_BASE && addr < mm->free_area_cache) {
+ if (addr >= TASK_UNMAPPED_BASE && addr < mm->free_area_cache)
mm->free_area_cache = addr;
- mm->cached_hole_size = ~0UL;
- }
}
/*
@@ -1457,7 +1454,7 @@ arch_get_unmapped_area_topdown(struct file *filp, const unsigned long addr0,
{
struct vm_area_struct *vma;
struct mm_struct *mm = current->mm;
- unsigned long addr = addr0;
+ unsigned long addr = addr0, start_addr;
/* requested length too big for entire address space */
if (len > TASK_SIZE)
@@ -1481,22 +1478,14 @@ arch_get_unmapped_area_topdown(struct file *filp, const unsigned long addr0,
mm->free_area_cache = mm->mmap_base;
}
+try_again:
/* either no address requested or can't fit in requested address hole */
- addr = mm->free_area_cache;
-
- /* make sure it can fit in the remaining address space */
- if (addr > len) {
- vma = find_vma(mm, addr-len);
- if (!vma || addr <= vma->vm_start)
- /* remember the address as a hint for next time */
- return (mm->free_area_cache = addr-len);
- }
-
- if (mm->mmap_base < len)
- goto bottomup;
+ start_addr = addr = mm->free_area_cache;
- addr = mm->mmap_base-len;
+ if (addr < len)
+ goto fail;
+ addr -= len;
do {
/*
* Lookup failure means no vma is above this address,
@@ -1516,7 +1505,21 @@ arch_get_unmapped_area_topdown(struct file *filp, const unsigned long addr0,
addr = vma->vm_start-len;
} while (len < vma->vm_start);
-bottomup:
+fail:
+ /*
+ * if hint left us with no space for the requested
+ * mapping then try again:
+ *
+ * Note: this is different with the case of bottomup
+ * which does the fully line-search, but we use find_vma
+ * here that causes some holes skipped.
+ */
+ if (start_addr != mm->mmap_base) {
+ mm->free_area_cache = mm->mmap_base;
+ mm->cached_hole_size = 0;
+ goto try_again;
+ }
+
/*
* A failed mmap() very likely causes application failure,
* so fall back to the bottom-up function here. This scenario
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