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-rw-r--r--Documentation/nommu-mmap.txt10
-rw-r--r--mm/nommu.c14
2 files changed, 19 insertions, 5 deletions
diff --git a/Documentation/nommu-mmap.txt b/Documentation/nommu-mmap.txt
index 4db7c18bf68..7714f57caad 100644
--- a/Documentation/nommu-mmap.txt
+++ b/Documentation/nommu-mmap.txt
@@ -138,6 +138,16 @@ mode. The former through the usual mechanism, the latter through files created
on ramfs or tmpfs mounts.
+=======
+FUTEXES
+=======
+
+Futexes are supported in NOMMU mode if the arch supports them. An error will
+be given if an address passed to the futex system call lies outside the
+mappings made by a process or if the mapping in which the address lies does not
+support futexes (such as an I/O chardev mapping).
+
+
=============
NO-MMU MREMAP
=============
diff --git a/mm/nommu.c b/mm/nommu.c
index 23cfa8ec914..56454066219 100644
--- a/mm/nommu.c
+++ b/mm/nommu.c
@@ -350,6 +350,15 @@ struct vm_area_struct *find_vma(struct mm_struct *mm, unsigned long addr)
EXPORT_SYMBOL(find_vma);
/*
+ * find a VMA
+ * - we don't extend stack VMAs under NOMMU conditions
+ */
+struct vm_area_struct *find_extend_vma(struct mm_struct *mm, unsigned long addr)
+{
+ return find_vma(mm, addr);
+}
+
+/*
* look up the first VMA exactly that exactly matches addr
* - should be called with mm->mmap_sem at least held readlocked
*/
@@ -1153,11 +1162,6 @@ struct page *follow_page(struct vm_area_struct *vma, unsigned long address,
return NULL;
}
-struct vm_area_struct *find_extend_vma(struct mm_struct *mm, unsigned long addr)
-{
- return NULL;
-}
-
int remap_pfn_range(struct vm_area_struct *vma, unsigned long from,
unsigned long to, unsigned long size, pgprot_t prot)
{