The get_vm_area() allocates one extra guard page, and stores the augmented
size in area->size. But the ioremap/iounmap code on x86 relies on finding
the original size in area->size (otherwise it does change the attribute
of some random device in the linear-map by using a wrong size in
ioremap_change_attr() ). The problem is avoided by not using an extra guard
page for VM_IOREMAP allocations (if somebody can think of an easy way to
store the original size across ioremap()/iounmap() calls, that could be
a more elegant solution).
Signed-off-by: Loic Prylli <[EMAIL PROTECTED]>
---
mm/vmalloc.c | 5 +++--
1 files changed, 3 insertions(+), 2 deletions(-)
diff --git a/mm/vmalloc.c b/mm/vmalloc.c
index af77e17..efd0093 100644
--- a/mm/vmalloc.c
+++ b/mm/vmalloc.c
@@ -196,9 +196,10 @@ static struct vm_struct *__get_vm_area_node(unsigned long
size, unsigned long fl
return NULL;
/*
- * We always allocate a guard page.
+ * We allocate a guard page (except for ioremap() which relies on
area->size == size)
*/
- size += PAGE_SIZE;
+ if (!(flags & VM_IOREMAP))
+ size += PAGE_SIZE;
write_lock(&vmlist_lock);
for (p = &vmlist; (tmp = *p) != NULL ;p = &tmp->next) {
--
1.5.2.2
--
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