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authorJeremy Fitzhardinge <jeremy@goop.org>2007-07-21 17:11:35 +0200
committerLinus Torvalds <torvalds@woody.linux-foundation.org>2007-07-21 18:37:14 -0700
commit9585116ba09f1d8c52d0a1346e20bb9d443e9c02 (patch)
treec3380b477754d3d2d77fa8dbd08f0b0d08fdcadf /include
parenta2900975ef3f1df33c83e750cc1e490de3374ca8 (diff)
i386: fix iounmap's use of vm_struct's size field
get_vm_area always returns an area with an adjacent guard page. That guard page is included in vm_struct.size. iounmap uses vm_struct.size to determine how much address space needs to have change_page_attr applied to it, which will BUG if applied to the guard page. This patch adds a helper function - get_vm_area_size() in linux/vmalloc.h - to return the actual size of a vm area, and uses it to make iounmap do the right thing. There are probably other places which should be using get_vm_area_size(). Thanks to Dave Young <hidave.darkstar@gmail.com> for debugging the problem. [ Andi, it wasn't clear to me whether x86_64 needs the same fix. ] Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com> Cc: Dave Young <hidave.darkstar@gmail.com> Cc: Chuck Ebbert <cebbert@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Andi Kleen <ak@suse.de> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'include')
-rw-r--r--include/linux/vmalloc.h7
1 files changed, 7 insertions, 0 deletions
diff --git a/include/linux/vmalloc.h b/include/linux/vmalloc.h
index c2b10cae5da5..89338b468d0d 100644
--- a/include/linux/vmalloc.h
+++ b/include/linux/vmalloc.h
@@ -58,6 +58,13 @@ void vmalloc_sync_all(void);
/*
* Lowlevel-APIs (not for driver use!)
*/
+
+static inline size_t get_vm_area_size(const struct vm_struct *area)
+{
+ /* return actual size without guard page */
+ return area->size - PAGE_SIZE;
+}
+
extern struct vm_struct *get_vm_area(unsigned long size, unsigned long flags);
extern struct vm_struct *__get_vm_area(unsigned long size, unsigned long flags,
unsigned long start, unsigned long end);