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authorAndi Kleen <ak@suse.de>2005-05-20 14:27:57 -0700
committerLinus Torvalds <torvalds@ppc970.osdl.org>2005-05-20 15:48:20 -0700
commit7856dfeb23c16ef3d8dac8871b4d5b93c70b59b9 (patch)
tree0e9f799c3882dce14b49356c6db10bb6f4ba1713 /mm
parentc4d1fcf3a2ea89b6d6221fa8b4588c77aff50995 (diff)
[PATCH] x86_64: Fixed guard page handling again in iounmap
Caused oopses again. Also fix potential mismatch in checking if change_page_attr was needed. To do it without races I needed to change mm/vmalloc.c to export a __remove_vm_area that does not take vmlist lock. Noticed by Terence Ripperda and based on a patch of his. Signed-off-by: Andi Kleen <ak@suse.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'mm')
-rw-r--r--mm/vmalloc.c33
1 files changed, 20 insertions, 13 deletions
diff --git a/mm/vmalloc.c b/mm/vmalloc.c
index 2bd83e5c2bbf..8ff16a1eee6a 100644
--- a/mm/vmalloc.c
+++ b/mm/vmalloc.c
@@ -248,31 +248,20 @@ struct vm_struct *get_vm_area(unsigned long size, unsigned long flags)
return __get_vm_area(size, flags, VMALLOC_START, VMALLOC_END);
}
-/**
- * remove_vm_area - find and remove a contingous kernel virtual area
- *
- * @addr: base address
- *
- * Search for the kernel VM area starting at @addr, and remove it.
- * This function returns the found VM area, but using it is NOT safe
- * on SMP machines.
- */
-struct vm_struct *remove_vm_area(void *addr)
+/* Caller must hold vmlist_lock */
+struct vm_struct *__remove_vm_area(void *addr)
{
struct vm_struct **p, *tmp;
- write_lock(&vmlist_lock);
for (p = &vmlist ; (tmp = *p) != NULL ;p = &tmp->next) {
if (tmp->addr == addr)
goto found;
}
- write_unlock(&vmlist_lock);
return NULL;
found:
unmap_vm_area(tmp);
*p = tmp->next;
- write_unlock(&vmlist_lock);
/*
* Remove the guard page.
@@ -281,6 +270,24 @@ found:
return tmp;
}
+/**
+ * remove_vm_area - find and remove a contingous kernel virtual area
+ *
+ * @addr: base address
+ *
+ * Search for the kernel VM area starting at @addr, and remove it.
+ * This function returns the found VM area, but using it is NOT safe
+ * on SMP machines, except for its size or flags.
+ */
+struct vm_struct *remove_vm_area(void *addr)
+{
+ struct vm_struct *v;
+ write_lock(&vmlist_lock);
+ v = __remove_vm_area(addr);
+ write_unlock(&vmlist_lock);
+ return v;
+}
+
void __vunmap(void *addr, int deallocate_pages)
{
struct vm_struct *area;