Permalink
Browse files

mm: fix faulty initialization in vmalloc_init()

commit dbda591 upstream.

The transfer of ->flags causes some of the static mapping virtual
addresses to be prematurely freed (before the mapping is removed) because
VM_LAZY_FREE gets "set" if tmp->flags has VM_IOREMAP set.  This might
cause subsequent vmalloc/ioremap calls to fail because it might allocate
one of the freed virtual address ranges that aren't unmapped.

va->flags has different types of flags from tmp->flags.  If a region with
VM_IOREMAP set is registered with vm_area_add_early(), it will be removed
by __purge_vmap_area_lazy().

Fix vmalloc_init() to correctly initialize vmap_area for the given
vm_struct.

Also initialise va->vm.  If it is not set, find_vm_area() for the early
vm regions will always fail.

Signed-off-by: KyongHo Cho <pullip.cho@samsung.com>
Cc: "Olav Haugan" <ohaugan@codeaurora.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
  • Loading branch information...
pullipcho authored and bwhacks committed May 29, 2012
1 parent 15db5b6 commit 39083c6db7e18732e872fed0c2f2427de12a622a
Showing with 2 additions and 1 deletion.
  1. +2 −1 mm/vmalloc.c
View
@@ -1160,9 +1160,10 @@ void __init vmalloc_init(void)
/* Import existing vmlist entries. */
for (tmp = vmlist; tmp; tmp = tmp->next) {
va = kzalloc(sizeof(struct vmap_area), GFP_NOWAIT);
- va->flags = tmp->flags | VM_VM_AREA;
+ va->flags = VM_VM_AREA;
va->va_start = (unsigned long)tmp->addr;
va->va_end = va->va_start + tmp->size;
+ va->vm = tmp;
__insert_vmap_area(va);
}

0 comments on commit 39083c6

Please sign in to comment.