On Fri, May 25, 2012 at 9:24 AM, Olav Haugan [off-list ref] wrote:

quoted

-----Original Message-----
On Thu, 24 May 2012 17:32:56 +0900
KyongHo [off-list ref] wrote:

quoted

--- a/mm/vmalloc.c
+++ b/mm/vmalloc.c

@@ -1185,9 +1185,10 @@ 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;

quoted

quoted

+           va->flags = VM_VM_AREA;

This change is a mystery.  Why do we no longer transfer ->flags?

I was actually debugging the same exact issue today. This transfer of

flags

actually 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.

Thanks for description.

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().

 Cho KyongHo.
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.infradead.org/pipermail/linux-arm-kernel/attachments/20120525/ce9087e9/attachment-0001.html>