On Wed, Apr 08, 2020 at 01:58:58PM +0200, Christoph Hellwig wrote:

Hi all,

Peter noticed that with some dumb luck you can toast the kernel address
space with exported vmalloc symbols.

I used this as an opportunity to decruft the vmalloc.c API and make it
much more systematic.  This also removes any chance to create vmalloc
mappings outside the designated areas or using executable permissions
from modules.  Besides that it removes more than 300 lines of code.

I haven't read all your patches yet.

Have you tested it on 32-bit ARM, where the module area is located
_below_ PAGE_OFFSET and outside of the vmalloc area?

-- 
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