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Date:   Mon, 3 Feb 2020 09:38:11 -0800
From:   Christoph Hellwig <hch@infradead.org>
To:     Kees Cook <keescook@chromium.org>
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Subject: Re: [kernel-hardening] [PATCH 09/38] usercopy: Mark kmalloc caches
 as usercopy caches
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On Thu, Jan 30, 2020 at 11:23:38AM -0800, Kees Cook wrote:
> Hm, looks like it's allocated from the low 16MB. Seems like poor naming!
> :) There seems to be a LOT of stuff using GFP_DMA, and it seems unlikely
> those are all expecting low addresses?

Most of that is either completely or partially bogus.  Besides the
weird S/390 stuff pretty much everything should be using the dma
allocators.  A couple really messed up drivers even pass GFP_DMA*
to the dma allocator, but my patches to fix that up seem to be stuck.