Messages in this thread | | | Date | Wed, 9 Mar 2011 02:33:04 +0000 | From | Al Viro <> | Subject | Re: [PATCH 0/6] enable writing to /proc/pid/mem |
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On Tue, Mar 08, 2011 at 09:15:25PM -0500, Stephen Wilson wrote:
> I think we could also remove the intermediate copy in both mem_read() and > mem_write() as well, but I think such optimizations could be left for > follow on patches.
How? We do copy_.._user() in there; it can trigger page faults and that's not something you want while holding mmap_sem on some mm. Looks like a deadlock country... So we can't do that from inside access_process_vm() or its analogs, which means buffering in caller.
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