On Wed, 2013-07-17 at 15:25 -0400, Dave Jones wrote:
On Tue, Jul 16, 2013 at 03:39:35PM +0200, Reindl Harald wrote:
is there a strong performance-wise reason for "Strict user copy checks: Disabled" - IMHO if something may make things more secure while not have a dramatically performance impact security in doubt should go first
Are that the checks enabled by CONFIG_DEBUG_STRICT_USER_COPY_CHECKS? If so, they don't do anything on x86_64 (which Harald seems to be using), do they?
And please note that on x86_32 one will still see compiler warnings if that Kconfig symbol is not set.
And also note that recently (I think since v3.10, but I haven't checked) actually no copy_from_user() related warnings show up when building for x86_32 and using Fedora-based .config. At least, they don't show up anymore when I build locally. I'm not sure what caused that.
Paul Bolle