On Tue, Sep 04, 2018 at 10:10:09AM +0100, Suzuki K Poulose wrote:
commit 4c4a39dd5fe2d13e2d2fa5fceb8ef95d19fc389a upstream
If there is a mismatch in the I/D min line size, we must always use the system wide safe value both in applications and in the kernel, while performing cache operations. However, we have been checking more bits than just the min line sizes, which triggers false negatives. We may need to trap the user accesses in such cases, but not necessarily patch the kernel.
This patch fixes the check to do the right thing as advertised. A new capability will be added to check mismatches in other fields and ensure we trap the CTR accesses.
Fixes: be68a8aaf925 ("arm64: cpufeature: Fix CTR_EL0 field definitions") Cc: stable@vger.kernel.org # v4.9
Why 4.9? be68a8aaf925 only showed up in 4.16 and was backported only to 4.14-stable. Not to 4.9-stable from what I can tell.
thanks,
greg k-h