On Mon, Feb 26, 2024 at 02:22:30PM +0200, Nikolay Borisov wrote:
Here's the recently merged mds improvement patches adapted to latest stable tree. I've only compile tested them, but since I have also done similar backports for older kernels I'm sure they should work. The main difference is in the definition of the CLEAR_CPU_BUFFERS macro since 5.4 doesn't contains the alternative relocation handling logic hence the verw instruction is moved out of the alternative definition and instead we have a jump which skips the verw instruction there. That way the relocation will be handled by the toolchain rather than the kernel.
Since I don't know if I will have time to work on the other branches this patchset can be used as basis for the rest of the stable kernels. The main difference would be which bit is used for CLEAR_CPU_BUFFERS. For kernel 6.6 the 2nd patch can be used verbatim from upstrem (unlike this modified version) since the alternative relocation did land in v6.5. However, even if used as-is from this patchset it's not a problem.
As mentioned on IRC, I can't take these now, without the newer branches fixed first, otherwise someone could upgrade and have a regression.
So I'll hold off on these until we backports for all of the other stable trees as well.
thanks,
greg k-h