Re: [PATCH 5.10 0/4] x86/speculation: Make {JMP,CALL}_NOSPEC Consistent

[Greg KH <gregkh@linuxfoundation.org>]

On Wed, Sep 03, 2025 at 03:49:59PM -0700, Suraj Jitindar Singh wrote:
> The 4 patches in this series make the JMP_NOSPEC and CALL_NOSPEC macros used
> in the kernel consistent with what is generated by the compiler.
> 
> ("x86,nospec: Simplify {JMP,CALL}_NOSPEC") was merged in v6.0 and the remaining
> 3 patches in this series were merged in v6.15. All 4 were included in kernels
> v5.15+ as prerequisites for the backport of the ITS mitigations [1].
> 
> None of these patches were included in the backport of the ITS mitigations to
> the 5.10 kernel [2]. They all apply cleanly and are applicable to the 5.10
> kernel. Thus I see no reason that they weren't applied here, unless someone can
> correct me?
> 
> I am sending them for inclusion in the 5.10 kernel as this kernel is still
> actively maintained for these kind of vulnerability mitigations and as such
> having these patches will unify the handling of these cases with subsequent
> kernel versions easing code understanding and the ease of backports in the
> future.

Also, you only really have about 1 more year left for this kernel
version, why not take the time to move any systems that are somehow
still using this to a more modern kernel instead?  What's preventing
that from happening?

Running any x86 systems on this old kernel right now is probably not a
good idea given the huge number of unfixed bugs in it...

thanks,

greg k-h