On Fri, Feb 16, 2024 at 07:57:01AM -0800, Linus Torvalds wrote:

I didn't think to mark these for stable in the commits, but they definitely should go into the stable queue, since it's a known mis-compilation of the kvm nested guest code with gcc-11 otherwise.

The bug technically affects other gcc versions too, but apparently not so that we'd actually notice.

It's two commits:

4356e9f841f7 ("work around gcc bugs with 'asm goto' with outputs") 68fb3ca0e408 ("update workarounds for gcc "asm goto" issue")

where the first one works around the problem, and the second one ("update") just ends up pinpointing exactly which gcc versions are affected so that future gcc releases won't get the unnecessary workaround.

Technically only the first one really needs to go into stable. The second one is more of a judgement call - do you want to match upstream, and do you care about the (very slight) code generation improvement with updated gcc versions?

I've queued both up for 6.6.y and 6.7.y and they took a bit of hand-holding to get merged. I gave up at 6.1.y and if anyone wants them there, I'll gladly take a working backport, but I'm not going to attempt it.

thanks,

greg k-h