Re: [PATCH 5.18 000/231] 5.18.13-rc1 review

Peter Zijlstra
2022-07-20T21:47:29Z

On Wed, Jul 20, 2022 at 12:57:26PM -0500, Justin Forbes wrote:
> On Wed, Jul 20, 2022 at 10:28:33AM -0700, Linus Torvalds wrote:
> > [ Adding PeterZ and Jiri to the participants. ]
> >
> > Looks like 5.18.13 added that commit 9bb2ec608a20 ("objtool: Update
> > Retpoline validation") but I don't see 3131ef39fb03 ("x86/asm/32: Fix
> > ANNOTATE_UNRET_SAFE use on 32-bit") in that list.
>
> It should be noted that the build doesn't fail, it just warns.
> I am guessing the 32bit failure is what promoted someone to look at
> the logs to begin with and notice the warn initially. I just verified
> that it exists in our builds of 5.18.13-rc1, but not on mainline builds.
> I am gueesing it is because commit 9bb2ec608a20 ("objtool: Update Retpoline
> validation") should be followed up with at least commit f43b9876e857c
> ("x86/retbleed: Add fine grained Kconfig knobs")

Still updateing the stable repro to see what the actual code looks like,
but that warning seems to suggest the -mfunction-return=thunk-extern
compiler argument went missing.

For all the files objtool complains about, does the V=1 build output
show that option?