Re: objtool warnings on 4.14-stable/gcc-7.3.0

[Greg KH]

On Wed, Feb 14, 2018 at 04:24:12PM -0600, Josh Poimboeuf wrote:
> On Wed, Feb 14, 2018 at 04:11:15PM +0100, Arnd Bergmann wrote:
> > Hi Josh,
> > 
> > I recently did some randconfig testing with a plain 4.14-stable kernel
> > and gcc-7.3.0, and came across three distinct objtool warnings:
> > 
> > drivers/misc/lkdtm_bugs.o: warning: objtool:
> > lkdtm_CORRUPT_LIST_ADD()+0x15: return with modified stack frame
> > 
> > crypto/asymmetric_keys/x509_cert_parser.o: warning: objtool:
> > x509_note_pkey_algo()+0xa4: sibling call from callable instruction
> > with modified stack frame
> > 
> > drivers/infiniband/hw/bnxt_re/qplib_fp.o: warning: objtool:
> > bnxt_qplib_poll_cq()+0x106: sibling call from callable instruction
> > with modified stack frame
> > 
> > It's likely that this is the complete set at the moment, I saw each
> > one multiple times,
> > but did not see any others. I'll reply with the respective object
> > files for your reference,
> > in case these are so far unknown to you. There are only a handful of randconfig
> > warnings we see overall in the kernel these days (at least on x86 and arm64), so
> > even if they are false-positive, it would be great to get rid of the
> > output so we can
> > do randconfig testing on 4.14.y and treat any output from 'make -s' as
> > a regression.
> > I did not check
> 
> The third one has been fixed upstream with
> 
>   99ce7962d52d ("objtool: Fix switch-table detection")
> 
> ... so we should put that one into stable.

Now queued up, thanks.

greg k-h