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

From: Arnd Bergmann
Date: Wed Feb 28 2018 - 06:26:12 EST


On Wed, Feb 28, 2018 at 3:20 AM, Josh Poimboeuf <jpoimboe@xxxxxxxxxx> wrote:
> On Wed, Feb 14, 2018 at 04:45:25PM -0600, Josh Poimboeuf wrote:
>> 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:
>> > > crypto/asymmetric_keys/x509_cert_parser.o: warning: objtool:
>> > > x509_note_pkey_algo()+0xa4: sibling call from callable instruction
>> > > with modified stack frame
>>
>> From a quick glance, this looks like yet another switch statement
>> detection issue. I'll need to dig into it more (unless PeterZ, my shiny
>> new co-maintainer, wants to take a look!)
>
> Arnd, can you test this fix?

It took me a while, as I had lost the earlier reproducer and am
currently testing
linux-next/gcc-8 whereas the report was for v4.14/gcc-7.

I have finally found a new reproducer on linux-next/gcc-7 and confirmed that
the warning is fixed now, both for gcc-7 and gcc-8.

Thanks for the fix!

Arnd