Re: [PATCH 0/7] objtool: retpoline validation

[Peter Zijlstra]

On Thu, Feb 01, 2018 at 09:28:56AM -0600, Josh Poimboeuf wrote:
> On Thu, Feb 01, 2018 at 03:34:21PM +0100, Peter Zijlstra wrote:
> > There are the retpoline validation patches; they work with the __noretpoline
> > thing from David.
> 
> Have you run this through 0-day bot yet? 

Yes, it complains a _lot_ because no retpoline supported compiler.

> A manual awk/sed found another
> one, which objtool confirms:
> 
>   drivers/watchdog/.tmp_hpwdt.o: warning: objtool: .text+0x24: indirect call found in RETPOLINE build

That is the only known one left. It calls into BIOS code, so its not
safe and using a retpoline for it is pointless since nobody audited the
BIOS code.