Re: [tip:x86/tdx 8/12] vmlinux.o: warning: objtool: __tdx_hypercall+0x128: __tdx_hypercall_failed() is missing a __noreturn annotation

From: Huang, Kai
Date: Wed Sep 13 2023 - 23:21:43 EST


On Thu, 2023-09-14 at 01:23 +0000, Huang, Kai wrote:
> On Thu, 2023-09-14 at 09:05 +0800, kernel test robot wrote:
> > tree: https://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git x86/tdx
> > head: 7b804135d4d1f0a2b9dda69c6303d3f2dcbe9d37
> > commit: c641cfb5c157b6c3062a824fd8ba190bf06fb952 [8/12] x86/tdx: Make TDX_HYPERCALL asm similar to TDX_MODULE_CALL
> > config: x86_64-rhel-8.3-bpf (https://download.01.org/0day-ci/archive/20230914/202309140828.9RdmlH2Z-lkp@xxxxxxxxx/config)
> > compiler: gcc-12 (Debian 12.2.0-14) 12.2.0
> > reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20230914/202309140828.9RdmlH2Z-lkp@xxxxxxxxx/reproduce)
> >
> > If you fix the issue in a separate patch/commit (i.e. not just a new version of
> > the same patch/commit), kindly add following tags
> > > Reported-by: kernel test robot <lkp@xxxxxxxxx>
> > > Closes: https://lore.kernel.org/oe-kbuild-all/202309140828.9RdmlH2Z-lkp@xxxxxxxxx/
> >
> > All warnings (new ones prefixed by >>):
> >
> > > > vmlinux.o: warning: objtool: __tdx_hypercall+0x128: __tdx_hypercall_failed() is missing a __noreturn annotation
> >
>
> Hmm.. The __tdx_hypercall_failed() is already annotated with __noreturn (I
> explicitly added it to silent such warning):
>
> /* Called from __tdx_hypercall() for unrecoverable failure */
> noinstr void __noreturn __tdx_hypercall_failed(void)
> {
> instrumentation_begin();
> panic("TDVMCALL failed. TDX module bug?");
> }
>
> Not sure why the objtool is still complaining this?
>

It appears the __noreturn must be annotated to the function declaration but not
the function body. I'll send out the fix as soon as I confirm the fix with LKP.

Sorry for the noise.
>