On Tue, Aug 17, 2021 at 12:17:31PM +0100, Andrew Cooper wrote:
> On 17/08/2021 12:14, Marek Marczykowski-Górecki wrote:
> > On Tue, Aug 17, 2021 at 11:56:56AM +0100, Andrew Cooper wrote:
> >> Some versions of GCC complain with:
> >>
> >> traps.c:405:22: error: 'get_shstk_bottom' defined but not used
> >> [-Werror=unused-function]
> >> static unsigned long get_shstk_bottom(unsigned long sp)
> >> ^~~~~~~~~~~~~~~~
> >> cc1: all warnings being treated as errors
> >>
> >> Change #ifdef to if ( IS_ENABLED(...) ) to make the sole user of
> >> get_shstk_bottom() visible to the compiler.
> >>
> >> Fixes: 35727551c070 ("x86/cet: Fix shskt manipulation error with
> >> BUGFRAME_{warn,run_fn}")
> >> Signed-off-by: Andrew Cooper <[email protected]>
> >> ---
> >> CC: Jan Beulich <[email protected]>
> >> CC: Roger Pau Monné <[email protected]>
> >> CC: Wei Liu <[email protected]>
> >> CC: Marek Marczykowski-Górecki <[email protected]>
> >>
> >> Not actually tested. I don't seem to have a new enough GCC to hand.
> > I have just compile-tested it and it seems to fix the issue (indeed it
> > failed before with CONFIG_XEN_SHSTK disabled).
>
> Oh, thanks!And I can confirm it doesn't break anything runtime (but that's pretty obvious looking at the patch). > >> Most of the delta here is indentation. This diff is more easily reviewed > >> with > >> `git show --ignore-all-space` > > Wouldn't this make the compiler include the code even if > > CONFIG_XEN_SHSTK is disabled (not a huge issue...)? Or is it smart > > enough to optimize it out in that case? > > Its a trivial dead-code elimination example, and yes - the compiler is > smart enough. :) -- Best Regards, Marek Marczykowski-Górecki Invisible Things Lab
signature.asc
Description: PGP signature
