Re: [PATCH] x86/irqflags: mark native_restore_fl extern inline

[Greg Kroah-Hartman]

On Tue, Aug 28, 2018 at 08:02:37AM +0200, Juergen Gross wrote:
> On 28/08/18 07:13, Greg Kroah-Hartman wrote:
> > On Mon, Aug 27, 2018 at 02:40:09PM -0700, Nick Desaulniers wrote:
> >> Fixes commit 208cbb325589 ("x86/irqflags: Provide a declaration for
> >> native_save_fl")
> >>
> >> This should have been marked extern inline in order to pick up the out
> >> of line definition in arch/x86/kernel/irqflags.S.
> >>
> >> Cc: stable@xxxxxxxxxxxxxxx # 4.18, 4.14, 4.9, 4.4
> >> Reported-by: Ben Hutchings <ben.hutchings@xxxxxxxxxxxxxxx>
> >> Signed-off-by: Nick Desaulniers <ndesaulniers@xxxxxxxxxx>
> >> ---
> >>  arch/x86/include/asm/irqflags.h | 3 ++-
> >>  1 file changed, 2 insertions(+), 1 deletion(-)
> >>
> >> diff --git a/arch/x86/include/asm/irqflags.h b/arch/x86/include/asm/irqflags.h
> >> index c14f2a74b2be..15450a675031 100644
> >> --- a/arch/x86/include/asm/irqflags.h
> >> +++ b/arch/x86/include/asm/irqflags.h
> >> @@ -33,7 +33,8 @@ extern inline unsigned long native_save_fl(void)
> >>  	return flags;
> >>  }
> >>  
> >> -static inline void native_restore_fl(unsigned long flags)
> >> +extern inline void native_restore_fl(unsigned long flags);
> >> +extern inline void native_restore_fl(unsigned long flags)
> > 
> > This looks odd to me, but my coffee hasn't kicked in yet this morning.
> > Why do you need both lines here?  Shouldn't the actual function be
> > sufficient?  If not, a comment explaining this would be nice.
> 
> Look just some lines further up:
> 
> /* Declaration required for gcc < 4.9 to prevent
> -Werror=missing-prototypes */
> extern inline unsigned long native_save_fl(void);
> extern inline unsigned long native_save_fl(void)

Ugh, my fault, I'll go shut up now...

stupid gcc...