[PATCH v3 33/38] arm64: Avoid cpus_have_const_cap() for ARM64_WORKAROUND_1742098

[Catalin Marinas]

On Fri, Oct 13, 2023 at 11:53:53AM +0100, Mark Rutland wrote:
> On Tue, Oct 10, 2023 at 11:31:34AM +0100, Mark Rutland wrote:
> >  static void elf_hwcap_fixup(void)
> >  {
> > -#ifdef CONFIG_ARM64_ERRATUM_1742098
> > -	if (cpus_have_const_cap(ARM64_WORKAROUND_1742098))
> > +	if (cpus_have_cap(ARM64_WORKAROUND_1742098))
> >  		compat_elf_hwcap2 &= ~COMPAT_HWCAP2_AES;
> > -#endif /* ARM64_ERRATUM_1742098 */
> >  }
> 
> The kbuild test robot pointed out that this is broken for CONFIG_COMPAT=n,
> since compat_elf_hwcap2 is only defined when CONFIG_COMPAT=y. As
> CONFIG_ARM64_ERRATUM_1742098 depends on CONFIG_COMPAT, this worked prior to this patch.
> 
> I've changed that locally to:
> 
> | static void elf_hwcap_fixup(void)
> | {
> | #ifdef CONFIG_COMPAT
> | 	if (cpus_have_cap(ARM64_WORKAROUND_1742098))
> | 		compat_elf_hwcap2 &= ~COMPAT_HWCAP2_AES;
> | #endif /* CONFIG_COMPAT */
> | }
> 
> ... since the ifdeffery is protecting the use of 'compat_elf_hwcap2', and the
> cpucap is now elided by virtue of cpucap_is_possible().
> 
> Catalin, aside from the minor fixup above, are you happy to pick this for v6.7?
> 
> I can post a v4 with that change (and the commit message updated accordingly).

I can pick it up and fold the above in. Not sure what you want to update
the commit message to (just mention the need for #ifdef CONFIG_COMPAT?)

-- 
Catalin