diff mbox series

[v5,25/29] arm64: allow LTO_CLANG and THINLTO to be selected

Message ID 20201009161338.657380-26-samitolvanen@google.com
State New, archived
Headers show
Series Add support for Clang LTO | expand

Commit Message

Sami Tolvanen Oct. 9, 2020, 4:13 p.m. UTC
Allow CONFIG_LTO_CLANG and CONFIG_THINLTO to be enabled.

Signed-off-by: Sami Tolvanen <samitolvanen@google.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
---
 arch/arm64/Kconfig | 2 ++
 1 file changed, 2 insertions(+)

Comments

Will Deacon Oct. 12, 2020, 8:31 a.m. UTC | #1
On Fri, Oct 09, 2020 at 09:13:34AM -0700, Sami Tolvanen wrote:
> Allow CONFIG_LTO_CLANG and CONFIG_THINLTO to be enabled.
> 
> Signed-off-by: Sami Tolvanen <samitolvanen@google.com>
> Reviewed-by: Kees Cook <keescook@chromium.org>
> ---
>  arch/arm64/Kconfig | 2 ++
>  1 file changed, 2 insertions(+)
> 
> diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
> index ad522b021f35..7016d193864f 100644
> --- a/arch/arm64/Kconfig
> +++ b/arch/arm64/Kconfig
> @@ -72,6 +72,8 @@ config ARM64
>  	select ARCH_USE_SYM_ANNOTATIONS
>  	select ARCH_SUPPORTS_MEMORY_FAILURE
>  	select ARCH_SUPPORTS_SHADOW_CALL_STACK if CC_HAVE_SHADOW_CALL_STACK
> +	select ARCH_SUPPORTS_LTO_CLANG
> +	select ARCH_SUPPORTS_THINLTO

Please don't enable this for arm64 until we have the dependency stuff sorted
out. I posted patches [1] for this before, but I think they should be part
of this series as they don't make sense on their own.

Will

[1] https://git.kernel.org/pub/scm/linux/kernel/git/will/linux.git/log/?h=rwonce/read-barrier-depends
Kees Cook Oct. 12, 2020, 8:44 p.m. UTC | #2
On Mon, Oct 12, 2020 at 09:31:16AM +0100, Will Deacon wrote:
> On Fri, Oct 09, 2020 at 09:13:34AM -0700, Sami Tolvanen wrote:
> > Allow CONFIG_LTO_CLANG and CONFIG_THINLTO to be enabled.
> > 
> > Signed-off-by: Sami Tolvanen <samitolvanen@google.com>
> > Reviewed-by: Kees Cook <keescook@chromium.org>
> > ---
> >  arch/arm64/Kconfig | 2 ++
> >  1 file changed, 2 insertions(+)
> > 
> > diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
> > index ad522b021f35..7016d193864f 100644
> > --- a/arch/arm64/Kconfig
> > +++ b/arch/arm64/Kconfig
> > @@ -72,6 +72,8 @@ config ARM64
> >  	select ARCH_USE_SYM_ANNOTATIONS
> >  	select ARCH_SUPPORTS_MEMORY_FAILURE
> >  	select ARCH_SUPPORTS_SHADOW_CALL_STACK if CC_HAVE_SHADOW_CALL_STACK
> > +	select ARCH_SUPPORTS_LTO_CLANG
> > +	select ARCH_SUPPORTS_THINLTO
> 
> Please don't enable this for arm64 until we have the dependency stuff sorted
> out. I posted patches [1] for this before, but I think they should be part
> of this series as they don't make sense on their own.

Oh, hm. We've been trying to trim down this series, since it's already
quite large. Why can't [1] land first? It would make this easier to deal
with, IMO.

> [1] https://git.kernel.org/pub/scm/linux/kernel/git/will/linux.git/log/?h=rwonce/read-barrier-depends
Will Deacon Oct. 12, 2020, 8:51 p.m. UTC | #3
On Mon, Oct 12, 2020 at 01:44:56PM -0700, Kees Cook wrote:
> On Mon, Oct 12, 2020 at 09:31:16AM +0100, Will Deacon wrote:
> > On Fri, Oct 09, 2020 at 09:13:34AM -0700, Sami Tolvanen wrote:
> > > Allow CONFIG_LTO_CLANG and CONFIG_THINLTO to be enabled.
> > > 
> > > Signed-off-by: Sami Tolvanen <samitolvanen@google.com>
> > > Reviewed-by: Kees Cook <keescook@chromium.org>
> > > ---
> > >  arch/arm64/Kconfig | 2 ++
> > >  1 file changed, 2 insertions(+)
> > > 
> > > diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
> > > index ad522b021f35..7016d193864f 100644
> > > --- a/arch/arm64/Kconfig
> > > +++ b/arch/arm64/Kconfig
> > > @@ -72,6 +72,8 @@ config ARM64
> > >  	select ARCH_USE_SYM_ANNOTATIONS
> > >  	select ARCH_SUPPORTS_MEMORY_FAILURE
> > >  	select ARCH_SUPPORTS_SHADOW_CALL_STACK if CC_HAVE_SHADOW_CALL_STACK
> > > +	select ARCH_SUPPORTS_LTO_CLANG
> > > +	select ARCH_SUPPORTS_THINLTO
> > 
> > Please don't enable this for arm64 until we have the dependency stuff sorted
> > out. I posted patches [1] for this before, but I think they should be part
> > of this series as they don't make sense on their own.
> 
> Oh, hm. We've been trying to trim down this series, since it's already
> quite large. Why can't [1] land first? It would make this easier to deal
> with, IMO.

I'm happy to handle [1] along with the LTO Kconfig change when the time
comes, if that helps. I just don't want to merge dead code!

Will

> > [1] https://git.kernel.org/pub/scm/linux/kernel/git/will/linux.git/log/?h=rwonce/read-barrier-depends
Kees Cook Oct. 12, 2020, 9:02 p.m. UTC | #4
On Mon, Oct 12, 2020 at 09:51:09PM +0100, Will Deacon wrote:
> On Mon, Oct 12, 2020 at 01:44:56PM -0700, Kees Cook wrote:
> > On Mon, Oct 12, 2020 at 09:31:16AM +0100, Will Deacon wrote:
> > > On Fri, Oct 09, 2020 at 09:13:34AM -0700, Sami Tolvanen wrote:
> > > > Allow CONFIG_LTO_CLANG and CONFIG_THINLTO to be enabled.
> > > > 
> > > > Signed-off-by: Sami Tolvanen <samitolvanen@google.com>
> > > > Reviewed-by: Kees Cook <keescook@chromium.org>
> > > > ---
> > > >  arch/arm64/Kconfig | 2 ++
> > > >  1 file changed, 2 insertions(+)
> > > > 
> > > > diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
> > > > index ad522b021f35..7016d193864f 100644
> > > > --- a/arch/arm64/Kconfig
> > > > +++ b/arch/arm64/Kconfig
> > > > @@ -72,6 +72,8 @@ config ARM64
> > > >  	select ARCH_USE_SYM_ANNOTATIONS
> > > >  	select ARCH_SUPPORTS_MEMORY_FAILURE
> > > >  	select ARCH_SUPPORTS_SHADOW_CALL_STACK if CC_HAVE_SHADOW_CALL_STACK
> > > > +	select ARCH_SUPPORTS_LTO_CLANG
> > > > +	select ARCH_SUPPORTS_THINLTO
> > > 
> > > Please don't enable this for arm64 until we have the dependency stuff sorted
> > > out. I posted patches [1] for this before, but I think they should be part
> > > of this series as they don't make sense on their own.
> > 
> > Oh, hm. We've been trying to trim down this series, since it's already
> > quite large. Why can't [1] land first? It would make this easier to deal
> > with, IMO.
> 
> I'm happy to handle [1] along with the LTO Kconfig change when the time
> comes, if that helps. I just don't want to merge dead code!

Okay, understood. Thanks!

> 
> Will
> 
> > > [1] https://git.kernel.org/pub/scm/linux/kernel/git/will/linux.git/log/?h=rwonce/read-barrier-depends
diff mbox series

Patch

diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index ad522b021f35..7016d193864f 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -72,6 +72,8 @@  config ARM64
 	select ARCH_USE_SYM_ANNOTATIONS
 	select ARCH_SUPPORTS_MEMORY_FAILURE
 	select ARCH_SUPPORTS_SHADOW_CALL_STACK if CC_HAVE_SHADOW_CALL_STACK
+	select ARCH_SUPPORTS_LTO_CLANG
+	select ARCH_SUPPORTS_THINLTO
 	select ARCH_SUPPORTS_ATOMIC_RMW
 	select ARCH_SUPPORTS_INT128 if CC_HAS_INT128 && (GCC_VERSION >= 50000 || CC_IS_CLANG)
 	select ARCH_SUPPORTS_NUMA_BALANCING