Re: [PATCH 08/46] static_call, lto: Mark static keys as __visible

Josh Poimboeuf
2022-11-14T18:57:26Z

On Mon, Nov 14, 2022 at 12:43:06PM +0100, Jiri Slaby (SUSE) wrote:
> From: Andi Kleen <andi@firstfloor.org>
>
> Symbols referenced from assembler (either directly or e.f. from
> DEFINE_STATIC_KEY()) need to be global and visible in gcc LTO because
> they could end up in a different object file than the assembler. This
> can lead to linker errors without this patch.
>
> So mark static call functions as __visible, namely static keys here.
>
> Cc: Peter Zijlstra <peterz@infradead.org>
> Cc: Josh Poimboeuf <jpoimboe@kernel.org>
> Cc: Jason Baron <jbaron@akamai.com>
> Cc: Steven Rostedt <rostedt@goodmis.org>
> Cc: Ard Biesheuvel <ardb@kernel.org>
> Signed-off-by: Andi Kleen <andi@firstfloor.org>
> Signed-off-by: Martin Liska <mliska@suse.cz>
> Signed-off-by: Jiri Slaby <jslaby@suse.cz>
> ---
> include/linux/static_call.h | 12 ++++++------
> 1 file changed, 6 insertions(+), 6 deletions(-)
>
> diff --git a/include/linux/static_call.h b/include/linux/static_call.h
> index df53bed9d71f..e629ab0c4ca3 100644
> --- a/include/linux/static_call.h
> +++ b/include/linux/static_call.h
> @@ -182,7 +182,7 @@ extern long __static_call_return0(void);
>
> #define DEFINE_STATIC_CALL(name, _func) \
> DECLARE_STATIC_CALL(name, _func); \
> - struct static_call_key STATIC_CALL_KEY(name) = { \
> + __visible struct static_call_key STATIC_CALL_KEY(name) = { \

Why not __visible_on_lto?

--
Josh