Re: [PATCH] mn10300: fix build error of missing fpu_save()

From: David Howells
Date: Mon Jan 23 2017 - 18:26:25 EST


Randy Dunlap <rdunlap@xxxxxxxxxxxxx> wrote:

> b. make <asm/switch_to.h> know about CONFIG_FPU not enabled
>
> David, which one do you prefer?

b.

> From: Randy Dunlap <rdunlap@xxxxxxxxxxxxx>
>
> When CONFIG_FPU is not enabled on arch/mn10300, <asm/switch_to.h>
> causes a build error with a call to fpu_save():
>
> kernel/built-in.o: In function `.L410':
> core.c:(.sched.text+0x28a): undefined reference to `fpu_save'
>
> Fix this by defining switch_fpu() in <asm/switch_to.h> only when
> CONFIG_FPU is enabled.
>
> Signed-off-by: Randy Dunlap <rdunlap@xxxxxxxxxxxxx>
> Reported-by: kbuild test robot <fengguang.wu@xxxxxxxxx>
> Cc: David Howells <dhowells@xxxxxxxxxx>
> ---
> arch/mn10300/include/asm/switch_to.h | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> --- lnx-410-rc4.orig/arch/mn10300/include/asm/switch_to.h
> +++ lnx-410-rc4/arch/mn10300/include/asm/switch_to.h
> @@ -16,7 +16,7 @@
> struct task_struct;
> struct thread_struct;
>
> -#if !defined(CONFIG_LAZY_SAVE_FPU)
> +#if defined(CONFIG_FPU) && !defined(CONFIG_LAZY_SAVE_FPU)
> struct fpu_state_struct;
> extern asmlinkage void fpu_save(struct fpu_state_struct *);
> #define switch_fpu(prev, next) \

Reviewed-by: David Howells <dhowells@xxxxxxxxxx>