Re: [BUG] x86_64: build failure in switch_fpu() due to missing x86_task_fpu() declaration (v6.16)

[H. Peter Anvin]

On August 8, 2025 6:18:12 PM PDT, andreasx0 <andreasx0@xxxxxxxxxxxxxx> wrote:
>Hello,
>When building Linux kernel v6.16 for x86_64, I encountered a build failure:
>
>  In file included from arch/x86/kernel/process_64.c:46:
>  ./arch/x86/include/asm/fpu/sched.h:37:39: error: implicit declaration of function ‘x86_task_fpu’; did you mean ‘set_task_cpu’? [-Wimplicit-function-declaration]
>     37 |                 struct fpu *old_fpu = x86_task_fpu(old);
>        |                                       ^~~~~~~~~~~~
>        |                                       set_task_cpu
>  ./arch/x86/include/asm/fpu/sched.h:37:39: error: initialization of ‘struct fpu *’ from ‘int’ makes pointer from integer without a cast [-Wint-conversion]
>
>
>Thanks
What is your .config file?