Re: [PATCH] powerpc/interrupt: Put braces around empty body in an 'if' statement

[Christophe Leroy]

Le 19/06/2022 à 05:11, Souptick Joarder a écrit :
> From: "Souptick Joarder (HPE)" <jrdr.linux@xxxxxxxxx>
> 
> Kernel test robot throws warning ->
> 
> arch/powerpc/kernel/interrupt.c:
> In function 'interrupt_exit_kernel_prepare':
> 
>>> arch/powerpc/kernel/interrupt.c:542:55: warning: suggest
> braces around empty body in an 'if' statement [-Wempty-body]
>       542 |                 CT_WARN_ON(ct_state() == CONTEXT_USER);
> 
> Fix it by adding braces.

There must be no braces for single 'if' statement , see 
https://docs.kernel.org/process/coding-style.html#placing-braces-and-spaces

The problem is likely that CT_WARN_ON() is empty in some CONFIGs.
You have to fix it, for instance by changing it to a "do { } while (0)"

> 
> Reported-by: Kernel test robot <lkp@xxxxxxxxx>
> Signed-off-by: Souptick Joarder (HPE) <jrdr.linux@xxxxxxxxx>
> ---
>   arch/powerpc/kernel/interrupt.c | 3 ++-
>   1 file changed, 2 insertions(+), 1 deletion(-)
> 
> diff --git a/arch/powerpc/kernel/interrupt.c b/arch/powerpc/kernel/interrupt.c
> index 784ea3289c84..b8a918bab48f 100644
> --- a/arch/powerpc/kernel/interrupt.c
> +++ b/arch/powerpc/kernel/interrupt.c
> @@ -538,8 +538,9 @@ notrace unsigned long interrupt_exit_kernel_prepare(struct pt_regs *regs)
>           * CT_WARN_ON comes here via program_check_exception,
>           * so avoid recursion.
>           */
> -       if (TRAP(regs) != INTERRUPT_PROGRAM)
> +       if (TRAP(regs) != INTERRUPT_PROGRAM) {
>                  CT_WARN_ON(ct_state() == CONTEXT_USER);
> +       }
> 
>          kuap = kuap_get_and_assert_locked();
> 
> --
> 2.25.1
>