Re: [PATCH] tracing: fprobe: Remove __packed from generic __fprobe_header

[Masami Hiramatsu (Google) <mhiramat@kernel.org>]

Hi Markus,

Thanks for ping me.

On Tue, 28 Apr 2026 10:30:29 +0200
"Markus Schneider-Pargmann (The Capable Hub)" <msp@baylibre.com> wrote:

> fp pointer and unsigned long have the same size on all relevant
> architectures that build Linux. Furthermore this struct is only used in
> architectures that do not set ARCH_DEFINE_ENCODE_FPROBE_HEADER which is
> set only for 64bit architectures (apart from LoongArch).
> 
> Both fields are aligned on these architectures so the struct with
> __packed and without it are the same.
> 
> Remove the __packed as it is unnecessary.
> 
> Fixes: 4346ba160409 ("fprobe: Rewrite fprobe on function-graph tracer")

NOTE: This is not a Fix, but just cleanup or minor update. Or, you have
any problem with this __packed attribute?

Unless there is no problem (or any concern), I would like to keep this
as it is.

Thank you,

> Signed-off-by: Markus Schneider-Pargmann (The Capable Hub) <msp@baylibre.com>
> ---
>  kernel/trace/fprobe.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/kernel/trace/fprobe.c b/kernel/trace/fprobe.c
> index cc49ebd2a773..21751dcdb7b9 100644
> --- a/kernel/trace/fprobe.c
> +++ b/kernel/trace/fprobe.c
> @@ -181,7 +181,7 @@ static inline void read_fprobe_header(unsigned long *stack,
>  struct __fprobe_header {
>  	struct fprobe *fp;
>  	unsigned long size_words;
> -} __packed;
> +};
>  
>  #define FPROBE_HEADER_SIZE_IN_LONG	SIZE_IN_LONG(sizeof(struct __fprobe_header))
>  
> 
> ---
> base-commit: 254f49634ee16a731174d2ae34bc50bd5f45e731
> change-id: 20260427-topic-fprobe-packed-v7-1-f44f9bbdedf6
> 
> Best regards,
> --  
> Markus Schneider-Pargmann (The Capable Hub) <msp@baylibre.com>
> 


-- 
Masami Hiramatsu (Google) <mhiramat@kernel.org>