On Wed, Jan 03, 2024 at 04:31:55PM -0700, Daniel Xu wrote:
> This commit adds support for optional flags on BTF_SET8s.
> struct btf_id_set8 already supported 32 bits worth of flags, but was
> only used for alignment purposes before.
>
> We now use these bits to encode flags. The next commit will tag all
> kfunc sets with a flag so that pahole can recognize which
> BTF_ID_FLAGS(func, ..) are actual kfuncs.
>
> Signed-off-by: Daniel Xu <dxu@xxxxxxxxx>
> ---
> include/linux/btf_ids.h | 14 +++++++++-----
> 1 file changed, 9 insertions(+), 5 deletions(-)
>
> diff --git a/include/linux/btf_ids.h b/include/linux/btf_ids.h
> index a9cb10b0e2e9..88f914579fa1 100644
> --- a/include/linux/btf_ids.h
> +++ b/include/linux/btf_ids.h
> @@ -183,17 +183,21 @@ extern struct btf_id_set name;
> * .word (1 << 3) | (1 << 1) | (1 << 2)
> *
> */
> -#define __BTF_SET8_START(name, scope) \
> +#define ___BTF_SET8_START(name, scope, flags) \
> asm( \
> ".pushsection " BTF_IDS_SECTION ",\"a\"; \n" \
> "." #scope " __BTF_ID__set8__" #name "; \n" \
> "__BTF_ID__set8__" #name ":; \n" \
> -".zero 8 \n" \
> +".zero 4 \n" \
> +".long " #flags "\n" \
> ".popsection; \n");
>
> -#define BTF_SET8_START(name) \
> +#define __BTF_SET8_START(name, scope, flags, ...) \
> +___BTF_SET8_START(name, scope, flags)
> +
> +#define BTF_SET8_START(name, ...) \
> __BTF_ID_LIST(name, local) \
> -__BTF_SET8_START(name, local)
> +__BTF_SET8_START(name, local, ##__VA_ARGS__, 0)
I think it'd better to use something like:
BTF_SET8_KFUNCS_START(fsverity_set_ids)
instead of:
BTF_SET8_START(fsverity_set_ids, BTF_SET8_KFUNC)
and to keep current BTF_SET8_START without flags argument, like:
#define BTF_SET8_START(name) \
__BTF_SET8_START(... , 0, ...
#define BTF_SET8_KFUNCS_START(name) \
__BTF_SET8_START(... , BTF_SET8_KFUNC, ...
also I'd rename BTF_SET8_KFUNC to BTF_SET8_KFUNCS (with S)
do you have the pahole changes somewhere? would be great to
see all the related changes and try the whole thing
jirka
>
> #define BTF_SET8_END(name) \
> asm( \
> @@ -214,7 +218,7 @@ extern struct btf_id_set8 name;
> #define BTF_SET_START(name) static struct btf_id_set __maybe_unused name = { 0 };
> #define BTF_SET_START_GLOBAL(name) static struct btf_id_set __maybe_unused name = { 0 };
> #define BTF_SET_END(name)
> -#define BTF_SET8_START(name) static struct btf_id_set8 __maybe_unused name = { 0 };
> +#define BTF_SET8_START(name, ...) static struct btf_id_set8 __maybe_unused name = { 0 };
> #define BTF_SET8_END(name)
>
> #endif /* CONFIG_DEBUG_INFO_BTF */
> --
> 2.42.1
>
