Re: [PATCH] scripts: dummy-tools, add pahole

From: Masahiro Yamada
Date: Thu Apr 14 2022 - 05:35:48 EST


On Thu, Apr 14, 2022 at 6:14 PM Jiri Slaby <jslaby@xxxxxxx> wrote:
>
> CONFIG_PAHOLE_VERSION is a part of a config since the commit below. And
> when multiple people update the config, this value constantly changes.
> Even if they use dummy scripts.
>
> To fix this:
> * add a pahole dummy script returning v99.99 -> 9999
> * call it in Makefile taking CROSS_COMPILE into account.
>
> The latter happens only if $(CROSS_COMPILE)pahole really exists. This is
> because a cross pahole likely exists only in dummy tools now, not in
> real cross tools.


I do not think this is the right thing to do.

(As I said somewhere, I am opposed to checking pahole version in Kconfig).


Also, $(CROSS_COMPILE)pahole looks insane.

You can create a dummy pahole in your local system.

$ echo 'echo v99.99' > $HOME/bin/dummy-pahole
$ chmod +x $HOME/bin/dummy-pahole
$ make CROSS_COMPILE=scripts/dummy-tools PAHOLE=dummy-pahole menuconfig









> Fixes: 613fe1692377 (kbuild: Add CONFIG_PAHOLE_VERSION)
> Cc: Masahiro Yamada <masahiroy@xxxxxxxxxx>
> Cc: Michal Marek <michal.lkml@xxxxxxxxxxx>
> Cc: Nick Desaulniers <ndesaulniers@xxxxxxxxxx>
> Cc: linux-kbuild@xxxxxxxxxxxxxxx
> Signed-off-by: Jiri Slaby <jslaby@xxxxxxx>
> ---
> Makefile | 2 +-
> scripts/dummy-tools/pahole | 4 ++++
> 2 files changed, 5 insertions(+), 1 deletion(-)
> create mode 100755 scripts/dummy-tools/pahole
>
> diff --git a/Makefile b/Makefile
> index ecbd42f3451a..2ef722ba0a41 100644
> --- a/Makefile
> +++ b/Makefile
> @@ -502,7 +502,7 @@ RUSTFMT = rustfmt
> CLIPPY_DRIVER = clippy-driver
> BINDGEN = bindgen
> CARGO = cargo
> -PAHOLE = pahole
> +PAHOLE = $(if $(wildcard $(CROSS_COMPILE)pahole),$(CROSS_COMPILE)pahole,pahole)
> RESOLVE_BTFIDS = $(objtree)/tools/bpf/resolve_btfids/resolve_btfids
> LEX = flex
> YACC = bison
> diff --git a/scripts/dummy-tools/pahole b/scripts/dummy-tools/pahole
> new file mode 100755
> index 000000000000..53501a36fa71
> --- /dev/null
> +++ b/scripts/dummy-tools/pahole
> @@ -0,0 +1,4 @@
> +#!/bin/sh
> +# SPDX-License-Identifier: GPL-2.0-only
> +
> +echo v99.99
> --
> 2.35.2
>


--
Best Regards
Masahiro Yamada