Re: [PATCH] kbuild: avoid scripts/kallsyms parsing /dev/null

From: Daniel Gomez
Date: Wed Aug 07 2024 - 15:03:30 EST


On Thu, Aug 08, 2024 at 03:03:00AM GMT, Masahiro Yamada wrote:
> On macOS, getline() sets ENOTTY to errno if it is requested to read
> from /dev/null.
>
> If this is worth fixing, I would rather pass an empty file to
> scripts/kallsyms instead of adding the ugly #ifdef __APPLE__.
>
> Fixes: c442db3f49f2 ("kbuild: remove PROVIDE() for kallsyms symbols")
> Reported-by: Daniel Gomez <da.gomez@xxxxxxxxxxx>
> Closes: https://lore.kernel.org/all/20240807-macos-build-support-v1-12-4cd1ded85694@xxxxxxxxxxx/
> Signed-off-by: Masahiro Yamada <masahiroy@xxxxxxxxxx>
> ---
>
> scripts/link-vmlinux.sh | 3 ++-
> 1 file changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/scripts/link-vmlinux.sh b/scripts/link-vmlinux.sh
> index f7b2503cdba9..41c68ae3415d 100755
> --- a/scripts/link-vmlinux.sh
> +++ b/scripts/link-vmlinux.sh
> @@ -219,7 +219,8 @@ kallsymso=
> strip_debug=
>
> if is_enabled CONFIG_KALLSYMS; then
> - kallsyms /dev/null .tmp_vmlinux0.kallsyms
> + truncate -s0 .tmp_vmlinux.kallsyms0.syms

This looks nicer. Thanks for a quick alternative!

I prefer self explained commands and use the larger argument if available:
truncate --size=0 .tmp_vmlinux.kallsyms0.syms

But other than that, LGTM.

Reviewed-by: Daniel Gomez <da.gomez@xxxxxxxxxxx>

> + kallsyms .tmp_vmlinux.kallsyms0.syms .tmp_vmlinux0.kallsyms
> fi
>
> if is_enabled CONFIG_KALLSYMS || is_enabled CONFIG_DEBUG_INFO_BTF; then
> --
> 2.43.0
>