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From:   Masahiro Yamada <masahiroy@kernel.org>
Date:   Mon, 4 May 2020 16:18:16 +0900
Message-ID: <CAK7LNAQ55OPgiUOdoXDHqD_p3ntiUctqmVhAmO9fRuoq=uAV7g@mail.gmail.com>
Subject: Re: [PATCH v2] scripts: headers_install: Exit with error on config leak
To:     Siddharth Gupta <sidgup@codeaurora.org>
Cc:     Sam Ravnborg <sam@ravnborg.org>,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
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On Sun, May 3, 2020 at 12:29 PM Siddharth Gupta <sidgup@codeaurora.org> wrote:
>
> Misuse of CONFIG_* in UAPI headers should result in an error as it exposes
> configuration of different targets to userspace.


Sorry, I missed to point out this.

This statement is not precious; it does not expose the kernel
configuration at all.

include/generated/autoconf.h is not available from userspace.
So, all the CONFIG options are undefined.

Could you reword the commit somehow?


>
> Signed-off-by: Siddharth Gupta <sidgup@codeaurora.org>
> ---
>  scripts/headers_install.sh | 11 ++++++-----
>  1 file changed, 6 insertions(+), 5 deletions(-)
>
> diff --git a/scripts/headers_install.sh b/scripts/headers_install.sh
> index a07668a..94a8335 100755
> --- a/scripts/headers_install.sh
> +++ b/scripts/headers_install.sh
> @@ -64,7 +64,7 @@ configs=$(sed -e '
>         d
>  ' $OUTFILE)
>
> -# The entries in the following list are not warned.
> +# The entries in the following list do not result in an error.
>  # Please do not add a new entry. This list is only for existing ones.
>  # The list will be reduced gradually, and deleted eventually. (hopefully)
>  #
> @@ -98,18 +98,19 @@ include/uapi/linux/raw.h:CONFIG_MAX_RAW_DEVS
>
>  for c in $configs
>  do
> -       warn=1
> +       leak_error=1
>
>         for ignore in $config_leak_ignores
>         do
>                 if echo "$INFILE:$c" | grep -q "$ignore$"; then
> -                       warn=
> +                       leak_error=
>                         break
>                 fi
>         done
>
> -       if [ "$warn" = 1 ]; then
> -               echo "warning: $INFILE: leak $c to user-space" >&2
> +       if [ "$leak_error" = 1 ]; then
> +               echo "error: $INFILE: leak $c to user-space" >&2
> +               exit 1
>         fi
>  done
>
> --
> Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
> a Linux Foundation Collaborative Project


-- 
Best Regards
Masahiro Yamada