linux-kernel - Re: [PATCH 1/4] modpost: delegate updating namespaces to separate function

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Message-ID: <20191011142426.vwfhw4dtyy4nfzkv@willie-the-truck>
Date:   Fri, 11 Oct 2019 15:24:27 +0100
From:   Will Deacon <will@...nel.org>
To:     Matthias Maennich <maennich@...gle.com>
Cc:     linux-kernel@...r.kernel.org, kernel-team@...roid.com,
        Jessica Yu <jeyu@...nel.org>,
        Masahiro Yamada <yamada.masahiro@...ionext.com>,
        Martijn Coenen <maco@...roid.com>,
        Lucas De Marchi <lucas.de.marchi@...il.com>,
        Shaun Ruffell <sruffell@...ffell.net>,
        Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        linux-kbuild@...r.kernel.org, linux-modules@...r.kernel.org
Subject: Re: [PATCH 1/4] modpost: delegate updating namespaces to separate
 function

On Thu, Oct 10, 2019 at 04:14:40PM +0100, Matthias Maennich wrote:
> Let the function 'sym_update_namespace' take care of updating the
> namespace for a symbol. While this currently only replaces one single
> location where namespaces are updated, in a following patch, this
> function will get more call sites.
> 
> The function signature is intentionally close to sym_update_crc and
> taking the name by char* seems like unnecessary work as the symbol has
> to be looked up again. In a later patch of this series, this concern
> will be addressed.
> 
> This function ensures that symbol::namespace is either NULL or has a
> valid non-empty value. Previously, the empty string was considered 'no
> namespace' as well and this lead to confusion.
> 
> Signed-off-by: Matthias Maennich <maennich@...gle.com>
> ---
>  scripts/mod/modpost.c | 21 ++++++++++++++++++---
>  1 file changed, 18 insertions(+), 3 deletions(-)
> 
> diff --git a/scripts/mod/modpost.c b/scripts/mod/modpost.c
> index 4d2cdb4d71e3..9f5dcdff4d2f 100644
> --- a/scripts/mod/modpost.c
> +++ b/scripts/mod/modpost.c
> @@ -362,6 +362,22 @@ static char *sym_extract_namespace(const char **symname)
>  	return namespace;
>  }
>  
> +static void sym_update_namespace(const char *symname, const char *namespace)
> +{
> +       struct symbol *s = find_symbol(symname);
> +       /* That symbol should have been created earlier and thus this is
> +        * actually an assertion. */
> +       if (!s) {
> +               merror("Could not update namespace(%s) for symbol %s\n",
> +                      namespace, symname);
> +               return;
> +       }
> +
> +       free(s->namespace);
> +       s->namespace =
> +	       namespace && namespace[0] ? NOFAIL(strdup(namespace)) : NULL;
> +}

You made me look up C operator precedence again, but it's fine so:

Acked-by: Will Deacon <will@...nel.org>

Will