linux-kernel - Re: [PATCH 2/4] modpost: make updating the symbol namespace explict

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Message-ID: <20191011142437.ypdp7fni4jk43dnv@willie-the-truck>
Date:   Fri, 11 Oct 2019 15:24:38 +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 2/4] modpost: make updating the symbol namespace explict

On Thu, Oct 10, 2019 at 04:14:41PM +0100, Matthias Maennich wrote:
> Setting the symbol namespace of a symbol within sym_add_exported feels
> displaced and lead to issues in the current implementation of symbol
> namespaces. This patch makes updating the namespace an explicit call to
> decouple it from adding a symbol to the export list.
> 
> Signed-off-by: Matthias Maennich <maennich@...gle.com>
> ---
>  scripts/mod/modpost.c | 12 ++++++------
>  1 file changed, 6 insertions(+), 6 deletions(-)
> 
> diff --git a/scripts/mod/modpost.c b/scripts/mod/modpost.c
> index 9f5dcdff4d2f..46137b730447 100644
> --- a/scripts/mod/modpost.c
> +++ b/scripts/mod/modpost.c
> @@ -382,8 +382,8 @@ static void sym_update_namespace(const char *symname, const char *namespace)
>   * Add an exported symbol - it may have already been added without a
>   * CRC, in this case just update the CRC
>   **/
> -static struct symbol *sym_add_exported(const char *name, const char *namespace,
> -				       struct module *mod, enum export export)
> +static struct symbol *sym_add_exported(const char *name, struct module *mod,
> +				       enum export export)
>  {
>  	struct symbol *s = find_symbol(name);
>  
> @@ -399,7 +399,6 @@ static struct symbol *sym_add_exported(const char *name, const char *namespace,
>  			s->module = mod;
>  		}
>  	}
> -	sym_update_namespace(name, namespace);
>  	s->preloaded = 0;
>  	s->vmlinux   = is_vmlinux(mod->name);
>  	s->kernel    = 0;
> @@ -761,7 +760,8 @@ static void handle_modversions(struct module *mod, struct elf_info *info,
>  		if (strstarts(symname, "__ksymtab_")) {
>  			name = symname + strlen("__ksymtab_");
>  			namespace = sym_extract_namespace(&name);
> -			sym_add_exported(name, namespace, mod, export);
> +			sym_add_exported(name, mod, export);
> +			sym_update_namespace(name, namespace);
>  			free(namespace);
>  		}
>  		if (strcmp(symname, "init_module") == 0)
> @@ -2469,12 +2469,12 @@ static void read_dump(const char *fname, unsigned int kernel)
>  			mod = new_module(modname);
>  			mod->skip = 1;
>  		}
> -		s = sym_add_exported(symname, namespace, mod,
> -				     export_no(export));
> +		s = sym_add_exported(symname, mod, export_no(export));
>  		s->kernel    = kernel;
>  		s->preloaded = 1;
>  		s->is_static = 0;
>  		sym_update_crc(symname, mod, crc, export_no(export));
> +		sym_update_namespace(symname, namespace);

This changes the order wrt setting the namespace and sym_update_crc(), but
that doesn't seem to matter, so:

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

Will