Re: [PATCH v2 0/4] export/modpost: avoid renaming __ksymtab entries for symbol namespaces

[Jessica Yu]

+++ Matthias Maennich [18/10/19 10:31 +0100]:
> The introduction of the symbol namespace patches changed the way symbols are
> named in the ksymtab entries. That caused userland tools to fail (such as
> kmod's depmod). As depmod is used as part of the kernel build it was worth
> having another look whether this name change can be avoided.
>
> The main purpose of this series is to restore the original ksymtab entry names.
> For that to happen and to remove some rough edges around that, the relevant
> parts in modpost got a small refactoring as to when and how namespaces are
> evaluated and set in the symbol struct.
>
> Eventually, the namespace values can be read from __kstrtabns_ entries and
> their corresponding __ksymtab_strings values. That removes the need to carry
> the namespace names within the (anyway unique) symbol name entries.
>
> The last patch of this series is adopted from Masahiro [1]. By allowing 'no
> namespace' to be represented as empty string, large chunks of
> include/linux/export.h could be consolidated. Technically, this last patch is
> not absolutely necessary to fix functionality. It addresses concerns about
> maintainability and readability. While I strongly suggest sending all of the
> patches for 5.4, the last one could possible deferred to the next merge window.
>
> This patch applies to the modules-linus [2] branch.

Hi!

I've applied the first three patches to modules-linus, inbound for -rc5.

Patch 4/4 was agreed to be for 5.5, and will be applied to
modules-next once I rebase that branch against -rc5.

Thanks!

Jessica

> Changes since v2:
> - restored correct authorship for [4/4]
> - add missing contributor tags
> - fixed typos and code style (spaces/tabs)
>
> [1] https://lore.kernel.org/lkml/20190927093603.9140-5-yamada.masahiro@xxxxxxxxxxxxx/
> [2] https://git.kernel.org/pub/scm/linux/kernel/git/jeyu/linux.git/log/?h=modules-linus
>
> Cc: Jessica Yu <jeyu@xxxxxxxxxx>
> Cc: Masahiro Yamada <yamada.masahiro@xxxxxxxxxxxxx>
> Cc: Martijn Coenen <maco@xxxxxxxxxxx>
> Cc: Lucas De Marchi <lucas.de.marchi@xxxxxxxxx>
> Cc: Shaun Ruffell <sruffell@xxxxxxxxxxxx>
> Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
> Cc: Will Deacon <will@xxxxxxxxxx>
> Cc: linux-kbuild@xxxxxxxxxxxxxxx
> Cc: linux-modules@xxxxxxxxxxxxxxx
>
>
> Masahiro Yamada (1):
>  export: avoid code duplication in include/linux/export.h
>
> Matthias Maennich (3):
>  modpost: delegate updating namespaces to separate function
>  modpost: make updating the symbol namespace explicit
>  symbol namespaces: revert to previous __ksymtab name scheme
>
> include/linux/export.h | 97 +++++++++++++-----------------------------
> kernel/module.c        |  2 +-
> scripts/mod/modpost.c  | 59 ++++++++++++++++---------
> scripts/mod/modpost.h  |  1 +
> 4 files changed, 71 insertions(+), 88 deletions(-)
>
> Interdiff against v1:
> diff --git a/scripts/mod/modpost.c b/scripts/mod/modpost.c
> index 7cf0065ac95f..0bf7eab80d9f 100644
> --- a/scripts/mod/modpost.c
> +++ b/scripts/mod/modpost.c
> @@ -357,18 +357,21 @@ static const char *namespace_from_kstrtabns(struct elf_info *info,
>
> 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;
> +	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;
> }
>
> /**
> --
> 2.23.0.866.gb869b98d4c-goog