linux-modules.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Lucas De Marchi <lucas.de.marchi@gmail.com>
To: Takashi Iwai <tiwai@suse.de>
Cc: linux-modules <linux-modules@vger.kernel.org>,
	"Michal Suchánek" <msuchanek@suse.cz>
Subject: Re: [PATCH] modinfo: don't parse built-in for explicitly given module files
Date: Wed, 18 Aug 2021 12:13:24 -0700	[thread overview]
Message-ID: <CAKi4VAJVvY3=JdSZm-GD1hJqyCPYaYz-jBJ_REeY5BakVb6_ww@mail.gmail.com> (raw)
In-Reply-To: <20210818112203.24863-1-tiwai@suse.de>

On Wed, Aug 18, 2021 at 4:23 AM Takashi Iwai <tiwai@suse.de> wrote:
>
> A recent bug report showed that modinfo doesn't give the signature
> information for certain modules, and it turned out to happen only on
> the modules that are built-in on the running kernel; then modinfo
> skips the signature check, as if the target module file never exists.
> The behavior is, however, inconsistent when modinfo is performed for
> external modules (no matter which kernel version is) and the module
> file path is explicitly given by a command-line argument, which
> guarantees the presence of the module file itself.
>
> This patch addresses the regression by checking the presence of the
> module path at first before checking the built-in module.
>
> Fixes: e7e2cb61fa9f ("modinfo: Show information about built-in modules")
> BugLink: https://bugzilla.opensuse.org/show_bug.cgi?id=1189537
> Signed-off-by: Takashi Iwai <tiwai@suse.de>
> ---
>  libkmod/libkmod-module.c | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/libkmod/libkmod-module.c b/libkmod/libkmod-module.c
> index 6e0ff1a99604..9e878a5345a1 100644
> --- a/libkmod/libkmod-module.c
> +++ b/libkmod/libkmod-module.c
> @@ -2292,7 +2292,8 @@ KMOD_EXPORT int kmod_module_get_info(const struct kmod_module *mod, struct kmod_
>         assert(*list == NULL);
>
>         /* remove const: this can only change internal state */
> -       if (kmod_module_is_builtin((struct kmod_module *)mod)) {
> +       if (!kmod_module_get_path(mod) &&
> +           kmod_module_is_builtin((struct kmod_module *)mod)) {

thanks for spotting this... but I'm not sure this is the right fix.
kmod_module_is_builtin() shouldn't return true if the module was
created by path rather than lookup. It seems we should rather set
mod->builtin = KMOD_MODULE_BUILTIN_NO in
kmod_module_new_from_path(). This would also fix the use of
kmod_module_is_builtin() directly by applications.

Since the builtin check uses lazy initialization,  the default is
KMOD_MODULE_BUILTIN_UNKNOWN, hence the bug here.

Lucas De Marchi

>                 count = kmod_builtin_get_modinfo(mod->ctx,
>                                                 kmod_module_get_name(mod),
>                                                 &strings);
> --
> 2.26.2
>

  parent reply	other threads:[~2021-08-18 19:13 UTC|newest]

Thread overview: 9+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-08-18 11:22 Takashi Iwai
2021-08-18 11:41 ` Michal Suchánek
2021-08-18 12:05 ` Petr Vorel
2021-08-18 19:13 ` Lucas De Marchi [this message]
2021-08-18 20:52   ` [PATCH] libkmod: Set builtin to no when module is created from path Michal Suchanek
2021-08-18 21:23     ` Lucas De Marchi
2021-08-18 21:24     ` [PATCH v2] " Lucas De Marchi
2021-08-18 21:24       ` [PATCH] " Lucas De Marchi
2021-08-19 15:28       ` [PATCH v2] " Petr Vorel

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to='CAKi4VAJVvY3=JdSZm-GD1hJqyCPYaYz-jBJ_REeY5BakVb6_ww@mail.gmail.com' \
    --to=lucas.de.marchi@gmail.com \
    --cc=linux-modules@vger.kernel.org \
    --cc=msuchanek@suse.cz \
    --cc=tiwai@suse.de \
    --subject='Re: [PATCH] modinfo: don'\''t parse built-in for explicitly given module files' \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).