Re: [PATCH v1] module: Fix prefix for module.sig_enforce module param

From: Aaron Tomlin <atomlin@redhat.com>
To: Saravana Kannan <saravanak@google.com>
Cc: Luis Chamberlain <mcgrof@kernel.org>,
	Christophe Leroy <christophe.leroy@csgroup.eu>,
	cl@linux.com, mbenes@suse.cz, akpm@linux-foundation.org,
	jeyu@kernel.org, linux-kernel@vger.kernel.org,
	linux-modules@vger.kernel.org, void@manifault.com,
	atomlin@atomlin.com, allen.lkml@gmail.com, joe@perches.com,
	msuchanek@suse.de, oleksandr@natalenko.name,
	jason.wessel@windriver.com, pmladek@suse.com,
	daniel.thompson@linaro.org, hch@infradead.org,
	kernel-team@android.com
Subject: Re: [PATCH v1] module: Fix prefix for module.sig_enforce module param
Date: Thu, 2 Jun 2022 20:35:13 +0100	[thread overview]
Message-ID: <20220602193513.ppya4als32dkvv4l@ava.usersys.com> (raw)
In-Reply-To: <20220602035653.4167316-1-saravanak@google.com>

On Wed 2022-06-01 20:56 -0700, Saravana Kannan wrote:
> Commit cfc1d277891e ("module: Move all into module/") changed the prefix
> of the module param by moving/renaming files. A later commit also moves
> the module_param() into a different file, thereby changing the prefix
> yet again.
> 
> This would break kernel cmdline compatibility and also userspace
> compatibility at /sys/module/module/parameters/sig_enforce.
> 
> So, set the prefix back to "module.".
> 
> Cc: Aaron Tomlin <atomlin@redhat.com>
> Cc: mcgrof@kernel.org
> Cc: christophe.leroy@csgroup.eu
> Cc: cl@linux.com
> Cc: mbenes@suse.cz
> Cc: akpm@linux-foundation.org
> Cc: jeyu@kernel.org
> Cc: linux-kernel@vger.kernel.org
> Cc: linux-modules@vger.kernel.org
> Cc: void@manifault.com
> Cc: atomlin@atomlin.com
> Cc: allen.lkml@gmail.com
> Cc: joe@perches.com
> Cc: msuchanek@suse.de
> Cc: oleksandr@natalenko.name
> Cc: jason.wessel@windriver.com
> Cc: pmladek@suse.com
> Cc: daniel.thompson@linaro.org
> Cc: hch@infradead.org
> Fixes: cfc1d277891e ("module: Move all into module/")
> Signed-off-by: Saravana Kannan <saravanak@google.com>
> ---
> Sending this patch in case my analysis in [1] was right.
> 
> [1] - https://lore.kernel.org/lkml/20220602034111.4163292-1-saravanak@google.com/
> 
> -Saravana
> 
>  kernel/module/signing.c | 5 +++++
>  1 file changed, 5 insertions(+)
> 
> diff --git a/kernel/module/signing.c b/kernel/module/signing.c
> index 85c8999dfecf..6b0672e4417b 100644
> --- a/kernel/module/signing.c
> +++ b/kernel/module/signing.c
> @@ -16,6 +16,11 @@
>  #include <uapi/linux/module.h>
>  #include "internal.h"
>  
> +#ifdef MODULE_PARAM_PREFIX
> +#undef MODULE_PARAM_PREFIX
> +#endif
> +#define MODULE_PARAM_PREFIX "module."
> +
>  static bool sig_enforce = IS_ENABLED(CONFIG_MODULE_SIG_FORCE);
>  module_param(sig_enforce, bool_enable_only, 0644);
>  
> -- 
> 2.36.1.255.ge46751e96f-goog
> 

Oops! Thanks Saravana.

Reviewed-by: Aaron Tomlin <atomlin@redhat.com>

-- 
Aaron Tomlin