Re: [PATCH] dynamic debug: move ddebug_remove_module() down into free_module()

[Andrew Morton <akpm@linux-foundation.org>]

On Wed, 14 Jul 2010 16:00:57 -0400
Jason Baron <jbaron@redhat.com> wrote:

> move the call to ddebug_remove_module() down into free_module(). In this way
> it should be called from all error paths. Currently, we are missing the
> remove if the module init routine fails.
> 
> Signed-off-by: Jason Baron <jbaron@redhat.com>
> Reported-by: Thomas Renninger <trenn@suse.de>
> Tested-by: Thomas Renninger <trenn@suse.de>
> CC: akpm@linux-foundation.org
> CC: andi@firstfloor.org
> CC: hare@suse.de
> CC: trenn@suse.de
> CC: yehuda@hq.newdream.net
> CC: linux-kernel@vger.kernel.org

Crappy changelog doesn't describe the bug we're fixing.  It should.

It's

	echo "file ec.c +p" >/sys/kernel/debug/dynamic_debug/control

causes an oops, yes?

> diff --git a/kernel/module.c b/kernel/module.c
> index 5d2d281..6c56282 100644
> --- a/kernel/module.c
> +++ b/kernel/module.c
> @@ -787,7 +787,6 @@ SYSCALL_DEFINE2(delete_module, const char __user *, name_user,
>  
>  	/* Store the name of the last unloaded module for diagnostic purposes */
>  	strlcpy(last_unloaded_module, mod->name, sizeof(last_unloaded_module));
> -	ddebug_remove_module(mod->name);
>  
>  	free_module(mod);
>  	return 0;
> @@ -1550,6 +1549,9 @@ static void free_module(struct module *mod)
>  	remove_sect_attrs(mod);
>  	mod_kobject_remove(mod);
>  
> +	/* Remove dynamic debug info */
> +	ddebug_remove_module(mod->name);
> +
>  	/* Arch-specific cleanup. */
>  	module_arch_cleanup(mod);

Should we backport this into 2.6.34.x?  Earlier?