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Date:   Thu, 5 May 2022 23:35:29 +0200
From:   Andi Shyti <andi.shyti@linux.intel.com>
To:     Mauro Carvalho Chehab <mchehab@kernel.org>
Cc:     Luis Chamberlain <mcgrof@kernel.org>, alsa-devel@alsa-project.org,
        mauro.chehab@linux.intel.com, David Airlie <airlied@linux.ie>,
        Greg KH <gregkh@linuxfoundation.org>,
        intel-gfx@lists.freedesktop.org,
        Lucas De Marchi <lucas.demarchi@intel.com>,
        Takashi Iwai <tiwai@suse.com>, dri-devel@lists.freedesktop.org,
        Jaroslav Kysela <perex@perex.cz>,
        Kai Vehmanen <kai.vehmanen@intel.com>,
        linux-modules@vger.kernel.org,
        Dan Williams <dan.j.williams@intel.com>,
        linux-kernel@vger.kernel.org,
        Pierre-Louis Bossart <pierre-louis.bossart@intel.com>
Subject: Re: [Intel-gfx] [PATCH v5 1/2] module: update dependencies at
 try_module_get()
Message-ID: <YnRDIfthGJXdY23h@intel.intel>
References: <cover.1651348913.git.mchehab@kernel.org>
 <ad2a9fe66cf502e2e2e2325f1f04d0fae36aa82b.1651348913.git.mchehab@kernel.org>
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In-Reply-To: <ad2a9fe66cf502e2e2e2325f1f04d0fae36aa82b.1651348913.git.mchehab@kernel.org>
Precedence: bulk

Hi Mauro,

[...]

> +static int ref_module_dependency(struct module *mod, struct module *this)
> +{
> +	int ret;
> +
> +	if (!this || !this->name)
> +		return -EINVAL;
> +
> +	if (mod == this)
> +		return 0;
> +
> +	mutex_lock(&module_mutex);
> +
> +	ret = ref_module(this, mod);
> +
> +#ifdef CONFIG_MODULE_UNLOAD
> +	if (ret)
> +		goto ret;
> +
> +	ret = sysfs_create_link(mod->holders_dir,
> +				&this->mkobj.kobj, this->name);
> +#endif
> +
> +ret:
> +	mutex_unlock(&module_mutex);
> +	return ret;
> +}
> +
>  /* Clear the unload stuff of the module. */
>  static void module_unload_free(struct module *mod)
>  {
> @@ -841,24 +886,16 @@ void __module_get(struct module *module)
>  }
>  EXPORT_SYMBOL(__module_get);
>  
> -bool try_module_get(struct module *module)
> +bool try_module_get_owner(struct module *module, struct module *this)
>  {
> -	bool ret = true;
> +	int ret = __try_module_get(module);
>  
> -	if (module) {
> -		preempt_disable();
> -		/* Note: here, we can fail to get a reference */
> -		if (likely(module_is_live(module) &&
> -			   atomic_inc_not_zero(&module->refcnt) != 0))
> -			trace_module_get(module, _RET_IP_);
> -		else
> -			ret = false;
> +	if (ret)
> +		ref_module_dependency(module, this);

do we care about the return value here?

Andi

>  
> -		preempt_enable();
> -	}
>  	return ret;
>  }
> -EXPORT_SYMBOL(try_module_get);
> +EXPORT_SYMBOL(try_module_get_owner);
>  
>  void module_put(struct module *module)
>  {
> -- 
> 2.35.1