linux-kernel - Re: [PATCH v3 03/11] devm-helpers: introduce devm_mutex

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <CAHp75Vc1zZFWB8PPrg8oeAKz9aHnQrrSjdGyGd8mWcmeZdJ9qA@mail.gmail.com>
Date:   Thu, 14 Dec 2023 00:36:31 +0200
From:   Andy Shevchenko <andy.shevchenko@...il.com>
To:     George Stark <gnstark@...utedevices.com>
Cc:     pavel@....cz, lee@...nel.org, vadimp@...dia.com,
        mpe@...erman.id.au, npiggin@...il.com, christophe.leroy@...roup.eu,
        hdegoede@...hat.com, mazziesaccount@...il.com,
        peterz@...radead.org, mingo@...hat.com, will@...nel.org,
        longman@...hat.com, boqun.feng@...il.com, nikitos.tr@...il.com,
        linux-leds@...r.kernel.org, linux-kernel@...r.kernel.org,
        linuxppc-dev@...ts.ozlabs.org, kernel@...utedevices.com
Subject: Re: [PATCH v3 03/11] devm-helpers: introduce devm_mutex_init

On Thu, Dec 14, 2023 at 12:30 AM George Stark <gnstark@...utedevices.com> wrote:
>
> Using of devm API leads to a certain order of releasing resources.
> So all dependent resources which are not devm-wrapped should be deleted
> with respect to devm-release order. Mutex is one of such objects that
> often is bound to other resources and has no own devm wrapper.
> Since mutex_destroy() actually does nothing in non-debug builds
> frequently calling mutex_destroy() is just ignored which is safe for now
> but wrong formally and can lead to a problem if mutex_destroy() is
> extended so introduce devm_mutex_init().

...

> +#ifdef mutex_destroy
> +static inline void devm_mutex_release(void *res)
> +{
> +       mutex_destroy(res);
> +}
> +#endif
> +
> +/**
> + * devm_mutex_init - Resource-managed mutex initialization
> + * @dev:       Device which lifetime mutex is bound to
> + * @lock:      Pointer to a mutex
> + *
> + * Initialize mutex which is automatically destroyed when the driver is detached.
> + *
> + * Returns: 0 on success or a negative error code on failure.
> + */
> +static inline int devm_mutex_init(struct device *dev, struct mutex *lock)
> +{
> +       mutex_init(lock);
> +#ifdef mutex_destroy
> +       return devm_add_action_or_reset(dev, devm_mutex_release, lock);
> +#else
> +       return 0;
> +#endif
> +}

If this is going to be accepted, you may decrease the amount of ifdeffery.

#ifdef ...
#else
#define devm_mutex_init(dev, lock)  mutex_init(lock)
#endif


-- 
With Best Regards,
Andy Shevchenko