linux-kernel - Re: [PATCH 7/7] driver-core : convert semaphore to mutex in struct class

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 for Android: free password hash cracker in your pocket

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

Message-ID: <20080116083442.GA2307@ff.dom.local>
Date:	Wed, 16 Jan 2008 09:34:43 +0100
From:	Jarek Poplawski <jarkao2@...il.com>
To:	Dave Young <hidave.darkstar@...il.com>
Cc:	Greg KH <gregkh@...e.de>, stefanr@...6.in-berlin.de,
	david-b@...bell.net, stern@...land.harvard.edu,
	linux-kernel@...r.kernel.org
Subject: Re: [PATCH 7/7] driver-core : convert semaphore to mutex in struct
	class

On Wed, Jan 16, 2008 at 09:03:03AM +0800, Dave Young wrote:
...
> The lockdep warining was posted in the below thread, actually, I have
> built and run this patced kernel for several days, there's no more
> warnings.
> http://lkml.org/lkml/2008/1/3/2

Right... But, with something like this:

... have_some_fun(... cls)
{
	mutex_lock_nested(&cls->mutex, SINGLE_DEPTH_NESTING);
	have_other_fun(cls);
	mutex_unlock(&cls->mutex);

}

... have_more_fun(...)
{
	...

	mutex_init(&cls->mutex);

	mutex_lock(&cls->mutex);
	have_some_fun(cls);
	mutex_unlock(&cls->mutex);
}

probably you wouldn't get any lockdep warning too...

Of course, if we know all the locking is right such proper lockdep
annotating shouldn't matter too much. (And of course this could be
improved later.)

Regards,
Jarek P.
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/