linux-kernel - Re: [PATCH] debugfs: don't access 4 bytes for a boolean

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Message-ID: <20150914153102.GE32551@linux>
Date:	Mon, 14 Sep 2015 21:01:02 +0530
From:	Viresh Kumar <viresh.kumar@...aro.org>
To:	Arnd Bergmann <arnd@...db.de>
Cc:	linaro-kernel@...ts.linaro.org, gregkh@...uxfoundation.org,
	sboyd@...eaurora.org, Rafael Wysocki <rjw@...ysocki.net>,
	open list <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH] debugfs: don't access 4 bytes for a boolean

On 14-09-15, 17:25, Arnd Bergmann wrote:
> I'd say that the argument to debugfs_create_bool() has to match the
> access in the functions you are modifying, as well as whatever
> gets passed into it by callers.
> 
> By accessing only the first byte, you break all drivers that
> call debugfs_create_bool() with a four-byte argument, at least
> on big-endian systems!
> 
> If we change any part of this, we need to audit the existing 31 callers
> of the function and change them all to use a bool type.

Right, so I have already sent a new version of this patch which should
be able to take care of stuff you pointed out.

> In the problem that you saw, what prevented gcc from printing a
> compile-time warning about debugfs_create_bool() being called with
> a bool argument?

A forced cast to u32 * :)

-- 
viresh
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