linux-kernel - Re: [PATCH] power: supply: sbs-battery: simplify DT parsing

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]

Date:   Wed, 7 Sep 2016 01:55:23 +0200
From:   Sebastian Reichel <sre@...nel.org>
To:     Arnd Bergmann <arnd@...db.de>
Cc:     Phil Reid <preid@...ctromag.com.au>,
        YH Huang <yh.huang@...iatek.com>,
        Joshua Clayton <stillcompiling@...il.com>,
        linux-pm@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH] power: supply: sbs-battery: simplify DT parsing

Hi Arnd,

On Tue, Sep 06, 2016 at 03:16:33PM +0200, Arnd Bergmann wrote:
> After the change to use the gpio descriptor interface, we get a warning if
> -Wmaybe-uninitialized is added back to the build flags (it is currently
> disabled:
> 
> drivers/power/supply/sbs-battery.c: In function 'sbs_probe':
> drivers/power/supply/sbs-battery.c:760:28: error: 'pdata' may be used uninitialized in this function [-Werror=maybe-uninitialized]
> 
> The problem is that if neither the DT properties nor a platform_data
> pointer are provided, the chip->pdata pointer gets set to an uninitialized
> value.
> 
> Looking at the code some more, I found that the sbs_of_populate_pdata
> function is more complex than necessary and has confusing calling
> conventions of possibly returning a valid pointer, a NULL pointer
> or an ERR_PTR pointer (in addition to the uninitialized pointer).
> 
> To fix all of that, this gets rid of the chip->pdata pointer and
> simply moves the two integers into the sbs_info structure. This
> makes it much clearer from reading sbs_probe() what the precedence
> of the three possible values are (pdata, DT, hardcoded defaults)
> and completely avoids the #ifdef CONFIG_OF guards as
> of_property_read_u32() gets replaced with a compile-time stub
> when that is disabled, and returns an error if passed a NULL of_node
> pointer.
> 
> Signed-off-by: Arnd Bergmann <arnd@...db.de>
> Fixes: 3b5dd3a49496 ("power: supply: sbs-battery: Use gpio_desc and sleeping calls for battery detect")

Patch looks fine to me. Actually I already asked Phil to
implement your change [0]. I just queued it to power-supply's
for-next branch.

[0] https://marc.info/?l=linux-pm&m=147273382018953&w=2

-- Sebastian

Download attachment "signature.asc" of type "application/pgp-signature" (820 bytes)