Re: [PATCH] media: i2c: adv748x: Fix unsafe macros

From: Hans Verkuil <hverkuil@xs4all.nl>
To: Nathan Chancellor <natechancellor@gmail.com>,
	"Gustavo A. R. Silva" <gustavo@embeddedor.com>
Cc: Kieran Bingham <kieran.bingham+renesas@ideasonboard.com>,
	Mauro Carvalho Chehab <mchehab@kernel.org>,
	Hans Verkuil <hans.verkuil@cisco.com>,
	Dmitry Vyukov <dvyukov@google.com>,
	linux-media@vger.kernel.org, linux-kernel@vger.kernel.org,
	clang-built-linux@googlegroups.com
Subject: Re: [PATCH] media: i2c: adv748x: Fix unsafe macros
Date: Fri, 17 Jan 2020 08:25:41 +0100	[thread overview]
Message-ID: <a729415d-1304-9722-2433-129bd2255188@xs4all.nl> (raw)
In-Reply-To: <20200113231413.GA23583@ubuntu-x2-xlarge-x86>

On 1/14/20 12:14 AM, Nathan Chancellor wrote:
> On Tue, Oct 22, 2019 at 08:25:22AM -0500, Gustavo A. R. Silva wrote:
>> Enclose multiple macro parameters in parentheses in order to
>> make such macros safer and fix the Clang warning below:
>>
>> drivers/media/i2c/adv748x/adv748x-afe.c:452:12: warning: operator '?:'
>> has lower precedence than '|'; '|' will be evaluated first
>> [-Wbitwise-conditional-parentheses]
>>
>> ret = sdp_clrset(state, ADV748X_SDP_FRP, ADV748X_SDP_FRP_MASK, enable
>> ? ctrl->val - 1 : 0);
>>
>> Fixes: 3e89586a64df ("media: i2c: adv748x: add adv748x driver")
>> Reported-by: Dmitry Vyukov <dvyukov@google.com>
>> Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com
> 
> It doesn't look like this was picked up? I still see this warning on
> 5.5-rc6 and next-20200113.

It's been picked up some time ago and will appear in 5.6.

Regards,

	Hans

> 
> If it helps:
> 
> Reviewed-by: Nathan Chancellor <natechancellor@gmail.com>
> 
>> ---
>>  drivers/media/i2c/adv748x/adv748x.h | 8 ++++----
>>  1 file changed, 4 insertions(+), 4 deletions(-)
>>
>> diff --git a/drivers/media/i2c/adv748x/adv748x.h b/drivers/media/i2c/adv748x/adv748x.h
>> index 5042f9e94aee..fccb388ce179 100644
>> --- a/drivers/media/i2c/adv748x/adv748x.h
>> +++ b/drivers/media/i2c/adv748x/adv748x.h
>> @@ -394,10 +394,10 @@ int adv748x_write_block(struct adv748x_state *state, int client_page,
>>  
>>  #define io_read(s, r) adv748x_read(s, ADV748X_PAGE_IO, r)
>>  #define io_write(s, r, v) adv748x_write(s, ADV748X_PAGE_IO, r, v)
>> -#define io_clrset(s, r, m, v) io_write(s, r, (io_read(s, r) & ~m) | v)
>> +#define io_clrset(s, r, m, v) io_write(s, r, (io_read(s, r) & ~(m)) | (v))
>>  
>>  #define hdmi_read(s, r) adv748x_read(s, ADV748X_PAGE_HDMI, r)
>> -#define hdmi_read16(s, r, m) (((hdmi_read(s, r) << 8) | hdmi_read(s, r+1)) & m)
>> +#define hdmi_read16(s, r, m) (((hdmi_read(s, r) << 8) | hdmi_read(s, (r)+1)) & (m))
>>  #define hdmi_write(s, r, v) adv748x_write(s, ADV748X_PAGE_HDMI, r, v)
>>  
>>  #define repeater_read(s, r) adv748x_read(s, ADV748X_PAGE_REPEATER, r)
>> @@ -405,11 +405,11 @@ int adv748x_write_block(struct adv748x_state *state, int client_page,
>>  
>>  #define sdp_read(s, r) adv748x_read(s, ADV748X_PAGE_SDP, r)
>>  #define sdp_write(s, r, v) adv748x_write(s, ADV748X_PAGE_SDP, r, v)
>> -#define sdp_clrset(s, r, m, v) sdp_write(s, r, (sdp_read(s, r) & ~m) | v)
>> +#define sdp_clrset(s, r, m, v) sdp_write(s, r, (sdp_read(s, r) & ~(m)) | (v))
>>  
>>  #define cp_read(s, r) adv748x_read(s, ADV748X_PAGE_CP, r)
>>  #define cp_write(s, r, v) adv748x_write(s, ADV748X_PAGE_CP, r, v)
>> -#define cp_clrset(s, r, m, v) cp_write(s, r, (cp_read(s, r) & ~m) | v)
>> +#define cp_clrset(s, r, m, v) cp_write(s, r, (cp_read(s, r) & ~(m)) | (v))
>>  
>>  #define tx_read(t, r) adv748x_read(t->state, t->page, r)
>>  #define tx_write(t, r, v) adv748x_write(t->state, t->page, r, v)
>> -- 
>> 2.23.0
>>