linux-kernel - [PATCH 3.2 101/147] ASoC: adau1373: adau1373_hw

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]

Date:   Mon, 06 Nov 2017 23:03:07 +0000
From:   Ben Hutchings <ben@...adent.org.uk>
To:     linux-kernel@...r.kernel.org, stable@...r.kernel.org
CC:     akpm@...ux-foundation.org, "Lars-Peter Clausen" <lars@...afoo.de>,
        "Mark Brown" <broonie@...nsource.wolfsonmicro.com>,
        "Tim Gardner" <tim.gardner@...onical.com>
Subject: [PATCH 3.2 101/147] ASoC: adau1373: adau1373_hw_params: Silence
 overflow warning

3.2.95-rc1 review patch.  If anyone has any objections, please let me know.

------------------

From: Tim Gardner <tim.gardner@...onical.com>

commit 14a1b8ca172f4cfbc544051a729d85a380447a82 upstream.

ADAU1373_BCLKDIV_SOURCE is defined as BIT(5) which uses UL constants. On
amd64 the result of the ones complement operator is then truncated to
unsigned int according to the prototype of snd_soc_update_bits(). I think
gcc is correctly warning that the upper 32 bits are lost.

sound/soc/codecs/adau1373.c: In function 'adau1373_hw_params':
sound/soc/codecs/adau1373.c:940:3: warning: large integer implicitly truncated to unsigned type [-Woverflow]

gcc version 4.6.3

Add 2 more BCLKDIV mask macros as explained by Lars:

The BCLKDIV has three fields. The bitclock divider (bit 0-1), the samplerate
(bit 2-4) and the source select (bit 5). Here we want to update the bitclock
divider field and the samplerate field. When I wrote the code I was lazy and
used ~ADAU1373_BCLKDIV_SOURCE as the mask, which for this register is
functionally equivalent to ADAU1373_BCLKDIV_SR_MASK | ADAU1373_BCLKDIV_BCLK_MASK.

Signed-off-by: Tim Gardner <tim.gardner@...onical.com>
Acked-by: Lars-Peter Clausen <lars@...afoo.de>
Signed-off-by: Mark Brown <broonie@...nsource.wolfsonmicro.com>
Signed-off-by: Ben Hutchings <ben@...adent.org.uk>
---
 sound/soc/codecs/adau1373.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

--- a/sound/soc/codecs/adau1373.c
+++ b/sound/soc/codecs/adau1373.c
@@ -133,6 +133,8 @@ struct adau1373 {
 #define ADAU1373_DAI_FORMAT_DSP		0x3

 #define ADAU1373_BCLKDIV_SOURCE		BIT(5)
+#define ADAU1373_BCLKDIV_SR_MASK	(0x07 << 2)
+#define ADAU1373_BCLKDIV_BCLK_MASK	0x03
 #define ADAU1373_BCLKDIV_32		0x03
 #define ADAU1373_BCLKDIV_64		0x02
 #define ADAU1373_BCLKDIV_128		0x01
@@ -937,7 +939,8 @@ static int adau1373_hw_params(struct snd
 	adau1373_dai->enable_src = (div != 0);

 	snd_soc_update_bits(codec, ADAU1373_BCLKDIV(dai->id),
-		~ADAU1373_BCLKDIV_SOURCE, (div << 2) | ADAU1373_BCLKDIV_64);
+		ADAU1373_BCLKDIV_SR_MASK | ADAU1373_BCLKDIV_BCLK_MASK,
+		(div << 2) | ADAU1373_BCLKDIV_64);

 	switch (params_format(params)) {
 	case SNDRV_PCM_FORMAT_S16_LE: