linux-kernel - [PATCH] regmap: fix bulk writes on paged registers

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-next>] [day] [month] [year] [list]

Date:   Wed, 12 Jun 2019 12:03:43 +0100
From:   Srinivas Kandagatla <srinivas.kandagatla@...aro.org>
To:     broonie@...nel.org
Cc:     alsa-devel@...a-project.org, linux-kernel@...r.kernel.org,
        gregkh@...uxfoundation.org,
        Srinivas Kandagatla <srinivas.kandagatla@...aro.org>
Subject: [PATCH] regmap: fix bulk writes on paged registers

On buses like SlimBus and SoundWire which does not support
gather_writes yet in regmap, A bulk write on paged register
would be silently ignored after programming page.
This is because local variable 'ret' value in regmap_raw_write_impl()
gets reset to 0 once page register is written successfully and the
code below checks for 'ret' value to be -ENOTSUPP before linearising
the write buffer to send to bus->write().

Fix this by resetting the 'ret' value to -ENOTSUPP in cases where
gather_writes() is not supported or single register write is
not possible.

Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@...aro.org>
---
 drivers/base/regmap/regmap.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/base/regmap/regmap.c b/drivers/base/regmap/regmap.c
index f1025452bb39..19f57ccfbe1d 100644
--- a/drivers/base/regmap/regmap.c
+++ b/drivers/base/regmap/regmap.c
@@ -1637,6 +1637,8 @@ static int _regmap_raw_write_impl(struct regmap *map, unsigned int reg,
 					     map->format.reg_bytes +
 					     map->format.pad_bytes,
 					     val, val_len);
+	else
+		ret = -ENOTSUPP;

 	/* If that didn't work fall back on linearising by hand. */
 	if (ret == -ENOTSUPP) {
-- 
2.21.0