[PATCH] regmap: Silence warning on invalid zero length read

[PATCH] regmap: Silence warning on invalid zero length read

[Mark Brown]

Zero length reads make no sense in a regmap context and are likely to
trigger bugs further down the stack so insert an error check, also
silencing compiler warnings about use of ret in cases where we iterate
per register.

Reported-by: Russell King <linux@arm.linux.org.uk>
Signed-off-by: Mark Brown <broonie@kernel.org>
---

Not even compile tested yet.

 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 7111d04f2621..db1102e9c34d 100644
--- a/drivers/base/regmap/regmap.c
+++ b/drivers/base/regmap/regmap.c
@@ -2179,6 +2179,8 @@ int regmap_raw_read(struct regmap *map, unsigned int reg, void *val,
 		return -EINVAL;
 	if (reg % map->reg_stride)
 		return -EINVAL;
+	if (val_count == 0)
+		return -EINVAL;
 
 	map->lock(map->lock_arg);
 
-- 
2.1.4

Applied "regmap: Silence warning on invalid zero length read" to the regmap tree

[Mark Brown]

The patch

   regmap: Silence warning on invalid zero length read

has been applied to the regmap tree at

   git://git.kernel.org/pub/scm/linux/kernel/git/broonie/regmap.git 

All being well this means that it will be integrated into the linux-next
tree (usually sometime in the next 24 hours) and sent to Linus during
the next merge window (or sooner if it is a bug fix), however if
problems are discovered then the patch may be dropped or reverted.  

You may get further e-mails resulting from automated or manual testing
and review of the tree, please engage with people reporting problems and
send followup patches addressing any issues that are reported if needed.

If any updates are required or you are submitting further changes they
should be sent as incremental updates against current git, existing
patches will not be replaced.

Please add any relevant lists and maintainers to the CCs when replying
to this mail.

Thanks,
Mark

>From fa3eec7791b0fe27e3112804a71ba445ff336a6b Mon Sep 17 00:00:00 2001
From: Mark Brown <broonie@kernel.org>
Date: Wed, 1 Jul 2015 23:51:43 +0100
Subject: [PATCH] regmap: Silence warning on invalid zero length read

Zero length reads make no sense in a regmap context and are likely to
trigger bugs further down the stack so insert an error check, also
silencing compiler warnings about use of ret in cases where we iterate
per register.

Reported-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Mark Brown <broonie@kernel.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 8894b992043e..9c1f856842a3 100644
--- a/drivers/base/regmap/regmap.c
+++ b/drivers/base/regmap/regmap.c
@@ -2180,6 +2180,8 @@ int regmap_raw_read(struct regmap *map, unsigned int reg, void *val,
 		return -EINVAL;
 	if (reg % map->reg_stride)
 		return -EINVAL;
+	if (val_count == 0)
+		return -EINVAL;
 
 	map->lock(map->lock_arg);
 
-- 
2.1.4