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authorMaxime Coquelin <maxime.coquelin@st.com>2015-06-16 13:53:19 +0200
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2015-07-21 10:10:13 -0700
commita615d483d22b2c3f0b413d74b6f3e6e4f2726acd (patch)
tree2d4d3becb443f9ddc8bfbb305db5288746b630a0 /drivers
parent6f6b43216e3f1a9c3254f475b5446892d954852d (diff)
regmap: Fix possible shift overflow in regmap_field_init()
commit 921cc29473a0d7c109105c1876ddb432f4a4be7d upstream. The way the mask is generated in regmap_field_init() is wrong. Indeed, a field initialized with msb = 31 and lsb = 0 provokes a shift overflow while calculating the mask field. On some 32 bits architectures, such as x86, the generated mask is 0, instead of the expected 0xffffffff. This patch uses GENMASK() to fix the problem, as this macro is already safe regarding shift overflow. Signed-off-by: Maxime Coquelin <maxime.coquelin@st.com> Signed-off-by: Mark Brown <broonie@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers')
-rw-r--r--drivers/base/regmap/regmap.c3
1 files changed, 1 insertions, 2 deletions
diff --git a/drivers/base/regmap/regmap.c b/drivers/base/regmap/regmap.c
index ac2342c3cb9a..7c6e8948ac2c 100644
--- a/drivers/base/regmap/regmap.c
+++ b/drivers/base/regmap/regmap.c
@@ -945,11 +945,10 @@ EXPORT_SYMBOL_GPL(devm_regmap_init);
static void regmap_field_init(struct regmap_field *rm_field,
struct regmap *regmap, struct reg_field reg_field)
{
- int field_bits = reg_field.msb - reg_field.lsb + 1;
rm_field->regmap = regmap;
rm_field->reg = reg_field.reg;
rm_field->shift = reg_field.lsb;
- rm_field->mask = ((BIT(field_bits) - 1) << reg_field.lsb);
+ rm_field->mask = GENMASK(reg_field.msb, reg_field.lsb);
rm_field->id_size = reg_field.id_size;
rm_field->id_offset = reg_field.id_offset;
}