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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 10:10:04 -0700
commit6489f7a496378983980e8219dfaeaf66d581590b (patch)
treecd31af24f8bd9ba0c916d85e10c889b3720c6457
parent88822cdb258714ce2fdc9a6eed87e7dd7d205a6b (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>
-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 9f7f78ede01b..1c76dcb502cf 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;
}