Commit 921cc294 authored by Maxime Coquelin's avatar Maxime Coquelin Committed by Mark Brown

regmap: Fix possible shift overflow in regmap_field_init()

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: 's avatarMaxime Coquelin <maxime.coquelin@st.com>
Signed-off-by: 's avatarMark Brown <broonie@kernel.org>
Cc: stable@vger.kernel.org
parent b787f68c
......@@ -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;
}
......
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