From a615d483d22b2c3f0b413d74b6f3e6e4f2726acd Mon Sep 17 00:00:00 2001 From: Maxime Coquelin Date: Tue, 16 Jun 2015 13:53:19 +0200 Subject: 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 Signed-off-by: Mark Brown Signed-off-by: Greg Kroah-Hartman --- drivers/base/regmap/regmap.c | 3 +-- 1 file changed, 1 insertion(+), 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; } -- cgit v1.2.3