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authorMaxime Coquelin <maxime.coquelin@st.com>2015-06-16 13:53:19 +0200
committerMark Brown <broonie@kernel.org>2015-06-16 12:58:22 +0100
commit921cc29473a0d7c109105c1876ddb432f4a4be7d (patch)
treeb5d577496add5052fa5facd1c969d9df93251236 /drivers/base
parentb787f68c36d49bb1d9236f403813641efa74a031 (diff)
downloadlinux-921cc29473a0d7c109105c1876ddb432f4a4be7d.tar.bz2
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: Maxime Coquelin <maxime.coquelin@st.com> Signed-off-by: Mark Brown <broonie@kernel.org> Cc: stable@vger.kernel.org
Diffstat (limited to 'drivers/base')
-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 6273ff072f3e..e5194f698d66 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;
}