| Message ID | 1455634402-1997203-1-git-send-email-arnd@arndb.de (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On 16.02.2016 23:53, Arnd Bergmann wrote: > The s5m8767_pmic_probe() function calls s5m8767_get_register() to > read data without checking the return code, which produces a compile-time > warning when that data is accessed: > > drivers/regulator/s5m8767.c: In function 's5m8767_pmic_probe': > drivers/regulator/s5m8767.c:924:7: error: 'enable_reg' may be used uninitialized in this function [-Werror=maybe-uninitialized] > drivers/regulator/s5m8767.c:944:30: error: 'enable_val' may be used uninitialized in this function [-Werror=maybe-uninitialized] > > This changes the s5m8767_get_register() function to return a -EINVAL > not just for an invalid register number but also for an invalid > regulator number, as both would result in returning uninitialized > data. The s5m8767_pmic_probe() function is then changed accordingly > to fail on a read error, as all the other callers of s5m8767_get_register() > already do. > > In practice this probably cannot happen, as we don't call > s5m8767_get_register() with invalid arguments, but the gcc > warning seems valid in principle, in terms writing safe > error checking. > > Signed-off-by: Arnd Bergmann <arnd@arndb.de> > Fixes: 9c4c60554acf ("regulator: s5m8767: Convert to use regulator_[enable|disable|is_enabled]_regmap") > --- > drivers/regulator/s5m8767.c | 13 +++++++++---- > 1 file changed, 9 insertions(+), 4 deletions(-) > Reviewed-by: Krzysztof Kozlowski <k.kozlowski@samsung.com> Best regards, Krzysztof
diff --git a/drivers/regulator/s5m8767.c b/drivers/regulator/s5m8767.c index 58f5d3b8e981..27343e1c43ef 100644 --- a/drivers/regulator/s5m8767.c +++ b/drivers/regulator/s5m8767.c @@ -202,9 +202,10 @@ static int s5m8767_get_register(struct s5m8767_info *s5m8767, int reg_id, } } - if (i < s5m8767->num_regulators) - *enable_ctrl = - s5m8767_opmode_reg[reg_id][mode] << S5M8767_ENCTRL_SHIFT; + if (i >= s5m8767->num_regulators) + return -EINVAL; + + *enable_ctrl = s5m8767_opmode_reg[reg_id][mode] << S5M8767_ENCTRL_SHIFT; return 0; } @@ -937,8 +938,12 @@ static int s5m8767_pmic_probe(struct platform_device *pdev) else regulators[id].vsel_mask = 0xff; - s5m8767_get_register(s5m8767, id, &enable_reg, + ret = s5m8767_get_register(s5m8767, id, &enable_reg, &enable_val); + if (ret) { + dev_err(s5m8767->dev, "error reading registers\n"); + return ret; + } regulators[id].enable_reg = enable_reg; regulators[id].enable_mask = S5M8767_ENCTRL_MASK; regulators[id].enable_val = enable_val;
The s5m8767_pmic_probe() function calls s5m8767_get_register() to read data without checking the return code, which produces a compile-time warning when that data is accessed: drivers/regulator/s5m8767.c: In function 's5m8767_pmic_probe': drivers/regulator/s5m8767.c:924:7: error: 'enable_reg' may be used uninitialized in this function [-Werror=maybe-uninitialized] drivers/regulator/s5m8767.c:944:30: error: 'enable_val' may be used uninitialized in this function [-Werror=maybe-uninitialized] This changes the s5m8767_get_register() function to return a -EINVAL not just for an invalid register number but also for an invalid regulator number, as both would result in returning uninitialized data. The s5m8767_pmic_probe() function is then changed accordingly to fail on a read error, as all the other callers of s5m8767_get_register() already do. In practice this probably cannot happen, as we don't call s5m8767_get_register() with invalid arguments, but the gcc warning seems valid in principle, in terms writing safe error checking. Signed-off-by: Arnd Bergmann <arnd@arndb.de> Fixes: 9c4c60554acf ("regulator: s5m8767: Convert to use regulator_[enable|disable|is_enabled]_regmap") --- drivers/regulator/s5m8767.c | 13 +++++++++---- 1 file changed, 9 insertions(+), 4 deletions(-)