* [PATCH] regulator: s5m8767: fix get_register() error handling
@ 2016-02-16 14:53 Arnd Bergmann
2016-02-17 0:00 ` Krzysztof Kozlowski
0 siblings, 1 reply; 2+ messages in thread
From: Arnd Bergmann @ 2016-02-16 14:53 UTC (permalink / raw)
To: linux-arm-kernel
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(-)
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;
--
2.7.0
^ permalink raw reply related [flat|nested] 2+ messages in thread
* [PATCH] regulator: s5m8767: fix get_register() error handling
2016-02-16 14:53 [PATCH] regulator: s5m8767: fix get_register() error handling Arnd Bergmann
@ 2016-02-17 0:00 ` Krzysztof Kozlowski
0 siblings, 0 replies; 2+ messages in thread
From: Krzysztof Kozlowski @ 2016-02-17 0:00 UTC (permalink / raw)
To: linux-arm-kernel
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
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