* [PATCH] power: supply: max17042_battery: fix some usage of uninitialized variables
@ 2019-10-03 17:29 Yizhuo
2019-10-14 3:23 ` Sebastian Reichel
0 siblings, 1 reply; 4+ messages in thread
From: Yizhuo @ 2019-10-03 17:29 UTC (permalink / raw)
Cc: csong, zhiyunq, Yizhuo, Sebastian Reichel, linux-pm, linux-kernel
Several functions in this file are trying to use regmap_read() to
initialize the specific variable, however, if regmap_read() fails,
the variable could be uninitialized but used directly, which is
potentially unsafe. The return value of regmap_read() should be
checked and handled. The same case also happens in function
max17042_thread_handler() but it needs more effort to patch.
Signed-off-by: Yizhuo <yzhai003@ucr.edu>
---
drivers/power/supply/max17042_battery.c | 23 +++++++++++++++++++----
1 file changed, 19 insertions(+), 4 deletions(-)
diff --git a/drivers/power/supply/max17042_battery.c b/drivers/power/supply/max17042_battery.c
index e6a2dacaa730..b897776a2749 100644
--- a/drivers/power/supply/max17042_battery.c
+++ b/drivers/power/supply/max17042_battery.c
@@ -675,8 +675,12 @@ static void max17042_reset_vfsoc0_reg(struct max17042_chip *chip)
{
unsigned int vfSoc;
struct regmap *map = chip->regmap;
+ int ret;
+
+ ret = regmap_read(map, MAX17042_VFSOC, &vfSoc);
+ if (ret)
+ return;
- regmap_read(map, MAX17042_VFSOC, &vfSoc);
regmap_write(map, MAX17042_VFSOC0Enable, VFSOC0_UNLOCK);
max17042_write_verify_reg(map, MAX17042_VFSOC0, vfSoc);
regmap_write(map, MAX17042_VFSOC0Enable, VFSOC0_LOCK);
@@ -686,12 +690,18 @@ static void max17042_load_new_capacity_params(struct max17042_chip *chip)
{
u32 full_cap0, rep_cap, dq_acc, vfSoc;
u32 rem_cap;
+ int ret;
struct max17042_config_data *config = chip->pdata->config_data;
struct regmap *map = chip->regmap;
- regmap_read(map, MAX17042_FullCAP0, &full_cap0);
- regmap_read(map, MAX17042_VFSOC, &vfSoc);
+ ret = regmap_read(map, MAX17042_FullCAP0, &full_cap0);
+ if (ret)
+ return;
+
+ ret = regmap_read(map, MAX17042_VFSOC, &vfSoc);
+ if (ret)
+ return;
/* fg_vfSoc needs to shifted by 8 bits to get the
* perc in 1% accuracy, to get the right rem_cap multiply
@@ -1108,7 +1118,12 @@ static int max17042_probe(struct i2c_client *client,
if (!client->irq)
regmap_write(chip->regmap, MAX17042_SALRT_Th, 0xff00);
- regmap_read(chip->regmap, MAX17042_STATUS, &val);
+ ret = regmap_read(chip->regmap, MAX17042_STATUS, &val);
+ if (ret) {
+ dev_err(&client->dev, "Failed to get MAX17042_STATUS.\n");
+ return ret;
+ }
+
if (val & STATUS_POR_BIT) {
INIT_WORK(&chip->work, max17042_init_worker);
ret = devm_add_action(&client->dev, max17042_stop_work, chip);
--
2.17.1
^ permalink raw reply related [flat|nested] 4+ messages in thread* Re: [PATCH] power: supply: max17042_battery: fix some usage of uninitialized variables
2019-10-03 17:29 [PATCH] power: supply: max17042_battery: fix some usage of uninitialized variables Yizhuo
@ 2019-10-14 3:23 ` Sebastian Reichel
0 siblings, 0 replies; 4+ messages in thread
From: Sebastian Reichel @ 2019-10-14 3:23 UTC (permalink / raw)
To: Yizhuo; +Cc: csong, zhiyunq, linux-pm, linux-kernel
[-- Attachment #1: Type: text/plain, Size: 2968 bytes --]
Hi,
On Thu, Oct 03, 2019 at 10:29:48AM -0700, Yizhuo wrote:
> Several functions in this file are trying to use regmap_read() to
> initialize the specific variable, however, if regmap_read() fails,
> the variable could be uninitialized but used directly, which is
> potentially unsafe. The return value of regmap_read() should be
> checked and handled. The same case also happens in function
> max17042_thread_handler() but it needs more effort to patch.
>
> Signed-off-by: Yizhuo <yzhai003@ucr.edu>
> ---
This does not improve the situation much. You should change the
functions from 'void' to 'int' return code and propagate the error
code, otherwise the following code assumes everything to be correct.
Also the Signed-off-by name and the patch author's name seems to be
incomplete.
Thanks,
-- Sebastian
> drivers/power/supply/max17042_battery.c | 23 +++++++++++++++++++----
> 1 file changed, 19 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/power/supply/max17042_battery.c b/drivers/power/supply/max17042_battery.c
> index e6a2dacaa730..b897776a2749 100644
> --- a/drivers/power/supply/max17042_battery.c
> +++ b/drivers/power/supply/max17042_battery.c
> @@ -675,8 +675,12 @@ static void max17042_reset_vfsoc0_reg(struct max17042_chip *chip)
> {
> unsigned int vfSoc;
> struct regmap *map = chip->regmap;
> + int ret;
> +
> + ret = regmap_read(map, MAX17042_VFSOC, &vfSoc);
> + if (ret)
> + return;
>
> - regmap_read(map, MAX17042_VFSOC, &vfSoc);
> regmap_write(map, MAX17042_VFSOC0Enable, VFSOC0_UNLOCK);
> max17042_write_verify_reg(map, MAX17042_VFSOC0, vfSoc);
> regmap_write(map, MAX17042_VFSOC0Enable, VFSOC0_LOCK);
> @@ -686,12 +690,18 @@ static void max17042_load_new_capacity_params(struct max17042_chip *chip)
> {
> u32 full_cap0, rep_cap, dq_acc, vfSoc;
> u32 rem_cap;
> + int ret;
>
> struct max17042_config_data *config = chip->pdata->config_data;
> struct regmap *map = chip->regmap;
>
> - regmap_read(map, MAX17042_FullCAP0, &full_cap0);
> - regmap_read(map, MAX17042_VFSOC, &vfSoc);
> + ret = regmap_read(map, MAX17042_FullCAP0, &full_cap0);
> + if (ret)
> + return;
> +
> + ret = regmap_read(map, MAX17042_VFSOC, &vfSoc);
> + if (ret)
> + return;
>
> /* fg_vfSoc needs to shifted by 8 bits to get the
> * perc in 1% accuracy, to get the right rem_cap multiply
> @@ -1108,7 +1118,12 @@ static int max17042_probe(struct i2c_client *client,
> if (!client->irq)
> regmap_write(chip->regmap, MAX17042_SALRT_Th, 0xff00);
>
> - regmap_read(chip->regmap, MAX17042_STATUS, &val);
> + ret = regmap_read(chip->regmap, MAX17042_STATUS, &val);
> + if (ret) {
> + dev_err(&client->dev, "Failed to get MAX17042_STATUS.\n");
> + return ret;
> + }
> +
> if (val & STATUS_POR_BIT) {
> INIT_WORK(&chip->work, max17042_init_worker);
> ret = devm_add_action(&client->dev, max17042_stop_work, chip);
> --
> 2.17.1
>
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^ permalink raw reply [flat|nested] 4+ messages in thread
* [PATCH] power: supply: max17042_battery: fix some usage of uninitialized variables
@ 2019-10-02 15:55 Yizhuo
2019-10-02 20:51 ` kbuild test robot
0 siblings, 1 reply; 4+ messages in thread
From: Yizhuo @ 2019-10-02 15:55 UTC (permalink / raw)
Cc: csong, zhiyunq, Yizhuo, Sebastian Reichel, linux-pm, linux-kernel
Several functions in this file are trying to use regmap_read() to
initialize the specific variable, however, if regmap_read() fails,
the variable could be uninitialized but used directly, which is
potentially unsafe. The return value of regmap_read() should be
checked and handled. The same case also happens in function
max17042_thread_handler() but it needs more effort to patch.
Signed-off-by: Yizhuo <yzhai003@ucr.edu>
---
drivers/power/supply/max17042_battery.c | 23 +++++++++++++++++++----
1 file changed, 19 insertions(+), 4 deletions(-)
diff --git a/drivers/power/supply/max17042_battery.c b/drivers/power/supply/max17042_battery.c
index e6a2dacaa730..8e5727010ed2 100644
--- a/drivers/power/supply/max17042_battery.c
+++ b/drivers/power/supply/max17042_battery.c
@@ -675,8 +675,12 @@ static void max17042_reset_vfsoc0_reg(struct max17042_chip *chip)
{
unsigned int vfSoc;
struct regmap *map = chip->regmap;
+ int ret;
+
+ ret = regmap_read(map, MAX17042_VFSOC, &vfSoc);
+ if (ret)
+ return;
- regmap_read(map, MAX17042_VFSOC, &vfSoc);
regmap_write(map, MAX17042_VFSOC0Enable, VFSOC0_UNLOCK);
max17042_write_verify_reg(map, MAX17042_VFSOC0, vfSoc);
regmap_write(map, MAX17042_VFSOC0Enable, VFSOC0_LOCK);
@@ -686,12 +690,18 @@ static void max17042_load_new_capacity_params(struct max17042_chip *chip)
{
u32 full_cap0, rep_cap, dq_acc, vfSoc;
u32 rem_cap;
+ int ret;
struct max17042_config_data *config = chip->pdata->config_data;
struct regmap *map = chip->regmap;
- regmap_read(map, MAX17042_FullCAP0, &full_cap0);
- regmap_read(map, MAX17042_VFSOC, &vfSoc);
+ ret = regmap_read(map, MAX17042_FullCAP0, &full_cap0);
+ if (ret)
+ return ret;
+
+ ret = regmap_read(map, MAX17042_VFSOC, &vfSoc);
+ if (ret)
+ return ret;
/* fg_vfSoc needs to shifted by 8 bits to get the
* perc in 1% accuracy, to get the right rem_cap multiply
@@ -1108,7 +1118,12 @@ static int max17042_probe(struct i2c_client *client,
if (!client->irq)
regmap_write(chip->regmap, MAX17042_SALRT_Th, 0xff00);
- regmap_read(chip->regmap, MAX17042_STATUS, &val);
+ ret = regmap_read(chip->regmap, MAX17042_STATUS, &val);
+ if (ret) {
+ dev_err(&client->dev, "Failed to get MAX17042_STATUS.\n");
+ return ret;
+ }
+
if (val & STATUS_POR_BIT) {
INIT_WORK(&chip->work, max17042_init_worker);
ret = devm_add_action(&client->dev, max17042_stop_work, chip);
--
2.17.1
^ permalink raw reply related [flat|nested] 4+ messages in thread* Re: [PATCH] power: supply: max17042_battery: fix some usage of uninitialized variables
2019-10-02 15:55 Yizhuo
@ 2019-10-02 20:51 ` kbuild test robot
0 siblings, 0 replies; 4+ messages in thread
From: kbuild test robot @ 2019-10-02 20:51 UTC (permalink / raw)
To: Yizhuo
Cc: kbuild-all, csong, zhiyunq, Yizhuo, Sebastian Reichel, linux-pm,
linux-kernel
[-- Attachment #1: Type: text/plain, Size: 3667 bytes --]
Hi Yizhuo,
Thank you for the patch! Perhaps something to improve:
[auto build test WARNING on power-supply/for-next]
[cannot apply to v5.4-rc1 next-20191002]
[if your patch is applied to the wrong git tree, please drop us a note to help
improve the system. BTW, we also suggest to use '--base' option to specify the
base tree in git format-patch, please see https://stackoverflow.com/a/37406982]
url: https://github.com/0day-ci/linux/commits/Yizhuo/power-supply-max17042_battery-fix-some-usage-of-uninitialized-variables/20191003-040948
base: https://git.kernel.org/pub/scm/linux/kernel/git/sre/linux-power-supply.git for-next
config: sh-allmodconfig (attached as .config)
compiler: sh4-linux-gcc (GCC) 7.4.0
reproduce:
wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
chmod +x ~/bin/make.cross
# save the attached .config to linux build tree
GCC_VERSION=7.4.0 make.cross ARCH=sh
If you fix the issue, kindly add following tag
Reported-by: kbuild test robot <lkp@intel.com>
All warnings (new ones prefixed by >>):
drivers/power/supply/max17042_battery.c: In function 'max17042_load_new_capacity_params':
>> drivers/power/supply/max17042_battery.c:697:10: warning: 'return' with a value, in function returning void
return ret;
^~~
drivers/power/supply/max17042_battery.c:686:13: note: declared here
static void max17042_load_new_capacity_params(struct max17042_chip *chip)
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
drivers/power/supply/max17042_battery.c:701:10: warning: 'return' with a value, in function returning void
return ret;
^~~
drivers/power/supply/max17042_battery.c:686:13: note: declared here
static void max17042_load_new_capacity_params(struct max17042_chip *chip)
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
vim +/return +697 drivers/power/supply/max17042_battery.c
685
686 static void max17042_load_new_capacity_params(struct max17042_chip *chip)
687 {
688 u32 full_cap0, rep_cap, dq_acc, vfSoc;
689 u32 rem_cap;
690 int ret;
691
692 struct max17042_config_data *config = chip->pdata->config_data;
693 struct regmap *map = chip->regmap;
694
695 ret = regmap_read(map, MAX17042_FullCAP0, &full_cap0);
696 if (ret)
> 697 return ret;
698
699 ret = regmap_read(map, MAX17042_VFSOC, &vfSoc);
700 if (ret)
701 return ret;
702
703 /* fg_vfSoc needs to shifted by 8 bits to get the
704 * perc in 1% accuracy, to get the right rem_cap multiply
705 * full_cap0, fg_vfSoc and devide by 100
706 */
707 rem_cap = ((vfSoc >> 8) * full_cap0) / 100;
708 max17042_write_verify_reg(map, MAX17042_RemCap, rem_cap);
709
710 rep_cap = rem_cap;
711 max17042_write_verify_reg(map, MAX17042_RepCap, rep_cap);
712
713 /* Write dQ_acc to 200% of Capacity and dP_acc to 200% */
714 dq_acc = config->fullcap / dQ_ACC_DIV;
715 max17042_write_verify_reg(map, MAX17042_dQacc, dq_acc);
716 max17042_write_verify_reg(map, MAX17042_dPacc, dP_ACC_200);
717
718 max17042_write_verify_reg(map, MAX17042_FullCAP,
719 config->fullcap);
720 regmap_write(map, MAX17042_DesignCap,
721 config->design_cap);
722 max17042_write_verify_reg(map, MAX17042_FullCAPNom,
723 config->fullcapnom);
724 /* Update SOC register with new SOC */
725 regmap_write(map, MAX17042_RepSOC, vfSoc);
726 }
727
---
0-DAY kernel test infrastructure Open Source Technology Center
https://lists.01.org/pipermail/kbuild-all Intel Corporation
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2019-10-03 17:29 [PATCH] power: supply: max17042_battery: fix some usage of uninitialized variables Yizhuo
2019-10-14 3:23 ` Sebastian Reichel
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2019-10-02 15:55 Yizhuo
2019-10-02 20:51 ` kbuild test robot
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