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From:   Amit Kucheria <amit.kucheria@verdurent.com>
Date:   Wed, 29 Apr 2020 02:03:33 +0530
Message-ID: <CAHLCerPm=FssMWhccXbJiCaxakDb-Trz_uOpCAmtwEyaQkeqxQ@mail.gmail.com>
Subject: Re: [PATCH v2] thermal: ti-soc-thermal: avoid dereferencing ERR_PTR
To:     Sudip Mukherjee <sudipm.mukherjee@gmail.com>
Cc:     Eduardo Valentin <edubezval@gmail.com>, Keerthy <j-keerthy@ti.com>,
        Zhang Rui <rui.zhang@intel.com>,
        Daniel Lezcano <daniel.lezcano@linaro.org>,
        LKML <linux-kernel@vger.kernel.org>,
        Linux PM list <linux-pm@vger.kernel.org>,
        linux-omap@vger.kernel.org
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On Fri, Apr 24, 2020 at 9:49 PM Sudip Mukherjee
<sudipm.mukherjee@gmail.com> wrote:
>
> On error the function ti_bandgap_get_sensor_data() returns the error
> code in ERR_PTR() but we only checked if the return value is NULL or
> not. And, so we can dereference an error code inside ERR_PTR.
> While at it, convert a check to IS_ERR_OR_NULL.
>
> Signed-off-by: Sudip Mukherjee <sudipm.mukherjee@gmail.com>
Reviewed-by: Amit Kucheria <amit.kucheria@linaro.org>

> ---
>  drivers/thermal/ti-soc-thermal/ti-thermal-common.c | 6 +++---
>  1 file changed, 3 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/thermal/ti-soc-thermal/ti-thermal-common.c b/drivers/thermal/ti-soc-thermal/ti-thermal-common.c
> index d3e959d01606..85776db4bf34 100644
> --- a/drivers/thermal/ti-soc-thermal/ti-thermal-common.c
> +++ b/drivers/thermal/ti-soc-thermal/ti-thermal-common.c
> @@ -169,7 +169,7 @@ int ti_thermal_expose_sensor(struct ti_bandgap *bgp, int id,
>
>         data = ti_bandgap_get_sensor_data(bgp, id);
>
> -       if (!data || IS_ERR(data))
> +       if (!IS_ERR_OR_NULL(data))
>                 data = ti_thermal_build_data(bgp, id);
>
>         if (!data)
> @@ -196,7 +196,7 @@ int ti_thermal_remove_sensor(struct ti_bandgap *bgp, int id)
>
>         data = ti_bandgap_get_sensor_data(bgp, id);
>
> -       if (data && data->ti_thermal) {
> +       if (!IS_ERR_OR_NULL(data) && data->ti_thermal) {
>                 if (data->our_zone)
>                         thermal_zone_device_unregister(data->ti_thermal);
>         }
> @@ -262,7 +262,7 @@ int ti_thermal_unregister_cpu_cooling(struct ti_bandgap *bgp, int id)
>
>         data = ti_bandgap_get_sensor_data(bgp, id);
>
> -       if (data) {
> +       if (!IS_ERR_OR_NULL(data)) {
>                 cpufreq_cooling_unregister(data->cool_dev);
>                 if (data->policy)
>                         cpufreq_cpu_put(data->policy);
> --
> 2.11.0
>