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SubjectRe: [PATCH] hwmon: coretemp: avoid RDMSR interruptions to isolated CPUs
On Fri, Dec 23, 2022 at 01:48:14PM +0300, Dan Carpenter wrote:
> Hi Marcelo,
>
> https://git-scm.com/docs/git-format-patch#_base_tree_information]
>
> url: https://github.com/intel-lab-lkp/linux/commits/Marcelo-Tosatti/hwmon-coretemp-avoid-RDMSR-interruptions-to-isolated-CPUs/20221215-204904
> patch link: https://lore.kernel.org/r/Y5sWMEG0xCl9bgEi%40tpad
> patch subject: [PATCH] hwmon: coretemp: avoid RDMSR interruptions to isolated CPUs
> config: i386-randconfig-m021
> compiler: gcc-11 (Debian 11.3.0-8) 11.3.0
>
> If you fix the issue, kindly add following tag where applicable
> | Reported-by: kernel test robot <lkp@intel.com>
> | Reported-by: Dan Carpenter <error27@gmail.com>
>
> smatch warnings:
> drivers/hwmon/coretemp.c:181 show_temp() warn: inconsistent returns '&tdata->update_lock'.
>
> vim +181 drivers/hwmon/coretemp.c
>
> 199e0de7f5df31 Durgadoss R 2011-05-20 154 static ssize_t show_temp(struct device *dev,
> 199e0de7f5df31 Durgadoss R 2011-05-20 155 struct device_attribute *devattr, char *buf)
> 199e0de7f5df31 Durgadoss R 2011-05-20 156 {
> bebe467823c0d8 Rudolf Marek 2007-05-08 157 u32 eax, edx;
> 199e0de7f5df31 Durgadoss R 2011-05-20 158 struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
> 199e0de7f5df31 Durgadoss R 2011-05-20 159 struct platform_data *pdata = dev_get_drvdata(dev);
> 199e0de7f5df31 Durgadoss R 2011-05-20 160 struct temp_data *tdata = pdata->core_data[attr->index];
> 199e0de7f5df31 Durgadoss R 2011-05-20 161
> 199e0de7f5df31 Durgadoss R 2011-05-20 162 mutex_lock(&tdata->update_lock);
> bebe467823c0d8 Rudolf Marek 2007-05-08 163
> 199e0de7f5df31 Durgadoss R 2011-05-20 164 /* Check whether the time interval has elapsed */
> 199e0de7f5df31 Durgadoss R 2011-05-20 165 if (!tdata->valid || time_after(jiffies, tdata->last_updated + HZ)) {
> e78264610cd902 Marcelo Tosatti 2022-12-15 166 if (!housekeeping_cpu(tdata->cpu, HK_TYPE_MISC))
> e78264610cd902 Marcelo Tosatti 2022-12-15 167 return -EINVAL;
>
> mutex_unlock(&tdata->update_lock);
>
> 199e0de7f5df31 Durgadoss R 2011-05-20 168 rdmsr_on_cpu(tdata->cpu, tdata->status_reg, &eax, &edx);
> bf6ea084ebb54c Guenter Roeck 2013-11-20 169 /*
> bf6ea084ebb54c Guenter Roeck 2013-11-20 170 * Ignore the valid bit. In all observed cases the register
> bf6ea084ebb54c Guenter Roeck 2013-11-20 171 * value is either low or zero if the valid bit is 0.
> bf6ea084ebb54c Guenter Roeck 2013-11-20 172 * Return it instead of reporting an error which doesn't
> bf6ea084ebb54c Guenter Roeck 2013-11-20 173 * really help at all.
> bf6ea084ebb54c Guenter Roeck 2013-11-20 174 */
> bf6ea084ebb54c Guenter Roeck 2013-11-20 175 tdata->temp = tdata->tjmax - ((eax >> 16) & 0x7f) * 1000;
> 952a11ca32a604 Paul Fertser 2021-09-24 176 tdata->valid = true;
> 199e0de7f5df31 Durgadoss R 2011-05-20 177 tdata->last_updated = jiffies;
> bebe467823c0d8 Rudolf Marek 2007-05-08 178 }
> bebe467823c0d8 Rudolf Marek 2007-05-08 179
> 199e0de7f5df31 Durgadoss R 2011-05-20 180 mutex_unlock(&tdata->update_lock);
> bf6ea084ebb54c Guenter Roeck 2013-11-20 @181 return sprintf(buf, "%d\n", tdata->temp);
> bebe467823c0d8 Rudolf Marek 2007-05-08 182 }
>
> --
> 0-DAY CI Kernel Test Service
> https://01.org/lkp

Thanks,

v3 of the patch should not suffer from this issue.

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