| Message ID | 20230303161910.3195805-1-srinivas.pandruvada@linux.intel.com (mailing list archive) |
|---|---|
| State | Mainlined, archived |
| Headers | show |
| Series | thermal: int340x: processor_thermal: Fix deadlock | expand |
On Fri, Mar 03, 2023 at 08:19:09AM -0800, Srinivas Pandruvada wrote: > From: Srinivas Pandruvada <srinivas.pandruvada@intel.com> > > When user space updates the trip point there is a deadlock, which results > in caller gets blocked forever. > > Commit 05eeee2b51b4 ("thermal/core: Protect sysfs accesses to thermal > operations with thermal zone mutex"), added a mutex for tz->lock in the > function trip_point_temp_store(). Hence, trip set callback() can't > call any thermal zone API as they are protected with the same mutex lock. > > The callback here calling thermal_zone_device_enable(), which will result > in deadlock. > > Move the thermal_zone_device_enable() to proc_thermal_pci_probe() to > avoid this deadlock. > > Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@intel.com> > Cc: stable@vger.kernel.org > --- > The commit which caused this issue was added during v6.2 cycle. What commit exactly? Always list that as a Fixes: tag if you know this. thanks, greg k-h
On Fri, Mar 3, 2023 at 7:52 PM Greg KH <gregkh@linuxfoundation.org> wrote: > > On Fri, Mar 03, 2023 at 08:19:09AM -0800, Srinivas Pandruvada wrote: > > From: Srinivas Pandruvada <srinivas.pandruvada@intel.com> > > > > When user space updates the trip point there is a deadlock, which results > > in caller gets blocked forever. > > > > Commit 05eeee2b51b4 ("thermal/core: Protect sysfs accesses to thermal > > operations with thermal zone mutex"), added a mutex for tz->lock in the > > function trip_point_temp_store(). Hence, trip set callback() can't > > call any thermal zone API as they are protected with the same mutex lock. > > > > The callback here calling thermal_zone_device_enable(), which will result > > in deadlock. > > > > Move the thermal_zone_device_enable() to proc_thermal_pci_probe() to > > avoid this deadlock. > > > > Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@intel.com> > > Cc: stable@vger.kernel.org > > --- > > The commit which caused this issue was added during v6.2 cycle. > > What commit exactly? Always list that as a Fixes: tag if you know this. It's there in the changelog above. I'll add a Fixes: tag to this one when applying it. Cheers!
On Fri, Mar 3, 2023 at 5:19 PM Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com> wrote: > > From: Srinivas Pandruvada <srinivas.pandruvada@intel.com> > > When user space updates the trip point there is a deadlock, which results > in caller gets blocked forever. > > Commit 05eeee2b51b4 ("thermal/core: Protect sysfs accesses to thermal > operations with thermal zone mutex"), added a mutex for tz->lock in the > function trip_point_temp_store(). Hence, trip set callback() can't > call any thermal zone API as they are protected with the same mutex lock. > > The callback here calling thermal_zone_device_enable(), which will result > in deadlock. > > Move the thermal_zone_device_enable() to proc_thermal_pci_probe() to > avoid this deadlock. > > Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@intel.com> > Cc: stable@vger.kernel.org > --- > The commit which caused this issue was added during v6.2 cycle. > > .../intel/int340x_thermal/processor_thermal_device_pci.c | 5 ++++- > 1 file changed, 4 insertions(+), 1 deletion(-) > > diff --git a/drivers/thermal/intel/int340x_thermal/processor_thermal_device_pci.c b/drivers/thermal/intel/int340x_thermal/processor_thermal_device_pci.c > index bf1b1cdfade4..acc11ad56975 100644 > --- a/drivers/thermal/intel/int340x_thermal/processor_thermal_device_pci.c > +++ b/drivers/thermal/intel/int340x_thermal/processor_thermal_device_pci.c > @@ -194,7 +194,6 @@ static int sys_set_trip_temp(struct thermal_zone_device *tzd, int trip, int temp > proc_thermal_mmio_write(pci_info, PROC_THERMAL_MMIO_THRES_0, _temp); > proc_thermal_mmio_write(pci_info, PROC_THERMAL_MMIO_INT_ENABLE_0, 1); > > - thermal_zone_device_enable(tzd); > pci_info->stored_thres = temp; > > return 0; > @@ -277,6 +276,10 @@ static int proc_thermal_pci_probe(struct pci_dev *pdev, const struct pci_device_ > goto err_free_vectors; > } > > + ret = thermal_zone_device_enable(pci_info->tzone); > + if (ret) > + goto err_free_vectors; > + > return 0; > > err_free_vectors: > -- Now queued up for 6.3-rc with a Fixes: tag added, thanks!
diff --git a/drivers/thermal/intel/int340x_thermal/processor_thermal_device_pci.c b/drivers/thermal/intel/int340x_thermal/processor_thermal_device_pci.c index bf1b1cdfade4..acc11ad56975 100644 --- a/drivers/thermal/intel/int340x_thermal/processor_thermal_device_pci.c +++ b/drivers/thermal/intel/int340x_thermal/processor_thermal_device_pci.c @@ -194,7 +194,6 @@ static int sys_set_trip_temp(struct thermal_zone_device *tzd, int trip, int temp proc_thermal_mmio_write(pci_info, PROC_THERMAL_MMIO_THRES_0, _temp); proc_thermal_mmio_write(pci_info, PROC_THERMAL_MMIO_INT_ENABLE_0, 1); - thermal_zone_device_enable(tzd); pci_info->stored_thres = temp; return 0; @@ -277,6 +276,10 @@ static int proc_thermal_pci_probe(struct pci_dev *pdev, const struct pci_device_ goto err_free_vectors; } + ret = thermal_zone_device_enable(pci_info->tzone); + if (ret) + goto err_free_vectors; + return 0; err_free_vectors: