| Message ID | 5073E4CC.3090600@jp.fujitsu.com (mailing list archive) |
|---|---|
| State | Superseded, archived |
| Headers | show |
On Tue, 2012-10-09 at 17:48 +0900, Yasuaki Ishimatsu wrote: > acpi_bus_trim() stops removing devices, when acpi_bus_remove() return error > number. But acpi_bus_remove() cannot return error number correctly. > acpi_bus_remove() only return -EINVAL, when dev argument is NULL. Thus even if > device cannot be removed correctly, acpi_bus_trim() ignores and continues to > remove devices. acpi_bus_hot_remove_device() uses acpi_bus_trim() for removing > devices. Therefore acpi_bus_hot_remove_device() can send "_EJ0" to firmware, > even if the device is running on the system. In this case, the system cannot > work well. > > Vasilis hit the bug at memory hotplug and reported it as follow: > https://lkml.org/lkml/2012/9/26/318 > > So acpi_bus_trim() should check whether device was removed or not correctly. > The patch adds error check into some functions to remove the device. > > Applying the patch, acpi_bus_trim() stops removing devices when failing > to remove the device. But I think there is no impact with the > exceptionof CPU and Memory hotplug path. Because other device also fails > but the fail is an irregular case like device is NULL. > > Signed-off-by: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com> > > --- > drivers/acpi/scan.c | 15 ++++++++++++--- > drivers/base/dd.c | 22 +++++++++++++++++----- > include/linux/device.h | 2 +- > 3 files changed, 30 insertions(+), 9 deletions(-) > > Index: linux-3.6/drivers/acpi/scan.c > =================================================================== > --- linux-3.6.orig/drivers/acpi/scan.c 2012-10-09 17:25:40.956496325 +0900 > +++ linux-3.6/drivers/acpi/scan.c 2012-10-09 17:25:55.405497800 +0900 > @@ -445,12 +445,17 @@ static int acpi_device_remove(struct dev > { > struct acpi_device *acpi_dev = to_acpi_device(dev); > struct acpi_driver *acpi_drv = acpi_dev->driver; > + int ret; > > if (acpi_drv) { > if (acpi_drv->ops.notify) > acpi_device_remove_notify_handler(acpi_dev); > - if (acpi_drv->ops.remove) > - acpi_drv->ops.remove(acpi_dev, acpi_dev->removal_type); > + if (acpi_drv->ops.remove) { > + ret = acpi_drv->ops.remove(acpi_dev, > + acpi_dev->removal_type); > + if (ret) Hi Yasuaki, Shouldn't the notify handler be reinstalled here if it was removed by the acpi_device_remove_notify_handler() above? Thanks, -Toshi > + return ret; > + } > } > acpi_dev->driver = NULL; > acpi_dev->driver_data = NULL; > @@ -1226,11 +1231,15 @@ static int acpi_device_set_context(struc > > static int acpi_bus_remove(struct acpi_device *dev, int rmdevice) > { > + int ret; > + > if (!dev) > return -EINVAL; > > dev->removal_type = ACPI_BUS_REMOVAL_EJECT; > - device_release_driver(&dev->dev); > + ret = device_release_driver(&dev->dev); > + if (ret) > + return ret; > > if (!rmdevice) > return 0; > Index: linux-3.6/drivers/base/dd.c > =================================================================== > --- linux-3.6.orig/drivers/base/dd.c 2012-10-01 08:47:46.000000000 +0900 > +++ linux-3.6/drivers/base/dd.c 2012-10-09 17:25:55.442497825 +0900 > @@ -475,9 +475,10 @@ EXPORT_SYMBOL_GPL(driver_attach); > * __device_release_driver() must be called with @dev lock held. > * When called for a USB interface, @dev->parent lock must be held as well. > */ > -static void __device_release_driver(struct device *dev) > +static int __device_release_driver(struct device *dev) > { > struct device_driver *drv; > + int ret = 0; > > drv = dev->driver; > if (drv) { > @@ -493,9 +494,11 @@ static void __device_release_driver(stru > pm_runtime_put_sync(dev); > > if (dev->bus && dev->bus->remove) > - dev->bus->remove(dev); > + ret = dev->bus->remove(dev); > else if (drv->remove) > - drv->remove(dev); > + ret = drv->remove(dev); > + if (ret) > + goto rollback; > devres_release_all(dev); > dev->driver = NULL; > dev_set_drvdata(dev, NULL); > @@ -506,6 +509,12 @@ static void __device_release_driver(stru > dev); > > } > + > + return ret; > + > +rollback: > + driver_sysfs_add(dev); > + return ret; > } > > /** > @@ -515,16 +524,19 @@ static void __device_release_driver(stru > * Manually detach device from driver. > * When called for a USB interface, @dev->parent lock must be held. > */ > -void device_release_driver(struct device *dev) > +int device_release_driver(struct device *dev) > { > + int ret; > /* > * If anyone calls device_release_driver() recursively from > * within their ->remove callback for the same device, they > * will deadlock right here. > */ > device_lock(dev); > - __device_release_driver(dev); > + ret = __device_release_driver(dev); > device_unlock(dev); > + > + return ret; > } > EXPORT_SYMBOL_GPL(device_release_driver); > > Index: linux-3.6/include/linux/device.h > =================================================================== > --- linux-3.6.orig/include/linux/device.h 2012-10-01 08:47:46.000000000 +0900 > +++ linux-3.6/include/linux/device.h 2012-10-09 17:25:55.479497852 +0900 > @@ -834,7 +834,7 @@ static inline void *dev_get_platdata(con > * for information on use. > */ > extern int __must_check device_bind_driver(struct device *dev); > -extern void device_release_driver(struct device *dev); > +extern int device_release_driver(struct device *dev); > extern int __must_check device_attach(struct device *dev); > extern int __must_check driver_attach(struct device_driver *drv); > extern int __must_check device_reprobe(struct device *dev); > -- To unsubscribe from this list: send the line "unsubscribe linux-acpi" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Hi Toshi, 2012/10/10 1:36, Toshi Kani wrote: > On Tue, 2012-10-09 at 17:48 +0900, Yasuaki Ishimatsu wrote: >> acpi_bus_trim() stops removing devices, when acpi_bus_remove() return error >> number. But acpi_bus_remove() cannot return error number correctly. >> acpi_bus_remove() only return -EINVAL, when dev argument is NULL. Thus even if >> device cannot be removed correctly, acpi_bus_trim() ignores and continues to >> remove devices. acpi_bus_hot_remove_device() uses acpi_bus_trim() for removing >> devices. Therefore acpi_bus_hot_remove_device() can send "_EJ0" to firmware, >> even if the device is running on the system. In this case, the system cannot >> work well. >> >> Vasilis hit the bug at memory hotplug and reported it as follow: >> https://lkml.org/lkml/2012/9/26/318 >> >> So acpi_bus_trim() should check whether device was removed or not correctly. >> The patch adds error check into some functions to remove the device. >> >> Applying the patch, acpi_bus_trim() stops removing devices when failing >> to remove the device. But I think there is no impact with the >> exceptionof CPU and Memory hotplug path. Because other device also fails >> but the fail is an irregular case like device is NULL. >> >> Signed-off-by: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com> >> >> --- >> drivers/acpi/scan.c | 15 ++++++++++++--- >> drivers/base/dd.c | 22 +++++++++++++++++----- >> include/linux/device.h | 2 +- >> 3 files changed, 30 insertions(+), 9 deletions(-) >> >> Index: linux-3.6/drivers/acpi/scan.c >> =================================================================== >> --- linux-3.6.orig/drivers/acpi/scan.c 2012-10-09 17:25:40.956496325 +0900 >> +++ linux-3.6/drivers/acpi/scan.c 2012-10-09 17:25:55.405497800 +0900 >> @@ -445,12 +445,17 @@ static int acpi_device_remove(struct dev >> { >> struct acpi_device *acpi_dev = to_acpi_device(dev); >> struct acpi_driver *acpi_drv = acpi_dev->driver; >> + int ret; >> >> if (acpi_drv) { >> if (acpi_drv->ops.notify) >> acpi_device_remove_notify_handler(acpi_dev); >> - if (acpi_drv->ops.remove) >> - acpi_drv->ops.remove(acpi_dev, acpi_dev->removal_type); >> + if (acpi_drv->ops.remove) { >> + ret = acpi_drv->ops.remove(acpi_dev, >> + acpi_dev->removal_type); >> + if (ret) > > Hi Yasuaki, > > Shouldn't the notify handler be reinstalled here if it was removed by > the acpi_device_remove_notify_handler() above? I do not reinstall the notify handler. The function has not been removed on linux-3.6. And the patch is created on linux-3.6. So the function remains in the patch. Thanks, Yasuaki Ishimatsu > > Thanks, > -Toshi > >> + return ret; >> + } >> } >> acpi_dev->driver = NULL; >> acpi_dev->driver_data = NULL; >> @@ -1226,11 +1231,15 @@ static int acpi_device_set_context(struc >> >> static int acpi_bus_remove(struct acpi_device *dev, int rmdevice) >> { >> + int ret; >> + >> if (!dev) >> return -EINVAL; >> >> dev->removal_type = ACPI_BUS_REMOVAL_EJECT; >> - device_release_driver(&dev->dev); >> + ret = device_release_driver(&dev->dev); >> + if (ret) >> + return ret; >> >> if (!rmdevice) >> return 0; >> Index: linux-3.6/drivers/base/dd.c >> =================================================================== >> --- linux-3.6.orig/drivers/base/dd.c 2012-10-01 08:47:46.000000000 +0900 >> +++ linux-3.6/drivers/base/dd.c 2012-10-09 17:25:55.442497825 +0900 >> @@ -475,9 +475,10 @@ EXPORT_SYMBOL_GPL(driver_attach); >> * __device_release_driver() must be called with @dev lock held. >> * When called for a USB interface, @dev->parent lock must be held as well. >> */ >> -static void __device_release_driver(struct device *dev) >> +static int __device_release_driver(struct device *dev) >> { >> struct device_driver *drv; >> + int ret = 0; >> >> drv = dev->driver; >> if (drv) { >> @@ -493,9 +494,11 @@ static void __device_release_driver(stru >> pm_runtime_put_sync(dev); >> >> if (dev->bus && dev->bus->remove) >> - dev->bus->remove(dev); >> + ret = dev->bus->remove(dev); >> else if (drv->remove) >> - drv->remove(dev); >> + ret = drv->remove(dev); >> + if (ret) >> + goto rollback; >> devres_release_all(dev); >> dev->driver = NULL; >> dev_set_drvdata(dev, NULL); >> @@ -506,6 +509,12 @@ static void __device_release_driver(stru >> dev); >> >> } >> + >> + return ret; >> + >> +rollback: >> + driver_sysfs_add(dev); >> + return ret; >> } >> >> /** >> @@ -515,16 +524,19 @@ static void __device_release_driver(stru >> * Manually detach device from driver. >> * When called for a USB interface, @dev->parent lock must be held. >> */ >> -void device_release_driver(struct device *dev) >> +int device_release_driver(struct device *dev) >> { >> + int ret; >> /* >> * If anyone calls device_release_driver() recursively from >> * within their ->remove callback for the same device, they >> * will deadlock right here. >> */ >> device_lock(dev); >> - __device_release_driver(dev); >> + ret = __device_release_driver(dev); >> device_unlock(dev); >> + >> + return ret; >> } >> EXPORT_SYMBOL_GPL(device_release_driver); >> >> Index: linux-3.6/include/linux/device.h >> =================================================================== >> --- linux-3.6.orig/include/linux/device.h 2012-10-01 08:47:46.000000000 +0900 >> +++ linux-3.6/include/linux/device.h 2012-10-09 17:25:55.479497852 +0900 >> @@ -834,7 +834,7 @@ static inline void *dev_get_platdata(con >> * for information on use. >> */ >> extern int __must_check device_bind_driver(struct device *dev); >> -extern void device_release_driver(struct device *dev); >> +extern int device_release_driver(struct device *dev); >> extern int __must_check device_attach(struct device *dev); >> extern int __must_check driver_attach(struct device_driver *drv); >> extern int __must_check device_reprobe(struct device *dev); >> > > -- To unsubscribe from this list: send the line "unsubscribe linux-acpi" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Wed, 2012-10-10 at 10:07 +0900, Yasuaki Ishimatsu wrote: : > >> if (acpi_drv) { > >> if (acpi_drv->ops.notify) > >> acpi_device_remove_notify_handler(acpi_dev); THIS CALL > >> - if (acpi_drv->ops.remove) > >> - acpi_drv->ops.remove(acpi_dev, acpi_dev->removal_type); > >> + if (acpi_drv->ops.remove) { > >> + ret = acpi_drv->ops.remove(acpi_dev, > >> + acpi_dev->removal_type); > >> + if (ret) > > > > Hi Yasuaki, > > > > Shouldn't the notify handler be reinstalled here if it was removed by > > the acpi_device_remove_notify_handler() above? > > I do not reinstall the notify handler. > The function has not been removed on linux-3.6. And the patch is created > on linux-3.6. So the function remains in the patch. Umm... I am not sure what you meant. Let me clarify my comment. When acpi_drv->ops.remove() failed, I thought we would need to roll-back the procedure done by the acpi_device_remove_notify_handler() call, which I indicated as "THIS CALL" above. So, in this error path, don't we need something like below? if (acpi_drv->ops.notify) acpi_device_install_notify_handler(acpi_dev) Thanks, -Toshi -- To unsubscribe from this list: send the line "unsubscribe linux-acpi" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Hi Toshi, 2012/10/10 22:01, Toshi Kani wrote: > On Wed, 2012-10-10 at 10:07 +0900, Yasuaki Ishimatsu wrote: > : >>>> if (acpi_drv) { >>>> if (acpi_drv->ops.notify) >>>> acpi_device_remove_notify_handler(acpi_dev); > > THIS CALL > >>>> - if (acpi_drv->ops.remove) >>>> - acpi_drv->ops.remove(acpi_dev, acpi_dev->removal_type); >>>> + if (acpi_drv->ops.remove) { >>>> + ret = acpi_drv->ops.remove(acpi_dev, >>>> + acpi_dev->removal_type); >>>> + if (ret) >>> >>> Hi Yasuaki, >>> >>> Shouldn't the notify handler be reinstalled here if it was removed by >>> the acpi_device_remove_notify_handler() above? >> >> I do not reinstall the notify handler. >> The function has not been removed on linux-3.6. And the patch is created >> on linux-3.6. So the function remains in the patch. > > Umm... I am not sure what you meant. Let me clarify my comment. When > acpi_drv->ops.remove() failed, I thought we would need to roll-back the > procedure done by the acpi_device_remove_notify_handler() call, which I > indicated as "THIS CALL" above. So, in this error path, don't we need > something like below? > > if (acpi_drv->ops.notify) > acpi_device_install_notify_handler(acpi_dev) I understood what you said. I'll update it. Thanks, Yasuaki Ishimatsu > > Thanks, > -Toshi > > > > -- To unsubscribe from this list: send the line "unsubscribe linux-acpi" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Index: linux-3.6/drivers/acpi/scan.c =================================================================== --- linux-3.6.orig/drivers/acpi/scan.c 2012-10-09 17:25:40.956496325 +0900 +++ linux-3.6/drivers/acpi/scan.c 2012-10-09 17:25:55.405497800 +0900 @@ -445,12 +445,17 @@ static int acpi_device_remove(struct dev { struct acpi_device *acpi_dev = to_acpi_device(dev); struct acpi_driver *acpi_drv = acpi_dev->driver; + int ret; if (acpi_drv) { if (acpi_drv->ops.notify) acpi_device_remove_notify_handler(acpi_dev); - if (acpi_drv->ops.remove) - acpi_drv->ops.remove(acpi_dev, acpi_dev->removal_type); + if (acpi_drv->ops.remove) { + ret = acpi_drv->ops.remove(acpi_dev, + acpi_dev->removal_type); + if (ret) + return ret; + } } acpi_dev->driver = NULL; acpi_dev->driver_data = NULL; @@ -1226,11 +1231,15 @@ static int acpi_device_set_context(struc static int acpi_bus_remove(struct acpi_device *dev, int rmdevice) { + int ret; + if (!dev) return -EINVAL; dev->removal_type = ACPI_BUS_REMOVAL_EJECT; - device_release_driver(&dev->dev); + ret = device_release_driver(&dev->dev); + if (ret) + return ret; if (!rmdevice) return 0; Index: linux-3.6/drivers/base/dd.c =================================================================== --- linux-3.6.orig/drivers/base/dd.c 2012-10-01 08:47:46.000000000 +0900 +++ linux-3.6/drivers/base/dd.c 2012-10-09 17:25:55.442497825 +0900 @@ -475,9 +475,10 @@ EXPORT_SYMBOL_GPL(driver_attach); * __device_release_driver() must be called with @dev lock held. * When called for a USB interface, @dev->parent lock must be held as well. */ -static void __device_release_driver(struct device *dev) +static int __device_release_driver(struct device *dev) { struct device_driver *drv; + int ret = 0; drv = dev->driver; if (drv) { @@ -493,9 +494,11 @@ static void __device_release_driver(stru pm_runtime_put_sync(dev); if (dev->bus && dev->bus->remove) - dev->bus->remove(dev); + ret = dev->bus->remove(dev); else if (drv->remove) - drv->remove(dev); + ret = drv->remove(dev); + if (ret) + goto rollback; devres_release_all(dev); dev->driver = NULL; dev_set_drvdata(dev, NULL); @@ -506,6 +509,12 @@ static void __device_release_driver(stru dev); } + + return ret; + +rollback: + driver_sysfs_add(dev); + return ret; } /** @@ -515,16 +524,19 @@ static void __device_release_driver(stru * Manually detach device from driver. * When called for a USB interface, @dev->parent lock must be held. */ -void device_release_driver(struct device *dev) +int device_release_driver(struct device *dev) { + int ret; /* * If anyone calls device_release_driver() recursively from * within their ->remove callback for the same device, they * will deadlock right here. */ device_lock(dev); - __device_release_driver(dev); + ret = __device_release_driver(dev); device_unlock(dev); + + return ret; } EXPORT_SYMBOL_GPL(device_release_driver); Index: linux-3.6/include/linux/device.h =================================================================== --- linux-3.6.orig/include/linux/device.h 2012-10-01 08:47:46.000000000 +0900 +++ linux-3.6/include/linux/device.h 2012-10-09 17:25:55.479497852 +0900 @@ -834,7 +834,7 @@ static inline void *dev_get_platdata(con * for information on use. */ extern int __must_check device_bind_driver(struct device *dev); -extern void device_release_driver(struct device *dev); +extern int device_release_driver(struct device *dev); extern int __must_check device_attach(struct device *dev); extern int __must_check driver_attach(struct device_driver *drv); extern int __must_check device_reprobe(struct device *dev);
acpi_bus_trim() stops removing devices, when acpi_bus_remove() return error number. But acpi_bus_remove() cannot return error number correctly. acpi_bus_remove() only return -EINVAL, when dev argument is NULL. Thus even if device cannot be removed correctly, acpi_bus_trim() ignores and continues to remove devices. acpi_bus_hot_remove_device() uses acpi_bus_trim() for removing devices. Therefore acpi_bus_hot_remove_device() can send "_EJ0" to firmware, even if the device is running on the system. In this case, the system cannot work well. Vasilis hit the bug at memory hotplug and reported it as follow: https://lkml.org/lkml/2012/9/26/318 So acpi_bus_trim() should check whether device was removed or not correctly. The patch adds error check into some functions to remove the device. Applying the patch, acpi_bus_trim() stops removing devices when failing to remove the device. But I think there is no impact with the exceptionof CPU and Memory hotplug path. Because other device also fails but the fail is an irregular case like device is NULL. Signed-off-by: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com> --- drivers/acpi/scan.c | 15 ++++++++++++--- drivers/base/dd.c | 22 +++++++++++++++++----- include/linux/device.h | 2 +- 3 files changed, 30 insertions(+), 9 deletions(-) -- To unsubscribe from this list: send the line "unsubscribe linux-acpi" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html