| Message ID | 20220809083112.v4.2.Ief1110784c6c1c3ac0ee5677c2d28d785af8686d@changeid (mailing list archive) |
|---|---|
| State | Superseded |
| Headers | show |
| Series | [v4,1/5] sysfs: Add attribute info for /sys/devices/.../coredump_disabled | expand |
| Context | Check | Description |
|---|---|---|
| tedd_an/pre-ci_am | success | Success |
| tedd_an/checkpatch | success | Checkpatch PASS |
| tedd_an/gitlint | success | Gitlint PASS |
| tedd_an/subjectprefix | fail | "Bluetooth: " is not specified in the subject |
On Tue, Aug 09, 2022 at 08:35:24AM -0700, Manish Mandlik wrote: > The /sys/class/devcoredump/disabled provides only one-way disable > functionality. Also, disabling devcoredump using it disables the > devcoredump functionality for everyone who is using it. > > Provide a way to selectively enable/disable devcoredump for the device > which is bound to a driver that implements the '.coredump()' callback. > > This adds the 'coredump_disabled' driver attribute. When the driver > implements the '.coredump()' callback, 'coredump_disabled' file is added > along with the 'coredump' file in the sysfs folder of the device upon > driver binding. The file is removed when the driver is unbound. > > Drivers can use this attribute to enable/disable devcoredump and the > userspace can write 0 or 1 to /sys/devices/.../coredump_disabled sysfs > entry to control enabling/disabling of devcoredump for that device. > > Signed-off-by: Manish Mandlik <mmandlik@google.com> > Reviewed-by: Abhishek Pandit-Subedi <abhishekpandit@chromium.org> > --- > > Changes in v4: > - New patch in the series > > drivers/base/dd.c | 43 +++++++++++++++++++++++++++++++++++--- > drivers/base/devcoredump.c | 2 +- > include/linux/device.h | 4 ++++ > 3 files changed, 45 insertions(+), 4 deletions(-) You can't add a new sysfs file without also a Documentation/ABI update at the same time :( thanks, greg k-h
On Tue, Aug 09, 2022 at 08:35:24AM -0700, Manish Mandlik wrote: > The /sys/class/devcoredump/disabled provides only one-way disable > functionality. Also, disabling devcoredump using it disables the > devcoredump functionality for everyone who is using it. > > Provide a way to selectively enable/disable devcoredump for the device > which is bound to a driver that implements the '.coredump()' callback. > > This adds the 'coredump_disabled' driver attribute. When the driver > implements the '.coredump()' callback, 'coredump_disabled' file is added > along with the 'coredump' file in the sysfs folder of the device upon > driver binding. The file is removed when the driver is unbound. > > Drivers can use this attribute to enable/disable devcoredump and the > userspace can write 0 or 1 to /sys/devices/.../coredump_disabled sysfs > entry to control enabling/disabling of devcoredump for that device. > > Signed-off-by: Manish Mandlik <mmandlik@google.com> > Reviewed-by: Abhishek Pandit-Subedi <abhishekpandit@chromium.org> > --- > > Changes in v4: > - New patch in the series > > drivers/base/dd.c | 43 +++++++++++++++++++++++++++++++++++--- > drivers/base/devcoredump.c | 2 +- > include/linux/device.h | 4 ++++ > 3 files changed, 45 insertions(+), 4 deletions(-) > > diff --git a/drivers/base/dd.c b/drivers/base/dd.c > index 11b0fb6414d3..c76d1145c6d9 100644 > --- a/drivers/base/dd.c > +++ b/drivers/base/dd.c > @@ -426,6 +426,31 @@ static ssize_t coredump_store(struct device *dev, struct device_attribute *attr, > } > static DEVICE_ATTR_WO(coredump); > > +static ssize_t coredump_disabled_show(struct device *dev, > + struct device_attribute *attr, > + char *buf) > +{ > + return scnprintf(buf, 3, "%d\n", dev->coredump_disabled); Also, please use sysfs_emit() for any sysfs file output. It's in all active kernels for a very long time now. > +} > + > +static ssize_t coredump_disabled_store(struct device *dev, > + struct device_attribute *attr, > + const char *buf, size_t count) > +{ > + long coredump_disabled; > + > + if (!kstrtol(buf, 10, &coredump_disabled)) { > + /* Consider any non-zero value as true */ We have a "Y/N/0/1/y/n" check function for sysfs store callbacks that you should use instead. > + if (coredump_disabled) > + dev->coredump_disabled = true; > + else > + dev->coredump_disabled = false; > + } > + > + return count; > +} > +static DEVICE_ATTR_RW(coredump_disabled); > + > static int driver_sysfs_add(struct device *dev) > { > int ret; > @@ -448,9 +473,19 @@ static int driver_sysfs_add(struct device *dev) > return 0; > > ret = device_create_file(dev, &dev_attr_coredump); > - if (!ret) > - return 0; > + if (ret) > + goto rm_driver; > + > + ret = device_create_file(dev, &dev_attr_coredump_disabled); Please use an attribute group now that you have multiple files. > + if (ret) > + goto rm_coredump; > > + return 0; > + > +rm_coredump: > + device_remove_file(dev, &dev_attr_coredump); > + > +rm_driver: > sysfs_remove_link(&dev->kobj, "driver"); > > rm_dev: > @@ -466,8 +501,10 @@ static void driver_sysfs_remove(struct device *dev) > struct device_driver *drv = dev->driver; > > if (drv) { > - if (drv->coredump) > + if (drv->coredump) { > + device_remove_file(dev, &dev_attr_coredump_disabled); > device_remove_file(dev, &dev_attr_coredump); > + } > sysfs_remove_link(&drv->p->kobj, kobject_name(&dev->kobj)); > sysfs_remove_link(&dev->kobj, "driver"); > } > diff --git a/drivers/base/devcoredump.c b/drivers/base/devcoredump.c > index f4d794d6bb85..c5e9af9f3181 100644 > --- a/drivers/base/devcoredump.c > +++ b/drivers/base/devcoredump.c > @@ -255,7 +255,7 @@ void dev_coredumpm(struct device *dev, struct module *owner, > struct devcd_entry *devcd; > struct device *existing; > > - if (devcd_disabled) > + if (devcd_disabled || dev->coredump_disabled) > goto free; > > existing = class_find_device(&devcd_class, NULL, dev, > diff --git a/include/linux/device.h b/include/linux/device.h > index dc941997795c..120dd656f99d 100644 > --- a/include/linux/device.h > +++ b/include/linux/device.h > @@ -469,6 +469,8 @@ struct device_physical_location { > * This identifies the device type and carries type-specific > * information. > * @mutex: Mutex to synchronize calls to its driver. > + * @coredump_disabled: Can be used by drivers to selectively enable/disable the > + * coredump for a particular device via sysfs entry. > * @bus: Type of bus device is on. > * @driver: Which driver has allocated this > * @platform_data: Platform data specific to the device. > @@ -561,6 +563,8 @@ struct device { > const char *init_name; /* initial name of the device */ > const struct device_type *type; > > + bool coredump_disabled; > + That just hosed the alignment in this structure :( Please be aware of how memory layouts for common kernel structures are managed, and try not to add holes when you do not need to. thanks, greg k-h
diff --git a/drivers/base/dd.c b/drivers/base/dd.c index 11b0fb6414d3..c76d1145c6d9 100644 --- a/drivers/base/dd.c +++ b/drivers/base/dd.c @@ -426,6 +426,31 @@ static ssize_t coredump_store(struct device *dev, struct device_attribute *attr, } static DEVICE_ATTR_WO(coredump); +static ssize_t coredump_disabled_show(struct device *dev, + struct device_attribute *attr, + char *buf) +{ + return scnprintf(buf, 3, "%d\n", dev->coredump_disabled); +} + +static ssize_t coredump_disabled_store(struct device *dev, + struct device_attribute *attr, + const char *buf, size_t count) +{ + long coredump_disabled; + + if (!kstrtol(buf, 10, &coredump_disabled)) { + /* Consider any non-zero value as true */ + if (coredump_disabled) + dev->coredump_disabled = true; + else + dev->coredump_disabled = false; + } + + return count; +} +static DEVICE_ATTR_RW(coredump_disabled); + static int driver_sysfs_add(struct device *dev) { int ret; @@ -448,9 +473,19 @@ static int driver_sysfs_add(struct device *dev) return 0; ret = device_create_file(dev, &dev_attr_coredump); - if (!ret) - return 0; + if (ret) + goto rm_driver; + + ret = device_create_file(dev, &dev_attr_coredump_disabled); + if (ret) + goto rm_coredump; + return 0; + +rm_coredump: + device_remove_file(dev, &dev_attr_coredump); + +rm_driver: sysfs_remove_link(&dev->kobj, "driver"); rm_dev: @@ -466,8 +501,10 @@ static void driver_sysfs_remove(struct device *dev) struct device_driver *drv = dev->driver; if (drv) { - if (drv->coredump) + if (drv->coredump) { + device_remove_file(dev, &dev_attr_coredump_disabled); device_remove_file(dev, &dev_attr_coredump); + } sysfs_remove_link(&drv->p->kobj, kobject_name(&dev->kobj)); sysfs_remove_link(&dev->kobj, "driver"); } diff --git a/drivers/base/devcoredump.c b/drivers/base/devcoredump.c index f4d794d6bb85..c5e9af9f3181 100644 --- a/drivers/base/devcoredump.c +++ b/drivers/base/devcoredump.c @@ -255,7 +255,7 @@ void dev_coredumpm(struct device *dev, struct module *owner, struct devcd_entry *devcd; struct device *existing; - if (devcd_disabled) + if (devcd_disabled || dev->coredump_disabled) goto free; existing = class_find_device(&devcd_class, NULL, dev, diff --git a/include/linux/device.h b/include/linux/device.h index dc941997795c..120dd656f99d 100644 --- a/include/linux/device.h +++ b/include/linux/device.h @@ -469,6 +469,8 @@ struct device_physical_location { * This identifies the device type and carries type-specific * information. * @mutex: Mutex to synchronize calls to its driver. + * @coredump_disabled: Can be used by drivers to selectively enable/disable the + * coredump for a particular device via sysfs entry. * @bus: Type of bus device is on. * @driver: Which driver has allocated this * @platform_data: Platform data specific to the device. @@ -561,6 +563,8 @@ struct device { const char *init_name; /* initial name of the device */ const struct device_type *type; + bool coredump_disabled; + struct bus_type *bus; /* type of bus device is on */ struct device_driver *driver; /* which driver has allocated this device */