diff options
Diffstat (limited to 'drivers/base/devcoredump.c')
| -rw-r--r-- | drivers/base/devcoredump.c | 68 |
1 files changed, 45 insertions, 23 deletions
diff --git a/drivers/base/devcoredump.c b/drivers/base/devcoredump.c index 7e2d1f0d903a..64840e5d5fcc 100644 --- a/drivers/base/devcoredump.c +++ b/drivers/base/devcoredump.c @@ -18,9 +18,6 @@ static struct class devcd_class; /* global disable flag, for security purposes */ static bool devcd_disabled; -/* if data isn't read by userspace after 5 minutes then delete it */ -#define DEVCD_TIMEOUT (HZ * 60 * 5) - struct devcd_entry { struct device devcd_dev; void *data; @@ -109,7 +106,7 @@ static void devcd_del(struct work_struct *wk) } static ssize_t devcd_data_read(struct file *filp, struct kobject *kobj, - struct bin_attribute *bin_attr, + const struct bin_attribute *bin_attr, char *buffer, loff_t offset, size_t count) { struct device *dev = kobj_to_dev(kobj); @@ -119,7 +116,7 @@ static ssize_t devcd_data_read(struct file *filp, struct kobject *kobj, } static ssize_t devcd_data_write(struct file *filp, struct kobject *kobj, - struct bin_attribute *bin_attr, + const struct bin_attribute *bin_attr, char *buffer, loff_t offset, size_t count) { struct device *dev = kobj_to_dev(kobj); @@ -135,19 +132,15 @@ static ssize_t devcd_data_write(struct file *filp, struct kobject *kobj, return count; } -static struct bin_attribute devcd_attr_data = { - .attr = { .name = "data", .mode = S_IRUSR | S_IWUSR, }, - .size = 0, - .read = devcd_data_read, - .write = devcd_data_write, -}; +static const struct bin_attribute devcd_attr_data = + __BIN_ATTR(data, 0600, devcd_data_read, devcd_data_write, 0); -static struct bin_attribute *devcd_dev_bin_attrs[] = { +static const struct bin_attribute *const devcd_dev_bin_attrs[] = { &devcd_attr_data, NULL, }; static const struct attribute_group devcd_dev_group = { - .bin_attrs = devcd_dev_bin_attrs, + .bin_attrs_new = devcd_dev_bin_attrs, }; static const struct attribute_group *devcd_dev_groups[] = { @@ -189,9 +182,9 @@ static ssize_t disabled_show(const struct class *class, const struct class_attri * mutex_lock(&devcd->mutex); * * - * In the above diagram, It looks like disabled_store() would be racing with parallely + * In the above diagram, it looks like disabled_store() would be racing with parallelly * running devcd_del() and result in memory abort while acquiring devcd->mutex which - * is called after kfree of devcd memory after dropping its last reference with + * is called after kfree of devcd memory after dropping its last reference with * put_device(). However, this will not happens as fn(dev, data) runs * with its own reference to device via klist_node so it is not its last reference. * so, above situation would not occur. @@ -288,6 +281,8 @@ static void devcd_free_sgtable(void *data) * @offset: start copy from @offset@ bytes from the head of the data * in the given scatterlist * @data_len: the length of the data in the sg_table + * + * Returns: the number of bytes copied */ static ssize_t devcd_read_from_sgtable(char *buffer, loff_t offset, size_t buf_len, void *data, @@ -305,7 +300,31 @@ static ssize_t devcd_read_from_sgtable(char *buffer, loff_t offset, } /** - * dev_coredumpm - create device coredump with read/free methods + * dev_coredump_put - remove device coredump + * @dev: the struct device for the crashed device + * + * dev_coredump_put() removes coredump, if exists, for a given device from + * the file system and free its associated data otherwise, does nothing. + * + * It is useful for modules that do not want to keep coredump + * available after its unload. + */ +void dev_coredump_put(struct device *dev) +{ + struct device *existing; + + existing = class_find_device(&devcd_class, NULL, dev, + devcd_match_failing); + if (existing) { + devcd_free(existing, NULL); + put_device(existing); + } +} +EXPORT_SYMBOL_GPL(dev_coredump_put); + +/** + * dev_coredumpm_timeout - create device coredump with read/free methods with a + * custom timeout. * @dev: the struct device for the crashed device * @owner: the module that contains the read/free functions, use %THIS_MODULE * @data: data cookie for the @read/@free functions @@ -313,17 +332,20 @@ static ssize_t devcd_read_from_sgtable(char *buffer, loff_t offset, * @gfp: allocation flags * @read: function to read from the given buffer * @free: function to free the given buffer + * @timeout: time in jiffies to remove coredump * * Creates a new device coredump for the given device. If a previous one hasn't * been read yet, the new coredump is discarded. The data lifetime is determined * by the device coredump framework and when it is no longer needed the @free * function will be called to free the data. */ -void dev_coredumpm(struct device *dev, struct module *owner, - void *data, size_t datalen, gfp_t gfp, - ssize_t (*read)(char *buffer, loff_t offset, size_t count, - void *data, size_t datalen), - void (*free)(void *data)) +void dev_coredumpm_timeout(struct device *dev, struct module *owner, + void *data, size_t datalen, gfp_t gfp, + ssize_t (*read)(char *buffer, loff_t offset, + size_t count, void *data, + size_t datalen), + void (*free)(void *data), + unsigned long timeout) { static atomic_t devcd_count = ATOMIC_INIT(0); struct devcd_entry *devcd; @@ -380,7 +402,7 @@ void dev_coredumpm(struct device *dev, struct module *owner, dev_set_uevent_suppress(&devcd->devcd_dev, false); kobject_uevent(&devcd->devcd_dev.kobj, KOBJ_ADD); INIT_DELAYED_WORK(&devcd->del_wk, devcd_del); - schedule_delayed_work(&devcd->del_wk, DEVCD_TIMEOUT); + schedule_delayed_work(&devcd->del_wk, timeout); mutex_unlock(&devcd->mutex); return; put_device: @@ -391,7 +413,7 @@ void dev_coredumpm(struct device *dev, struct module *owner, free: free(data); } -EXPORT_SYMBOL_GPL(dev_coredumpm); +EXPORT_SYMBOL_GPL(dev_coredumpm_timeout); /** * dev_coredumpsg - create device coredump that uses scatterlist as data |