Loading...
1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Copyright(c) 2014 Intel Mobile Communications GmbH
4 * Copyright(c) 2015 Intel Deutschland GmbH
5 *
6 * Author: Johannes Berg <johannes@sipsolutions.net>
7 */
8#include <linux/module.h>
9#include <linux/device.h>
10#include <linux/devcoredump.h>
11#include <linux/list.h>
12#include <linux/slab.h>
13#include <linux/fs.h>
14#include <linux/workqueue.h>
15
16static struct class devcd_class;
17
18/* global disable flag, for security purposes */
19static bool devcd_disabled;
20
21/* if data isn't read by userspace after 5 minutes then delete it */
22#define DEVCD_TIMEOUT (HZ * 60 * 5)
23
24struct devcd_entry {
25 struct device devcd_dev;
26 void *data;
27 size_t datalen;
28 /*
29 * Here, mutex is required to serialize the calls to del_wk work between
30 * user/kernel space which happens when devcd is added with device_add()
31 * and that sends uevent to user space. User space reads the uevents,
32 * and calls to devcd_data_write() which try to modify the work which is
33 * not even initialized/queued from devcoredump.
34 *
35 *
36 *
37 * cpu0(X) cpu1(Y)
38 *
39 * dev_coredump() uevent sent to user space
40 * device_add() ======================> user space process Y reads the
41 * uevents writes to devcd fd
42 * which results into writes to
43 *
44 * devcd_data_write()
45 * mod_delayed_work()
46 * try_to_grab_pending()
47 * del_timer()
48 * debug_assert_init()
49 * INIT_DELAYED_WORK()
50 * schedule_delayed_work()
51 *
52 *
53 * Also, mutex alone would not be enough to avoid scheduling of
54 * del_wk work after it get flush from a call to devcd_free()
55 * mentioned as below.
56 *
57 * disabled_store()
58 * devcd_free()
59 * mutex_lock() devcd_data_write()
60 * flush_delayed_work()
61 * mutex_unlock()
62 * mutex_lock()
63 * mod_delayed_work()
64 * mutex_unlock()
65 * So, delete_work flag is required.
66 */
67 struct mutex mutex;
68 bool delete_work;
69 struct module *owner;
70 ssize_t (*read)(char *buffer, loff_t offset, size_t count,
71 void *data, size_t datalen);
72 void (*free)(void *data);
73 struct delayed_work del_wk;
74 struct device *failing_dev;
75};
76
77static struct devcd_entry *dev_to_devcd(struct device *dev)
78{
79 return container_of(dev, struct devcd_entry, devcd_dev);
80}
81
82static void devcd_dev_release(struct device *dev)
83{
84 struct devcd_entry *devcd = dev_to_devcd(dev);
85
86 devcd->free(devcd->data);
87 module_put(devcd->owner);
88
89 /*
90 * this seems racy, but I don't see a notifier or such on
91 * a struct device to know when it goes away?
92 */
93 if (devcd->failing_dev->kobj.sd)
94 sysfs_delete_link(&devcd->failing_dev->kobj, &dev->kobj,
95 "devcoredump");
96
97 put_device(devcd->failing_dev);
98 kfree(devcd);
99}
100
101static void devcd_del(struct work_struct *wk)
102{
103 struct devcd_entry *devcd;
104
105 devcd = container_of(wk, struct devcd_entry, del_wk.work);
106
107 device_del(&devcd->devcd_dev);
108 put_device(&devcd->devcd_dev);
109}
110
111static ssize_t devcd_data_read(struct file *filp, struct kobject *kobj,
112 struct bin_attribute *bin_attr,
113 char *buffer, loff_t offset, size_t count)
114{
115 struct device *dev = kobj_to_dev(kobj);
116 struct devcd_entry *devcd = dev_to_devcd(dev);
117
118 return devcd->read(buffer, offset, count, devcd->data, devcd->datalen);
119}
120
121static ssize_t devcd_data_write(struct file *filp, struct kobject *kobj,
122 struct bin_attribute *bin_attr,
123 char *buffer, loff_t offset, size_t count)
124{
125 struct device *dev = kobj_to_dev(kobj);
126 struct devcd_entry *devcd = dev_to_devcd(dev);
127
128 mutex_lock(&devcd->mutex);
129 if (!devcd->delete_work) {
130 devcd->delete_work = true;
131 mod_delayed_work(system_wq, &devcd->del_wk, 0);
132 }
133 mutex_unlock(&devcd->mutex);
134
135 return count;
136}
137
138static struct bin_attribute devcd_attr_data = {
139 .attr = { .name = "data", .mode = S_IRUSR | S_IWUSR, },
140 .size = 0,
141 .read = devcd_data_read,
142 .write = devcd_data_write,
143};
144
145static struct bin_attribute *devcd_dev_bin_attrs[] = {
146 &devcd_attr_data, NULL,
147};
148
149static const struct attribute_group devcd_dev_group = {
150 .bin_attrs = devcd_dev_bin_attrs,
151};
152
153static const struct attribute_group *devcd_dev_groups[] = {
154 &devcd_dev_group, NULL,
155};
156
157static int devcd_free(struct device *dev, void *data)
158{
159 struct devcd_entry *devcd = dev_to_devcd(dev);
160
161 mutex_lock(&devcd->mutex);
162 if (!devcd->delete_work)
163 devcd->delete_work = true;
164
165 flush_delayed_work(&devcd->del_wk);
166 mutex_unlock(&devcd->mutex);
167 return 0;
168}
169
170static ssize_t disabled_show(const struct class *class, const struct class_attribute *attr,
171 char *buf)
172{
173 return sysfs_emit(buf, "%d\n", devcd_disabled);
174}
175
176/*
177 *
178 * disabled_store() worker()
179 * class_for_each_device(&devcd_class,
180 * NULL, NULL, devcd_free)
181 * ...
182 * ...
183 * while ((dev = class_dev_iter_next(&iter))
184 * devcd_del()
185 * device_del()
186 * put_device() <- last reference
187 * error = fn(dev, data) devcd_dev_release()
188 * devcd_free(dev, data) kfree(devcd)
189 * mutex_lock(&devcd->mutex);
190 *
191 *
192 * In the above diagram, It looks like disabled_store() would be racing with parallely
193 * running devcd_del() and result in memory abort while acquiring devcd->mutex which
194 * is called after kfree of devcd memory after dropping its last reference with
195 * put_device(). However, this will not happens as fn(dev, data) runs
196 * with its own reference to device via klist_node so it is not its last reference.
197 * so, above situation would not occur.
198 */
199
200static ssize_t disabled_store(const struct class *class, const struct class_attribute *attr,
201 const char *buf, size_t count)
202{
203 long tmp = simple_strtol(buf, NULL, 10);
204
205 /*
206 * This essentially makes the attribute write-once, since you can't
207 * go back to not having it disabled. This is intentional, it serves
208 * as a system lockdown feature.
209 */
210 if (tmp != 1)
211 return -EINVAL;
212
213 devcd_disabled = true;
214
215 class_for_each_device(&devcd_class, NULL, NULL, devcd_free);
216
217 return count;
218}
219static CLASS_ATTR_RW(disabled);
220
221static struct attribute *devcd_class_attrs[] = {
222 &class_attr_disabled.attr,
223 NULL,
224};
225ATTRIBUTE_GROUPS(devcd_class);
226
227static struct class devcd_class = {
228 .name = "devcoredump",
229 .dev_release = devcd_dev_release,
230 .dev_groups = devcd_dev_groups,
231 .class_groups = devcd_class_groups,
232};
233
234static ssize_t devcd_readv(char *buffer, loff_t offset, size_t count,
235 void *data, size_t datalen)
236{
237 return memory_read_from_buffer(buffer, count, &offset, data, datalen);
238}
239
240static void devcd_freev(void *data)
241{
242 vfree(data);
243}
244
245/**
246 * dev_coredumpv - create device coredump with vmalloc data
247 * @dev: the struct device for the crashed device
248 * @data: vmalloc data containing the device coredump
249 * @datalen: length of the data
250 * @gfp: allocation flags
251 *
252 * This function takes ownership of the vmalloc'ed data and will free
253 * it when it is no longer used. See dev_coredumpm() for more information.
254 */
255void dev_coredumpv(struct device *dev, void *data, size_t datalen,
256 gfp_t gfp)
257{
258 dev_coredumpm(dev, NULL, data, datalen, gfp, devcd_readv, devcd_freev);
259}
260EXPORT_SYMBOL_GPL(dev_coredumpv);
261
262static int devcd_match_failing(struct device *dev, const void *failing)
263{
264 struct devcd_entry *devcd = dev_to_devcd(dev);
265
266 return devcd->failing_dev == failing;
267}
268
269/**
270 * devcd_free_sgtable - free all the memory of the given scatterlist table
271 * (i.e. both pages and scatterlist instances)
272 * NOTE: if two tables allocated with devcd_alloc_sgtable and then chained
273 * using the sg_chain function then that function should be called only once
274 * on the chained table
275 * @data: pointer to sg_table to free
276 */
277static void devcd_free_sgtable(void *data)
278{
279 _devcd_free_sgtable(data);
280}
281
282/**
283 * devcd_read_from_sgtable - copy data from sg_table to a given buffer
284 * and return the number of bytes read
285 * @buffer: the buffer to copy the data to it
286 * @buf_len: the length of the buffer
287 * @data: the scatterlist table to copy from
288 * @offset: start copy from @offset@ bytes from the head of the data
289 * in the given scatterlist
290 * @data_len: the length of the data in the sg_table
291 */
292static ssize_t devcd_read_from_sgtable(char *buffer, loff_t offset,
293 size_t buf_len, void *data,
294 size_t data_len)
295{
296 struct scatterlist *table = data;
297
298 if (offset > data_len)
299 return -EINVAL;
300
301 if (offset + buf_len > data_len)
302 buf_len = data_len - offset;
303 return sg_pcopy_to_buffer(table, sg_nents(table), buffer, buf_len,
304 offset);
305}
306
307/**
308 * dev_coredumpm - create device coredump with read/free methods
309 * @dev: the struct device for the crashed device
310 * @owner: the module that contains the read/free functions, use %THIS_MODULE
311 * @data: data cookie for the @read/@free functions
312 * @datalen: length of the data
313 * @gfp: allocation flags
314 * @read: function to read from the given buffer
315 * @free: function to free the given buffer
316 *
317 * Creates a new device coredump for the given device. If a previous one hasn't
318 * been read yet, the new coredump is discarded. The data lifetime is determined
319 * by the device coredump framework and when it is no longer needed the @free
320 * function will be called to free the data.
321 */
322void dev_coredumpm(struct device *dev, struct module *owner,
323 void *data, size_t datalen, gfp_t gfp,
324 ssize_t (*read)(char *buffer, loff_t offset, size_t count,
325 void *data, size_t datalen),
326 void (*free)(void *data))
327{
328 static atomic_t devcd_count = ATOMIC_INIT(0);
329 struct devcd_entry *devcd;
330 struct device *existing;
331
332 if (devcd_disabled)
333 goto free;
334
335 existing = class_find_device(&devcd_class, NULL, dev,
336 devcd_match_failing);
337 if (existing) {
338 put_device(existing);
339 goto free;
340 }
341
342 if (!try_module_get(owner))
343 goto free;
344
345 devcd = kzalloc(sizeof(*devcd), gfp);
346 if (!devcd)
347 goto put_module;
348
349 devcd->owner = owner;
350 devcd->data = data;
351 devcd->datalen = datalen;
352 devcd->read = read;
353 devcd->free = free;
354 devcd->failing_dev = get_device(dev);
355 devcd->delete_work = false;
356
357 mutex_init(&devcd->mutex);
358 device_initialize(&devcd->devcd_dev);
359
360 dev_set_name(&devcd->devcd_dev, "devcd%d",
361 atomic_inc_return(&devcd_count));
362 devcd->devcd_dev.class = &devcd_class;
363
364 mutex_lock(&devcd->mutex);
365 dev_set_uevent_suppress(&devcd->devcd_dev, true);
366 if (device_add(&devcd->devcd_dev))
367 goto put_device;
368
369 /*
370 * These should normally not fail, but there is no problem
371 * continuing without the links, so just warn instead of
372 * failing.
373 */
374 if (sysfs_create_link(&devcd->devcd_dev.kobj, &dev->kobj,
375 "failing_device") ||
376 sysfs_create_link(&dev->kobj, &devcd->devcd_dev.kobj,
377 "devcoredump"))
378 dev_warn(dev, "devcoredump create_link failed\n");
379
380 dev_set_uevent_suppress(&devcd->devcd_dev, false);
381 kobject_uevent(&devcd->devcd_dev.kobj, KOBJ_ADD);
382 INIT_DELAYED_WORK(&devcd->del_wk, devcd_del);
383 schedule_delayed_work(&devcd->del_wk, DEVCD_TIMEOUT);
384 mutex_unlock(&devcd->mutex);
385 return;
386 put_device:
387 put_device(&devcd->devcd_dev);
388 mutex_unlock(&devcd->mutex);
389 put_module:
390 module_put(owner);
391 free:
392 free(data);
393}
394EXPORT_SYMBOL_GPL(dev_coredumpm);
395
396/**
397 * dev_coredumpsg - create device coredump that uses scatterlist as data
398 * parameter
399 * @dev: the struct device for the crashed device
400 * @table: the dump data
401 * @datalen: length of the data
402 * @gfp: allocation flags
403 *
404 * Creates a new device coredump for the given device. If a previous one hasn't
405 * been read yet, the new coredump is discarded. The data lifetime is determined
406 * by the device coredump framework and when it is no longer needed
407 * it will free the data.
408 */
409void dev_coredumpsg(struct device *dev, struct scatterlist *table,
410 size_t datalen, gfp_t gfp)
411{
412 dev_coredumpm(dev, NULL, table, datalen, gfp, devcd_read_from_sgtable,
413 devcd_free_sgtable);
414}
415EXPORT_SYMBOL_GPL(dev_coredumpsg);
416
417static int __init devcoredump_init(void)
418{
419 return class_register(&devcd_class);
420}
421__initcall(devcoredump_init);
422
423static void __exit devcoredump_exit(void)
424{
425 class_for_each_device(&devcd_class, NULL, NULL, devcd_free);
426 class_unregister(&devcd_class);
427}
428__exitcall(devcoredump_exit);
1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Copyright(c) 2014 Intel Mobile Communications GmbH
4 * Copyright(c) 2015 Intel Deutschland GmbH
5 *
6 * Author: Johannes Berg <johannes@sipsolutions.net>
7 */
8#include <linux/module.h>
9#include <linux/device.h>
10#include <linux/devcoredump.h>
11#include <linux/list.h>
12#include <linux/slab.h>
13#include <linux/fs.h>
14#include <linux/workqueue.h>
15
16static struct class devcd_class;
17
18/* global disable flag, for security purposes */
19static bool devcd_disabled;
20
21/* if data isn't read by userspace after 5 minutes then delete it */
22#define DEVCD_TIMEOUT (HZ * 60 * 5)
23
24struct devcd_entry {
25 struct device devcd_dev;
26 void *data;
27 size_t datalen;
28 struct module *owner;
29 ssize_t (*read)(char *buffer, loff_t offset, size_t count,
30 void *data, size_t datalen);
31 void (*free)(void *data);
32 struct delayed_work del_wk;
33 struct device *failing_dev;
34};
35
36static struct devcd_entry *dev_to_devcd(struct device *dev)
37{
38 return container_of(dev, struct devcd_entry, devcd_dev);
39}
40
41static void devcd_dev_release(struct device *dev)
42{
43 struct devcd_entry *devcd = dev_to_devcd(dev);
44
45 devcd->free(devcd->data);
46 module_put(devcd->owner);
47
48 /*
49 * this seems racy, but I don't see a notifier or such on
50 * a struct device to know when it goes away?
51 */
52 if (devcd->failing_dev->kobj.sd)
53 sysfs_delete_link(&devcd->failing_dev->kobj, &dev->kobj,
54 "devcoredump");
55
56 put_device(devcd->failing_dev);
57 kfree(devcd);
58}
59
60static void devcd_del(struct work_struct *wk)
61{
62 struct devcd_entry *devcd;
63
64 devcd = container_of(wk, struct devcd_entry, del_wk.work);
65
66 device_del(&devcd->devcd_dev);
67 put_device(&devcd->devcd_dev);
68}
69
70static ssize_t devcd_data_read(struct file *filp, struct kobject *kobj,
71 struct bin_attribute *bin_attr,
72 char *buffer, loff_t offset, size_t count)
73{
74 struct device *dev = kobj_to_dev(kobj);
75 struct devcd_entry *devcd = dev_to_devcd(dev);
76
77 return devcd->read(buffer, offset, count, devcd->data, devcd->datalen);
78}
79
80static ssize_t devcd_data_write(struct file *filp, struct kobject *kobj,
81 struct bin_attribute *bin_attr,
82 char *buffer, loff_t offset, size_t count)
83{
84 struct device *dev = kobj_to_dev(kobj);
85 struct devcd_entry *devcd = dev_to_devcd(dev);
86
87 mod_delayed_work(system_wq, &devcd->del_wk, 0);
88
89 return count;
90}
91
92static struct bin_attribute devcd_attr_data = {
93 .attr = { .name = "data", .mode = S_IRUSR | S_IWUSR, },
94 .size = 0,
95 .read = devcd_data_read,
96 .write = devcd_data_write,
97};
98
99static struct bin_attribute *devcd_dev_bin_attrs[] = {
100 &devcd_attr_data, NULL,
101};
102
103static const struct attribute_group devcd_dev_group = {
104 .bin_attrs = devcd_dev_bin_attrs,
105};
106
107static const struct attribute_group *devcd_dev_groups[] = {
108 &devcd_dev_group, NULL,
109};
110
111static int devcd_free(struct device *dev, void *data)
112{
113 struct devcd_entry *devcd = dev_to_devcd(dev);
114
115 flush_delayed_work(&devcd->del_wk);
116 return 0;
117}
118
119static ssize_t disabled_show(struct class *class, struct class_attribute *attr,
120 char *buf)
121{
122 return sysfs_emit(buf, "%d\n", devcd_disabled);
123}
124
125static ssize_t disabled_store(struct class *class, struct class_attribute *attr,
126 const char *buf, size_t count)
127{
128 long tmp = simple_strtol(buf, NULL, 10);
129
130 /*
131 * This essentially makes the attribute write-once, since you can't
132 * go back to not having it disabled. This is intentional, it serves
133 * as a system lockdown feature.
134 */
135 if (tmp != 1)
136 return -EINVAL;
137
138 devcd_disabled = true;
139
140 class_for_each_device(&devcd_class, NULL, NULL, devcd_free);
141
142 return count;
143}
144static CLASS_ATTR_RW(disabled);
145
146static struct attribute *devcd_class_attrs[] = {
147 &class_attr_disabled.attr,
148 NULL,
149};
150ATTRIBUTE_GROUPS(devcd_class);
151
152static struct class devcd_class = {
153 .name = "devcoredump",
154 .owner = THIS_MODULE,
155 .dev_release = devcd_dev_release,
156 .dev_groups = devcd_dev_groups,
157 .class_groups = devcd_class_groups,
158};
159
160static ssize_t devcd_readv(char *buffer, loff_t offset, size_t count,
161 void *data, size_t datalen)
162{
163 return memory_read_from_buffer(buffer, count, &offset, data, datalen);
164}
165
166static void devcd_freev(void *data)
167{
168 vfree(data);
169}
170
171/**
172 * dev_coredumpv - create device coredump with vmalloc data
173 * @dev: the struct device for the crashed device
174 * @data: vmalloc data containing the device coredump
175 * @datalen: length of the data
176 * @gfp: allocation flags
177 *
178 * This function takes ownership of the vmalloc'ed data and will free
179 * it when it is no longer used. See dev_coredumpm() for more information.
180 */
181void dev_coredumpv(struct device *dev, void *data, size_t datalen,
182 gfp_t gfp)
183{
184 dev_coredumpm(dev, NULL, data, datalen, gfp, devcd_readv, devcd_freev);
185}
186EXPORT_SYMBOL_GPL(dev_coredumpv);
187
188static int devcd_match_failing(struct device *dev, const void *failing)
189{
190 struct devcd_entry *devcd = dev_to_devcd(dev);
191
192 return devcd->failing_dev == failing;
193}
194
195/**
196 * devcd_free_sgtable - free all the memory of the given scatterlist table
197 * (i.e. both pages and scatterlist instances)
198 * NOTE: if two tables allocated with devcd_alloc_sgtable and then chained
199 * using the sg_chain function then that function should be called only once
200 * on the chained table
201 * @data: pointer to sg_table to free
202 */
203static void devcd_free_sgtable(void *data)
204{
205 _devcd_free_sgtable(data);
206}
207
208/**
209 * devcd_read_from_sgtable - copy data from sg_table to a given buffer
210 * and return the number of bytes read
211 * @buffer: the buffer to copy the data to it
212 * @buf_len: the length of the buffer
213 * @data: the scatterlist table to copy from
214 * @offset: start copy from @offset@ bytes from the head of the data
215 * in the given scatterlist
216 * @data_len: the length of the data in the sg_table
217 */
218static ssize_t devcd_read_from_sgtable(char *buffer, loff_t offset,
219 size_t buf_len, void *data,
220 size_t data_len)
221{
222 struct scatterlist *table = data;
223
224 if (offset > data_len)
225 return -EINVAL;
226
227 if (offset + buf_len > data_len)
228 buf_len = data_len - offset;
229 return sg_pcopy_to_buffer(table, sg_nents(table), buffer, buf_len,
230 offset);
231}
232
233/**
234 * dev_coredumpm - create device coredump with read/free methods
235 * @dev: the struct device for the crashed device
236 * @owner: the module that contains the read/free functions, use %THIS_MODULE
237 * @data: data cookie for the @read/@free functions
238 * @datalen: length of the data
239 * @gfp: allocation flags
240 * @read: function to read from the given buffer
241 * @free: function to free the given buffer
242 *
243 * Creates a new device coredump for the given device. If a previous one hasn't
244 * been read yet, the new coredump is discarded. The data lifetime is determined
245 * by the device coredump framework and when it is no longer needed the @free
246 * function will be called to free the data.
247 */
248void dev_coredumpm(struct device *dev, struct module *owner,
249 void *data, size_t datalen, gfp_t gfp,
250 ssize_t (*read)(char *buffer, loff_t offset, size_t count,
251 void *data, size_t datalen),
252 void (*free)(void *data))
253{
254 static atomic_t devcd_count = ATOMIC_INIT(0);
255 struct devcd_entry *devcd;
256 struct device *existing;
257
258 if (devcd_disabled)
259 goto free;
260
261 existing = class_find_device(&devcd_class, NULL, dev,
262 devcd_match_failing);
263 if (existing) {
264 put_device(existing);
265 goto free;
266 }
267
268 if (!try_module_get(owner))
269 goto free;
270
271 devcd = kzalloc(sizeof(*devcd), gfp);
272 if (!devcd)
273 goto put_module;
274
275 devcd->owner = owner;
276 devcd->data = data;
277 devcd->datalen = datalen;
278 devcd->read = read;
279 devcd->free = free;
280 devcd->failing_dev = get_device(dev);
281
282 device_initialize(&devcd->devcd_dev);
283
284 dev_set_name(&devcd->devcd_dev, "devcd%d",
285 atomic_inc_return(&devcd_count));
286 devcd->devcd_dev.class = &devcd_class;
287
288 if (device_add(&devcd->devcd_dev))
289 goto put_device;
290
291 /*
292 * These should normally not fail, but there is no problem
293 * continuing without the links, so just warn instead of
294 * failing.
295 */
296 if (sysfs_create_link(&devcd->devcd_dev.kobj, &dev->kobj,
297 "failing_device") ||
298 sysfs_create_link(&dev->kobj, &devcd->devcd_dev.kobj,
299 "devcoredump"))
300 dev_warn(dev, "devcoredump create_link failed\n");
301
302 INIT_DELAYED_WORK(&devcd->del_wk, devcd_del);
303 schedule_delayed_work(&devcd->del_wk, DEVCD_TIMEOUT);
304
305 return;
306 put_device:
307 put_device(&devcd->devcd_dev);
308 put_module:
309 module_put(owner);
310 free:
311 free(data);
312}
313EXPORT_SYMBOL_GPL(dev_coredumpm);
314
315/**
316 * dev_coredumpsg - create device coredump that uses scatterlist as data
317 * parameter
318 * @dev: the struct device for the crashed device
319 * @table: the dump data
320 * @datalen: length of the data
321 * @gfp: allocation flags
322 *
323 * Creates a new device coredump for the given device. If a previous one hasn't
324 * been read yet, the new coredump is discarded. The data lifetime is determined
325 * by the device coredump framework and when it is no longer needed
326 * it will free the data.
327 */
328void dev_coredumpsg(struct device *dev, struct scatterlist *table,
329 size_t datalen, gfp_t gfp)
330{
331 dev_coredumpm(dev, NULL, table, datalen, gfp, devcd_read_from_sgtable,
332 devcd_free_sgtable);
333}
334EXPORT_SYMBOL_GPL(dev_coredumpsg);
335
336static int __init devcoredump_init(void)
337{
338 return class_register(&devcd_class);
339}
340__initcall(devcoredump_init);
341
342static void __exit devcoredump_exit(void)
343{
344 class_for_each_device(&devcd_class, NULL, NULL, devcd_free);
345 class_unregister(&devcd_class);
346}
347__exitcall(devcoredump_exit);