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git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
tjh.dev
kernel
os
linux
[S390] ccwgroup: add locking around drvdata access
Several processes may concurrently try to create a group device
from the same ccw_device(s). Add locking arround the drvdata
access to prevent race conditions.
Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
authored by Sebastian Ott and committed by Martin Schwidefsky c560d105 a65a3e82
+7
drivers/s390/cio/ccwgroup.c
+7
drivers/s390/cio/ccwgroup.c
···
123
124
for (i = 0; i < gdev->count; i++) {
125
if (gdev->cdev[i]) {
126
if (dev_get_drvdata(&gdev->cdev[i]->dev) == gdev)
127
dev_set_drvdata(&gdev->cdev[i]->dev, NULL);
128
put_device(&gdev->cdev[i]->dev);
129
}
130
}
···
264
goto error;
265
}
266
/* Don't allow a device to belong to more than one group. */
267
if (dev_get_drvdata(&gdev->cdev[i]->dev)) {
268
rc = -EINVAL;
269
goto error;
270
}
271
dev_set_drvdata(&gdev->cdev[i]->dev, gdev);
272
}
273
/* Check for sufficient number of bus ids. */
274
if (i < num_devices && !curr_buf) {
···
308
error:
309
for (i = 0; i < num_devices; i++)
310
if (gdev->cdev[i]) {
311
if (dev_get_drvdata(&gdev->cdev[i]->dev) == gdev)
312
dev_set_drvdata(&gdev->cdev[i]->dev, NULL);
313
put_device(&gdev->cdev[i]->dev);
314
gdev->cdev[i] = NULL;
315
}
···
123
124
for (i = 0; i < gdev->count; i++) {
125
if (gdev->cdev[i]) {
126
+
spin_lock_irq(gdev->cdev[i]->ccwlock);
127
if (dev_get_drvdata(&gdev->cdev[i]->dev) == gdev)
128
dev_set_drvdata(&gdev->cdev[i]->dev, NULL);
129
+
spin_unlock_irq(gdev->cdev[i]->ccwlock);
130
put_device(&gdev->cdev[i]->dev);
131
}
132
}
···
262
goto error;
263
}
264
/* Don't allow a device to belong to more than one group. */
265
+
spin_lock_irq(gdev->cdev[i]->ccwlock);
266
if (dev_get_drvdata(&gdev->cdev[i]->dev)) {
267
+
spin_unlock_irq(gdev->cdev[i]->ccwlock);
268
rc = -EINVAL;
269
goto error;
270
}
271
dev_set_drvdata(&gdev->cdev[i]->dev, gdev);
272
+
spin_unlock_irq(gdev->cdev[i]->ccwlock);
273
}
274
/* Check for sufficient number of bus ids. */
275
if (i < num_devices && !curr_buf) {
···
303
error:
304
for (i = 0; i < num_devices; i++)
305
if (gdev->cdev[i]) {
306
+
spin_lock_irq(gdev->cdev[i]->ccwlock);
307
if (dev_get_drvdata(&gdev->cdev[i]->dev) == gdev)
308
dev_set_drvdata(&gdev->cdev[i]->dev, NULL);
309
+
spin_unlock_irq(gdev->cdev[i]->ccwlock);
310
put_device(&gdev->cdev[i]->dev);
311
gdev->cdev[i] = NULL;
312
}