Commit 0d4a7bc12ffecd3ba41dd94179cc5b272b71ce8a
1 parent
3fa8749e58
Exists in
master
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UIO: BKL removal
Fill in needed locking around idr accesses, then remove the big kernel lock from the UIO driver. Since there are no in-tree UIO drivers with open() methods, no further BKL pushdown is required. Acked-by: Hans J. Koch <hjk@linutronix.de> Acked-by: Greg Kroah-Hartman <gregkh@suse.de> Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Showing 1 changed file with 8 additions and 6 deletions Side-by-side Diff
drivers/uio/uio.c
| ... | ... | @@ -47,6 +47,9 @@ |
| 47 | 47 | struct class *class; |
| 48 | 48 | } *uio_class; |
| 49 | 49 | |
| 50 | +/* Protect idr accesses */ | |
| 51 | +static DEFINE_MUTEX(minor_lock); | |
| 52 | + | |
| 50 | 53 | /* |
| 51 | 54 | * attributes |
| 52 | 55 | */ |
| ... | ... | @@ -231,7 +234,6 @@ |
| 231 | 234 | |
| 232 | 235 | static int uio_get_minor(struct uio_device *idev) |
| 233 | 236 | { |
| 234 | - static DEFINE_MUTEX(minor_lock); | |
| 235 | 237 | int retval = -ENOMEM; |
| 236 | 238 | int id; |
| 237 | 239 | |
| 238 | 240 | |
| ... | ... | @@ -253,7 +255,9 @@ |
| 253 | 255 | |
| 254 | 256 | static void uio_free_minor(struct uio_device *idev) |
| 255 | 257 | { |
| 258 | + mutex_lock(&minor_lock); | |
| 256 | 259 | idr_remove(&uio_idr, idev->minor); |
| 260 | + mutex_unlock(&minor_lock); | |
| 257 | 261 | } |
| 258 | 262 | |
| 259 | 263 | /** |
| 260 | 264 | |
| ... | ... | @@ -297,8 +301,9 @@ |
| 297 | 301 | struct uio_listener *listener; |
| 298 | 302 | int ret = 0; |
| 299 | 303 | |
| 300 | - lock_kernel(); | |
| 304 | + mutex_lock(&minor_lock); | |
| 301 | 305 | idev = idr_find(&uio_idr, iminor(inode)); |
| 306 | + mutex_unlock(&minor_lock); | |
| 302 | 307 | if (!idev) { |
| 303 | 308 | ret = -ENODEV; |
| 304 | 309 | goto out; |
| 305 | 310 | |
| 306 | 311 | |
| 307 | 312 | |
| 308 | 313 | |
| ... | ... | @@ -324,18 +329,15 @@ |
| 324 | 329 | if (ret) |
| 325 | 330 | goto err_infoopen; |
| 326 | 331 | } |
| 327 | - unlock_kernel(); | |
| 328 | 332 | return 0; |
| 329 | 333 | |
| 330 | 334 | err_infoopen: |
| 331 | - | |
| 332 | 335 | kfree(listener); |
| 333 | -err_alloc_listener: | |
| 334 | 336 | |
| 337 | +err_alloc_listener: | |
| 335 | 338 | module_put(idev->owner); |
| 336 | 339 | |
| 337 | 340 | out: |
| 338 | - unlock_kernel(); | |
| 339 | 341 | return ret; |
| 340 | 342 | } |
| 341 | 343 |