arch/um/kernel/skas/uaccess.c:269: warning: Function parameter or member 'op' not described in 'arch_futex_atomic_op_inuser'

From: kernel test robot
Date: Sat Oct 14 2023 - 22:52:41 EST


tree: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master
head: dc9b2e683bcba017588b9aaad80f442ad004a48f
commit: dd3035a21ba7ccaa883d7107d357ad06320d78fc um: add a UML specific futex implementation
date: 2 years, 4 months ago
config: um-allnoconfig (https://download.01.org/0day-ci/archive/20231015/202310151047.a07DrQNV-lkp@xxxxxxxxx/config)
compiler: gcc-12 (Debian 12.2.0-14) 12.2.0
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20231015/202310151047.a07DrQNV-lkp@xxxxxxxxx/reproduce)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@xxxxxxxxx>
| Closes: https://lore.kernel.org/oe-kbuild-all/202310151047.a07DrQNV-lkp@xxxxxxxxx/

All warnings (new ones prefixed by >>):

>> arch/um/kernel/skas/uaccess.c:269: warning: Function parameter or member 'op' not described in 'arch_futex_atomic_op_inuser'
>> arch/um/kernel/skas/uaccess.c:269: warning: Function parameter or member 'oparg' not described in 'arch_futex_atomic_op_inuser'
>> arch/um/kernel/skas/uaccess.c:269: warning: Function parameter or member 'oval' not described in 'arch_futex_atomic_op_inuser'
>> arch/um/kernel/skas/uaccess.c:269: warning: Excess function parameter 'encoded_op' description in 'arch_futex_atomic_op_inuser'


vim +269 arch/um/kernel/skas/uaccess.c

252
253 /**
254 * arch_futex_atomic_op_inuser() - Atomic arithmetic operation with constant
255 * argument and comparison of the previous
256 * futex value with another constant.
257 *
258 * @encoded_op: encoded operation to execute
259 * @uaddr: pointer to user space address
260 *
261 * Return:
262 * 0 - On success
263 * -EFAULT - User access resulted in a page fault
264 * -EAGAIN - Atomic operation was unable to complete due to contention
265 * -ENOSYS - Operation not supported
266 */
267
268 int arch_futex_atomic_op_inuser(int op, u32 oparg, int *oval, u32 __user *uaddr)
> 269 {
270 int oldval, ret;
271 struct page *page;
272 unsigned long addr = (unsigned long) uaddr;
273 pte_t *pte;
274
275 ret = -EFAULT;
276 if (!access_ok(uaddr, sizeof(*uaddr)))
277 return -EFAULT;
278 preempt_disable();
279 pte = maybe_map(addr, 1);
280 if (pte == NULL)
281 goto out_inuser;
282
283 page = pte_page(*pte);
284 #ifdef CONFIG_64BIT
285 pagefault_disable();
286 addr = (unsigned long) page_address(page) +
287 (((unsigned long) addr) & ~PAGE_MASK);
288 #else
289 addr = (unsigned long) kmap_atomic(page) +
290 ((unsigned long) addr & ~PAGE_MASK);
291 #endif
292 uaddr = (u32 *) addr;
293 oldval = *uaddr;
294
295 ret = 0;
296
297 switch (op) {
298 case FUTEX_OP_SET:
299 *uaddr = oparg;
300 break;
301 case FUTEX_OP_ADD:
302 *uaddr += oparg;
303 break;
304 case FUTEX_OP_OR:
305 *uaddr |= oparg;
306 break;
307 case FUTEX_OP_ANDN:
308 *uaddr &= ~oparg;
309 break;
310 case FUTEX_OP_XOR:
311 *uaddr ^= oparg;
312 break;
313 default:
314 ret = -ENOSYS;
315 }
316 #ifdef CONFIG_64BIT
317 pagefault_enable();
318 #else
319 kunmap_atomic((void *)addr);
320 #endif
321
322 out_inuser:
323 preempt_enable();
324
325 if (ret == 0)
326 *oval = oldval;
327
328 return ret;
329 }
330 EXPORT_SYMBOL(arch_futex_atomic_op_inuser);
331

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