drivers/gpu/drm/xe/xe_gt_pagefault.c:340:17: warning: writing 16 bytes into a region of size 0

From: kernel test robot
Date: Mon Jan 15 2024 - 22:09:19 EST

tree: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master
head: 052d534373b7ed33712a63d5e17b2b6cdbce84fd
commit: 5c0553cdc811bb6af4f1bfef178bd07fc16a797e drm/xe: Replace XE_WARN_ON with drm_warn when just printing a string
date: 4 weeks ago
config: s390-randconfig-r071-20240116 (https://download.01.org/0day-ci/archive/20240116/202401161031.hjGJHMiJ-lkp@xxxxxxxxx/config)
compiler: s390-linux-gcc (GCC) 13.2.0
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20240116/202401161031.hjGJHMiJ-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/202401161031.hjGJHMiJ-lkp@xxxxxxxxx/

All warnings (new ones prefixed by >>):

drivers/gpu/drm/xe/xe_gt_pagefault.c: In function 'xe_guc_pagefault_handler':
>> drivers/gpu/drm/xe/xe_gt_pagefault.c:340:17: warning: writing 16 bytes into a region of size 0 [-Wstringop-overflow=]
340 | memcpy(pf_queue->data + pf_queue->tail, msg, len * sizeof(u32));
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
In file included from drivers/gpu/drm/xe/xe_device_types.h:16,
from drivers/gpu/drm/xe/xe_vm_types.h:16,
from drivers/gpu/drm/xe/xe_bo.h:11,
from drivers/gpu/drm/xe/xe_gt_pagefault.c:15:
drivers/gpu/drm/xe/xe_gt_types.h:102:25: note: at offset [1216, 265396] into destination object 'tile' of size 8
102 | struct xe_tile *tile;
| ^~~~


vim +340 drivers/gpu/drm/xe/xe_gt_pagefault.c

dd08ebf6c3525a Matthew Brost 2023-03-30 321
dd08ebf6c3525a Matthew Brost 2023-03-30 322 int xe_guc_pagefault_handler(struct xe_guc *guc, u32 *msg, u32 len)
dd08ebf6c3525a Matthew Brost 2023-03-30 323 {
dd08ebf6c3525a Matthew Brost 2023-03-30 324 struct xe_gt *gt = guc_to_gt(guc);
5c0553cdc811bb Francois Dugast 2023-09-12 325 struct xe_device *xe = gt_to_xe(gt);
dd08ebf6c3525a Matthew Brost 2023-03-30 326 struct pf_queue *pf_queue;
dd08ebf6c3525a Matthew Brost 2023-03-30 327 unsigned long flags;
dd08ebf6c3525a Matthew Brost 2023-03-30 328 u32 asid;
dd08ebf6c3525a Matthew Brost 2023-03-30 329 bool full;
dd08ebf6c3525a Matthew Brost 2023-03-30 330
dd08ebf6c3525a Matthew Brost 2023-03-30 331 if (unlikely(len != PF_MSG_LEN_DW))
dd08ebf6c3525a Matthew Brost 2023-03-30 332 return -EPROTO;
dd08ebf6c3525a Matthew Brost 2023-03-30 333
dd08ebf6c3525a Matthew Brost 2023-03-30 334 asid = FIELD_GET(PFD_ASID, msg[1]);
dd08ebf6c3525a Matthew Brost 2023-03-30 335 pf_queue = &gt->usm.pf_queue[asid % NUM_PF_QUEUE];
dd08ebf6c3525a Matthew Brost 2023-03-30 336
dd08ebf6c3525a Matthew Brost 2023-03-30 337 spin_lock_irqsave(&pf_queue->lock, flags);
dd08ebf6c3525a Matthew Brost 2023-03-30 338 full = pf_queue_full(pf_queue);
dd08ebf6c3525a Matthew Brost 2023-03-30 339 if (!full) {
dd08ebf6c3525a Matthew Brost 2023-03-30 @340 memcpy(pf_queue->data + pf_queue->tail, msg, len * sizeof(u32));
dd08ebf6c3525a Matthew Brost 2023-03-30 341 pf_queue->tail = (pf_queue->tail + len) % PF_QUEUE_NUM_DW;
dd08ebf6c3525a Matthew Brost 2023-03-30 342 queue_work(gt->usm.pf_wq, &pf_queue->worker);
dd08ebf6c3525a Matthew Brost 2023-03-30 343 } else {
5c0553cdc811bb Francois Dugast 2023-09-12 344 drm_warn(&xe->drm, "PF Queue full, shouldn't be possible");
dd08ebf6c3525a Matthew Brost 2023-03-30 345 }
dd08ebf6c3525a Matthew Brost 2023-03-30 346 spin_unlock_irqrestore(&pf_queue->lock, flags);
dd08ebf6c3525a Matthew Brost 2023-03-30 347
dd08ebf6c3525a Matthew Brost 2023-03-30 348 return full ? -ENOSPC : 0;
dd08ebf6c3525a Matthew Brost 2023-03-30 349 }
dd08ebf6c3525a Matthew Brost 2023-03-30 350

:::::: The code at line 340 was first introduced by commit
:::::: dd08ebf6c3525a7ea2186e636df064ea47281987 drm/xe: Introduce a new DRM driver for Intel GPUs

:::::: TO: Matthew Brost <matthew.brost@xxxxxxxxx>
:::::: CC: Rodrigo Vivi <rodrigo.vivi@xxxxxxxxx>

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