Hi Yu, FYI, the error/warning still remains. tree: https://gitee.com/openeuler/kernel.git openEuler-1.0-LTS head: 97f98c391a1fd153ae010a2faf73f9e03270da6e commit: ac91631e9ef7b530c02e40d10085072c08fb4a0a [1402/1402] blk-io-hierarchy: support new stage for bio lifetime config: arm64-allmodconfig (https://download.01.org/0day-ci/archive/20250110/202501100811.yzRNoGB1-lkp@i...) compiler: aarch64-linux-gcc (GCC) 14.2.0 reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20250110/202501100811.yzRNoGB1-lkp@i...) 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@intel.com> | Closes: https://lore.kernel.org/oe-kbuild-all/202501100811.yzRNoGB1-lkp@intel.com/ All warnings (new ones prefixed by >>):

...

block/blk-io-hierarchy/iodump.c:571:7: warning: no previous prototype for '__bio_stage_hierarchy_start' [-Wmissing-prototypes] 571 | void *__bio_stage_hierarchy_start(struct bio_stage_dump_data *bstage_ddata, | ^~~~~~~~~~~~~~~~~~~~~~~~~~~ In file included from include/asm-generic/preempt.h:5, from ./arch/arm64/include/generated/asm/preempt.h:1, from include/linux/preempt.h:81, from include/linux/spinlock.h:51, from include/linux/wait.h:9, from include/linux/wait_bit.h:8, from include/linux/fs.h:7, from include/linux/seq_file.h:11, from block/blk-io-hierarchy/iodump.c:14: In function 'check_object_size', inlined from 'check_copy_size' at include/linux/thread_info.h:90:2, inlined from 'copy_from_user' at include/linux/uaccess.h:143:6, inlined from 'threshold_store' at block/blk-io-hierarchy/iodump.c:273:6: include/linux/thread_info.h:59:17: warning: 'b' may be used uninitialized [-Wmaybe-uninitialized] 59 | __check_object_size(ptr, n, to_user); | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ include/linux/thread_info.h: In function 'threshold_store': include/linux/thread_info.h:52:13: note: by argument 1 of type 'const void *' to '__check_object_size' declared here 52 | extern void __check_object_size(const void *ptr, unsigned long n, | ^~~~~~~~~~~~~~~~~~~ block/blk-io-hierarchy/iodump.c:267:14: note: 'b' declared here 267 | char b[MAX_BUF_LEN + 1]; | ^

vim +/__bio_stage_hierarchy_start +571 block/blk-io-hierarchy/iodump.c 570

571 void *__bio_stage_hierarchy_start(struct bio_stage_dump_data *bstage_ddata, 572 loff_t *pos) 573 { 574 struct pos_data *pdata = &bstage_ddata->pdata; 575 struct rq_dump_data *rq_ddata = &bstage_ddata->rq_ddata; 576 577 retry: 578 if (stage_is_bio(pdata->stage)) { 579 struct list_head *list; 580 struct bio_dump_data *bio_ddata = 581 get_bio_stage_ddata(rq_ddata->q, pdata->stage); 582 583 if (!bio_ddata) { 584 bio_stage_start_next_stage(bstage_ddata, pos); 585 goto retry; 586 } 587 588 spin_lock_irq(&bio_ddata->lock); 589 list = seq_list_start(&bio_ddata->head, pdata->count); 590 if (list) 591 return list; 592 593 spin_unlock_irq(&bio_ddata->lock); 594 bio_stage_start_next_stage(bstage_ddata, pos); 595 goto retry; 596 } 597 598 if (pdata->stage == STAGE_BIO && 599 __rq_hierarchy_start(rq_ddata, pdata->count)) 600 return bstage_ddata; 601 602 return NULL; 603 } 604

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