Hi, I love your patch! Yet something to improve: [auto build test ERROR on linux/master] [also build test ERROR on linus/master hnaz-linux-mm/master v5.10-rc7] [cannot apply to mmotm/master rcu/dev rcu/rcu/next next-20201208] [If your patch is applied to the wrong git tree, kindly drop us a note. And when submitting patch, we suggest to use '--base' as documented in https://git-scm.com/docs/git-format-patch] url: https://github.com/0day-ci/linux/commits/paulmck-kernel-org/mm-Add-mem_du... base: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git 09162bc32c880a791c6c0668ce0745cf7958f576 config: x86_64-randconfig-a004-20201208 (attached as .config) compiler: gcc-9 (Debian 9.3.0-15) 9.3.0 reproduce (this is a W=1 build): # https://github.com/0day-ci/linux/commit/c49050a9b3235279954c0b5d82abd90fa... git remote add linux-review https://github.com/0day-ci/linux git fetch --no-tags linux-review paulmck-kernel-org/mm-Add-mem_dump_obj-to-print-source-of-memory-block/20201209-091546 git checkout c49050a9b3235279954c0b5d82abd90fa09d9359 # save the attached .config to linux build tree make W=1 ARCH=x86_64 If you fix the issue, kindly add following tag as appropriate Reported-by: kernel test robot <lkp(a)intel.com&gt; All errors (new ones prefixed by >>): ld: mm/slab_common.o: in function `kmem_dump_obj': vim +589 mm/slab_common.c 557 558 /** 559 * kmem_dump_obj - Print available slab provenance information 560 * @object: slab object for which to find provenance information. 561 * 562 * This function uses pr_cont(), so that the caller is expected to have 563 * printed out whatever preamble is appropriate. The provenance information 564 * depends on the type of object and on how much debugging is enabled. 565 * For a slab-cache object, the fact that it is a slab object is printed, 566 * and, if available, the slab name, return address, and stack trace from 567 * the allocation of that object. 568 * 569 * This function will splat if passed a pointer to a non-slab object. 570 * If you are not sure what type of object you have, you should instead 571 * use mem_dump_obj(). 572 */ 573 void kmem_dump_obj(void *object) 574 { 575 int i; 576 struct page *page; 577 struct kmem_provenance kp; 578 579 if (WARN_ON_ONCE(!virt_addr_valid(object))) 580 return; 581 page = virt_to_head_page(object); 582 if (WARN_ON_ONCE(!PageSlab(page))) { 583 pr_cont(" non-slab memory.\n"); 584 return; 585 } 586 kp.kp_ptr = object; 587 kp.kp_page = page; 588 kp.kp_nstack = KS_ADDRS_COUNT; 590 if (page->slab_cache) 591 pr_cont(" slab %s", page->slab_cache->name); 592 else 593 pr_cont(" slab "); 594 if (kp.kp_ret) 595 pr_cont(" allocated at %pS\n", kp.kp_ret); 596 else 597 pr_cont("\n"); 598 if (kp.kp_stack[0]) { 599 for (i = 0; i < ARRAY_SIZE(kp.kp_stack); i++) { 600 if (!kp.kp_stack[i]) 601 break; 602 pr_info(" %pS\n", kp.kp_stack[i]); 603 } 604 } 605 } 606 EXPORT_SYMBOL_GPL(kmem_dump_obj); 607 --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org