Hi Lorenzo, kernel test robot noticed the following build warnings: [auto build test WARNING on akpm-mm/mm-everything] url: https://github.com/intel-lab-lkp/linux/commits/Lorenzo-Stoakes/mm-simplify-vma-merge-structure-and-expand-comments/20250127-235322 base: https://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm.git mm-everything patch link: https://lore.kernel.org/r/ef00aec42a892fe6ac9557b3a11f18f30a2e51b3.1737929364.git.lorenzo.stoakes%40oracle.com patch subject: [PATCH 5/5] mm: completely abstract unnecessary adj_start calculation config: hexagon-randconfig-002-20250128 (https://download.01.org/0day-ci/archive/20250128/202501280408.9NtSz2Lt-lkp@xxxxxxxxx/config) compiler: clang version 14.0.6 (https://github.com/llvm/llvm-project f28c006a5895fc0e329fe15fead81e37457cb1d1) reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20250128/202501280408.9NtSz2Lt-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/202501280408.9NtSz2Lt-lkp@xxxxxxxxx/ All warnings (new ones prefixed by >>): >> mm/vma.c:518:50: warning: incompatible pointer to integer conversion passing 'void *' to parameter of type 'long' [-Wint-conversion] vma_adjust_trans_huge(vma, vma->vm_start, addr, NULL); ^~~~ include/linux/stddef.h:8:14: note: expanded from macro 'NULL' #define NULL ((void *)0) ^~~~~~~~~~~ include/linux/huge_mm.h:574:12: note: passing argument to parameter 'adjust_next' here long adjust_next) ^ >> mm/vma.c:704:10: warning: incompatible pointer to integer conversion passing 'struct vm_area_struct *' to parameter of type 'long' [-Wint-conversion] adj_middle ? vmg->middle : NULL); ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ include/linux/huge_mm.h:574:12: note: passing argument to parameter 'adjust_next' here long adjust_next) ^ mm/vma.c:1141:41: warning: incompatible pointer to integer conversion passing 'void *' to parameter of type 'long' [-Wint-conversion] vma_adjust_trans_huge(vma, start, end, NULL); ^~~~ include/linux/stddef.h:8:14: note: expanded from macro 'NULL' #define NULL ((void *)0) ^~~~~~~~~~~ include/linux/huge_mm.h:574:12: note: passing argument to parameter 'adjust_next' here long adjust_next) ^ 3 warnings generated. vim +518 mm/vma.c 459 460 /* 461 * __split_vma() bypasses sysctl_max_map_count checking. We use this where it 462 * has already been checked or doesn't make sense to fail. 463 * VMA Iterator will point to the original VMA. 464 */ 465 static __must_check int 466 __split_vma(struct vma_iterator *vmi, struct vm_area_struct *vma, 467 unsigned long addr, int new_below) 468 { 469 struct vma_prepare vp; 470 struct vm_area_struct *new; 471 int err; 472 473 WARN_ON(vma->vm_start >= addr); 474 WARN_ON(vma->vm_end <= addr); 475 476 if (vma->vm_ops && vma->vm_ops->may_split) { 477 err = vma->vm_ops->may_split(vma, addr); 478 if (err) 479 return err; 480 } 481 482 new = vm_area_dup(vma); 483 if (!new) 484 return -ENOMEM; 485 486 if (new_below) { 487 new->vm_end = addr; 488 } else { 489 new->vm_start = addr; 490 new->vm_pgoff += ((addr - vma->vm_start) >> PAGE_SHIFT); 491 } 492 493 err = -ENOMEM; 494 vma_iter_config(vmi, new->vm_start, new->vm_end); 495 if (vma_iter_prealloc(vmi, new)) 496 goto out_free_vma; 497 498 err = vma_dup_policy(vma, new); 499 if (err) 500 goto out_free_vmi; 501 502 err = anon_vma_clone(new, vma); 503 if (err) 504 goto out_free_mpol; 505 506 if (new->vm_file) 507 get_file(new->vm_file); 508 509 if (new->vm_ops && new->vm_ops->open) 510 new->vm_ops->open(new); 511 512 vma_start_write(vma); 513 vma_start_write(new); 514 515 init_vma_prep(&vp, vma); 516 vp.insert = new; 517 vma_prepare(&vp); > 518 vma_adjust_trans_huge(vma, vma->vm_start, addr, NULL); 519 520 if (new_below) { 521 vma->vm_start = addr; 522 vma->vm_pgoff += (addr - new->vm_start) >> PAGE_SHIFT; 523 } else { 524 vma->vm_end = addr; 525 } 526 527 /* vma_complete stores the new vma */ 528 vma_complete(&vp, vmi, vma->vm_mm); 529 validate_mm(vma->vm_mm); 530 531 /* Success. */ 532 if (new_below) 533 vma_next(vmi); 534 else 535 vma_prev(vmi); 536 537 return 0; 538 539 out_free_mpol: 540 mpol_put(vma_policy(new)); 541 out_free_vmi: 542 vma_iter_free(vmi); 543 out_free_vma: 544 vm_area_free(new); 545 return err; 546 } 547 548 /* 549 * Split a vma into two pieces at address 'addr', a new vma is allocated 550 * either for the first part or the tail. 551 */ 552 static int split_vma(struct vma_iterator *vmi, struct vm_area_struct *vma, 553 unsigned long addr, int new_below) 554 { 555 if (vma->vm_mm->map_count >= sysctl_max_map_count) 556 return -ENOMEM; 557 558 return __split_vma(vmi, vma, addr, new_below); 559 } 560 561 /* 562 * dup_anon_vma() - Helper function to duplicate anon_vma 563 * @dst: The destination VMA 564 * @src: The source VMA 565 * @dup: Pointer to the destination VMA when successful. 566 * 567 * Returns: 0 on success. 568 */ 569 static int dup_anon_vma(struct vm_area_struct *dst, 570 struct vm_area_struct *src, struct vm_area_struct **dup) 571 { 572 /* 573 * Easily overlooked: when mprotect shifts the boundary, make sure the 574 * expanding vma has anon_vma set if the shrinking vma had, to cover any 575 * anon pages imported. 576 */ 577 if (src->anon_vma && !dst->anon_vma) { 578 int ret; 579 580 vma_assert_write_locked(dst); 581 dst->anon_vma = src->anon_vma; 582 ret = anon_vma_clone(dst, src); 583 if (ret) 584 return ret; 585 586 *dup = dst; 587 } 588 589 return 0; 590 } 591 592 #ifdef CONFIG_DEBUG_VM_MAPLE_TREE 593 void validate_mm(struct mm_struct *mm) 594 { 595 int bug = 0; 596 int i = 0; 597 struct vm_area_struct *vma; 598 VMA_ITERATOR(vmi, mm, 0); 599 600 mt_validate(&mm->mm_mt); 601 for_each_vma(vmi, vma) { 602 #ifdef CONFIG_DEBUG_VM_RB 603 struct anon_vma *anon_vma = vma->anon_vma; 604 struct anon_vma_chain *avc; 605 #endif 606 unsigned long vmi_start, vmi_end; 607 bool warn = 0; 608 609 vmi_start = vma_iter_addr(&vmi); 610 vmi_end = vma_iter_end(&vmi); 611 if (VM_WARN_ON_ONCE_MM(vma->vm_end != vmi_end, mm)) 612 warn = 1; 613 614 if (VM_WARN_ON_ONCE_MM(vma->vm_start != vmi_start, mm)) 615 warn = 1; 616 617 if (warn) { 618 pr_emerg("issue in %s\n", current->comm); 619 dump_stack(); 620 dump_vma(vma); 621 pr_emerg("tree range: %px start %lx end %lx\n", vma, 622 vmi_start, vmi_end - 1); 623 vma_iter_dump_tree(&vmi); 624 } 625 626 #ifdef CONFIG_DEBUG_VM_RB 627 if (anon_vma) { 628 anon_vma_lock_read(anon_vma); 629 list_for_each_entry(avc, &vma->anon_vma_chain, same_vma) 630 anon_vma_interval_tree_verify(avc); 631 anon_vma_unlock_read(anon_vma); 632 } 633 #endif 634 /* Check for a infinite loop */ 635 if (++i > mm->map_count + 10) { 636 i = -1; 637 break; 638 } 639 } 640 if (i != mm->map_count) { 641 pr_emerg("map_count %d vma iterator %d\n", mm->map_count, i); 642 bug = 1; 643 } 644 VM_BUG_ON_MM(bug, mm); 645 } 646 #endif /* CONFIG_DEBUG_VM_MAPLE_TREE */ 647 648 /* 649 * Based on the vmg flag indicating whether we need to adjust the vm_start field 650 * for the middle or next VMA, we calculate what the range of the newly adjusted 651 * VMA ought to be, and set the VMA's range accordingly. 652 */ 653 static void vmg_adjust_set_range(struct vma_merge_struct *vmg) 654 { 655 unsigned long flags = vmg->merge_flags; 656 struct vm_area_struct *adjust; 657 pgoff_t pgoff; 658 659 if (flags & __VMG_FLAG_ADJUST_MIDDLE_START) { 660 adjust = vmg->middle; 661 pgoff = adjust->vm_pgoff + PHYS_PFN(vmg->end - adjust->vm_start); 662 } else if (flags & __VMG_FLAG_ADJUST_NEXT_START) { 663 adjust = vmg->next; 664 pgoff = adjust->vm_pgoff - PHYS_PFN(adjust->vm_start - vmg->end); 665 } else { 666 return; 667 } 668 669 vma_set_range(adjust, vmg->end, adjust->vm_end, pgoff); 670 } 671 672 /* 673 * Actually perform the VMA merge operation. 674 * 675 * On success, returns the merged VMA. Otherwise returns NULL. 676 */ 677 static int commit_merge(struct vma_merge_struct *vmg) 678 { 679 struct vm_area_struct *vma; 680 struct vma_prepare vp; 681 bool adj_middle = vmg->merge_flags & __VMG_FLAG_ADJUST_MIDDLE_START; 682 683 if (vmg->merge_flags & __VMG_FLAG_ADJUST_NEXT_START) { 684 /* In this case we manipulate middle and return next. */ 685 vma = vmg->middle; 686 vma_iter_config(vmg->vmi, vmg->end, vmg->next->vm_end); 687 } else { 688 vma = vmg->target; 689 /* Note: vma iterator must be pointing to 'start'. */ 690 vma_iter_config(vmg->vmi, vmg->start, vmg->end); 691 } 692 693 init_multi_vma_prep(&vp, vma, vmg); 694 695 if (vma_iter_prealloc(vmg->vmi, vma)) 696 return -ENOMEM; 697 698 vma_prepare(&vp); 699 /* 700 * THP pages may need to do additional splits if we increase 701 * middle->vm_start. 702 */ 703 vma_adjust_trans_huge(vma, vmg->start, vmg->end, > 704 adj_middle ? vmg->middle : NULL); 705 vma_set_range(vma, vmg->start, vmg->end, vmg->pgoff); 706 vmg_adjust_set_range(vmg); 707 vma_iter_store(vmg->vmi, vmg->target); 708 709 vma_complete(&vp, vmg->vmi, vma->vm_mm); 710 711 return 0; 712 } 713 -- 0-DAY CI Kernel Test Service https://github.com/intel/lkp-tests/wiki
