From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 1048F41C307; Fri, 22 May 2026 14:29:26 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1779460168; cv=none; b=twiRRhGyvwzJfv2EWzy3L7ow8ImTY2Nj+RKn185tFt1oXWk6aqdKvnWb7z19Uc1j5Epuj/GgLJU/RhOq2Ksr+A/BD+EgEKm277oOkC8yQXBKZbandBuE/oHPwHJUQab6cN+jpZzyMa9ezYmdb/iZKg9h3AVOJ8egeMImRdkLsts= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1779460168; c=relaxed/simple; bh=DlxbDb4SZlefabOJU2jtXr4/OddRb2k3jj6wjNgWpvM=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=s0BIxDPUbbPSqczJcYceTgXjLkFLeDQqhjUPJC7Yd5n7UesbumHnzePmufQUeekaQc8LQHTSb+YywypFdr9TXIrwO5Ry/I3YsnJL1ZCkB3IcojuFw18scp9rScYYQYBdHqtPO3BGO+rueLjvrBg2O6yx7da5pXwdZrquvYBk7i4= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=GHrHvjki; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="GHrHvjki" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 640F91F000E9; Fri, 22 May 2026 14:29:24 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1779460165; bh=DWn7bS7xQYbcdkvCx3KblzCl0rPLM9h158TSPP8Tg54=; h=Date:From:To:Cc:Subject:References:In-Reply-To; b=GHrHvjkiOmkRZM9ixd9uwv8EEG1pY16+fep9NZw9mKUJtjMy/tJTqexCiVmlyqVpJ hKUiXINzAjfxl3vmuWJb0IJBtAREvJBZMMXWWE5kdkFN2Qf1rNCXKHBrXMr100Z4jF WcXHxSJ0n/HBPwl81gvcqZEvs2oE8WX7utBEuaoS7WC4frd94zrZS/fx/32cdrgxrv GuWhtBdBtWA/iO5lXji/YY/QHWjfG+8IzUFxTXGTA4VQtCB26+4ioRue6iCg6NINNu PgKehxzIO5MSYAESXCTinNAkVyU1+BMerH7EaDc7+/MjTQQJ6pWziQOb8Nl6Q9pmn+ TcmtcRTs6QTlQ== Date: Fri, 22 May 2026 15:29:21 +0100 From: Lorenzo Stoakes To: kernel test robot Cc: oe-kbuild-all@lists.linux.dev, linux-kernel@vger.kernel.org, Andrew Morton , Linux Memory Management List Subject: Re: mm/mprotect.c:700:43: sparse: sparse: cast to non-scalar Message-ID: References: <202605161217.1mPJ49Gv-lkp@intel.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <202605161217.1mPJ49Gv-lkp@intel.com> On Sat, May 16, 2026 at 12:25:57PM +0800, kernel test robot wrote: > tree: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master > head: d458a240344c4369bf6f3da203f2779515177738 > commit: 3a6455d56bd7c4cfb1ea35ddae052943065e338e mm: convert do_brk_flags() to use vma_flags_t > date: 6 weeks ago > config: alpha-randconfig-r121-20260516 (https://download.01.org/0day-ci/archive/20260516/202605161217.1mPJ49Gv-lkp@intel.com/config) > compiler: alpha-linux-gcc (GCC) 15.2.0 > sparse: v0.6.5-rc1 > reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20260516/202605161217.1mPJ49Gv-lkp@intel.com/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 > | Fixes: 3a6455d56bd7 ("mm: convert do_brk_flags() to use vma_flags_t") > | Reported-by: kernel test robot > | Closes: https://lore.kernel.org/oe-kbuild-all/202605161217.1mPJ49Gv-lkp@intel.com/ > > sparse warnings: (new ones prefixed by >>) > >> mm/mprotect.c:700:43: sparse: sparse: cast to non-scalar > >> mm/mprotect.c:700:43: sparse: sparse: cast from non-scalar > mm/mprotect.c: note: in included file (through include/linux/mm.h, include/linux/pagewalk.h): > include/linux/pgtable.h:461:16: sparse: sparse: cast to non-scalar > include/linux/pgtable.h:461:16: sparse: sparse: cast from non-scalar > include/linux/pgtable.h:461:16: sparse: sparse: cast to non-scalar > include/linux/pgtable.h:461:16: sparse: sparse: cast from non-scalar > include/linux/pgtable.h:461:16: sparse: sparse: cast to non-scalar > include/linux/pgtable.h:461:16: sparse: sparse: cast from non-scalar > include/linux/pgtable.h:461:16: sparse: sparse: cast to non-scalar > include/linux/pgtable.h:461:16: sparse: sparse: cast from non-scalar > include/linux/pgtable.h:475:16: sparse: sparse: cast to non-scalar > include/linux/pgtable.h:475:16: sparse: sparse: cast from non-scalar > include/linux/pgtable.h:468:16: sparse: sparse: cast to non-scalar > include/linux/pgtable.h:468:16: sparse: sparse: cast from non-scalar > include/linux/pgtable.h:461:16: sparse: sparse: cast to non-scalar > include/linux/pgtable.h:461:16: sparse: sparse: cast from non-scalar > include/linux/pgtable.h:461:16: sparse: sparse: cast to non-scalar > include/linux/pgtable.h:461:16: sparse: sparse: cast from non-scalar > > vim +700 mm/mprotect.c > > 693 > 694 int > 695 mprotect_fixup(struct vma_iterator *vmi, struct mmu_gather *tlb, > 696 struct vm_area_struct *vma, struct vm_area_struct **pprev, > 697 unsigned long start, unsigned long end, vm_flags_t newflags) > 698 { > 699 struct mm_struct *mm = vma->vm_mm; > > 700 const vma_flags_t old_vma_flags = READ_ONCE(vma->flags); I think we can tolerate this, presumably because we're READ_ONCE()'ing, I don't think it's helpful necessarily to cast away the sparse stuff here. Cheers, Lorenzo > 701 vma_flags_t new_vma_flags = legacy_to_vma_flags(newflags); > 702 long nrpages = (end - start) >> PAGE_SHIFT; > 703 unsigned int mm_cp_flags = 0; > 704 unsigned long charged = 0; > 705 int error; > 706 > 707 if (vma_is_sealed(vma)) > 708 return -EPERM; > 709 > 710 if (vma_flags_same_pair(&old_vma_flags, &new_vma_flags)) { > 711 *pprev = vma; > 712 return 0; > 713 } > 714 > 715 /* > 716 * Do PROT_NONE PFN permission checks here when we can still > 717 * bail out without undoing a lot of state. This is a rather > 718 * uncommon case, so doesn't need to be very optimized. > 719 */ > 720 if (arch_has_pfn_modify_check() && > 721 vma_flags_test_any(&old_vma_flags, VMA_PFNMAP_BIT, > 722 VMA_MIXEDMAP_BIT) && > 723 !vma_flags_test_any_mask(&new_vma_flags, VMA_ACCESS_FLAGS)) { > 724 pgprot_t new_pgprot = vm_get_page_prot(newflags); > 725 > 726 error = walk_page_range(current->mm, start, end, > 727 &prot_none_walk_ops, &new_pgprot); > 728 if (error) > 729 return error; > 730 } > 731 > 732 /* > 733 * If we make a private mapping writable we increase our commit; > 734 * but (without finer accounting) cannot reduce our commit if we > 735 * make it unwritable again except in the anonymous case where no > 736 * anon_vma has yet to be assigned. > 737 * > 738 * hugetlb mapping were accounted for even if read-only so there is > 739 * no need to account for them here. > 740 */ > 741 if (vma_flags_test(&new_vma_flags, VMA_WRITE_BIT)) { > 742 /* Check space limits when area turns into data. */ > 743 if (!may_expand_vm(mm, &new_vma_flags, nrpages) && > 744 may_expand_vm(mm, &old_vma_flags, nrpages)) > 745 return -ENOMEM; > 746 if (!vma_flags_test_any(&old_vma_flags, > 747 VMA_ACCOUNT_BIT, VMA_WRITE_BIT, VMA_HUGETLB_BIT, > 748 VMA_SHARED_BIT, VMA_NORESERVE_BIT)) { > 749 charged = nrpages; > 750 if (security_vm_enough_memory_mm(mm, charged)) > 751 return -ENOMEM; > 752 vma_flags_set(&new_vma_flags, VMA_ACCOUNT_BIT); > 753 } > 754 } else if (vma_flags_test(&old_vma_flags, VMA_ACCOUNT_BIT) && > 755 vma_is_anonymous(vma) && !vma->anon_vma) { > 756 vma_flags_clear(&new_vma_flags, VMA_ACCOUNT_BIT); > 757 } > 758 > 759 newflags = vma_flags_to_legacy(new_vma_flags); > 760 vma = vma_modify_flags(vmi, *pprev, vma, start, end, &newflags); > 761 if (IS_ERR(vma)) { > 762 error = PTR_ERR(vma); > 763 goto fail; > 764 } > 765 new_vma_flags = legacy_to_vma_flags(newflags); > 766 > 767 *pprev = vma; > 768 > 769 /* > 770 * vm_flags and vm_page_prot are protected by the mmap_lock > 771 * held in write mode. > 772 */ > 773 vma_start_write(vma); > 774 vm_flags_reset_once(vma, newflags); > 775 if (vma_wants_manual_pte_write_upgrade(vma)) > 776 mm_cp_flags |= MM_CP_TRY_CHANGE_WRITABLE; > 777 vma_set_page_prot(vma); > 778 > 779 change_protection(tlb, vma, start, end, mm_cp_flags); > 780 > 781 if (vma_flags_test(&old_vma_flags, VMA_ACCOUNT_BIT) && > 782 !vma_flags_test(&new_vma_flags, VMA_ACCOUNT_BIT)) > 783 vm_unacct_memory(nrpages); > 784 > 785 /* > 786 * Private VM_LOCKED VMA becoming writable: trigger COW to avoid major > 787 * fault on access. > 788 */ > 789 if (vma_flags_test(&new_vma_flags, VMA_WRITE_BIT)) { > 790 const vma_flags_t mask = > 791 vma_flags_and(&old_vma_flags, VMA_WRITE_BIT, > 792 VMA_SHARED_BIT, VMA_LOCKED_BIT); > 793 > 794 if (vma_flags_same(&mask, VMA_LOCKED_BIT)) > 795 populate_vma_page_range(vma, start, end, NULL); > 796 } > 797 > 798 vm_stat_account(mm, vma_flags_to_legacy(old_vma_flags), -nrpages); > 799 vm_stat_account(mm, newflags, nrpages); > 800 perf_event_mmap(vma); > 801 return 0; > 802 > 803 fail: > 804 vm_unacct_memory(charged); > 805 return error; > 806 } > 807 > > -- > 0-DAY CI Kernel Test Service > https://github.com/intel/lkp-tests/wiki