From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 8542B22FDFA for ; Thu, 10 Jul 2025 21:46:19 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1752183980; cv=none; b=TLUAt5C2cB9KuUHS7UNeYRArHyftTWenP01LpnMlFL/andCoJCkqeYDR8fNs7HZuOqMylVY1lDUDSjhpjl7kj4drLp9fgKI38D37bgoHVgfG/0JWNGXC8nEA+66hyQlg96RXgT650wVPIhK07eT0vc6wKjr833UQJgnR6A6ppiU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1752183980; c=relaxed/simple; bh=YF6QppxtbsM1SccTnsX5pjAh+bA3YIA3m6vbWaeWoUQ=; h=Date:To:From:Subject:Message-Id; b=cVEu8xxbSmGJyz8zTKveBlio3C785U0ELOo0AabNQQKMvkFCQVxpPy8psUBcFfHG5i9pdoRH7C52knDjDXd26KlOCZV/gw/0HkB9bnMCiAo/s7trANgm41VIdMQRnc/kSNXt2beIYu3Kj/U5WD+HCVZmnhHhZ/TYXgmP8/SCYFw= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux-foundation.org header.i=@linux-foundation.org header.b=c8XcDGKc; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux-foundation.org header.i=@linux-foundation.org header.b="c8XcDGKc" Received: by smtp.kernel.org (Postfix) with ESMTPSA id A3F7FC4CEE3; Thu, 10 Jul 2025 21:46:19 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1752183979; bh=YF6QppxtbsM1SccTnsX5pjAh+bA3YIA3m6vbWaeWoUQ=; h=Date:To:From:Subject:From; b=c8XcDGKc5eR9noe5+fSdElMkMJzSLCS7pqdB++M2qvuodtno4XLUiBtF0D+NZd53j RPTvobPH+bGlNC24RTWOYLBA5zz9Y0aQNunyXYa566mzFxZEtQzc/hsfBW/ckM1+IW 3Obmz1MFT60VdWjjAg4oDL+pSsjor1g8UAFu+VZA= Date: Thu, 10 Jul 2025 14:46:19 -0700 To: mm-commits@vger.kernel.org,viro@zeniv.linux.org.uk,vbabka@suse.cz,riel@surriel.com,peterx@redhat.com,liam.howlett@oracle.com,jannh@google.com,jack@suse.cz,brauner@kernel.org,lorenzo.stoakes@oracle.com,akpm@linux-foundation.org From: Andrew Morton Subject: + mm-mremap-put-vma-check-and-prep-logic-into-helper-function.patch added to mm-new branch Message-Id: <20250710214619.A3F7FC4CEE3@smtp.kernel.org> Precedence: bulk X-Mailing-List: mm-commits@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: The patch titled Subject: mm/mremap: put VMA check and prep logic into helper function has been added to the -mm mm-new branch. Its filename is mm-mremap-put-vma-check-and-prep-logic-into-helper-function.patch This patch will shortly appear at https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-mremap-put-vma-check-and-prep-logic-into-helper-function.patch This patch will later appear in the mm-new branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Note, mm-new is a provisional staging ground for work-in-progress patches, and acceptance into mm-new is a notification for others take notice and to finish up reviews. Please do not hesitate to respond to review feedback and post updated versions to replace or incrementally fixup patches in mm-new. Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/process/submit-checklist.rst when testing your code *** The -mm tree is included into linux-next via the mm-everything branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm and is updated there every 2-3 working days ------------------------------------------------------ From: Lorenzo Stoakes Subject: mm/mremap: put VMA check and prep logic into helper function Date: Thu, 10 Jul 2025 16:50:27 +0100 Rather than lumping everything together in do_mremap(), add a new helper function, check_prep_vma(), to do the work relating to each VMA. This further lays groundwork for subsequent patches which will allow for batched VMA mremap(). Additionally, if we set vrm->new_addr == vrm->addr when prepping the VMA, this avoids us needing to do so in the expand VMA mlocked case. No functional change intended. Link: https://lkml.kernel.org/r/3048e54e92bb858493da5d9be3d5d80b1fee7325.1752162066.git.lorenzo.stoakes@oracle.com Signed-off-by: Lorenzo Stoakes Reviewed-by: Vlastimil Babka Cc: Al Viro Cc: Christian Brauner Cc: Jan Kara Cc: Jann Horn Cc: Liam Howlett Cc: Peter Xu Cc: Rik van Riel Signed-off-by: Andrew Morton --- mm/mremap.c | 58 ++++++++++++++++++++++++-------------------------- 1 file changed, 28 insertions(+), 30 deletions(-) --- a/mm/mremap.c~mm-mremap-put-vma-check-and-prep-logic-into-helper-function +++ a/mm/mremap.c @@ -1636,7 +1636,6 @@ static bool align_hugetlb(struct vma_rem static unsigned long expand_vma(struct vma_remap_struct *vrm) { unsigned long err; - unsigned long addr = vrm->addr; err = remap_is_valid(vrm); if (err) @@ -1651,16 +1650,8 @@ static unsigned long expand_vma(struct v if (err) return err; - /* - * We want to populate the newly expanded portion of the VMA to - * satisfy the expectation that mlock()'ing a VMA maintains all - * of its pages in memory. - */ - if (vrm->mlocked) - vrm->new_addr = addr; - /* OK we're done! */ - return addr; + return vrm->addr; } /* @@ -1716,10 +1707,33 @@ static unsigned long mremap_at(struct vm return -EINVAL; } +static int check_prep_vma(struct vma_remap_struct *vrm) +{ + struct vm_area_struct *vma = vrm->vma; + + if (!vma) + return -EFAULT; + + /* If mseal()'d, mremap() is prohibited. */ + if (!can_modify_vma(vma)) + return -EPERM; + + /* Align to hugetlb page size, if required. */ + if (is_vm_hugetlb_page(vma) && !align_hugetlb(vrm)) + return -EINVAL; + + vrm_set_delta(vrm); + vrm->remap_type = vrm_remap_type(vrm); + /* For convenience, we set new_addr even if VMA won't move. */ + if (!vrm_implies_new_addr(vrm)) + vrm->new_addr = vrm->addr; + + return 0; +} + static unsigned long do_mremap(struct vma_remap_struct *vrm) { struct mm_struct *mm = current->mm; - struct vm_area_struct *vma; unsigned long res; vrm->old_len = PAGE_ALIGN(vrm->old_len); @@ -1733,26 +1747,10 @@ static unsigned long do_mremap(struct vm return -EINTR; vrm->mmap_locked = true; - vma = vrm->vma = vma_lookup(mm, vrm->addr); - if (!vma) { - res = -EFAULT; - goto out; - } - - /* If mseal()'d, mremap() is prohibited. */ - if (!can_modify_vma(vma)) { - res = -EPERM; - goto out; - } - - /* Align to hugetlb page size, if required. */ - if (is_vm_hugetlb_page(vma) && !align_hugetlb(vrm)) { - res = -EINVAL; + vrm->vma = vma_lookup(current->mm, vrm->addr); + res = check_prep_vma(vrm); + if (res) goto out; - } - - vrm_set_delta(vrm); - vrm->remap_type = vrm_remap_type(vrm); /* Actually execute mremap. */ res = vrm_implies_new_addr(vrm) ? mremap_to(vrm) : mremap_at(vrm); _ Patches currently in -mm which might be from lorenzo.stoakes@oracle.com are mm-madvise-remove-the-visitor-pattern-and-thread-anon_vma-state.patch mm-madvise-thread-mm_struct-through-madvise_behavior.patch mm-madvise-thread-vma-range-state-through-madvise_behavior.patch mm-madvise-thread-all-madvise-state-through-madv_behavior.patch mm-madvise-eliminate-very-confusing-manipulation-of-prev-vma.patch mm-madvise-eliminate-very-confusing-manipulation-of-prev-vma-fix.patch tools-testing-selftests-add-mremap-unfaulted-faulted-test-cases.patch mm-mremap-perform-some-simple-cleanups.patch mm-mremap-refactor-initial-parameter-sanity-checks.patch mm-mremap-put-vma-check-and-prep-logic-into-helper-function.patch mm-mremap-cleanup-post-processing-stage-of-mremap.patch mm-mremap-use-an-explicit-uffd-failure-path-for-mremap.patch mm-mremap-check-remap-conditions-earlier.patch mm-mremap-move-remap_is_valid-into-check_prep_vma.patch mm-mremap-clean-up-mlock-populate-behaviour.patch mm-mremap-permit-mremap-move-of-multiple-vmas.patch tools-testing-selftests-extend-mremap_test-to-test-multi-vma-mremap.patch