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 7326553370 for ; Wed, 21 Aug 2024 02:07:54 +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=1724206074; cv=none; b=pHThYD/i5lVDtTfBX/sNqCMSRQkVxpVV51UBHBNKTE4wYlqRUQxJpEgQfZJY9wjsoUA6p29mJjZYfVFzHyf0C+v53TTWX6ymJo4dVzSLQdePZCoAhm+8LRkOE76BLwK4VT/U61dDEtJaOiRFFDo7R+adtnxc0IB8E45Ga0P++KE= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1724206074; c=relaxed/simple; bh=4i3cq7b/982IS8DmdNUjQ0GP3gmhOdq8+bm9S0YqUtA=; h=Date:To:From:Subject:Message-Id; b=jkBDIiFpfgBKWt0pVNTcr4uVkYfa0wfanmw5hLReBUqKSBPR1EntzvVit/ybq8uiNV4OJ171ft8XrdV3TBSymSSO4mGdsb5Ve5Fhd2IA+sBkFQsXbwdVIy+JjLGuABL+M+4VBfaHQQszgNer+OMndeDTgE+OZ/Klct1D+mizvtk= 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=aPwefiYg; 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="aPwefiYg" Received: by smtp.kernel.org (Postfix) with ESMTPSA id CCDA8C4AF17; Wed, 21 Aug 2024 02:07:53 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1724206073; bh=4i3cq7b/982IS8DmdNUjQ0GP3gmhOdq8+bm9S0YqUtA=; h=Date:To:From:Subject:From; b=aPwefiYgPiTUMB0vAhaIeSOg0wKIkm2UuCvs2BgaPkzOvPJ+K92W2LNfbX/esYnhe 4uQ8ebX4y3nZSQK0NKjVTxU8xA2wzENaBfLojEmC6TM+P+rBH0168An0YB3gauYCji NK4ZDWSguf/ISS/7d9/cOXqie2c+wY4g9jeBJKtQ= Date: Tue, 20 Aug 2024 19:07:53 -0700 To: mm-commits@vger.kernel.org,vbabka@suse.cz,torvalds@linux-foundation.org,shuah@kernel.org,mpe@ellerman.id.au,lorenzo.stoakes@oracle.com,Liam.Howlett@Oracle.com,kees@kernel.org,jeffxu@chromium.org,pedro.falcato@gmail.com,akpm@linux-foundation.org From: Andrew Morton Subject: + mm-munmap-replace-can_modify_mm-with-can_modify_vma.patch added to mm-unstable branch Message-Id: <20240821020753.CCDA8C4AF17@smtp.kernel.org> Precedence: bulk X-Mailing-List: mm-commits@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: The patch titled Subject: mm/munmap: replace can_modify_mm with can_modify_vma has been added to the -mm mm-unstable branch. Its filename is mm-munmap-replace-can_modify_mm-with-can_modify_vma.patch This patch will shortly appear at https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-munmap-replace-can_modify_mm-with-can_modify_vma.patch This patch will later appear in the mm-unstable branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm 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: Pedro Falcato Subject: mm/munmap: replace can_modify_mm with can_modify_vma Date: Sat, 17 Aug 2024 01:18:29 +0100 We were doing an extra mmap tree traversal just to check if the entire range is modifiable. This can be done when we iterate through the VMAs instead. Link: https://lkml.kernel.org/r/20240817-mseal-depessimize-v3-2-d8d2e037df30@gmail.com Signed-off-by: Pedro Falcato Reviewed-by: Liam R. Howlett Cc: Jeff Xu Cc: Kees Cook Cc: Linus Torvalds Cc: Lorenzo Stoakes Cc: Michael Ellerman Cc: Shuah Khan Cc: Vlastimil Babka Signed-off-by: Andrew Morton --- mm/mmap.c | 11 +---------- mm/vma.c | 19 ++++++++++++------- 2 files changed, 13 insertions(+), 17 deletions(-) --- a/mm/mmap.c~mm-munmap-replace-can_modify_mm-with-can_modify_vma +++ a/mm/mmap.c @@ -1740,16 +1740,7 @@ int do_vma_munmap(struct vma_iterator *v unsigned long start, unsigned long end, struct list_head *uf, bool unlock) { - struct mm_struct *mm = vma->vm_mm; - - /* - * Check if memory is sealed, prevent unmapping a sealed VMA. - * can_modify_mm assumes we have acquired the lock on MM. - */ - if (unlikely(!can_modify_mm(mm, start, end))) - return -EPERM; - - return do_vmi_align_munmap(vmi, vma, mm, start, end, uf, unlock); + return do_vmi_align_munmap(vmi, vma, vma->vm_mm, start, end, uf, unlock); } /* --- a/mm/vma.c~mm-munmap-replace-can_modify_mm-with-can_modify_vma +++ a/mm/vma.c @@ -712,6 +712,12 @@ do_vmi_align_munmap(struct vma_iterator if (end < vma->vm_end && mm->map_count >= sysctl_max_map_count) goto map_count_exceeded; + /* Don't bother splitting the VMA if we can't unmap it anyway */ + if (!can_modify_vma(vma)) { + error = -EPERM; + goto start_split_failed; + } + error = __split_vma(vmi, vma, start, 1); if (error) goto start_split_failed; @@ -723,6 +729,11 @@ do_vmi_align_munmap(struct vma_iterator */ next = vma; do { + if (!can_modify_vma(next)) { + error = -EPERM; + goto modify_vma_failed; + } + /* Does it split the end? */ if (next->vm_end > end) { error = __split_vma(vmi, next, end, 0); @@ -815,6 +826,7 @@ do_vmi_align_munmap(struct vma_iterator __mt_destroy(&mt_detach); return 0; +modify_vma_failed: clear_tree_failed: userfaultfd_error: munmap_gather_failed: @@ -860,13 +872,6 @@ int do_vmi_munmap(struct vma_iterator *v if (end == start) return -EINVAL; - /* - * Check if memory is sealed, prevent unmapping a sealed VMA. - * can_modify_mm assumes we have acquired the lock on MM. - */ - if (unlikely(!can_modify_mm(mm, start, end))) - return -EPERM; - /* Find the first overlapping VMA */ vma = vma_find(vmi, end); if (!vma) { _ Patches currently in -mm which might be from pedro.falcato@gmail.com are selftests-mm-add-mseal-test-for-no-discard-madvise.patch selftests-mm-add-mseal-test-for-no-discard-madvise-fix.patch mm-move-can_modify_vma-to-mm-vmah.patch mm-munmap-replace-can_modify_mm-with-can_modify_vma.patch mm-mprotect-replace-can_modify_mm-with-can_modify_vma.patch mm-mremap-replace-can_modify_mm-with-can_modify_vma.patch mseal-replace-can_modify_mm_madv-with-a-vma-variant.patch mm-remove-can_modify_mm.patch selftests-mm-add-more-mseal-traversal-tests.patch