From nobody Thu Apr 2 04:18:14 2026 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 70C493A5452 for ; Mon, 30 Mar 2026 13:50:17 +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=1774878617; cv=none; b=NAl5SsiHJpxGMXzbsLmrxgh7N/NkTZ+zE70IluKn9Zt3hVNRzb6RidK17TrG7hh/T2O17kZ/kdzOL/NJJ3c0Qf5iVKvmLzN4oop5CSOJaBLxSbStfAxLcn4XJIIONLIr6Mzfq4ZqC0BjetV/M0lckaAzsN7U7PYjaTsUyp0JPfI= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1774878617; c=relaxed/simple; bh=ecHvzGxq+ix6Lw/BhdjBmCYftEzFzAHOTU4CdCj7PLk=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=R2z4AuGMrB9MLPLWvplG3iVryyPg3lSre9hdXn6XbRahxOvhziS1WMvYODk6vTBBO9qxT3UkDDGaSdu9KtfoqO9RePjXAuiNo9XoH4inAwN6SiWJyhrg+k/UaO1Y8b/Q5N4UOuruPPWbsu3+/Wq0iDj5eI9di2/OBHZB4o9JG5M= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=KFmADJYz; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="KFmADJYz" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 4D1B0C4CEF7; Mon, 30 Mar 2026 13:50:16 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1774878616; bh=ecHvzGxq+ix6Lw/BhdjBmCYftEzFzAHOTU4CdCj7PLk=; h=From:To:Cc:Subject:Date:From; b=KFmADJYzfpN5ybl9s5WINuzTr17XoPZYKJPb5oaDW6nNu6x6pM2slYmVIAGXp0Ich Fi2177u43aCQZjRvpCHGfO8WtJ81IXTv0gr+5Pi2P1YwH0oZGaDeulFz6A6e/eDU3O hCFvCdyBR26Xk5Mm2HWbn/3ugPcUJEu/E1reOeUmbCTnuGUFEbHjtIB/ogFloT1w9i VEJgIAOJiHaSmam0qKPbKnYO0+SN2blg8zTW8b1cq70o+IskifcnyNBclGB/bUu5MF cNELZUldfTyFf9N9Lkig7PLZV2bEiZTGi5a7j7UO4tZBsVXTrFGxsHh9JLvvrvBAhi 0al2h/+vWnb0Q== From: "Lorenzo Stoakes (Oracle)" To: Andrew Morton Cc: "Liam R . Howlett" , Vlastimil Babka , Jann Horn , Pedro Falcato , David Hildenbrand , Mike Rapoport , Suren Baghdasaryan , Michal Hocko , linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: [PATCH] selftests/mm: add merge test for partial msealed range Date: Mon, 30 Mar 2026 14:50:11 +0100 Message-ID: <20260330135011.107036-1-ljs@kernel.org> X-Mailer: git-send-email 2.53.0 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" Commit 2697dd8ae721 ("mm/mseal: update VMA end correctly on merge") fixed an issue in the loop which iterates through VMAs applying mseal, which was triggered by mseal()'ing a range of VMAs where the second was mseal()'d and the first mergeable with it, once mseal()'d. Add a regression test to assert that this behaviour is correct. We place it in the merge selftests as this is strictly an issue with merging (via a vma_modify() invocation). It also assert that mseal()'d ranges are correctly merged as you'd expect. The test is implemented such that it is skipped if mseal() is not available on the system. Signed-off-by: Lorenzo Stoakes (Oracle) --- tools/testing/selftests/mm/merge.c | 75 ++++++++++++++++++++++++++++++ 1 file changed, 75 insertions(+) diff --git a/tools/testing/selftests/mm/merge.c b/tools/testing/selftests/m= m/merge.c index 10b686102b79..e8b8a91123bc 100644 --- a/tools/testing/selftests/mm/merge.c +++ b/tools/testing/selftests/mm/merge.c @@ -1217,6 +1217,81 @@ TEST_F(merge, mremap_correct_placed_faulted) ASSERT_EQ(procmap->query.vma_end, (unsigned long)ptr + 15 * page_size); } +TEST_F(merge, merge_vmas_with_mseal) +{ + unsigned int page_size =3D self->page_size; + struct procmap_fd *procmap =3D &self->procmap; + char *ptr, *ptr2, *ptr3; + /* We need our own as cannot munmap() once sealed. */ + char *carveout; + + /* Invalid mseal() call to see if implemented. */ + ASSERT_EQ(syscall(__NR_mseal, 0, 0, ~0UL), -1); + if (errno =3D=3D ENOSYS) + SKIP(return, "mseal not supported, skipping."); + + /* Map carveout. */ + carveout =3D mmap(NULL, 17 * page_size, PROT_NONE, + MAP_PRIVATE | MAP_ANON, -1, 0); + ASSERT_NE(carveout, MAP_FAILED); + + /* + * Map 3 separate VMAs: + * + * |-----------|-----------|-----------| + * | RW | RWE | RO | + * |-----------|-----------|-----------| + * ptr ptr2 ptr3 + */ + ptr =3D mmap(&carveout[page_size], 5 * page_size, PROT_READ | PROT_WRITE, + MAP_ANON | MAP_PRIVATE | MAP_FIXED, -1, 0); + ASSERT_NE(ptr, MAP_FAILED); + ptr2 =3D mmap(&carveout[page_size * 6], 5 * page_size, + PROT_READ | PROT_WRITE | PROT_EXEC, + MAP_ANON | MAP_PRIVATE | MAP_FIXED, -1, 0); + ASSERT_NE(ptr2, MAP_FAILED); + ptr3 =3D mmap(&carveout[page_size * 11], 5 * page_size, PROT_READ, + MAP_ANON | MAP_PRIVATE | MAP_FIXED, -1, 0); + ASSERT_NE(ptr3, MAP_FAILED); + + /* + * mseal the second VMA: + * + * |-----------|-----------|-----------| + * | RW | RWES | RO | + * |-----------|-----------|-----------| + * ptr ptr2 ptr3 + */ + ASSERT_EQ(syscall(__NR_mseal, (unsigned long)ptr2, 5 * page_size, 0), 0); + + /* Make first VMA mergeable upon mseal. */ + ASSERT_EQ(mprotect(ptr, 5 * page_size, + PROT_READ | PROT_WRITE | PROT_EXEC), 0); + /* + * At this point we have: + * + * |-----------|-----------|-----------| + * | RWE | RWES | RO | + * |-----------|-----------|-----------| + * ptr ptr2 ptr3 + * + * Now mseal all of the VMAs. + */ + ASSERT_EQ(syscall(__NR_mseal, (unsigned long)ptr, 15 * page_size, 0), 0); + + /* + * We should end up with: + * + * |-----------------------|-----------| + * | RWES | ROS | + * |-----------------------|-----------| + * ptr ptr3 + */ + ASSERT_TRUE(find_vma_procmap(procmap, ptr)); + ASSERT_EQ(procmap->query.vma_start, (unsigned long)ptr); + ASSERT_EQ(procmap->query.vma_end, (unsigned long)ptr + 10 * page_size); +} + TEST_F(merge_with_fork, mremap_faulted_to_unfaulted_prev) { struct procmap_fd *procmap =3D &self->procmap; -- 2.53.0