From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from out-2z4y-a135.jellyfish.systems (out-2z4y-a135.jellyfish.systems [198.54.127.135]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id E52A3356771 for ; Sun, 6 Sep 2026 14:46:46 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=198.54.127.135 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788706008; cv=none; b=JDerzlvJ60TYPzMg2l3RTV/IwB4k/oUR3Txoo6uQhRZhGqoNFR5KgfGRl5rAntwJd/3/8Vq+dqR0djWUekELVcdPejq3w6C7bKC3nFQxGLFxtT/m48Z7RvPJrcdIBBgUZ4PiKAop/CzvP8fxALDMN5LuaC0INwwDh3ra+WND3ZU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788706008; c=relaxed/simple; bh=WrNRVm5RGaSQs+DmqRDf6tKoYIKl+hzKmxJlGARYPj0=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=sRmNZVGuhWpMJElue2MSH8rPMIsfaqKmEqqoJstaplu/PkpOuQkX5uzh9HoIRr3aiK8Dy5XuC33XO+tK2nF/wz2vpJ31yp56pSVS+d4BsxMT6pCoB+cXlSTYlJLiwL+fROyQ6zIQy/p64WSN+Up6E7oZHw0B7aTmRZAVeHx8100= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=tychen.cc; spf=pass smtp.mailfrom=tychen.cc; dkim=pass (2048-bit key) header.d=tychen.cc header.i=@tychen.cc header.b=HeP+2KOE; arc=none smtp.client-ip=198.54.127.135 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=tychen.cc Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=tychen.cc Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=tychen.cc header.i=@tychen.cc header.b="HeP+2KOE" Received: from fedora (unknown [69.5.53.41]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mail.spacemail.com (Postfix) with ESMTPSA id 4hdCYy1G73z2xBH; Sun, 06 Sep 2026 14:41:09 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=tychen.cc; s=spacemail; t=1788705673; bh=BMfLqBwWKBeYU1egJqEuEAvuOmS9JC9iK50RUqn+x44=; h=From:To:Cc:Subject:Date:From; b=HeP+2KOEVEQwsAKbaTMLXL4OIo8jhFeapg2UDWFk/ihtHhBlMn0G7rLDNZQb0RUZg oG4fQ96wIcnDA1bVrRudHsIg+0JF0CXebElLDaqeTDNRjE3UZO2oniUBtwvAVS/R1U p6+IoLYu9X2dZZ6Eiv1DpMqdlpwhgSeYLUcl2/LOqyDZc8ba44BB7N26ig3QGrnPrW I74xQgrzk7yd8GJtYvSucSMgxghZOn44uos8PAAJbO+3C1+5VQntUEeOC47mdpB9gl RiMWukYLciZ9B8viExOLR88mODHjcckRaDLnGK3nYqCQ6oS6c3tj4bevfKTDopCWKb MCXN60d00Op6Q== From: Tianyi Chen To: ljs@kernel.org, "Liam R . Howlett" , Andrew Morton Cc: Tianyi Chen , Vlastimil Babka , Jann Horn , Pedro Falcato , linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: [PATCH] tools/testing/vma: cover hole filling through __mmap_region() Date: Sun, 6 Sep 2026 22:41:00 +0800 Message-ID: <20260906144100.849288-1-hi@tychen.cc> X-Mailer: git-send-email 2.55.0 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Envelope-From: hi@tychen.cc The mmap tests extend existing mappings one neighbor at a time, while merge tests construct merge state directly. Neither exercises filling a hole between compatible mappings through the mmap setup and completion path. Fill a gap through __mmap_region() and require both neighbors to merge into one VMA. Repeat with only the new mapping's execute permission set and require three separate VMAs. Check boundaries, permissions, page offsets, map_count and tree lookups across the mapped pages. The full VMA test suite passes all 28 tests with ASan and UBSan enabled. Assisted-by: LLM Signed-off-by: Tianyi Chen --- tools/testing/vma/tests/mmap.c | 75 ++++++++++++++++++++++++++++++++++ 1 file changed, 75 insertions(+) diff --git a/tools/testing/vma/tests/mmap.c b/tools/testing/vma/tests/mmap.c index c85bc000d1c..b66ec932a75 100644 --- a/tools/testing/vma/tests/mmap.c +++ b/tools/testing/vma/tests/mmap.c @@ -45,7 +45,82 @@ static bool test_mmap_region_basic(void) return true; } +static bool mmap_region_fill_hole(bool merge) +{ + const vma_flags_t vma_flags = mk_vma_flags(VMA_READ_BIT, VMA_WRITE_BIT, + VMA_MAYREAD_BIT, VMA_MAYWRITE_BIT, VMA_MAYEXEC_BIT); + vma_flags_t hole_flags = vma_flags; + struct mm_struct mm = {}; + struct vm_area_struct *vma; + unsigned long addr; + int count = 0; + VMA_ITERATOR(vmi, &mm, 0); + + current->mm = &mm; + if (!merge) + vma_flags_set(&hole_flags, VMA_EXEC_BIT); + + /* Leave a hole between two otherwise mergeable mappings. */ + addr = __mmap_region(NULL, 0x300000, 0x3000, vma_flags, 0x300, NULL); + ASSERT_EQ(addr, 0x300000); + addr = __mmap_region(NULL, 0x306000, 0x3000, vma_flags, 0x306, NULL); + ASSERT_EQ(addr, 0x306000); + ASSERT_EQ(mm.map_count, 2); + vma_iter_set(&vmi, 0x303000); + ASSERT_EQ(vma_iter_load(&vmi), NULL); + vma_iter_set(&vmi, 0x305fff); + ASSERT_EQ(vma_iter_load(&vmi), NULL); + + /* A single flag difference must prevent merging with either neighbor. */ + addr = __mmap_region(NULL, 0x303000, 0x3000, hole_flags, 0x303, NULL); + ASSERT_EQ(addr, 0x303000); + ASSERT_EQ(mm.map_count, merge ? 1 : 3); + + vma_iter_set(&vmi, 0); + for_each_vma(vmi, vma) { + unsigned long start = 0x300000 + count * 0x3000; + unsigned long end = merge ? 0x309000 : start + 0x3000; + VMA_ITERATOR(lookup, &mm, start); + + ASSERT_EQ(vma->vm_start, start); + ASSERT_EQ(vma->vm_end, end); + ASSERT_EQ(vma_start_pgoff(vma), start >> PAGE_SHIFT); + ASSERT_EQ(vma_start_anon_pgoff(vma), start >> PAGE_SHIFT); + ASSERT_TRUE(vma_test_all(vma, VMA_READ_BIT, VMA_WRITE_BIT, + VMA_MAYREAD_BIT, VMA_MAYWRITE_BIT, + VMA_MAYEXEC_BIT)); + ASSERT_EQ(vma_test(vma, VMA_EXEC_BIT), !merge && count == 1); + for (addr = start; addr < end; addr += PAGE_SIZE) { + vma_iter_set(&lookup, addr); + ASSERT_EQ(vma_iter_load(&lookup), vma); + vma_iter_set(&lookup, addr + PAGE_SIZE - 1); + ASSERT_EQ(vma_iter_load(&lookup), vma); + } + count++; + } + ASSERT_EQ(count, mm.map_count); + vma_iter_set(&vmi, 0x2fffff); + ASSERT_EQ(vma_iter_load(&vmi), NULL); + vma_iter_set(&vmi, 0x309000); + ASSERT_EQ(vma_iter_load(&vmi), NULL); + + ASSERT_EQ(cleanup_mm(&mm, &vmi), count); + return true; +} + +static bool test_mmap_region_fill_hole_merge(void) +{ + return mmap_region_fill_hole(true); +} + +static bool test_mmap_region_fill_hole_flags_mismatch(void) +{ + return mmap_region_fill_hole(false); +} + static void run_mmap_tests(int *num_tests, int *num_fail) { TEST(mmap_region_basic); + TEST(mmap_region_fill_hole_merge); + TEST(mmap_region_fill_hole_flags_mismatch); } -- 2.55.0