From nobody Tue Feb 10 16:43:59 2026 Received: from galois.linutronix.de (Galois.linutronix.de [193.142.43.55]) (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 B86E51A28D; Mon, 13 Jan 2025 13:17:13 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=193.142.43.55 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1736774235; cv=none; b=EAywfreqjMcjf/G6hBlgdJEOUfJVYtXYiTB2MBjXdRz41zUNEchuiFc8whd/P0sZi1e1zpOwu3C40eEh/5UqHeCRCfebKzyg09ogt2ponBxqpjJSa2sVHy0wkatYQAKSqsy8EOwBUUHYBZAqsU6SoPBTDbms4hGTKcPQlD4y5eI= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1736774235; c=relaxed/simple; bh=+J+pIjUkTrbA4CGXJ2S1U5YIbW5DfoH8SKBNfbwggwk=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:References: In-Reply-To:To:Cc; b=M5/LK/DbgKl06X2rL5HaREY1eiq9YQA8o9RgpgZkpIp5AWG5hJXm7gQaCbtUQCPsmPxp4SZ02zSUTRTYraMS3h0hq5GUiPi5I9YAqSL1bmNK/07fSiewMtE4tpE6BsaNyGCQiIRSgjES01gkL/iHsbqf5VGe+fA6JsKcXMU8HZk= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linutronix.de; spf=pass smtp.mailfrom=linutronix.de; dkim=pass (2048-bit key) header.d=linutronix.de header.i=@linutronix.de header.b=1CBuV9LM; dkim=permerror (0-bit key) header.d=linutronix.de header.i=@linutronix.de header.b=4mvRayE0; arc=none smtp.client-ip=193.142.43.55 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linutronix.de Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linutronix.de Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=linutronix.de header.i=@linutronix.de header.b="1CBuV9LM"; dkim=permerror (0-bit key) header.d=linutronix.de header.i=@linutronix.de header.b="4mvRayE0" From: =?utf-8?q?Thomas_Wei=C3=9Fschuh?= DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1736774232; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=BB2O49jg7bdHh5I8SFkvOSGpR/2gpeyIP8hG/oWKnuA=; b=1CBuV9LMXAMrlJ9IflbNljk0JXuo2zd1MPzCAD9297JXLmLapQgdndJiXwT9Vw1dv1uKvA 3kICr8J0Qe1Tq4VBT8i+HBZMz24xJjspAfUAPBBG8Hlg6ueJV0YyCI5RFnaBAG1OgXxsKq YapIM26nzRMoFgxDh73szQ+M2S2EEJ9gRWRIypMbuhzp1HP1p9qlmWMp6i2uZcRUHN+ABj exBQpNpNN6nUzy3zt3I1iNRjVKI3GKVsYRj43hvJtSVDXSxH5aF/yxKFFF0pU/tduSeWpL jAqd4m77yFE9yk/NJfqGzFRd/38BDctkg8gkUVC/8WmJLzSILbZAxQcBcL6GVA== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1736774232; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=BB2O49jg7bdHh5I8SFkvOSGpR/2gpeyIP8hG/oWKnuA=; b=4mvRayE0CAw8tX3kK9BfIK84n94lkVUmzadM8HdJlJ0M9Ts30Nn0HAT/7T/QT7TYsJ4nq9 3oA4maHReyzVsBAA== Date: Mon, 13 Jan 2025 14:15:36 +0100 Subject: [PATCH v3 2/4] selftests/mm: virtual_address_range: Unmap chunks after validation 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="utf-8" Content-Transfer-Encoding: quoted-printable Message-Id: <20250113-virtual_address_range-tests-v3-2-f4a8e6b7feed@linutronix.de> References: <20250113-virtual_address_range-tests-v3-0-f4a8e6b7feed@linutronix.de> In-Reply-To: <20250113-virtual_address_range-tests-v3-0-f4a8e6b7feed@linutronix.de> To: Andrew Morton , Shuah Khan , Dev Jain , Thomas Gleixner , David Hildenbrand Cc: linux-mm@kvack.org, linux-kselftest@vger.kernel.org, linux-kernel@vger.kernel.org, =?utf-8?q?Thomas_Wei=C3=9Fschuh?= X-Developer-Signature: v=1; a=ed25519-sha256; t=1736774229; l=3957; i=thomas.weissschuh@linutronix.de; s=20240209; h=from:subject:message-id; bh=+J+pIjUkTrbA4CGXJ2S1U5YIbW5DfoH8SKBNfbwggwk=; b=uq6vmORxXVZbLi6UjqFMoF/YkYKRm8KQxCroQXGFlQap/Mqol+by324sYz153F6iNnwjZ6KOL VMaXve+XTJRDEdc0V6gkAQOwLRX6E/dWtAUFFJK3OOzNeRGN9Dg8+3q X-Developer-Key: i=thomas.weissschuh@linutronix.de; a=ed25519; pk=pfvxvpFUDJV2h2nY0FidLUml22uGLSjByFbM6aqQQws= For each accessed chunk a PTE is created. More than 1GiB of PTEs is used in this way. Remove each PTE after validating a chunk to reduce peak memory usage. It is important to only unmap memory that previously mmap()ed, as unmapping other mappings like the stack, heap or executable mappings will crash the process. The mappings read from /proc/self/maps and the return values from mmap() don't allow a simple correlation due to merging and no guaranteed order. To correlate the pointers and mappings use prctl(PR_SET_VMA_ANON_NAME). While it introduces a test dependency, other alternatives would introduce runtime or development overhead. Fixes: 010409649885 ("selftests/mm: confirm VA exhaustion without reliance = on correctness of mmap()") Signed-off-by: Thomas Wei=C3=9Fschuh Acked-by: David Hildenbrand --- tools/testing/selftests/mm/config | 1 + tools/testing/selftests/mm/virtual_address_range.c | 33 ++++++++++++++++++= ++-- 2 files changed, 32 insertions(+), 2 deletions(-) diff --git a/tools/testing/selftests/mm/config b/tools/testing/selftests/mm= /config index 4309916f629e36498efb07eb606b2f0c49ee6211..a28baa536332f3fcfb1b83759b5= fbb432ae80178 100644 --- a/tools/testing/selftests/mm/config +++ b/tools/testing/selftests/mm/config @@ -7,3 +7,4 @@ CONFIG_TEST_HMM=3Dm CONFIG_GUP_TEST=3Dy CONFIG_TRANSPARENT_HUGEPAGE=3Dy CONFIG_MEM_SOFT_DIRTY=3Dy +CONFIG_ANON_VMA_NAME=3Dy diff --git a/tools/testing/selftests/mm/virtual_address_range.c b/tools/tes= ting/selftests/mm/virtual_address_range.c index ea6ccf49ef4c552f26317c2a40b09bca1a677f8f..386e4e46fa65b98af78dee4bb30= 144eb2b51f528 100644 --- a/tools/testing/selftests/mm/virtual_address_range.c +++ b/tools/testing/selftests/mm/virtual_address_range.c @@ -10,6 +10,7 @@ #include #include #include +#include #include #include #include @@ -82,6 +83,24 @@ static void validate_addr(char *ptr, int high_addr) ksft_exit_fail_msg("Bad address %lx\n", addr); } =20 +static void mark_range(char *ptr, size_t size) +{ + if (prctl(PR_SET_VMA, PR_SET_VMA_ANON_NAME, ptr, size, "virtual_address_r= ange") =3D=3D -1) { + if (errno =3D=3D EINVAL) { + /* Depends on CONFIG_ANON_VMA_NAME */ + ksft_test_result_skip("prctl(PR_SET_VMA_ANON_NAME) not supported\n"); + ksft_finished(); + } else { + ksft_exit_fail_perror("prctl(PR_SET_VMA_ANON_NAME) failed\n"); + } + } +} + +static int is_marked_vma(const char *vma_name) +{ + return vma_name && !strcmp(vma_name, "[anon:virtual_address_range]\n"); +} + static int validate_lower_address_hint(void) { char *ptr; @@ -116,12 +135,17 @@ static int validate_complete_va_space(void) =20 prev_end_addr =3D 0; while (fgets(line, sizeof(line), file)) { + const char *vma_name =3D NULL; + int vma_name_start =3D 0; unsigned long hop; =20 - if (sscanf(line, "%lx-%lx %s[rwxp-]", - &start_addr, &end_addr, prot) !=3D 3) + if (sscanf(line, "%lx-%lx %4s %*s %*s %*s %n", + &start_addr, &end_addr, prot, &vma_name_start) !=3D 3) ksft_exit_fail_msg("cannot parse /proc/self/maps\n"); =20 + if (vma_name_start) + vma_name =3D line + vma_name_start; + /* end of userspace mappings; ignore vsyscall mapping */ if (start_addr & (1UL << 63)) return 0; @@ -149,6 +173,9 @@ static int validate_complete_va_space(void) return 1; lseek(fd, 0, SEEK_SET); =20 + if (is_marked_vma(vma_name)) + munmap((char *)(start_addr + hop), MAP_CHUNK_SIZE); + hop +=3D MAP_CHUNK_SIZE; } } @@ -175,6 +202,7 @@ int main(int argc, char *argv[]) break; } =20 + mark_range(ptr[i], MAP_CHUNK_SIZE); validate_addr(ptr[i], 0); } lchunks =3D i; @@ -192,6 +220,7 @@ int main(int argc, char *argv[]) if (hptr[i] =3D=3D MAP_FAILED) break; =20 + mark_range(ptr[i], MAP_CHUNK_SIZE); validate_addr(hptr[i], 1); } hchunks =3D i; --=20 2.47.1