From patchwork Wed Feb 7 20:31:33 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: SeongJae Park X-Patchwork-Id: 771698 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 B668E12AAF6; Wed, 7 Feb 2024 20:31:46 +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=1707337906; cv=none; b=FpN/Y+Dbp93F6yCbjnWwAonJiA1I6SgiE84hsOYbUTu8YFg9mu8LMLJo1usvpT72/CypjwdJg5gaYLVAYFtRXeuGmLlvXE9wgM07j4h1Cafb2s/E9JkjASsCqo5sFOsJxnAPKnGvOeWNZlBJSTTT1a6uzjkesfx0vYjVrFWnul8= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1707337906; c=relaxed/simple; bh=hilY7j3dbTrTcHQNZ5cH9hllN5vVoaZDnsr9bRpaZZI=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=ZBGxHFtfjyI5itmAHYVftt62DVXZP7vD23DVCBbnsVI7FkImex4WfYF/gPR+X+EzI8eOnlCXa7TUGsnoH0QhwYR4lUwnWXNREsXEWjZPiDBkvG5jdmygQJawY0SSOcY5JUiIsa6z3B2INiZUIdBqmpjDrzvy3C1qGxeUNCGBK+A= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=ou2UWhF7; 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="ou2UWhF7" Received: by smtp.kernel.org (Postfix) with ESMTPSA id B7C72C43601; Wed, 7 Feb 2024 20:31:45 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1707337906; bh=hilY7j3dbTrTcHQNZ5cH9hllN5vVoaZDnsr9bRpaZZI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=ou2UWhF7rKY/SOJPhENMHQfU07MoTtvz7MvwRRiYyi+LjIzxD5rbLHTVaXLNHZNR9 lFR6S9udTLIzBtTPoxRQGoEdVNalxZkr/elBolMd/SfH5QFGWjwos7+/sf2oAiOq3O a6wJNdJoaYJLL6Pv7h+oUyC+TN00MUk5ipl7S00Kd4NrisZHeGUSddyvn2IdWwCrMQ hdF+ZGVnRCq6QPicoYIQAGTLPPsGo5wDuRIkS4FTPC6TdAnAI6C8OEOEiHLUXNw9HY rZHgPKwBjJ/k5VGnsnvlP2zcb9HXC8V/mPlVuA6CTPFbN9CplEBU2O9p3H+PGt2+3J 356gekiMFzpVg== From: SeongJae Park To: Andrew Morton Cc: SeongJae Park , Shuah Khan , damon@lists.linux.dev, linux-mm@kvack.org, linux-kselftest@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH 7/8] selftests/damon: add a test for the pid leak of dbgfs_target_ids_write() Date: Wed, 7 Feb 2024 12:31:33 -0800 Message-Id: <20240207203134.69976-8-sj@kernel.org> X-Mailer: git-send-email 2.39.2 In-Reply-To: <20240207203134.69976-1-sj@kernel.org> References: <20240207203134.69976-1-sj@kernel.org> Precedence: bulk X-Mailing-List: linux-kselftest@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Commit ebb3f994dd92 ("mm/damon/dbgfs: fix 'struct pid' leaks in 'dbgfs_target_ids_write()'") fixes a pid leak bug in DAMON debugfs interface, namely dbgfs_target_ids_write() function. Add a selftest for the issue to prevent the problem from mistakenly recurring. Signed-off-by: SeongJae Park --- tools/testing/selftests/damon/.gitignore | 1 + tools/testing/selftests/damon/Makefile | 2 + .../damon/debugfs_target_ids_pid_leak.c | 68 +++++++++++++++++++ .../damon/debugfs_target_ids_pid_leak.sh | 22 ++++++ 4 files changed, 93 insertions(+) create mode 100644 tools/testing/selftests/damon/debugfs_target_ids_pid_leak.c create mode 100755 tools/testing/selftests/damon/debugfs_target_ids_pid_leak.sh diff --git a/tools/testing/selftests/damon/.gitignore b/tools/testing/selftests/damon/.gitignore index 7d6c6e062be7..d861701f0327 100644 --- a/tools/testing/selftests/damon/.gitignore +++ b/tools/testing/selftests/damon/.gitignore @@ -1,3 +1,4 @@ # SPDX-License-Identifier: GPL-2.0-only huge_count_read_write debugfs_target_ids_read_before_terminate_race +debugfs_target_ids_pid_leak diff --git a/tools/testing/selftests/damon/Makefile b/tools/testing/selftests/damon/Makefile index 8a3a8df003db..789d6949c247 100644 --- a/tools/testing/selftests/damon/Makefile +++ b/tools/testing/selftests/damon/Makefile @@ -3,6 +3,7 @@ TEST_GEN_FILES += huge_count_read_write TEST_GEN_FILES += debugfs_target_ids_read_before_terminate_race +TEST_GEN_FILES += debugfs_target_ids_pid_leak TEST_GEN_FILES += access_memory TEST_FILES = _chk_dependency.sh _debugfs_common.sh @@ -11,6 +12,7 @@ TEST_PROGS += debugfs_empty_targets.sh debugfs_huge_count_read_write.sh TEST_PROGS += debugfs_duplicate_context_creation.sh TEST_PROGS += debugfs_rm_non_contexts.sh TEST_PROGS += debugfs_target_ids_read_before_terminate_race.sh +TEST_PROGS += debugfs_target_ids_pid_leak.sh TEST_PROGS += sysfs.sh sysfs_update_removed_scheme_dir.sh TEST_PROGS += sysfs_update_schemes_tried_regions_hang.py TEST_PROGS += sysfs_update_schemes_tried_regions_wss_estimation.py diff --git a/tools/testing/selftests/damon/debugfs_target_ids_pid_leak.c b/tools/testing/selftests/damon/debugfs_target_ids_pid_leak.c new file mode 100644 index 000000000000..0cc2eef7d142 --- /dev/null +++ b/tools/testing/selftests/damon/debugfs_target_ids_pid_leak.c @@ -0,0 +1,68 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Author: SeongJae Park + */ + +#define _GNU_SOURCE + +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#define DBGFS_TARGET_IDS "/sys/kernel/debug/damon/target_ids" + +static void write_targetid_exit(void) +{ + int target_ids_fd = open(DBGFS_TARGET_IDS, O_RDWR); + char pid_str[128]; + + snprintf(pid_str, sizeof(pid_str), "%d", getpid()); + write(target_ids_fd, pid_str, sizeof(pid_str)); + close(target_ids_fd); + exit(0); +} + +unsigned long msec_timestamp(void) +{ + struct timeval tv; + + gettimeofday(&tv, NULL); + return tv.tv_sec * 1000UL + tv.tv_usec / 1000; +} + +int main(int argc, char *argv[]) +{ + unsigned long start_ms; + int time_to_run, nr_forks = 0; + + if (argc != 2) { + fprintf(stderr, "Usage: %s \n", argv[0]); + exit(1); + } + time_to_run = atoi(argv[1]); + + start_ms = msec_timestamp(); + while (true) { + int pid = fork(); + + if (pid < 0) { + fprintf(stderr, "fork() failed\n"); + exit(1); + } + if (pid == 0) + write_targetid_exit(); + wait(NULL); + nr_forks++; + + if (msec_timestamp() - start_ms > time_to_run) + break; + } + printf("%d\n", nr_forks); + return 0; +} diff --git a/tools/testing/selftests/damon/debugfs_target_ids_pid_leak.sh b/tools/testing/selftests/damon/debugfs_target_ids_pid_leak.sh new file mode 100755 index 000000000000..31fe33c2b032 --- /dev/null +++ b/tools/testing/selftests/damon/debugfs_target_ids_pid_leak.sh @@ -0,0 +1,22 @@ +#!/bin/bash +# SPDX-License-Identifier: GPL-2.0 + +before=$(grep "^pid " /proc/slabinfo | awk '{print $2}') + +nr_leaks=$(./debugfs_target_ids_pid_leak 1000) +expected_after_max=$((before + nr_leaks / 2)) + +after=$(grep "^pid " /proc/slabinfo | awk '{print $2}') + +echo > /sys/kernel/debug/damon/target_ids + +echo "tried $nr_leaks pid leak" +echo "number of active pid slabs: $before -> $after" +echo "(up to $expected_after_max expected)" +if [ $after -gt $expected_after_max ] +then + echo "maybe pids are leaking" + exit 1 +else + exit 0 +fi