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 88D321CD3B for ; Wed, 7 Feb 2024 22:55:15 +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=1707346515; cv=none; b=abdrNY3OyNixZfWt7/lT+r5iAf4O4OXVTTSSTl58a8FAWx5blRybFdQS6Po4jnfMUewx5LIZkBBhLkw37tTHrnDxwzsiXM5yJY3ziRUVQm9IXamhJltF7RJ60gR4F9Eh6jTMnzdFEd6NVaszwUEItcyBFE0dWG/pf+VtZfznD/s= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1707346515; c=relaxed/simple; bh=PyLOh+N//1Upwd1Dc6a5+8K5oj6riWe75YNt39W8xp0=; h=Date:To:From:Subject:Message-Id; b=mr0YVntz5IJibxrbAB3+mmBjJ033uexgWwI2wu/kX1cdAWdULii+CWotAVBCvBQhHeFNbiKO2pCNetJsFN9BnesZ0XUKwpsWpIeU2vd8ctN8VX0svR/ocRpj9tGnIpbAVvy4QyS59vU27wIbjlfYuRloHOI3RiV6vhXpEE6non0= 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=cIIL4KiL; 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="cIIL4KiL" Received: by smtp.kernel.org (Postfix) with ESMTPSA id ED93BC433C7; Wed, 7 Feb 2024 22:55:14 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1707346515; bh=PyLOh+N//1Upwd1Dc6a5+8K5oj6riWe75YNt39W8xp0=; h=Date:To:From:Subject:From; b=cIIL4KiLruVv6rm8Db1cqQ3v+3m0fEiH54XFFAZceEbsRQ2GzUJHq6NtO/kVhKSBV hY81pLbWg+mIvfu9PqPpHEJY4vlKT+eqmBQPSsJog7dRLF0CM+TTDdPfSpzkIv2LjM 3xO900zXBLboCZRiStHR/cM8y5NEAKgzsGLIz3g4= Date: Wed, 07 Feb 2024 14:55:14 -0800 To: mm-commits@vger.kernel.org,shuah@kernel.org,sj@kernel.org,akpm@linux-foundation.org From: Andrew Morton Subject: + selftests-damon-add-a-test-for-a-race-between-target_ids_read-and-dbgfs_before_terminate.patch added to mm-unstable branch Message-Id: <20240207225514.ED93BC433C7@smtp.kernel.org> Precedence: bulk X-Mailing-List: mm-commits@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: The patch titled Subject: selftests/damon: add a test for a race between target_ids_read() and dbgfs_before_terminate() has been added to the -mm mm-unstable branch. Its filename is selftests-damon-add-a-test-for-a-race-between-target_ids_read-and-dbgfs_before_terminate.patch This patch will shortly appear at https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/selftests-damon-add-a-test-for-a-race-between-target_ids_read-and-dbgfs_before_terminate.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: SeongJae Park Subject: selftests/damon: add a test for a race between target_ids_read() and dbgfs_before_terminate() Date: Wed, 7 Feb 2024 12:31:32 -0800 commit 34796417964b ("mm/damon/dbgfs: protect targets destructions with kdamond_lock") fixed a race of DAMON debugfs interface. Specifically, the race was happening between target_ids_read() and dbgfs_before_terminate(). Add a test for the issue to prevent the problem from accidentally recurring. Link: https://lkml.kernel.org/r/20240207203134.69976-7-sj@kernel.org Signed-off-by: SeongJae Park Cc: Shuah Khan Signed-off-by: Andrew Morton --- tools/testing/selftests/damon/.gitignore | 1 tools/testing/selftests/damon/Makefile | 2 tools/testing/selftests/damon/debugfs_target_ids_read_before_terminate_race.c | 80 ++++++++++ tools/testing/selftests/damon/debugfs_target_ids_read_before_terminate_race.sh | 14 + 4 files changed, 97 insertions(+) --- /dev/null +++ a/tools/testing/selftests/damon/debugfs_target_ids_read_before_terminate_race.c @@ -0,0 +1,80 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Author: SeongJae Park + */ +#define _GNU_SOURCE + +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#define DBGFS_MONITOR_ON "/sys/kernel/debug/damon/monitor_on_DEPRECATED" +#define DBGFS_TARGET_IDS "/sys/kernel/debug/damon/target_ids" + +static void turn_damon_on_exit(void) +{ + int target_ids_fd = open(DBGFS_TARGET_IDS, O_RDWR); + int monitor_on_fd = open(DBGFS_MONITOR_ON, O_RDWR); + char pid_str[128]; + + snprintf(pid_str, sizeof(pid_str), "%d", getpid()); + write(target_ids_fd, pid_str, sizeof(pid_str)); + write(monitor_on_fd, "on\n", 3); + close(target_ids_fd); + close(monitor_on_fd); + usleep(1000); + exit(0); +} + +static void try_race(void) +{ + int target_ids_fd = open(DBGFS_TARGET_IDS, O_RDWR); + int pid = fork(); + int buf[256]; + + if (pid < 0) { + fprintf(stderr, "fork() failed\n"); + exit(1); + } + if (pid == 0) + turn_damon_on_exit(); + while (true) { + int status; + + read(target_ids_fd, buf, sizeof(buf)); + if (waitpid(-1, &status, WNOHANG) == pid) + break; + } + close(target_ids_fd); +} + +static inline uint64_t ts_to_ms(struct timespec *ts) +{ + return (uint64_t)ts->tv_sec * 1000 + (uint64_t)ts->tv_nsec / 1000000; +} + +int main(int argc, char *argv[]) +{ + struct timespec start_time, now; + int runtime_ms; + + if (argc != 2) { + fprintf(stderr, "Usage: %s \n", argv[0]); + exit(1); + } + runtime_ms = atoi(argv[1]); + clock_gettime(CLOCK_MONOTONIC, &start_time); + while (true) { + try_race(); + clock_gettime(CLOCK_MONOTONIC, &now); + if (ts_to_ms(&now) - ts_to_ms(&start_time) > runtime_ms) + break; + } + return 0; +} --- /dev/null +++ a/tools/testing/selftests/damon/debugfs_target_ids_read_before_terminate_race.sh @@ -0,0 +1,14 @@ +#!/bin/bash +# SPDX-License-Identifier: GPL-2.0 + +dmesg -C + +./debugfs_target_ids_read_before_terminate_race 5000 + +if dmesg | grep -q dbgfs_target_ids_read +then + dmesg + exit 1 +else + exit 0 +fi --- a/tools/testing/selftests/damon/.gitignore~selftests-damon-add-a-test-for-a-race-between-target_ids_read-and-dbgfs_before_terminate +++ a/tools/testing/selftests/damon/.gitignore @@ -1,2 +1,3 @@ # SPDX-License-Identifier: GPL-2.0-only huge_count_read_write +debugfs_target_ids_read_before_terminate_race --- a/tools/testing/selftests/damon/Makefile~selftests-damon-add-a-test-for-a-race-between-target_ids_read-and-dbgfs_before_terminate +++ a/tools/testing/selftests/damon/Makefile @@ -2,6 +2,7 @@ # Makefile for damon selftests TEST_GEN_FILES += huge_count_read_write +TEST_GEN_FILES += debugfs_target_ids_read_before_terminate_race TEST_GEN_FILES += access_memory TEST_FILES = _chk_dependency.sh _debugfs_common.sh @@ -9,6 +10,7 @@ TEST_PROGS = debugfs_attrs.sh debugfs_sc 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 += 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 _ Patches currently in -mm which might be from sj@kernel.org are mm-damon-sysfs-schemes-fix-wrong-damos-tried-regions-update-timeout-setup.patch mm-damon-core-check-apply-interval-in-damon_do_apply_schemes.patch docs-admin-guide-mm-damon-usage-use-sysfs-interface-for-tracepoints-example.patch mm-damon-rename-config_damon_dbgfs-to-damon_dbgfs_deprecated.patch mm-damon-dbgfs-implement-deprecation-notice-file.patch mm-damon-dbgfs-make-debugfs-interface-deprecation-message-a-macro.patch docs-admin-guide-mm-damon-usage-document-deprecated-file-of-damon-debugfs-interface.patch selftets-damon-prepare-for-monitor_on-file-renaming.patch mm-damon-dbgfs-rename-monitor_on-file-to-monitor_on_deprecated.patch docs-admin-guide-mm-damon-usage-update-for-monitor_on-renaming.patch docs-translations-damon-usage-update-for-monitor_on-renaming.patch mm-damon-sysfs-handle-state-file-inputs-for-every-sampling-interval-if-possible.patch selftests-damon-_damon_sysfs-support-damos-quota.patch selftests-damon-_damon_sysfs-support-damos-stats.patch selftests-damon-_damon_sysfs-support-damos-apply-interval.patch selftests-damon-add-a-test-for-damos-quota.patch selftests-damon-add-a-test-for-damos-apply-intervals.patch selftests-damon-add-a-test-for-a-race-between-target_ids_read-and-dbgfs_before_terminate.patch selftests-damon-add-a-test-for-the-pid-leak-of-dbgfs_target_ids_write.patch selftests-damon-_chk_dependency-get-debugfs-mount-point-from-proc-mounts.patch