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| author | SeongJae Park <sj@kernel.org> | 2024-02-07 12:31:33 -0800 |
|---|---|---|
| committer | Andrew Morton <akpm@linux-foundation.org> | 2024-02-22 10:24:56 -0800 |
| commit | f08db42b1c3a6c62ab13ac466f5d8d72d3dd79c5 (patch) | |
| tree | af4e4f76fc484b7f29ef3b6221bf668531974323 /tools | |
| parent | e6255a297628ddd7ead9cf8fb2ce11168595c89d (diff) | |
| download | linux-f08db42b1c3a6c62ab13ac466f5d8d72d3dd79c5.tar.gz linux-f08db42b1c3a6c62ab13ac466f5d8d72d3dd79c5.tar.bz2 linux-f08db42b1c3a6c62ab13ac466f5d8d72d3dd79c5.zip | |
selftests/damon: add a test for the pid leak of dbgfs_target_ids_write()
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.
Link: https://lkml.kernel.org/r/20240207203134.69976-8-sj@kernel.org
Signed-off-by: SeongJae Park <sj@kernel.org>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Diffstat (limited to 'tools')
4 files changed, 93 insertions, 0 deletions
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 <sj@kernel.org> + */ + +#define _GNU_SOURCE + +#include <fcntl.h> +#include <stdbool.h> +#include <stdint.h> +#include <stdio.h> +#include <stdlib.h> +#include <sys/types.h> +#include <sys/wait.h> +#include <sys/time.h> +#include <unistd.h> + +#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 <msecs to run>\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 100644 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 |