The patch titled Subject: selftests/damon: test debugfs file reads/writes with huge count has been added to the -mm tree. Its filename is selftests-damon-test-debugfs-file-reads-writes-with-huge-count.patch This patch should soon appear at https://ozlabs.org/~akpm/mmots/broken-out/selftests-damon-test-debugfs-file-reads-writes-with-huge-count.patch and later at https://ozlabs.org/~akpm/mmotm/broken-out/selftests-damon-test-debugfs-file-reads-writes-with-huge-count.patch 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 and is updated there every 3-4 working days ------------------------------------------------------ From: SeongJae Park <sj@xxxxxxxxxx> Subject: selftests/damon: test debugfs file reads/writes with huge count DAMON debugfs interface users were able to trigger warning by writing some files with arbitrarily large 'count' parameter. The issue is fixed with commit db7a347b26fe ("mm/damon/dbgfs: use '__GFP_NOWARN' for user-specified size buffer allocation"). This commit adds a test case for the issue in DAMON selftests to avoid future regressions. Link: https://lkml.kernel.org/r/20211201150440.1088-11-sj@xxxxxxxxxx Signed-off-by: SeongJae Park <sj@xxxxxxxxxx> Cc: Brendan Higgins <brendanhiggins@xxxxxxxxxx> Cc: Shuah Khan <shuah@xxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- tools/testing/selftests/damon/.gitignore | 2 tools/testing/selftests/damon/Makefile | 2 tools/testing/selftests/damon/debugfs_attrs.sh | 18 ++++ tools/testing/selftests/damon/huge_count_read_write.c | 39 ++++++++++ 4 files changed, 61 insertions(+) --- a/tools/testing/selftests/damon/debugfs_attrs.sh~selftests-damon-test-debugfs-file-reads-writes-with-huge-count +++ a/tools/testing/selftests/damon/debugfs_attrs.sh @@ -105,4 +105,22 @@ orig_monitor_on=$(cat "$DBGFS/monitor_on test_write_fail "$DBGFS/monitor_on" "on" "orig_monitor_on" "empty target ids" echo "$orig_target_ids" > "$DBGFS/target_ids" +# Test huge count read write +# ========================== + +dmesg -C + +for file in "$DBGFS/"* +do + ./huge_count_read_write "$file" +done + +if dmesg | grep -q WARNING +then + dmesg + exit 1 +else + exit 0 +fi + echo "PASS" --- /dev/null +++ a/tools/testing/selftests/damon/.gitignore @@ -0,0 +1,2 @@ +# SPDX-License-Identifier: GPL-2.0-only +huge_count_read_write --- /dev/null +++ a/tools/testing/selftests/damon/huge_count_read_write.c @@ -0,0 +1,39 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Author: SeongJae Park <sj@xxxxxxxxxx> + */ + +#include <fcntl.h> +#include <stdlib.h> +#include <unistd.h> +#include <stdio.h> + +void write_read_with_huge_count(char *file) +{ + int filedesc = open(file, O_RDWR); + char buf[25]; + int ret; + + printf("%s %s\n", __func__, file); + if (filedesc < 0) { + fprintf(stderr, "failed opening %s\n", file); + exit(1); + } + + write(filedesc, "", 0xfffffffful); + perror("after write: "); + ret = read(filedesc, buf, 0xfffffffful); + perror("after read: "); + close(filedesc); +} + +int main(int argc, char *argv[]) +{ + if (argc != 2) { + fprintf(stderr, "Usage: %s <file>\n", argv[0]); + exit(1); + } + write_read_with_huge_count(argv[1]); + + return 0; +} --- a/tools/testing/selftests/damon/Makefile~selftests-damon-test-debugfs-file-reads-writes-with-huge-count +++ a/tools/testing/selftests/damon/Makefile @@ -1,6 +1,8 @@ # SPDX-License-Identifier: GPL-2.0 # Makefile for damon selftests +TEST_GEN_FILES += huge_count_read_write + TEST_FILES = _chk_dependency.sh TEST_PROGS = debugfs_attrs.sh _ Patches currently in -mm which might be from sj@xxxxxxxxxx are timers-implement-usleep_idle_range.patch mm-damon-core-fix-fake-load-reports-due-to-uninterruptible-sleeps.patch mm-damon-core-use-better-timer-mechanisms-selection-threshold.patch mm-damon-dbgfs-remove-an-unnecessary-error-message.patch mm-damon-core-remove-unnecessary-error-messages.patch mm-damon-vaddr-remove-an-unnecessary-warning-message.patch mm-damon-vaddr-test-split-a-test-function-having-1024-bytes-frame-size.patch mm-damon-vaddr-test-remove-unnecessary-variables.patch selftests-damon-skip-test-if-damon-is-running.patch selftests-damon-test-damon-enabling-with-empty-target_ids-case.patch selftests-damon-test-wrong-damos-condition-ranges-input.patch selftests-damon-test-debugfs-file-reads-writes-with-huge-count.patch selftests-damon-split-test-cases.patch mm-damon-remove-some-no-need-func-definitions-in-damonh-file-fix.patch