From b4a002889d24979295ed3c2bf1d5fcfb3901026a Mon Sep 17 00:00:00 2001 From: SeongJae Park Date: Fri, 10 Dec 2021 14:46:55 -0800 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@kernel.org Signed-off-by: SeongJae Park Cc: Brendan Higgins Cc: Shuah Khan Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- .../selftests/damon/huge_count_read_write.c | 39 ++++++++++++++++++++++ 1 file changed, 39 insertions(+) create mode 100644 tools/testing/selftests/damon/huge_count_read_write.c (limited to 'tools/testing/selftests/damon/huge_count_read_write.c') diff --git a/tools/testing/selftests/damon/huge_count_read_write.c b/tools/testing/selftests/damon/huge_count_read_write.c new file mode 100644 index 000000000000..ad7a6b4cf338 --- /dev/null +++ b/tools/testing/selftests/damon/huge_count_read_write.c @@ -0,0 +1,39 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Author: SeongJae Park + */ + +#include +#include +#include +#include + +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 \n", argv[0]); + exit(1); + } + write_read_with_huge_count(argv[1]); + + return 0; +} -- cgit v1.2.3