From: SeongJae Park sj@kernel.org
commit b4a002889d24979295ed3c2bf1d5fcfb3901026a upstream.
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 sj@kernel.org Cc: Brendan Higgins brendanhiggins@google.com Cc: Shuah Khan shuah@kernel.org Signed-off-by: Andrew Morton akpm@linux-foundation.org Signed-off-by: Linus Torvalds torvalds@linux-foundation.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- 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(+) create mode 100644 tools/testing/selftests/damon/.gitignore create mode 100644 tools/testing/selftests/damon/huge_count_read_write.c
--- /dev/null +++ b/tools/testing/selftests/damon/.gitignore @@ -0,0 +1,2 @@ +# SPDX-License-Identifier: GPL-2.0-only +huge_count_read_write --- a/tools/testing/selftests/damon/Makefile +++ b/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
--- a/tools/testing/selftests/damon/debugfs_attrs.sh +++ b/tools/testing/selftests/damon/debugfs_attrs.sh @@ -72,4 +72,22 @@ test_write_succ "$file" "" "$orig_conten test_content "$file" "$orig_content" "" "empty input written" echo "$orig_content" > "$file"
+# 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 +++ b/tools/testing/selftests/damon/huge_count_read_write.c @@ -0,0 +1,39 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Author: SeongJae Park sj@kernel.org + */ + +#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; +}