On Wed, Dec 7, 2022 at 12:33 AM Wang Yufen <wangyufen@xxxxxxxxxx> wrote:
>
> Unsigned variable cannot be lesser than zero, So the return check of read_text() is invalid.
> To fix, add a new ssize_t variable read for read_text() return value check.
>
> Fixes: 6c26df84e1f2 ("selftests: cgroup: return -errno from cg_read()/cg_write() on failure")
Thanks for sending this, but a fix was already sent recently (by YueHaibing):
https://lore.kernel.org/lkml/20221105110611.28920-1-yuehaibing@xxxxxxxxxx/
, and it currently lives in the mm-nomm-stable branch in Andrew's tree
AFAICT as commit e410f7aa641d ("selftests: cgroup: fix unsigned
comparison with less than zero").
> Signed-off-by: Wang Yufen <wangyufen@xxxxxxxxxx>
> ---
> tools/testing/selftests/cgroup/cgroup_util.c | 5 +++--
> 1 file changed, 3 insertions(+), 2 deletions(-)
>
> diff --git a/tools/testing/selftests/cgroup/cgroup_util.c b/tools/testing/selftests/cgroup/cgroup_util.c
> index 4c52cc6..19137c0 100644
> --- a/tools/testing/selftests/cgroup/cgroup_util.c
> +++ b/tools/testing/selftests/cgroup/cgroup_util.c
> @@ -555,6 +555,7 @@ int proc_mount_contains(const char *option)
> ssize_t proc_read_text(int pid, bool thread, const char *item, char *buf, size_t size)
> {
> char path[PATH_MAX];
> + ssize_t read;
>
> if (!pid)
> snprintf(path, sizeof(path), "/proc/%s/%s",
> @@ -562,8 +563,8 @@ ssize_t proc_read_text(int pid, bool thread, const char *item, char *buf, size_t
> else
> snprintf(path, sizeof(path), "/proc/%d/%s", pid, item);
>
> - size = read_text(path, buf, size);
> - return size < 0 ? -1 : size;
> + read = read_text(path, buf, size);
> + return read < 0 ? -1 : read;
> }
>
> int proc_read_strstr(int pid, bool thread, const char *item, const char *needle)
> --
> 1.8.3.1
>
