[PATCH 6.0 0120/1073] selftests: cgroup: fix unsigned comparison with less than zero

Greg Kroah-Hartman
2022-12-28T15:08:55Z

From: YueHaibing <yuehaibing@huawei.com>

[ Upstream commit 333d073dee3a6865171d43e3b0a9ff688bff5891 ]

'size' is unsigned, it never less than zero.

Link: https://lkml.kernel.org/r/20221105110611.28920-1-yuehaibing@huawei.com
Fixes: 6c26df84e1f2 ("selftests: cgroup: return -errno from cg_read()/cg_write() on failure")
Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Reviewed-by: Yosry Ahmed <yosryahmed@google.com>
Acked-by: Roman Gushchin <roman.gushchin@linux.dev>
Reviewed-by: Kamalesh Babulal <kamalesh.babulal@oracle.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Tejun Heo <tj@kernel.org>
Cc: zefan li <lizefan.x@bytedance.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
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 4c52cc6f2f9c..e8bbbdb77e0d 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 ret;

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;
+ ret = read_text(path, buf, size);
+ return ret < 0 ? -1 : ret;
}

int proc_read_strstr(int pid, bool thread, const char *item, const char *needle)
--
2.35.1