Hi Michal,

Michal Koutný [off-list ref] 于2021年9月18日周六 上午12:41写道：

Hello Hao.

On Thu, Sep 16, 2021 at 09:53:55PM +0800, Hao Sun [off-list ref] wrote:

quoted

KCSAN reported the following data race during the kernel booting when
using Healer to fuzz the latest Linux kernel.
[...]
 cgroup_rstat_cpu_pop_updated kernel/cgroup/rstat.c:139 [inline]
 [...]
 cgroup_rstat_updated+0x53/0x1b0 kernel/cgroup/rstat.c:38

FWIW, it's a "safe" race between updaters and flushers (possibly
missing the latest update(s)). This is expected as explained in
cgroup_rstat_updated() comment.

Would it be better to add a `data_race` macro to the corresponding
location so that the false report can be disabled?
See https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/tools/memory-model/Documentation/access-marking.txt#n58
for more details.
Currently, fuzzer can not test the kernel with KCSAN enabled for a
long time, because cgroups setup is the basic step before executing
any test case.

Regards
Hao