On 2021-03-09 01:02:15 [-0800], Jia-Ju Bai wrote:
> When proc_create() returns NULL to entry, no error return code of
> create_proc_profile() is assigned.
> To fix this bug, err is assigned with -ENOMEM in this case.
I preserved what was in commit
c270a817196a9 ("profile: Fix CPU hotplug callback registration")
which was already in commit
c33fff0afbef4 ("kernel: use non-racy method for proc entries creation")
and goes back to its original introduction in history tree's commit
423284ee6eb52 ("[PATCH] consolidate prof_cpu_mask")
which is ignoring a failure here.
If we decide otherwise and not ignore the error then it would be good to
use an earlier commit so the change also makes into v4.4+ stable.
> Fixes: e722d8daafb9 ("profile: Convert to hotplug state machine")
> Reported-by: TOTE Robot <os...@tsinghua.edu.cn>
> Signed-off-by: Jia-Ju Bai <baijiaju1...@gmail.com>
> ---
> kernel/profile.c | 4 +++-
> 1 file changed, 3 insertions(+), 1 deletion(-)
>
> diff --git a/kernel/profile.c b/kernel/profile.c
> index 6f69a4195d56..65bf03bb8a5e 100644
> --- a/kernel/profile.c
> +++ b/kernel/profile.c
> @@ -549,8 +549,10 @@ int __ref create_proc_profile(void)
> #endif
> entry = proc_create("profile", S_IWUSR | S_IRUGO,
> NULL, &profile_proc_ops);
> - if (!entry)
> + if (!entry) {
> + err = -ENOMEM;
> goto err_state_onl;
> + }
> proc_set_size(entry, (1 + prof_len) * sizeof(atomic_t));
>
> return err;
Sebastian
