On Wed, 03 Aug 2022, Jiri Olsa wrote:
> On Wed, Aug 03, 2022 at 02:48:21PM +0100, Lee Jones wrote:
> > The documentation for find_pid() clearly states:
>
> nit: typo find_vpid
Sorry missed this.
Will fix.
> > "Must be called with the tasklist_lock or rcu_read_lock() held."
> >
> > Presently we do neither.
> >
> > Let's use find_get_pid() which searches for the vpid, then takes a
> > reference to it preventing early free, all within the safety of
> > rcu_read_lock(). Once we have our reference we can safely make use of
> > it up until the point it is put.
> >
> > Cc: Alexei Starovoitov <ast@xxxxxxxxxx>
> > Cc: Daniel Borkmann <daniel@xxxxxxxxxxxxx>
> > Cc: John Fastabend <john.fastabend@xxxxxxxxx>
> > Cc: Andrii Nakryiko <andrii@xxxxxxxxxx>
> > Cc: Martin KaFai Lau <martin.lau@xxxxxxxxx>
> > Cc: Song Liu <song@xxxxxxxxxx>
> > Cc: Yonghong Song <yhs@xxxxxx>
> > Cc: KP Singh <kpsingh@xxxxxxxxxx>
> > Cc: Stanislav Fomichev <sdf@xxxxxxxxxx>
> > Cc: Hao Luo <haoluo@xxxxxxxxxx>
> > Cc: Jiri Olsa <jolsa@xxxxxxxxxx>
> > Cc: bpf@xxxxxxxxxxxxxxx
> > Fixes: 41bdc4b40ed6f ("bpf: introduce bpf subcommand BPF_TASK_FD_QUERY")
> > Signed-off-by: Lee Jones <lee@xxxxxxxxxx>
>
> Acked-by: Jiri Olsa <jolsa@xxxxxxxxxx>
Thanks.
--
Lee Jones [李琼斯]
