diff options
| author |   Yonghong Song <yhs@fb.com> | 2020-08-18 15:23:10 -0700 |
|---|---|---|
| committer |   Alexei Starovoitov <ast@kernel.org> | 2020-08-18 17:36:23 -0700 |
| commit | e60572b8d4c39572be6857d1ec91fdf979f8775f (patch) | |
| tree | d4ab349e5c3baa0fb8f2f82ba9dd804e74ada523 /kernel | |
| parent | bpf: Fix a rcu_sched stall issue with bpf task/task_file iterator (diff) | |
| download | linux-dev-e60572b8d4c39572be6857d1ec91fdf979f8775f.tar.xz linux-dev-e60572b8d4c39572be6857d1ec91fdf979f8775f.zip | |
bpf: Avoid visit same object multiple times
Currently when traversing all tasks, the next tid
is always increased by one. This may result in
visiting the same task multiple times in a
pid namespace.
This patch fixed the issue by seting the next
tid as pid_nr_ns(pid, ns) + 1, similar to
funciton next_tgid().
Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Cc: Rik van Riel <riel@surriel.com>
Link: https://lore.kernel.org/bpf/20200818222310.2181500-1-yhs@fb.com
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/bpf/task_iter.c | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/kernel/bpf/task_iter.c b/kernel/bpf/task_iter.c index f21b5e1e4540..99af4cea1102 100644 --- a/kernel/bpf/task_iter.c +++ b/kernel/bpf/task_iter.c @@ -29,8 +29,9 @@ static struct task_struct *task_seq_get_next(struct pid_namespace *ns, rcu_read_lock(); retry: - pid = idr_get_next(&ns->idr, tid); + pid = find_ge_pid(*tid, ns); if (pid) { + *tid = pid_nr_ns(pid, ns); task = get_pid_task(pid, PIDTYPE_PID); if (!task) { ++*tid; |