From 61598093bbdd283a7edc367d900f223070ead8d2 Mon Sep 17 00:00:00 2001 From: hc <hc@nodka.com> Date: Fri, 10 May 2024 07:43:03 +0000 Subject: [PATCH] add ax88772C AX88772C_eeprom_tools --- kernel/kernel/pid_namespace.c | 17 +++++++++++++++++ 1 files changed, 17 insertions(+), 0 deletions(-) diff --git a/kernel/kernel/pid_namespace.c b/kernel/kernel/pid_namespace.c index ef8733e..2024368 100644 --- a/kernel/kernel/pid_namespace.c +++ b/kernel/kernel/pid_namespace.c @@ -251,7 +251,24 @@ set_current_state(TASK_INTERRUPTIBLE); if (pid_ns->pid_allocated == init_pids) break; + /* + * Release tasks_rcu_exit_srcu to avoid following deadlock: + * + * 1) TASK A unshare(CLONE_NEWPID) + * 2) TASK A fork() twice -> TASK B (child reaper for new ns) + * and TASK C + * 3) TASK B exits, kills TASK C, waits for TASK A to reap it + * 4) TASK A calls synchronize_rcu_tasks() + * -> synchronize_srcu(tasks_rcu_exit_srcu) + * 5) *DEADLOCK* + * + * It is considered safe to release tasks_rcu_exit_srcu here + * because we assume the current task can not be concurrently + * reaped at this point. + */ + exit_tasks_rcu_stop(); schedule(); + exit_tasks_rcu_start(); } __set_current_state(TASK_RUNNING); -- Gitblit v1.6.2