On 07/17, Oleg Nesterov wrote: > > On 07/17, Jiri Slaby wrote: > > > > On 17. 07. 20, 12:45, Jiri Slaby wrote: > > > Hi, > > > > > > the strace testsuite triggers this on 5.8-rc4 and -rc5 both on x86_64 > > > and i586: > > > > make check needs -jsomething, running is sequentially (-j1) doesn't > > trigger it. After the error, I cannot run anything. Like ps to find out > > what test caused the crash... > > Strange... I'll try to reproduce but I can't do this till Monday. > > Meanwhile, could you try the patch below? It needs CONFIG_DEBUG_ATOMIC_SLEEP.
please see the updated patch below, lets check ptrace_unfreeze() too. Oleg. diff --git a/kernel/ptrace.c b/kernel/ptrace.c index 43d6179508d6..71c76bc7dec6 100644 --- a/kernel/ptrace.c +++ b/kernel/ptrace.c @@ -180,6 +180,7 @@ static bool ptrace_freeze_traced(struct task_struct *task) spin_lock_irq(&task->sighand->siglock); if (task_is_traced(task) && !__fatal_signal_pending(task)) { + task->task_state_change = _THIS_IP_; task->state = __TASK_TRACED; ret = true; } @@ -203,8 +204,10 @@ static void ptrace_unfreeze_traced(struct task_struct *task) if (task->state == __TASK_TRACED) { if (__fatal_signal_pending(task)) wake_up_state(task, __TASK_TRACED); - else + else { + task->task_state_change = _THIS_IP_; task->state = TASK_TRACED; + } } spin_unlock_irq(&task->sighand->siglock); } diff --git a/kernel/signal.c b/kernel/signal.c index ee22ec78fd6d..ba4c4c9ed9b5 100644 --- a/kernel/signal.c +++ b/kernel/signal.c @@ -1914,7 +1914,9 @@ bool do_notify_parent(struct task_struct *tsk, int sig) BUG_ON(sig == -1); /* do_notify_parent_cldstop should have been called instead. */ - BUG_ON(task_is_stopped_or_traced(tsk)); + WARN(task_is_stopped_or_traced(tsk), + "exist with state=%ld set at %pS", + tsk->state, (void*)tsk->task_state_change); BUG_ON(!tsk->ptrace && (tsk->group_leader != tsk || !thread_group_empty(tsk))); @@ -2214,6 +2216,7 @@ static void ptrace_stop(int exit_code, int why, int clear_code, kernel_siginfo_t preempt_enable_no_resched(); freezable_schedule(); cgroup_leave_frozen(true); + WARN_ON(current->state); } else { /* * By the time we got the lock, our tracer went away. @@ -2393,6 +2396,7 @@ static bool do_signal_stop(int signr) /* Now we don't run again until woken by SIGCONT or SIGKILL */ cgroup_enter_frozen(); freezable_schedule(); + WARN_ON(current->state); return true; } else { /*