diff options
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/ptrace.c | 21 | ||||
| -rw-r--r-- | kernel/sched/core.c | 5 | ||||
| -rw-r--r-- | kernel/signal.c | 14 |
3 files changed, 15 insertions, 25 deletions
diff --git a/kernel/ptrace.c b/kernel/ptrace.c index 05953ac9f7bd..83ed28262708 100644 --- a/kernel/ptrace.c +++ b/kernel/ptrace.c @@ -197,7 +197,7 @@ static bool ptrace_freeze_traced(struct task_struct *task) spin_lock_irq(&task->sighand->siglock); if (task_is_traced(task) && !looks_like_a_spurious_pid(task) && !__fatal_signal_pending(task)) { - WRITE_ONCE(task->__state, __TASK_TRACED); + task->jobctl |= JOBCTL_PTRACE_FROZEN; ret = true; } spin_unlock_irq(&task->sighand->siglock); @@ -207,23 +207,19 @@ static bool ptrace_freeze_traced(struct task_struct *task) static void ptrace_unfreeze_traced(struct task_struct *task) { - if (READ_ONCE(task->__state) != __TASK_TRACED) - return; - - WARN_ON(!task->ptrace || task->parent != current); + unsigned long flags; /* - * PTRACE_LISTEN can allow ptrace_trap_notify to wake us up remotely. - * Recheck state under the lock to close this race. + * The child may be awake and may have cleared + * JOBCTL_PTRACE_FROZEN (see ptrace_resume). The child will + * not set JOBCTL_PTRACE_FROZEN or enter __TASK_TRACED anew. */ - spin_lock_irq(&task->sighand->siglock); - if (READ_ONCE(task->__state) == __TASK_TRACED) { + if (lock_task_sighand(task, &flags)) { + task->jobctl &= ~JOBCTL_PTRACE_FROZEN; if (__fatal_signal_pending(task)) wake_up_state(task, __TASK_TRACED); - else - WRITE_ONCE(task->__state, TASK_TRACED); + unlock_task_sighand(task, &flags); } - spin_unlock_irq(&task->sighand->siglock); } /** @@ -256,7 +252,6 @@ static int ptrace_check_attach(struct task_struct *child, bool ignore_state) */ read_lock(&tasklist_lock); if (child->ptrace && child->parent == current) { - WARN_ON(READ_ONCE(child->__state) == __TASK_TRACED); /* * child->sighand can't be NULL, release_task() * does ptrace_unlink() before __exit_signal(). diff --git a/kernel/sched/core.c b/kernel/sched/core.c index d575b4914925..3c351707e830 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -6304,10 +6304,7 @@ static void __sched notrace __schedule(unsigned int sched_mode) /* * We must load prev->state once (task_struct::state is volatile), such - * that: - * - * - we form a control dependency vs deactivate_task() below. - * - ptrace_{,un}freeze_traced() can change ->state underneath us. + * that we form a control dependency vs deactivate_task() below. */ prev_state = READ_ONCE(prev->__state); if (!(sched_mode & SM_MASK_PREEMPT) && prev_state) { diff --git a/kernel/signal.c b/kernel/signal.c index d2d0c753156c..a58b68a2d3c6 100644 --- a/kernel/signal.c +++ b/kernel/signal.c @@ -2209,14 +2209,12 @@ static int ptrace_stop(int exit_code, int why, unsigned long message, } /* - * schedule() will not sleep if there is a pending signal that - * can awaken the task. - * - * After this point ptrace_signal_wake_up will clear TASK_TRACED - * if ptrace_unlink happens. Handle previous ptrace_unlinks - * here to prevent ptrace_stop sleeping in schedule. + * After this point ptrace_signal_wake_up or signal_wake_up + * will clear TASK_TRACED if ptrace_unlink happens or a fatal + * signal comes in. Handle previous ptrace_unlinks and fatal + * signals here to prevent ptrace_stop sleeping in schedule. */ - if (!current->ptrace) + if (!current->ptrace || __fatal_signal_pending(current)) return exit_code; set_special_state(TASK_TRACED); @@ -2305,7 +2303,7 @@ static int ptrace_stop(int exit_code, int why, unsigned long message, current->exit_code = 0; /* LISTENING can be set only during STOP traps, clear it */ - current->jobctl &= ~JOBCTL_LISTENING; + current->jobctl &= ~(JOBCTL_LISTENING | JOBCTL_PTRACE_FROZEN); /* * Queued signals ignored us while we were stopped for tracing. |