diff options
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/exit.c | 5 | ||||
| -rw-r--r-- | kernel/signal.c | 4 | ||||
| -rw-r--r-- | kernel/trace/bpf_trace.h | 2 | ||||
| -rw-r--r-- | kernel/trace/preemptirq_delay_test.c | 1 | ||||
| -rw-r--r-- | kernel/trace/ring_buffer.c | 25 | ||||
| -rw-r--r-- | kernel/trace/rv/rv.c | 2 | ||||
| -rw-r--r-- | kernel/vhost_task.c | 53 |
7 files changed, 52 insertions, 40 deletions
diff --git a/kernel/exit.c b/kernel/exit.c index cd3aa9042f1a..f95a2c1338a8 100644 --- a/kernel/exit.c +++ b/kernel/exit.c @@ -413,10 +413,7 @@ static void coredump_task_exit(struct task_struct *tsk) tsk->flags |= PF_POSTCOREDUMP; core_state = tsk->signal->core_state; spin_unlock_irq(&tsk->sighand->siglock); - - /* The vhost_worker does not particpate in coredumps */ - if (core_state && - ((tsk->flags & (PF_IO_WORKER | PF_USER_WORKER)) != PF_USER_WORKER)) { + if (core_state) { struct core_thread self; self.task = current; diff --git a/kernel/signal.c b/kernel/signal.c index 01c4c46a51a8..1f9dd41c04be 100644 --- a/kernel/signal.c +++ b/kernel/signal.c @@ -1375,9 +1375,7 @@ int zap_other_threads(struct task_struct *p) for_other_threads(p, t) { task_clear_jobctl_pending(t, JOBCTL_PENDING_MASK); - /* Don't require de_thread to wait for the vhost_worker */ - if ((t->flags & (PF_IO_WORKER | PF_USER_WORKER)) != PF_USER_WORKER) - count++; + count++; /* Don't bother with already dead threads */ if (t->exit_state) diff --git a/kernel/trace/bpf_trace.h b/kernel/trace/bpf_trace.h index 9acbc11ac7bb..c4075b56becc 100644 --- a/kernel/trace/bpf_trace.h +++ b/kernel/trace/bpf_trace.h @@ -19,7 +19,7 @@ TRACE_EVENT(bpf_trace_printk, ), TP_fast_assign( - __assign_str(bpf_string, bpf_string); + __assign_str(bpf_string); ), TP_printk("%s", __get_str(bpf_string)) diff --git a/kernel/trace/preemptirq_delay_test.c b/kernel/trace/preemptirq_delay_test.c index 8c4ffd076162..cb0871fbdb07 100644 --- a/kernel/trace/preemptirq_delay_test.c +++ b/kernel/trace/preemptirq_delay_test.c @@ -215,4 +215,5 @@ static void __exit preemptirq_delay_exit(void) module_init(preemptirq_delay_init) module_exit(preemptirq_delay_exit) +MODULE_DESCRIPTION("Preempt / IRQ disable delay thread to test latency tracers"); MODULE_LICENSE("GPL v2"); diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c index 7345a8b625fb..28853966aa9a 100644 --- a/kernel/trace/ring_buffer.c +++ b/kernel/trace/ring_buffer.c @@ -1460,6 +1460,11 @@ static void rb_check_bpage(struct ring_buffer_per_cpu *cpu_buffer, * * As a safety measure we check to make sure the data pages have not * been corrupted. + * + * Callers of this function need to guarantee that the list of pages doesn't get + * modified during the check. In particular, if it's possible that the function + * is invoked with concurrent readers which can swap in a new reader page then + * the caller should take cpu_buffer->reader_lock. */ static void rb_check_pages(struct ring_buffer_per_cpu *cpu_buffer) { @@ -2210,8 +2215,12 @@ int ring_buffer_resize(struct trace_buffer *buffer, unsigned long size, */ synchronize_rcu(); for_each_buffer_cpu(buffer, cpu) { + unsigned long flags; + cpu_buffer = buffer->buffers[cpu]; + raw_spin_lock_irqsave(&cpu_buffer->reader_lock, flags); rb_check_pages(cpu_buffer); + raw_spin_unlock_irqrestore(&cpu_buffer->reader_lock, flags); } atomic_dec(&buffer->record_disabled); } @@ -5046,13 +5055,9 @@ EXPORT_SYMBOL_GPL(ring_buffer_consume); * @flags: gfp flags to use for memory allocation * * This performs the initial preparations necessary to iterate - * through the buffer. Memory is allocated, buffer recording + * through the buffer. Memory is allocated, buffer resizing * is disabled, and the iterator pointer is returned to the caller. * - * Disabling buffer recording prevents the reading from being - * corrupted. This is not a consuming read, so a producer is not - * expected. - * * After a sequence of ring_buffer_read_prepare calls, the user is * expected to make at least one call to ring_buffer_read_prepare_sync. * Afterwards, ring_buffer_read_start is invoked to get things going @@ -5139,8 +5144,7 @@ EXPORT_SYMBOL_GPL(ring_buffer_read_start); * ring_buffer_read_finish - finish reading the iterator of the buffer * @iter: The iterator retrieved by ring_buffer_start * - * This re-enables the recording to the buffer, and frees the - * iterator. + * This re-enables resizing of the buffer, and frees the iterator. */ void ring_buffer_read_finish(struct ring_buffer_iter *iter) @@ -5148,12 +5152,7 @@ ring_buffer_read_finish(struct ring_buffer_iter *iter) struct ring_buffer_per_cpu *cpu_buffer = iter->cpu_buffer; unsigned long flags; - /* - * Ring buffer is disabled from recording, here's a good place - * to check the integrity of the ring buffer. - * Must prevent readers from trying to read, as the check - * clears the HEAD page and readers require it. - */ + /* Use this opportunity to check the integrity of the ring buffer. */ raw_spin_lock_irqsave(&cpu_buffer->reader_lock, flags); rb_check_pages(cpu_buffer); raw_spin_unlock_irqrestore(&cpu_buffer->reader_lock, flags); diff --git a/kernel/trace/rv/rv.c b/kernel/trace/rv/rv.c index 2f68e93fff0b..df0745a42a3f 100644 --- a/kernel/trace/rv/rv.c +++ b/kernel/trace/rv/rv.c @@ -245,6 +245,7 @@ static int __rv_disable_monitor(struct rv_monitor_def *mdef, bool sync) /** * rv_disable_monitor - disable a given runtime monitor + * @mdef: Pointer to the monitor definition structure. * * Returns 0 on success. */ @@ -256,6 +257,7 @@ int rv_disable_monitor(struct rv_monitor_def *mdef) /** * rv_enable_monitor - enable a given runtime monitor + * @mdef: Pointer to the monitor definition structure. * * Returns 0 on success, error otherwise. */ diff --git a/kernel/vhost_task.c b/kernel/vhost_task.c index da35e5b7f047..8800f5acc007 100644 --- a/kernel/vhost_task.c +++ b/kernel/vhost_task.c @@ -10,38 +10,32 @@ enum vhost_task_flags { VHOST_TASK_FLAGS_STOP, + VHOST_TASK_FLAGS_KILLED, }; struct vhost_task { bool (*fn)(void *data); + void (*handle_sigkill)(void *data); void *data; struct completion exited; unsigned long flags; struct task_struct *task; + /* serialize SIGKILL and vhost_task_stop calls */ + struct mutex exit_mutex; }; static int vhost_task_fn(void *data) { struct vhost_task *vtsk = data; - bool dead = false; for (;;) { bool did_work; - if (!dead && signal_pending(current)) { + if (signal_pending(current)) { struct ksignal ksig; - /* - * Calling get_signal will block in SIGSTOP, - * or clear fatal_signal_pending, but remember - * what was set. - * - * This thread won't actually exit until all - * of the file descriptors are closed, and - * the release function is called. - */ - dead = get_signal(&ksig); - if (dead) - clear_thread_flag(TIF_SIGPENDING); + + if (get_signal(&ksig)) + break; } /* mb paired w/ vhost_task_stop */ @@ -57,7 +51,19 @@ static int vhost_task_fn(void *data) schedule(); } + mutex_lock(&vtsk->exit_mutex); + /* + * If a vhost_task_stop and SIGKILL race, we can ignore the SIGKILL. + * When the vhost layer has called vhost_task_stop it's already stopped + * new work and flushed. + */ + if (!test_bit(VHOST_TASK_FLAGS_STOP, &vtsk->flags)) { + set_bit(VHOST_TASK_FLAGS_KILLED, &vtsk->flags); + vtsk->handle_sigkill(vtsk->data); + } + mutex_unlock(&vtsk->exit_mutex); complete(&vtsk->exited); + do_exit(0); } @@ -78,12 +84,17 @@ EXPORT_SYMBOL_GPL(vhost_task_wake); * @vtsk: vhost_task to stop * * vhost_task_fn ensures the worker thread exits after - * VHOST_TASK_FLAGS_SOP becomes true. + * VHOST_TASK_FLAGS_STOP becomes true. */ void vhost_task_stop(struct vhost_task *vtsk) { - set_bit(VHOST_TASK_FLAGS_STOP, &vtsk->flags); - vhost_task_wake(vtsk); + mutex_lock(&vtsk->exit_mutex); + if (!test_bit(VHOST_TASK_FLAGS_KILLED, &vtsk->flags)) { + set_bit(VHOST_TASK_FLAGS_STOP, &vtsk->flags); + vhost_task_wake(vtsk); + } + mutex_unlock(&vtsk->exit_mutex); + /* * Make sure vhost_task_fn is no longer accessing the vhost_task before * freeing it below. @@ -96,14 +107,16 @@ EXPORT_SYMBOL_GPL(vhost_task_stop); /** * vhost_task_create - create a copy of a task to be used by the kernel * @fn: vhost worker function - * @arg: data to be passed to fn + * @handle_sigkill: vhost function to handle when we are killed + * @arg: data to be passed to fn and handled_kill * @name: the thread's name * * This returns a specialized task for use by the vhost layer or NULL on * failure. The returned task is inactive, and the caller must fire it up * through vhost_task_start(). */ -struct vhost_task *vhost_task_create(bool (*fn)(void *), void *arg, +struct vhost_task *vhost_task_create(bool (*fn)(void *), + void (*handle_sigkill)(void *), void *arg, const char *name) { struct kernel_clone_args args = { @@ -122,8 +135,10 @@ struct vhost_task *vhost_task_create(bool (*fn)(void *), void *arg, if (!vtsk) return NULL; init_completion(&vtsk->exited); + mutex_init(&vtsk->exit_mutex); vtsk->data = arg; vtsk->fn = fn; + vtsk->handle_sigkill = handle_sigkill; args.fn_arg = vtsk; |