5 files changed, 91 insertions, 20 deletions

diff --git a/kernel/trace/blktrace.c b/kernel/trace/blktrace.c
index e1c6d79fb4cc..2d6e93ab0478 100644
--- a/kernel/trace/blktrace.c
+++ b/kernel/trace/blktrace.c
@@ -512,8 +512,6 @@ static int do_blk_trace_setup(struct request_queue *q, char *name, dev_t dev,
 	dir = debugfs_lookup(buts->name, blk_debugfs_root);
 	if (!dir)
 		bt->dir = dir = debugfs_create_dir(buts->name, blk_debugfs_root);
-	if (!dir)
-		goto err;
 
 	bt->dev = dev;
 	atomic_set(&bt->dropped, 0);
@@ -522,12 +520,8 @@ static int do_blk_trace_setup(struct request_queue *q, char *name, dev_t dev,
 	ret = -EIO;
 	bt->dropped_file = debugfs_create_file("dropped", 0444, dir, bt,
 					       &blk_dropped_fops);
-	if (!bt->dropped_file)
-		goto err;
 
 	bt->msg_file = debugfs_create_file("msg", 0222, dir, bt, &blk_msg_fops);
-	if (!bt->msg_file)
-		goto err;
 
 	bt->rchan = relay_open("trace", dir, buts->buf_size,
 				buts->buf_nr, &blk_relay_callbacks, bt);
diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c
index 1c9a4745e596..ca1255d14576 100644
--- a/kernel/trace/bpf_trace.c
+++ b/kernel/trace/bpf_trace.c
@@ -19,6 +19,9 @@
 #include "trace_probe.h"
 #include "trace.h"
 
+#define bpf_event_rcu_dereference(p)					\
+	rcu_dereference_protected(p, lockdep_is_held(&bpf_event_mutex))
+
 #ifdef CONFIG_MODULES
 struct bpf_trace_module {
 	struct module *module;
@@ -591,6 +594,69 @@ static const struct bpf_func_proto bpf_probe_read_str_proto = {
 	.arg3_type	= ARG_ANYTHING,
 };
 
+struct send_signal_irq_work {
+	struct irq_work irq_work;
+	struct task_struct *task;
+	u32 sig;
+};
+
+static DEFINE_PER_CPU(struct send_signal_irq_work, send_signal_work);
+
+static void do_bpf_send_signal(struct irq_work *entry)
+{
+	struct send_signal_irq_work *work;
+
+	work = container_of(entry, struct send_signal_irq_work, irq_work);
+	group_send_sig_info(work->sig, SEND_SIG_PRIV, work->task, PIDTYPE_TGID);
+}
+
+BPF_CALL_1(bpf_send_signal, u32, sig)
+{
+	struct send_signal_irq_work *work = NULL;
+
+	/* Similar to bpf_probe_write_user, task needs to be
+	 * in a sound condition and kernel memory access be
+	 * permitted in order to send signal to the current
+	 * task.
+	 */
+	if (unlikely(current->flags & (PF_KTHREAD | PF_EXITING)))
+		return -EPERM;
+	if (unlikely(uaccess_kernel()))
+		return -EPERM;
+	if (unlikely(!nmi_uaccess_okay()))
+		return -EPERM;
+
+	if (in_nmi()) {
+		/* Do an early check on signal validity. Otherwise,
+		 * the error is lost in deferred irq_work.
+		 */
+		if (unlikely(!valid_signal(sig)))
+			return -EINVAL;
+
+		work = this_cpu_ptr(&send_signal_work);
+		if (work->irq_work.flags & IRQ_WORK_BUSY)
+			return -EBUSY;
+
+		/* Add the current task, which is the target of sending signal,
+		 * to the irq_work. The current task may change when queued
+		 * irq works get executed.
+		 */
+		work->task = current;
+		work->sig = sig;
+		irq_work_queue(&work->irq_work);
+		return 0;
+	}
+
+	return group_send_sig_info(sig, SEND_SIG_PRIV, current, PIDTYPE_TGID);
+}
+
+static const struct bpf_func_proto bpf_send_signal_proto = {
+	.func		= bpf_send_signal,
+	.gpl_only	= false,
+	.ret_type	= RET_INTEGER,
+	.arg1_type	= ARG_ANYTHING,
+};
+
 static const struct bpf_func_proto *
 tracing_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
 {
@@ -641,6 +707,8 @@ tracing_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
 	case BPF_FUNC_get_current_cgroup_id:
 		return &bpf_get_current_cgroup_id_proto;
 #endif
+	case BPF_FUNC_send_signal:
+		return &bpf_send_signal_proto;
 	default:
 		return NULL;
 	}
@@ -1102,7 +1170,7 @@ static DEFINE_MUTEX(bpf_event_mutex);
 int perf_event_attach_bpf_prog(struct perf_event *event,
 			       struct bpf_prog *prog)
 {
-	struct bpf_prog_array __rcu *old_array;
+	struct bpf_prog_array *old_array;
 	struct bpf_prog_array *new_array;
 	int ret = -EEXIST;
 
@@ -1120,7 +1188,7 @@ int perf_event_attach_bpf_prog(struct perf_event *event,
 	if (event->prog)
 		goto unlock;
 
-	old_array = event->tp_event->prog_array;
+	old_array = bpf_event_rcu_dereference(event->tp_event->prog_array);
 	if (old_array &&
 	    bpf_prog_array_length(old_array) >= BPF_TRACE_MAX_PROGS) {
 		ret = -E2BIG;
@@ -1143,7 +1211,7 @@ unlock:
 
 void perf_event_detach_bpf_prog(struct perf_event *event)
 {
-	struct bpf_prog_array __rcu *old_array;
+	struct bpf_prog_array *old_array;
 	struct bpf_prog_array *new_array;
 	int ret;
 
@@ -1152,7 +1220,7 @@ void perf_event_detach_bpf_prog(struct perf_event *event)
 	if (!event->prog)
 		goto unlock;
 
-	old_array = event->tp_event->prog_array;
+	old_array = bpf_event_rcu_dereference(event->tp_event->prog_array);
 	ret = bpf_prog_array_copy(old_array, event->prog, NULL, &new_array);
 	if (ret == -ENOENT)
 		goto unlock;
@@ -1174,6 +1242,7 @@ int perf_event_query_prog_array(struct perf_event *event, void __user *info)
 {
 	struct perf_event_query_bpf __user *uquery = info;
 	struct perf_event_query_bpf query = {};
+	struct bpf_prog_array *progs;
 	u32 *ids, prog_cnt, ids_len;
 	int ret;
 
@@ -1198,10 +1267,8 @@ int perf_event_query_prog_array(struct perf_event *event, void __user *info)
 	 */
 
 	mutex_lock(&bpf_event_mutex);
-	ret = bpf_prog_array_copy_info(event->tp_event->prog_array,
-				       ids,
-				       ids_len,
-				       &prog_cnt);
+	progs = bpf_event_rcu_dereference(event->tp_event->prog_array);
+	ret = bpf_prog_array_copy_info(progs, ids, ids_len, &prog_cnt);
 	mutex_unlock(&bpf_event_mutex);
 
 	if (copy_to_user(&uquery->prog_cnt, &prog_cnt, sizeof(prog_cnt)) ||
@@ -1364,6 +1431,20 @@ int bpf_get_perf_event_info(const struct perf_event *event, u32 *prog_id,
 	return err;
 }
 
+static int __init send_signal_irq_work_init(void)
+{
+	int cpu;
+	struct send_signal_irq_work *work;
+
+	for_each_possible_cpu(cpu) {
+		work = per_cpu_ptr(&send_signal_work, cpu);
+		init_irq_work(&work->irq_work, do_bpf_send_signal);
+	}
+	return 0;
+}
+
+subsys_initcall(send_signal_irq_work_init);
+
 #ifdef CONFIG_MODULES
 static int bpf_event_notify(struct notifier_block *nb, unsigned long op,
 			    void *module)
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index c3aabb576fe5..c90c687cf950 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -8618,10 +8618,6 @@ struct dentry *tracing_init_dentry(void)
 	 */
 	tr->dir = debugfs_create_automount("tracing", NULL,
 					   trace_automount, NULL);
-	if (!tr->dir) {
-		pr_warn_once("Could not create debugfs directory 'tracing'\n");
-		return ERR_PTR(-ENOMEM);
-	}
 
 	return NULL;
 }
diff --git a/kernel/trace/trace_hwlat.c b/kernel/trace/trace_hwlat.c
index 1e6db9cbe4dc..fa95139445b2 100644
--- a/kernel/trace/trace_hwlat.c
+++ b/kernel/trace/trace_hwlat.c
@@ -277,7 +277,7 @@ static void move_to_next_cpu(void)
 	 * of this thread, than stop migrating for the duration
 	 * of the current test.
 	 */
-	if (!cpumask_equal(current_mask, &current->cpus_allowed))
+	if (!cpumask_equal(current_mask, current->cpus_ptr))
 		goto disable;
 
 	get_online_cpus();
diff --git a/kernel/trace/trace_uprobe.c b/kernel/trace/trace_uprobe.c
index b55906c77ce0..7860e3f59fad 100644
--- a/kernel/trace/trace_uprobe.c
+++ b/kernel/trace/trace_uprobe.c
@@ -1336,7 +1336,7 @@ static inline void init_trace_event_call(struct trace_uprobe *tu,
 	call->event.funcs = &uprobe_funcs;
 	call->class->define_fields = uprobe_event_define_fields;
 
-	call->flags = TRACE_EVENT_FL_UPROBE;
+	call->flags = TRACE_EVENT_FL_UPROBE | TRACE_EVENT_FL_CAP_ANY;
 	call->class->reg = trace_uprobe_register;
 	call->data = tu;
 }