Merge tag 'trace-3.15' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

Pull tracing updates from Steven Rostedt:
 "Most of the changes were largely clean ups, and some documentation.
  But there were a few features that were added:

  Uprobes now work with event triggers and multi buffers and have
  support under ftrace and perf.

  The big feature is that the function tracer can now be used within the
  multi buffer instances.  That is, you can now trace some functions in
  one buffer, others in another buffer, all functions in a third buffer
  and so on.  They are basically agnostic from each other.  This only
  works for the function tracer and not for the function graph trace,
  although you can have the function graph tracer running in the top
  level buffer (or any tracer for that matter) and have different
  function tracing going on in the sub buffers"

* tag 'trace-3.15' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: (45 commits)
  tracing: Add BUG_ON when stack end location is over written
  tracepoint: Remove unused API functions
  Revert "tracing: Move event storage for array from macro to standalone function"
  ftrace: Constify ftrace_text_reserved
  tracepoints: API doc update to tracepoint_probe_register() return value
  tracepoints: API doc update to data argument
  ftrace: Fix compilation warning about control_ops_free
  ftrace/x86: BUG when ftrace recovery fails
  ftrace: Warn on error when modifying ftrace function
  ftrace: Remove freelist from struct dyn_ftrace
  ftrace: Do not pass data to ftrace_dyn_arch_init
  ftrace: Pass retval through return in ftrace_dyn_arch_init()
  ftrace: Inline the code from ftrace_dyn_table_alloc()
  ftrace: Cleanup of global variables ftrace_new_pgs and ftrace_update_cnt
  tracing: Evaluate len expression only once in __dynamic_array macro
  tracing: Correctly expand len expressions from __dynamic_array macro
  tracing/module: Replace include of tracepoint.h with jump_label.h in module.h
  tracing: Fix event header migrate.h to include tracepoint.h
  tracing: Fix event header writeback.h to include tracepoint.h
  tracing: Warn if a tracepoint is not set via debugfs
  ...

1 files changed, 134 insertions, 57 deletions

diff --git a/kernel/trace/trace_uprobe.c b/kernel/trace/trace_uprobe.c
index 79e52d9..e447336 100644
--- a/kernel/trace/trace_uprobe.c
+++ b/kernel/trace/trace_uprobe.c
@@ -260,6 +260,7 @@ alloc_trace_uprobe(const char *group, const char *event, int nargs, bool is_ret)
 		goto error;
 
 	INIT_LIST_HEAD(&tu->list);
+	INIT_LIST_HEAD(&tu->tp.files);
 	tu->consumer.handler = uprobe_dispatcher;
 	if (is_ret)
 		tu->consumer.ret_handler = uretprobe_dispatcher;
@@ -758,31 +759,32 @@ static void uprobe_buffer_put(struct uprobe_cpu_buffer *ucb)
 	mutex_unlock(&ucb->mutex);
 }
 
-static void uprobe_trace_print(struct trace_uprobe *tu,
-				unsigned long func, struct pt_regs *regs)
+static void __uprobe_trace_func(struct trace_uprobe *tu,
+				unsigned long func, struct pt_regs *regs,
+				struct uprobe_cpu_buffer *ucb, int dsize,
+				struct ftrace_event_file *ftrace_file)
 {
 	struct uprobe_trace_entry_head *entry;
 	struct ring_buffer_event *event;
 	struct ring_buffer *buffer;
-	struct uprobe_cpu_buffer *ucb;
 	void *data;
-	int size, dsize, esize;
+	int size, esize;
 	struct ftrace_event_call *call = &tu->tp.call;
 
-	dsize = __get_data_size(&tu->tp, regs);
-	esize = SIZEOF_TRACE_ENTRY(is_ret_probe(tu));
+	WARN_ON(call != ftrace_file->event_call);
 
-	if (WARN_ON_ONCE(!uprobe_cpu_buffer || tu->tp.size + dsize > PAGE_SIZE))
+	if (WARN_ON_ONCE(tu->tp.size + dsize > PAGE_SIZE))
 		return;
 
-	ucb = uprobe_buffer_get();
-	store_trace_args(esize, &tu->tp, regs, ucb->buf, dsize);
+	if (ftrace_trigger_soft_disabled(ftrace_file))
+		return;
 
+	esize = SIZEOF_TRACE_ENTRY(is_ret_probe(tu));
 	size = esize + tu->tp.size + dsize;
-	event = trace_current_buffer_lock_reserve(&buffer, call->event.type,
-						  size, 0, 0);
+	event = trace_event_buffer_lock_reserve(&buffer, ftrace_file,
+						call->event.type, size, 0, 0);
 	if (!event)
-		goto out;
+		return;
 
 	entry = ring_buffer_event_data(event);
 	if (is_ret_probe(tu)) {
@@ -796,25 +798,36 @@ static void uprobe_trace_print(struct trace_uprobe *tu,
 
 	memcpy(data, ucb->buf, tu->tp.size + dsize);
 
-	if (!call_filter_check_discard(call, entry, buffer, event))
-		trace_buffer_unlock_commit(buffer, event, 0, 0);
-
-out:
-	uprobe_buffer_put(ucb);
+	event_trigger_unlock_commit(ftrace_file, buffer, event, entry, 0, 0);
 }
 
 /* uprobe handler */
-static int uprobe_trace_func(struct trace_uprobe *tu, struct pt_regs *regs)
+static int uprobe_trace_func(struct trace_uprobe *tu, struct pt_regs *regs,
+			     struct uprobe_cpu_buffer *ucb, int dsize)
 {
-	if (!is_ret_probe(tu))
-		uprobe_trace_print(tu, 0, regs);
+	struct event_file_link *link;
+
+	if (is_ret_probe(tu))
+		return 0;
+
+	rcu_read_lock();
+	list_for_each_entry_rcu(link, &tu->tp.files, list)
+		__uprobe_trace_func(tu, 0, regs, ucb, dsize, link->file);
+	rcu_read_unlock();
+
 	return 0;
 }
 
 static void uretprobe_trace_func(struct trace_uprobe *tu, unsigned long func,
-				struct pt_regs *regs)
+				 struct pt_regs *regs,
+				 struct uprobe_cpu_buffer *ucb, int dsize)
 {
-	uprobe_trace_print(tu, func, regs);
+	struct event_file_link *link;
+
+	rcu_read_lock();
+	list_for_each_entry_rcu(link, &tu->tp.files, list)
+		__uprobe_trace_func(tu, func, regs, ucb, dsize, link->file);
+	rcu_read_unlock();
 }
 
 /* Event entry printers */
@@ -861,12 +874,24 @@ typedef bool (*filter_func_t)(struct uprobe_consumer *self,
 				struct mm_struct *mm);
 
 static int
-probe_event_enable(struct trace_uprobe *tu, int flag, filter_func_t filter)
+probe_event_enable(struct trace_uprobe *tu, struct ftrace_event_file *file,
+		   filter_func_t filter)
 {
-	int ret = 0;
+	bool enabled = trace_probe_is_enabled(&tu->tp);
+	struct event_file_link *link = NULL;
+	int ret;
+
+	if (file) {
+		link = kmalloc(sizeof(*link), GFP_KERNEL);
+		if (!link)
+			return -ENOMEM;
 
-	if (trace_probe_is_enabled(&tu->tp))
-		return -EINTR;
+		link->file = file;
+		list_add_tail_rcu(&link->list, &tu->tp.files);
+
+		tu->tp.flags |= TP_FLAG_TRACE;
+	} else
+		tu->tp.flags |= TP_FLAG_PROFILE;
 
 	ret = uprobe_buffer_enable();
 	if (ret < 0)
@@ -874,24 +899,49 @@ probe_event_enable(struct trace_uprobe *tu, int flag, filter_func_t filter)
 
 	WARN_ON(!uprobe_filter_is_empty(&tu->filter));
 
-	tu->tp.flags |= flag;
+	if (enabled)
+		return 0;
+
 	tu->consumer.filter = filter;
 	ret = uprobe_register(tu->inode, tu->offset, &tu->consumer);
-	if (ret)
-		tu->tp.flags &= ~flag;
+	if (ret) {
+		if (file) {
+			list_del(&link->list);
+			kfree(link);
+			tu->tp.flags &= ~TP_FLAG_TRACE;
+		} else
+			tu->tp.flags &= ~TP_FLAG_PROFILE;
+	}
 
 	return ret;
 }
 
-static void probe_event_disable(struct trace_uprobe *tu, int flag)
+static void
+probe_event_disable(struct trace_uprobe *tu, struct ftrace_event_file *file)
 {
 	if (!trace_probe_is_enabled(&tu->tp))
 		return;
 
+	if (file) {
+		struct event_file_link *link;
+
+		link = find_event_file_link(&tu->tp, file);
+		if (!link)
+			return;
+
+		list_del_rcu(&link->list);
+		/* synchronize with u{,ret}probe_trace_func */
+		synchronize_sched();
+		kfree(link);
+
+		if (!list_empty(&tu->tp.files))
+			return;
+	}
+
 	WARN_ON(!uprobe_filter_is_empty(&tu->filter));
 
 	uprobe_unregister(tu->inode, tu->offset, &tu->consumer);
-	tu->tp.flags &= ~flag;
+	tu->tp.flags &= file ? ~TP_FLAG_TRACE : ~TP_FLAG_PROFILE;
 
 	uprobe_buffer_disable();
 }
@@ -1014,31 +1064,24 @@ static bool uprobe_perf_filter(struct uprobe_consumer *uc,
 	return ret;
 }
 
-static void uprobe_perf_print(struct trace_uprobe *tu,
-				unsigned long func, struct pt_regs *regs)
+static void __uprobe_perf_func(struct trace_uprobe *tu,
+			       unsigned long func, struct pt_regs *regs,
+			       struct uprobe_cpu_buffer *ucb, int dsize)
 {
 	struct ftrace_event_call *call = &tu->tp.call;
 	struct uprobe_trace_entry_head *entry;
 	struct hlist_head *head;
-	struct uprobe_cpu_buffer *ucb;
 	void *data;
-	int size, dsize, esize;
+	int size, esize;
 	int rctx;
 
-	dsize = __get_data_size(&tu->tp, regs);
 	esize = SIZEOF_TRACE_ENTRY(is_ret_probe(tu));
 
-	if (WARN_ON_ONCE(!uprobe_cpu_buffer))
-		return;
-
 	size = esize + tu->tp.size + dsize;
 	size = ALIGN(size + sizeof(u32), sizeof(u64)) - sizeof(u32);
 	if (WARN_ONCE(size > PERF_MAX_TRACE_SIZE, "profile buffer not large enough"))
 		return;
 
-	ucb = uprobe_buffer_get();
-	store_trace_args(esize, &tu->tp, regs, ucb->buf, dsize);
-
 	preempt_disable();
 	head = this_cpu_ptr(call->perf_events);
 	if (hlist_empty(head))
@@ -1068,46 +1111,49 @@ static void uprobe_perf_print(struct trace_uprobe *tu,
 	perf_trace_buf_submit(entry, size, rctx, 0, 1, regs, head, NULL);
  out:
 	preempt_enable();
-	uprobe_buffer_put(ucb);
 }
 
 /* uprobe profile handler */
-static int uprobe_perf_func(struct trace_uprobe *tu, struct pt_regs *regs)
+static int uprobe_perf_func(struct trace_uprobe *tu, struct pt_regs *regs,
+			    struct uprobe_cpu_buffer *ucb, int dsize)
 {
 	if (!uprobe_perf_filter(&tu->consumer, 0, current->mm))
 		return UPROBE_HANDLER_REMOVE;
 
 	if (!is_ret_probe(tu))
-		uprobe_perf_print(tu, 0, regs);
+		__uprobe_perf_func(tu, 0, regs, ucb, dsize);
 	return 0;
 }
 
 static void uretprobe_perf_func(struct trace_uprobe *tu, unsigned long func,
-				struct pt_regs *regs)
+				struct pt_regs *regs,
+				struct uprobe_cpu_buffer *ucb, int dsize)
 {
-	uprobe_perf_print(tu, func, regs);
+	__uprobe_perf_func(tu, func, regs, ucb, dsize);
 }
 #endif	/* CONFIG_PERF_EVENTS */
 
-static
-int trace_uprobe_register(struct ftrace_event_call *event, enum trace_reg type, void *data)
+static int
+trace_uprobe_register(struct ftrace_event_call *event, enum trace_reg type,
+		      void *data)
 {
 	struct trace_uprobe *tu = event->data;
+	struct ftrace_event_file *file = data;
 
 	switch (type) {
 	case TRACE_REG_REGISTER:
-		return probe_event_enable(tu, TP_FLAG_TRACE, NULL);
+		return probe_event_enable(tu, file, NULL);
 
 	case TRACE_REG_UNREGISTER:
-		probe_event_disable(tu, TP_FLAG_TRACE);
+		probe_event_disable(tu, file);
 		return 0;
 
 #ifdef CONFIG_PERF_EVENTS
 	case TRACE_REG_PERF_REGISTER:
-		return probe_event_enable(tu, TP_FLAG_PROFILE, uprobe_perf_filter);
+		return probe_event_enable(tu, NULL, uprobe_perf_filter);
 
 	case TRACE_REG_PERF_UNREGISTER:
-		probe_event_disable(tu, TP_FLAG_PROFILE);
+		probe_event_disable(tu, NULL);
 		return 0;
 
 	case TRACE_REG_PERF_OPEN:
@@ -1127,8 +1173,11 @@ static int uprobe_dispatcher(struct uprobe_consumer *con, struct pt_regs *regs)
 {
 	struct trace_uprobe *tu;
 	struct uprobe_dispatch_data udd;
+	struct uprobe_cpu_buffer *ucb;
+	int dsize, esize;
 	int ret = 0;
 
+
 	tu = container_of(con, struct trace_uprobe, consumer);
 	tu->nhit++;
 
@@ -1137,13 +1186,29 @@ static int uprobe_dispatcher(struct uprobe_consumer *con, struct pt_regs *regs)
 
 	current->utask->vaddr = (unsigned long) &udd;
 
+#ifdef CONFIG_PERF_EVENTS
+	if ((tu->tp.flags & TP_FLAG_TRACE) == 0 &&
+	    !uprobe_perf_filter(&tu->consumer, 0, current->mm))
+		return UPROBE_HANDLER_REMOVE;
+#endif
+
+	if (WARN_ON_ONCE(!uprobe_cpu_buffer))
+		return 0;
+
+	dsize = __get_data_size(&tu->tp, regs);
+	esize = SIZEOF_TRACE_ENTRY(is_ret_probe(tu));
+
+	ucb = uprobe_buffer_get();
+	store_trace_args(esize, &tu->tp, regs, ucb->buf, dsize);
+
 	if (tu->tp.flags & TP_FLAG_TRACE)
-		ret |= uprobe_trace_func(tu, regs);
+		ret |= uprobe_trace_func(tu, regs, ucb, dsize);
 
 #ifdef CONFIG_PERF_EVENTS
 	if (tu->tp.flags & TP_FLAG_PROFILE)
-		ret |= uprobe_perf_func(tu, regs);
+		ret |= uprobe_perf_func(tu, regs, ucb, dsize);
 #endif
+	uprobe_buffer_put(ucb);
 	return ret;
 }
 
@@ -1152,6 +1217,8 @@ static int uretprobe_dispatcher(struct uprobe_consumer *con,
 {
 	struct trace_uprobe *tu;
 	struct uprobe_dispatch_data udd;
+	struct uprobe_cpu_buffer *ucb;
+	int dsize, esize;
 
 	tu = container_of(con, struct trace_uprobe, consumer);
 
@@ -1160,13 +1227,23 @@ static int uretprobe_dispatcher(struct uprobe_consumer *con,
 
 	current->utask->vaddr = (unsigned long) &udd;
 
+	if (WARN_ON_ONCE(!uprobe_cpu_buffer))
+		return 0;
+
+	dsize = __get_data_size(&tu->tp, regs);
+	esize = SIZEOF_TRACE_ENTRY(is_ret_probe(tu));
+
+	ucb = uprobe_buffer_get();
+	store_trace_args(esize, &tu->tp, regs, ucb->buf, dsize);
+
 	if (tu->tp.flags & TP_FLAG_TRACE)
-		uretprobe_trace_func(tu, func, regs);
+		uretprobe_trace_func(tu, func, regs, ucb, dsize);
 
 #ifdef CONFIG_PERF_EVENTS
 	if (tu->tp.flags & TP_FLAG_PROFILE)
-		uretprobe_perf_func(tu, func, regs);
+		uretprobe_perf_func(tu, func, regs, ucb, dsize);
 #endif
+	uprobe_buffer_put(ucb);
 	return 0;
 }