Merge tag 'trace-3.14' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

Pull tracing updates from Steven Rostedt:
 "This pull request has a new feature to ftrace, namely the trace event
  triggers by Tom Zanussi.  A trigger is a way to enable an action when
  an event is hit.  The actions are:

   o  trace on/off - enable or disable tracing
   o  snapshot     - save the current trace buffer in the snapshot
   o  stacktrace   - dump the current stack trace to the ringbuffer
   o  enable/disable events - enable or disable another event

  Namhyung Kim added updates to the tracing uprobes code.  Having the
  uprobes add support for fetch methods.

  The rest are various bug fixes with the new code, and minor ones for
  the old code"

* tag 'trace-3.14' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: (38 commits)
  tracing: Fix buggered tee(2) on tracing_pipe
  tracing: Have trace buffer point back to trace_array
  ftrace: Fix synchronization location disabling and freeing ftrace_ops
  ftrace: Have function graph only trace based on global_ops filters
  ftrace: Synchronize setting function_trace_op with ftrace_trace_function
  tracing: Show available event triggers when no trigger is set
  tracing: Consolidate event trigger code
  tracing: Fix counter for traceon/off event triggers
  tracing: Remove double-underscore naming in syscall trigger invocations
  tracing/kprobes: Add trace event trigger invocations
  tracing/probes: Fix build break on !CONFIG_KPROBE_EVENT
  tracing/uprobes: Add @+file_offset fetch method
  uprobes: Allocate ->utask before handler_chain() for tracing handlers
  tracing/uprobes: Add support for full argument access methods
  tracing/uprobes: Fetch args before reserving a ring buffer
  tracing/uprobes: Pass 'is_return' to traceprobe_parse_probe_arg()
  tracing/probes: Implement 'memory' fetch method for uprobes
  tracing/probes: Add fetch{,_size} member into deref fetch method
  tracing/probes: Move 'symbol' fetch method to kprobes
  tracing/probes: Implement 'stack' fetch method for uprobes
  ...

1 files changed, 4 insertions, 0 deletions

diff --git a/kernel/events/uprobes.c b/kernel/events/uprobes.c
index b886a5e7d4ff..307d87c0991a 100644
--- a/kernel/events/uprobes.c
+++ b/kernel/events/uprobes.c
@@ -1854,6 +1854,10 @@ static void handle_swbp(struct pt_regs *regs)
 	if (unlikely(!test_bit(UPROBE_COPY_INSN, &uprobe->flags)))
 		goto out;
 
+	/* Tracing handlers use ->utask to communicate with fetch methods */
+	if (!get_utask())
+		goto out;
+
 	handler_chain(uprobe, regs);
 	if (can_skip_sstep(uprobe, regs))
 		goto out;