Merge tag 'trace-v6.17-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace

Pull more tracing updates from Steven Rostedt:

 - Remove unneeded goto out statements

   Over time, the logic was restructured but left a "goto out" where the
   out label simply did a "return ret;". Instead of jumping to this out
   label, simply return immediately and remove the out label.

 - Add guard(ring_buffer_nest)

   Some calls to the tracing ring buffer can happen when the ring buffer
   is already being written to at the same context (for example, a
   trace_printk() in between a ring_buffer_lock_reserve() and a
   ring_buffer_unlock_commit()).

   In order to not trigger the recursion detection, these functions use
   ring_buffer_nest_start() and ring_buffer_nest_end(). Create a guard()
   for these functions so that their use cases can be simplified and not
   need to use goto for the release.

 - Clean up the tracing code with guard() and __free() logic

   There were several locations that were prime candidates for using
   guard() and __free() helpers. Switch them over to use them.

 - Fix output of function argument traces for unsigned int values

   The function tracer with "func-args" option set will record up to 6
   argument registers and then use BTF to format them for human
   consumption when the trace file is read. There are several arguments
   that are "unsigned long" and even "unsigned int" that are either and
   address or a mask. It is easier to understand if they were printed
   using hexadecimal instead of decimal. The old method just printed all
   non-pointer values as signed integers, which made it even worse for
   unsigned integers.

   For instance, instead of:

     __local_bh_disable_ip(ip=-2127311112, cnt=256) <-handle_softirqs

   show:

     __local_bh_disable_ip(ip=0xffffffff8133cef8, cnt=0x100) <-handle_softirqs"

* tag 'trace-v6.17-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
  tracing: Have unsigned int function args displayed as hexadecimal
  ring-buffer: Convert ring_buffer_write() to use guard(preempt_notrace)
  tracing: Use __free(kfree) in trace.c to remove gotos
  tracing: Add guard() around locks and mutexes in trace.c
  tracing: Add guard(ring_buffer_nest)
  tracing: Remove unneeded goto out logic

Author: torvalds

include/linux/ring_buffer.h

@@ -144,6 +144,9 @@ int ring_buffer_write(struct trace_buffer *buffer,
 void ring_buffer_nest_start(struct trace_buffer *buffer);
 void ring_buffer_nest_end(struct trace_buffer *buffer);
 
+DEFINE_GUARD(ring_buffer_nest, struct trace_buffer *,
+	     ring_buffer_nest_start(_T), ring_buffer_nest_end(_T))
+
 struct ring_buffer_event *
 ring_buffer_peek(struct trace_buffer *buffer, int cpu, u64 *ts,
 		 unsigned long *lost_events);

kernel/trace/ring_buffer.c

@@ -4812,26 +4812,26 @@ int ring_buffer_write(struct trace_buffer *buffer,
 	int ret = -EBUSY;
 	int cpu;
 
-	preempt_disable_notrace();
+	guard(preempt_notrace)();
 
 	if (atomic_read(&buffer->record_disabled))
-		goto out;
+		return -EBUSY;
 
 	cpu = raw_smp_processor_id();
 
 	if (!cpumask_test_cpu(cpu, buffer->cpumask))
-		goto out;
+		return -EBUSY;
 
 	cpu_buffer = buffer->buffers[cpu];
 
 	if (atomic_read(&cpu_buffer->record_disabled))
-		goto out;
+		return -EBUSY;
 
 	if (length > buffer->max_data_size)
-		goto out;
+		return -EBUSY;
 
 	if (unlikely(trace_recursive_lock(cpu_buffer)))
-		goto out;
+		return -EBUSY;
 
 	event = rb_reserve_next_event(buffer, cpu_buffer, length);
 	if (!event)
@@ -4849,10 +4849,6 @@ int ring_buffer_write(struct trace_buffer *buffer,
 
  out_unlock:
 	trace_recursive_unlock(cpu_buffer);
-
- out:
-	preempt_enable_notrace();
-
 	return ret;
 }
 EXPORT_SYMBOL_GPL(ring_buffer_write);