tracing: Add __print_dynamic_array() helper

JIRA: https://issues.redhat.com/browse/RHEL-52657
Tested: by AMD
Conflicts: trace headers aren't split in different stages like upstream; trace-events-sample is behind on the tests so the number of arguments is lower

commit e52750f
Author: Steven Rostedt <rostedt@goodmis.org>
Date:   Tue Oct 22 19:36:28 2024 +0000

    tracing: Add __print_dynamic_array() helper

    When printing a dynamic array in a trace event, the method is rather ugly.
    It has the format of:

      __print_array(__get_dynamic_array(array),
                __get_dynmaic_array_len(array) / el_size, el_size)

    Since dynamic arrays are known to the tracing infrastructure, create a
    helper macro that does the above for you.

      __print_dynamic_array(array, el_size)

    Which would expand to the same output.

    Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
    Signed-off-by: Avadhut Naik <avadhut.naik@amd.com>
    Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
    Reviewed-by: Qiuxu Zhuo <qiuxu.zhuo@intel.com>
    Link: https://lore.kernel.org/r/20241022194158.110073-3-avadhut.naik@amd.com

Signed-off-by: Aristeu Rozanski <arozansk@redhat.com>

Author: aristeu

include/trace/trace_events.h

@@ -428,6 +428,14 @@ TRACE_MAKE_SYSTEM_STR();
 		trace_print_array_seq(p, array, count, el_size);	\
 	})
 
+#undef __print_dynamic_array
+#define __print_dynamic_array(array, el_size)				\
+	({								\
+		__print_array(__get_dynamic_array(array),		\
+			      __get_dynamic_array_len(array) / (el_size), \
+			      (el_size));				\
+	})
+
 #undef __print_hex_dump
 #define __print_hex_dump(prefix_str, prefix_type,			\
 			 rowsize, groupsize, buf, len, ascii)		\
@@ -966,6 +974,7 @@ static inline void ftrace_test_probe_##call(void)			\
 #undef __get_rel_bitmask
 #undef __get_rel_sockaddr
 #undef __print_array
+#undef __print_dynamic_array
 #undef __print_hex_dump
 #undef __get_buf
 

samples/trace_events/trace-events-sample.h

@@ -277,7 +277,7 @@ TRACE_EVENT(foo_bar,
 		__assign_bitmask(cpus, cpumask_bits(mask), num_possible_cpus());
 	),
 
-	TP_printk("foo %s %d %s %s %s %s (%s)", __entry->foo, __entry->bar,
+	TP_printk("foo %s %d %s %s %s %s %s (%s)", __entry->foo, __entry->bar,
 
 /*
  * Notice here the use of some helper functions. This includes:
@@ -321,6 +321,11 @@ TRACE_EVENT(foo_bar,
 		  __print_array(__get_dynamic_array(list),
 				__get_dynamic_array_len(list) / sizeof(int),
 				sizeof(int)),
+
+/*     A shortcut is to use __print_dynamic_array for dynamic arrays */
+
+		  __print_dynamic_array(list, sizeof(int)),
+
 		  __get_str(str), __get_bitmask(cpus))
 );