linux/kernel/trace
Li Zefan 7fcb7c472f tracing/events: introduce __dynamic_array()
__string() is limited:

  - it's a char array, but we may want to define array with other types
  - a source string should be available, but we may just know the string size

We introduce __dynamic_array() to break those limitations, and __string()
becomes a wrapper of it. As a side effect, now __get_str() can be used
in TP_fast_assign but not only TP_print.

Take XFS for example, we have the string length in the dirent, but the
string itself is not NULL-terminated, so __dynamic_array() can be used:

TRACE_EVENT(xfs_dir2,
	TP_PROTO(struct xfs_da_args *args),
	TP_ARGS(args),

	TP_STRUCT__entry(
		__field(int, namelen)
		__dynamic_array(char, name, args->namelen + 1)
		...
	),

	TP_fast_assign(
		char *name = __get_str(name);

		if (args->namelen)
			memcpy(name, args->name, args->namelen);
		name[args->namelen] = '\0';

		__entry->namelen = args->namelen;
	),

	TP_printk("name %.*s namelen %d",
		  __entry->namelen ? __get_str(name) : NULL
		  __entry->namelen)
);

[ Impact: allow defining dynamic size arrays ]

Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
LKML-Reference: <4A2384D2.3080403@cn.fujitsu.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2009-06-01 23:25:15 -04:00
..
blktrace.c blktrace: remove debugfs entries on bad path 2009-05-19 10:29:21 +02:00
ftrace.c ftrace: add kernel command line function filtering 2009-06-01 23:23:10 -04:00
Kconfig tracing: combine the default tracers into one config 2009-06-01 23:23:55 -04:00
kmemtrace.c tracing/filters: use ring_buffer_discard_commit() in filter_check_discard() 2009-04-14 00:00:56 +02:00
Makefile Merge branch 'tracing/hw-branch-tracing' into tracing/core 2009-05-07 13:36:22 +02:00
ring_buffer_benchmark.c ring-buffer: check for divide by zero in ring-buffer-benchmark 2009-05-11 13:22:26 -04:00
ring_buffer.c ring-buffer: move code around to remove some branches 2009-05-11 23:33:06 -04:00
trace_boot.c tracing: use macros to denote usec and nsec per second 2009-04-07 14:43:06 +02:00
trace_branch.c Merge branch 'linus' into tracing/core 2009-05-07 11:17:34 +02:00
trace_clock.c
trace_event_profile.c tracing/events: fix concurrent access to ftrace_events list 2009-05-06 10:38:19 +02:00
trace_event_types.h tracing/filters: distinguish between signed and unsigned fields 2009-04-29 14:06:03 +02:00
trace_events_filter.c tracing/events: introduce __dynamic_array() 2009-06-01 23:25:15 -04:00
trace_events.c ftrace: clean up of using ftrace_event_enable_disable() 2009-05-26 03:30:31 +02:00
trace_export.c tracing/filters: distinguish between signed and unsigned fields 2009-04-29 14:06:03 +02:00
trace_functions_graph.c function-graph: add option to calculate graph time or not 2009-03-24 23:41:11 -04:00
trace_functions.c
trace_hw_branches.c Merge branch 'tracing/hw-branch-tracing' into tracing/core 2009-05-07 13:36:22 +02:00
trace_irqsoff.c
trace_mmiotrace.c tracing: use macros to denote usec and nsec per second 2009-04-07 14:43:06 +02:00
trace_nop.c
trace_output.c tracing: add __print_symbolic to trace events 2009-05-26 20:31:50 +02:00
trace_output.h tracing: add trace_event_read_lock() 2009-05-25 23:53:41 +02:00
trace_power.c Merge branch 'linus' into tracing/core 2009-05-07 11:17:34 +02:00
trace_printk.c tracing/ftrace: factorize the tracing files creation 2009-04-07 14:43:07 +02:00
trace_sched_switch.c tracing/events: move trace point headers into include/trace/events 2009-04-14 22:05:43 -04:00
trace_sched_wakeup.c tracing/wakeup: move access to wakeup_cpu into spinlock 2009-04-23 23:01:36 -04:00
trace_selftest_dynamic.c
trace_selftest.c x86, hw-branch-tracer: allocate selftest iterator on heap 2009-04-07 13:36:21 +02:00
trace_stack.c tracing/ftrace: factorize the tracing files creation 2009-04-07 14:43:07 +02:00
trace_stat.c Merge branch 'linus' into tracing/core 2009-04-07 13:47:45 +02:00
trace_stat.h tracing: add handler to trace_stat 2009-03-24 23:22:58 -04:00
trace_syscalls.c tracing/syscalls: use a dedicated file header 2009-04-09 05:43:32 +02:00
trace_sysprof.c tracing/ftrace: factorize the tracing files creation 2009-04-07 14:43:07 +02:00
trace_workqueue.c Merge branch 'linus' into tracing/core 2009-04-07 13:47:45 +02:00
trace.c trace: disable preemption before taking raw spinlocks 2009-05-28 01:21:03 +02:00
trace.h Merge branch 'tracing/hw-branch-tracing' into tracing/core 2009-05-07 13:36:22 +02:00