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authorDave Martin <Dave.Martin@arm.com>2015-01-28 15:48:53 +0300
committerSteven Rostedt <rostedt@goodmis.org>2015-01-28 18:34:47 +0300
commit6ea22486ba46bcb665de36514094d74575cd1330 (patch)
treeb0db72c5d2b7dc79a7937f05443a05f1ac5a64c4 /include/trace
parent69a1c994cc540cc84469acf9952f72b899b38e8b (diff)
downloadlinux-6ea22486ba46bcb665de36514094d74575cd1330.tar.xz
tracing: Add array printing helper
If a trace event contains an array, there is currently no standard way to format this for text output. Drivers are currently hacking around this by a) local hacks that use the trace_seq functionailty directly, or b) just not printing that information. For fixed size arrays, formatting of the elements can be open-coded, but this gets cumbersome for arrays of non-trivial size. These approaches result in non-standard content of the event format description delivered to userspace, so userland tools needs to be taught to understand and parse each array printing method individually. This patch implements a __print_array() helper that tracepoint implementations can use instead of reinventing it. A simple C-style syntax is used to delimit the array and its elements {like,this}. So that the helpers can be used with large static arrays as well as dynamic arrays, they take a pointer and element count: they can be used with __get_dynamic_array() for use with dynamic arrays. Link: http://lkml.kernel.org/r/1422449335-8289-2-git-send-email-javi.merino@arm.com Cc: Ingo Molnar <mingo@redhat.com> Signed-off-by: Dave Martin <Dave.Martin@arm.com> Signed-off-by: Javi Merino <javi.merino@arm.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Diffstat (limited to 'include/trace')
-rw-r--r--include/trace/ftrace.h9
1 files changed, 9 insertions, 0 deletions
diff --git a/include/trace/ftrace.h b/include/trace/ftrace.h
index 139b5067345b..304901fc5f34 100644
--- a/include/trace/ftrace.h
+++ b/include/trace/ftrace.h
@@ -263,6 +263,14 @@
#undef __print_hex
#define __print_hex(buf, buf_len) ftrace_print_hex_seq(p, buf, buf_len)
+#undef __print_array
+#define __print_array(array, count, el_size) \
+ ({ \
+ BUILD_BUG_ON(el_size != 1 && el_size != 2 && \
+ el_size != 4 && el_size != 8); \
+ ftrace_print_array_seq(p, array, count, el_size); \
+ })
+
#undef DECLARE_EVENT_CLASS
#define DECLARE_EVENT_CLASS(call, proto, args, tstruct, assign, print) \
static notrace enum print_line_t \
@@ -674,6 +682,7 @@ static inline void ftrace_test_probe_##call(void) \
#undef __get_dynamic_array_len
#undef __get_str
#undef __get_bitmask
+#undef __print_array
#undef TP_printk
#define TP_printk(fmt, args...) "\"" fmt "\", " __stringify(args)