[PATCH net-next 1/3] trace: add variant without spacing in trace_print_hex_seq

[Daniel Borkmann]

For upcoming tracepoint support for BPF, we want to dump the program's
tag. Format should be similar to __print_hex(), but without spacing.
Add a __print_hex_str() variant for exactly that purpose that reuses
trace_print_hex_seq().

Signed-off-by: Daniel Borkmann <daniel@xxxxxxxxxxxxx>
Cc: Steven Rostedt <rostedt@xxxxxxxxxxx>
Cc: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
---
 include/linux/trace_events.h | 3 ++-
 include/trace/trace_events.h | 8 +++++++-
 kernel/trace/trace_output.c  | 7 ++++---
 3 files changed, 13 insertions(+), 5 deletions(-)

diff --git a/include/linux/trace_events.h b/include/linux/trace_events.h
index be00761..cfa475a 100644
--- a/include/linux/trace_events.h
+++ b/include/linux/trace_events.h
@@ -33,7 +33,8 @@ const char *trace_print_bitmask_seq(struct trace_seq *p, void *bitmask_ptr,
 				    unsigned int bitmask_size);
 
 const char *trace_print_hex_seq(struct trace_seq *p,
-				const unsigned char *buf, int len);
+				const unsigned char *buf, int len,
+				bool spacing);
 
 const char *trace_print_array_seq(struct trace_seq *p,
 				   const void *buf, int count,
diff --git a/include/trace/trace_events.h b/include/trace/trace_events.h
index 467e12f..9f68462 100644
--- a/include/trace/trace_events.h
+++ b/include/trace/trace_events.h
@@ -297,7 +297,12 @@
 #endif
 
 #undef __print_hex
-#define __print_hex(buf, buf_len) trace_print_hex_seq(p, buf, buf_len)
+#define __print_hex(buf, buf_len)					\
+	trace_print_hex_seq(p, buf, buf_len, true)
+
+#undef __print_hex_str
+#define __print_hex_str(buf, buf_len)					\
+	trace_print_hex_seq(p, buf, buf_len, false)
 
 #undef __print_array
 #define __print_array(array, count, el_size)				\
@@ -711,6 +716,7 @@
 #undef __print_flags
 #undef __print_symbolic
 #undef __print_hex
+#undef __print_hex_str
 #undef __get_dynamic_array
 #undef __get_dynamic_array_len
 #undef __get_str
diff --git a/kernel/trace/trace_output.c b/kernel/trace/trace_output.c
index 5d33a73..30a144b1 100644
--- a/kernel/trace/trace_output.c
+++ b/kernel/trace/trace_output.c
@@ -163,14 +163,15 @@ enum print_line_t trace_print_printk_msg_only(struct trace_iterator *iter)
 EXPORT_SYMBOL_GPL(trace_print_bitmask_seq);
 
 const char *
-trace_print_hex_seq(struct trace_seq *p, const unsigned char *buf, int buf_len)
+trace_print_hex_seq(struct trace_seq *p, const unsigned char *buf, int buf_len,
+		    bool spacing)
 {
 	int i;
 	const char *ret = trace_seq_buffer_ptr(p);
 
 	for (i = 0; i < buf_len; i++)
-		trace_seq_printf(p, "%s%2.2x", i == 0 ? "" : " ", buf[i]);
-
+		trace_seq_printf(p, "%s%2.2x", !spacing || i == 0 ? "" : " ",
+				 buf[i]);
 	trace_seq_putc(p, 0);
 
 	return ret;
-- 
1.9.3