ftrace: fix hex output mode of ftrace

Fix the output of ftrace in hex mode as the hi/lo nibbles are output in
reverse order. Without this patch, the output of ftrace is:

raw mode : 6474 0 141531612444 0 140 + 6402 120 S
hex mode : 000091a4 00000000 000000023f1f50c1 00000000 c8 000000b2 00009120 87 ffff00c8 00000035

There is an inversion on ouput hex(6474) is 194a

[based on a patch by Philippe Reynes <tremyfr@yahoo.fr>]
Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

1 files changed, 2 insertions, 6 deletions

diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index 78d56614c95..36cbb873845 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -336,14 +336,12 @@ trace_seq_putmem(struct trace_seq *s, void *mem, size_t len)
 }
 
 #define HEX_CHARS 17
-static const char hex2asc[] = "0123456789abcdef";
 
 static int
 trace_seq_putmem_hex(struct trace_seq *s, void *mem, size_t len)
 {
         unsigned char hex[HEX_CHARS];
         unsigned char *data = mem;
-        unsigned char byte;
         int i, j;
 
         BUG_ON(len >= HEX_CHARS);
@@ -353,10 +351,8 @@ trace_seq_putmem_hex(struct trace_seq *s, void *mem, size_t len)
 #else
         for (i = len-1, j = 0; i >= 0; i--) {
 #endif
-                byte = data[i];
-
-                hex[j++] = hex2asc[byte & 0x0f];
-                hex[j++] = hex2asc[byte >> 4];
+                hex[j++] = hex_asc_hi(data[i]);
+                hex[j++] = hex_asc_lo(data[i]);
         }
         hex[j++] = ' ';