From 6a2cbc58d6c9d90cd74288cc497c2b45815bc064 Mon Sep 17 00:00:00 2001
From: Yun Zhou <yun.zhou@windriver.com>
Date: Sat, 26 Jun 2021 11:21:56 +0800
Subject: [PATCH] seq_buf: Make trace_seq_putmem_hex() support data longer than 8
Git-commit: 6a2cbc58d6c9d90cd74288cc497c2b45815bc064
Patch-mainline: v5.14-rc1
References: git-fixes

Since the raw memory 'data' does not go forward, it will dump repeated
data if the data length is more than 8. If we want to dump longer data
blocks, we need to repeatedly call macro SEQ_PUT_HEX_FIELD. I think it
is a bit redundant, and multiple function calls also affect the performance.

Link: https://lore.kernel.org/lkml/20210625122453.5e2fe304@oasis.local.home/
Link: https://lkml.kernel.org/r/20210626032156.47889-2-yun.zhou@windriver.com

Cc: stable@vger.kernel.org
Fixes: 6d2289f3faa7 ("tracing: Make trace_seq_putmem_hex() more robust")
Signed-off-by: Yun Zhou <yun.zhou@windriver.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Acked-by: Takashi Iwai <tiwai@suse.de>

---
 lib/seq_buf.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/lib/seq_buf.c b/lib/seq_buf.c
index 62c20596ef42..6dafde851333 100644
--- a/lib/seq_buf.c
+++ b/lib/seq_buf.c
@@ -245,12 +245,14 @@ int seq_buf_putmem_hex(struct seq_buf *s, const void *mem,
 			break;
 
 		/* j increments twice per loop */
-		len -= j / 2;
 		hex[j++] = ' ';
 
 		seq_buf_putmem(s, hex, j);
 		if (seq_buf_has_overflowed(s))
 			return -1;
+
+		len -= start_len;
+		data += start_len;
 	}
 	return 0;
 }
-- 
2.31.1