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From:   Viktor Rosendahl <Viktor.Rosendahl@bmw.de>
To:     Steven Rostedt <rostedt@goodmis.org>
CC:     jing yangyang <jing.yangyang@zte.com.cn>,
        <davidcomponentone@gmail.com>, <linux-kernel@vger.kernel.org>,
        Viktor Rosendahl <Viktor.Rosendahl@bmw.de>,
        Zeal Robot <zealci@zte.com.cn>
Subject: [PATCH] tools/latency-collector: Use correct size when writing queue_full_warning
Date:   Tue, 19 Oct 2021 18:07:01 +0200
Message-ID: <20211019160701.15587-1-Viktor.Rosendahl@bmw.de>
MIME-Version: 1.0
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Precedence: bulk

queue_full_warning is a pointer, so it is wrong to use sizeof to calculate
the number of characters of the string it points to. The effect is that we
only print out the first few characters of the warning string.

The correct way is to use strlen(). We don't need to add 1 to the strlen()
because we don't want to write the terminating null character to stdout.

Link: https://lore.kernel.org/r/8fd4bb65ef3da67feac9ce3258cdbe9824752cf1.1629198502.git.jing.yangyang@zte.com.cn
Link: https://lore.kernel.org/r/20211012025424.180781-1-davidcomponentone@gmail.com
Reported-by: Zeal Robot <zealci@zte.com.cn>
Signed-off-by: Viktor Rosendahl <Viktor.Rosendahl@bmw.de>
---
 tools/tracing/latency/latency-collector.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tools/tracing/latency/latency-collector.c b/tools/tracing/latency/latency-collector.c
index 3a2e6bb781a8..59a7f2346eab 100644
--- a/tools/tracing/latency/latency-collector.c
+++ b/tools/tracing/latency/latency-collector.c
@@ -1538,7 +1538,7 @@ static void tracing_loop(void)
 				mutex_lock(&print_mtx);
 				check_signals();
 				write_or_die(fd_stdout, queue_full_warning,
-					     sizeof(queue_full_warning));
+					     strlen(queue_full_warning));
 				mutex_unlock(&print_mtx);
 			}
 			modified--;
-- 
2.25.1