soundwire: debugfs: initialize ktime_t variables before div_u64

[PATCH] soundwire: debugfs: initialize ktime_t variables before div_u64

Posted by Rodrigo Gobbi 3 months, 3 weeks ago

The start_t and finish_t variables are not properly initialized
if errors happens over request_firmware actions. This was also detected by smatch:

drivers/soundwire/debugfs.c:301 cmd_go() error: uninitialized symbol 'finish_t'.
drivers/soundwire/debugfs.c:301 cmd_go() error: uninitialized symbol 'start_t'.

Signed-off-by: Rodrigo Gobbi <rodrigo.gobbi.7@gmail.com>
Reported-by: Dan Carpenter <dan.carpenter@linaro.org>
Closes: https://lore.kernel.org/linux-sound/0db6d0bf-7bac-43a7-b624-a00d3d2bf829@stanley.mountain/
Fixes: bb5cb09eedce ("soundwire: debugfs: add interface for BPT/BRA transfers")
---
 drivers/soundwire/debugfs.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/soundwire/debugfs.c b/drivers/soundwire/debugfs.c
index 3099ea074f10..951fc255e4eb 100644
--- a/drivers/soundwire/debugfs.c
+++ b/drivers/soundwire/debugfs.c
@@ -237,8 +237,8 @@ static int cmd_go(void *data, u64 value)
 {
 	const struct firmware *fw = NULL;
 	struct sdw_slave *slave = data;
-	ktime_t start_t;
-	ktime_t finish_t;
+	ktime_t start_t = 0;
+	ktime_t finish_t = 0;
 	int ret;
 
 	if (value != 1)
-- 
2.49.0

Re: [PATCH] soundwire: debugfs: initialize ktime_t variables before div_u64

Posted by Vinod Koul 3 months, 3 weeks ago

On 16-06-25, 22:48, Rodrigo Gobbi wrote:
> The start_t and finish_t variables are not properly initialized
> if errors happens over request_firmware actions. This was also detected by smatch:
> 
> drivers/soundwire/debugfs.c:301 cmd_go() error: uninitialized symbol 'finish_t'.
> drivers/soundwire/debugfs.c:301 cmd_go() error: uninitialized symbol 'start_t'.

Should we care about debug statement printing wrong time on error...
Rather than do this, better to move debug statement up so that it is not
executed on error scenario

> 
> Signed-off-by: Rodrigo Gobbi <rodrigo.gobbi.7@gmail.com>
> Reported-by: Dan Carpenter <dan.carpenter@linaro.org>
> Closes: https://lore.kernel.org/linux-sound/0db6d0bf-7bac-43a7-b624-a00d3d2bf829@stanley.mountain/
> Fixes: bb5cb09eedce ("soundwire: debugfs: add interface for BPT/BRA transfers")
> ---
>  drivers/soundwire/debugfs.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/soundwire/debugfs.c b/drivers/soundwire/debugfs.c
> index 3099ea074f10..951fc255e4eb 100644
> --- a/drivers/soundwire/debugfs.c
> +++ b/drivers/soundwire/debugfs.c
> @@ -237,8 +237,8 @@ static int cmd_go(void *data, u64 value)
>  {
>  	const struct firmware *fw = NULL;
>  	struct sdw_slave *slave = data;
> -	ktime_t start_t;
> -	ktime_t finish_t;
> +	ktime_t start_t = 0;
> +	ktime_t finish_t = 0;
>  	int ret;
>  
>  	if (value != 1)
> -- 
> 2.49.0

-- 
~Vinod