staging: comedi: tio: fix multiple missing break in switch bugs
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Message ID 20181011190520.GA12609@embeddedor.com
State New
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Series
  • staging: comedi: tio: fix multiple missing break in switch bugs
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Commit Message

Gustavo A. R. Silva Oct. 11, 2018, 7:05 p.m. UTC
Currently, there are multiple missing break statements in two switch code
blocks. This makes the execution path to fall all the way down through
to the default cases, which makes the function ni_tio_set_gate_src() to
always return -EINVAL.

Fix this by adding the missing break statements.

Also, notice that due to the absence of the break statements,
the following pieces of code are unreachable:

1078    if (ret)
1079            return ret;
1080    /* 3.  reenable & set mode to starts things back up */
1081    ni_tio_set_gate_mode(counter, src);

1098    if (ret)
1099            return ret;
1100    /* 3.  reenable & set mode to starts things back up */
1101    ni_tio_set_gate2_mode(counter, src);

So, by adding the missing breaks, this patch also fixes the problem
above.

Addresses-Coverity-ID: 1474165 ("Missing break in switch")
Addresses-Coverity-ID: 1474162 ("Structurally dead code")
Fixes: 347e244884c3 ("staging: comedi: tio: implement global tio/ctr routing")
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
---
 drivers/staging/comedi/drivers/ni_tio.c | 4 ++++
 1 file changed, 4 insertions(+)

Comments

Ian Abbott Oct. 12, 2018, 9:04 a.m. UTC | #1
On 11/10/2018 20:05, Gustavo A. R. Silva wrote:
> Currently, there are multiple missing break statements in two switch code
> blocks. This makes the execution path to fall all the way down through
> to the default cases, which makes the function ni_tio_set_gate_src() to
> always return -EINVAL.
> 
> Fix this by adding the missing break statements.
> 
> Also, notice that due to the absence of the break statements,
> the following pieces of code are unreachable:
> 
> 1078    if (ret)
> 1079            return ret;
> 1080    /* 3.  reenable & set mode to starts things back up */
> 1081    ni_tio_set_gate_mode(counter, src);
> 
> 1098    if (ret)
> 1099            return ret;
> 1100    /* 3.  reenable & set mode to starts things back up */
> 1101    ni_tio_set_gate2_mode(counter, src);
> 
> So, by adding the missing breaks, this patch also fixes the problem
> above.
> 
> Addresses-Coverity-ID: 1474165 ("Missing break in switch")
> Addresses-Coverity-ID: 1474162 ("Structurally dead code")
> Fixes: 347e244884c3 ("staging: comedi: tio: implement global tio/ctr routing")
> Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
> ---
>   drivers/staging/comedi/drivers/ni_tio.c | 4 ++++
>   1 file changed, 4 insertions(+)
> 
> diff --git a/drivers/staging/comedi/drivers/ni_tio.c b/drivers/staging/comedi/drivers/ni_tio.c
> index 838614e..0eb388c 100644
> --- a/drivers/staging/comedi/drivers/ni_tio.c
> +++ b/drivers/staging/comedi/drivers/ni_tio.c
> @@ -1070,8 +1070,10 @@ int ni_tio_set_gate_src(struct ni_gpct *counter,
>   		case ni_gpct_variant_e_series:
>   		case ni_gpct_variant_m_series:
>   			ret = ni_m_set_gate(counter, chan);
> +			break;
>   		case ni_gpct_variant_660x:
>   			ret = ni_660x_set_gate(counter, chan);
> +			break;
>   		default:
>   			return -EINVAL;
>   		}
> @@ -1090,8 +1092,10 @@ int ni_tio_set_gate_src(struct ni_gpct *counter,
>   		switch (counter_dev->variant) {
>   		case ni_gpct_variant_m_series:
>   			ret = ni_m_set_gate2(counter, chan);
> +			break;
>   		case ni_gpct_variant_660x:
>   			ret = ni_660x_set_gate2(counter, chan);
> +			break;
>   		default:
>   			return -EINVAL;
>   		}
> 

Thanks for catching that bug!

Reviewed-by: Ian Abbott <abbotti@mev.co.uk>
Gustavo A. R. Silva Oct. 12, 2018, 9:06 a.m. UTC | #2
On 10/12/18 11:04 AM, Ian Abbott wrote:
> On 11/10/2018 20:05, Gustavo A. R. Silva wrote:
>> Currently, there are multiple missing break statements in two switch code
>> blocks. This makes the execution path to fall all the way down through
>> to the default cases, which makes the function ni_tio_set_gate_src() to
>> always return -EINVAL.
>>
>> Fix this by adding the missing break statements.
>>
>> Also, notice that due to the absence of the break statements,
>> the following pieces of code are unreachable:
>>
>> 1078    if (ret)
>> 1079            return ret;
>> 1080    /* 3.  reenable & set mode to starts things back up */
>> 1081    ni_tio_set_gate_mode(counter, src);
>>
>> 1098    if (ret)
>> 1099            return ret;
>> 1100    /* 3.  reenable & set mode to starts things back up */
>> 1101    ni_tio_set_gate2_mode(counter, src);
>>
>> So, by adding the missing breaks, this patch also fixes the problem
>> above.
>>
>> Addresses-Coverity-ID: 1474165 ("Missing break in switch")
>> Addresses-Coverity-ID: 1474162 ("Structurally dead code")
>> Fixes: 347e244884c3 ("staging: comedi: tio: implement global tio/ctr routing")
>> Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
>> ---
>>   drivers/staging/comedi/drivers/ni_tio.c | 4 ++++
>>   1 file changed, 4 insertions(+)
>>
>> diff --git a/drivers/staging/comedi/drivers/ni_tio.c b/drivers/staging/comedi/drivers/ni_tio.c
>> index 838614e..0eb388c 100644
>> --- a/drivers/staging/comedi/drivers/ni_tio.c
>> +++ b/drivers/staging/comedi/drivers/ni_tio.c
>> @@ -1070,8 +1070,10 @@ int ni_tio_set_gate_src(struct ni_gpct *counter,
>>           case ni_gpct_variant_e_series:
>>           case ni_gpct_variant_m_series:
>>               ret = ni_m_set_gate(counter, chan);
>> +            break;
>>           case ni_gpct_variant_660x:
>>               ret = ni_660x_set_gate(counter, chan);
>> +            break;
>>           default:
>>               return -EINVAL;
>>           }
>> @@ -1090,8 +1092,10 @@ int ni_tio_set_gate_src(struct ni_gpct *counter,
>>           switch (counter_dev->variant) {
>>           case ni_gpct_variant_m_series:
>>               ret = ni_m_set_gate2(counter, chan);
>> +            break;
>>           case ni_gpct_variant_660x:
>>               ret = ni_660x_set_gate2(counter, chan);
>> +            break;
>>           default:
>>               return -EINVAL;
>>           }
>>
> 
> Thanks for catching that bug!
> 

Glad to help. :)

> Reviewed-by: Ian Abbott <abbotti@mev.co.uk>
> 

Thanks
--
Gustavo

Patch
diff mbox series

diff --git a/drivers/staging/comedi/drivers/ni_tio.c b/drivers/staging/comedi/drivers/ni_tio.c
index 838614e..0eb388c 100644
--- a/drivers/staging/comedi/drivers/ni_tio.c
+++ b/drivers/staging/comedi/drivers/ni_tio.c
@@ -1070,8 +1070,10 @@  int ni_tio_set_gate_src(struct ni_gpct *counter,
 		case ni_gpct_variant_e_series:
 		case ni_gpct_variant_m_series:
 			ret = ni_m_set_gate(counter, chan);
+			break;
 		case ni_gpct_variant_660x:
 			ret = ni_660x_set_gate(counter, chan);
+			break;
 		default:
 			return -EINVAL;
 		}
@@ -1090,8 +1092,10 @@  int ni_tio_set_gate_src(struct ni_gpct *counter,
 		switch (counter_dev->variant) {
 		case ni_gpct_variant_m_series:
 			ret = ni_m_set_gate2(counter, chan);
+			break;
 		case ni_gpct_variant_660x:
 			ret = ni_660x_set_gate2(counter, chan);
+			break;
 		default:
 			return -EINVAL;
 		}