[PATCH] kdb: kdb_main: mark expected switch fall-throughs

[PATCH] kdb: kdb_main: mark expected switch fall-throughs

[Gustavo A. R. Silva]

In preparation to enabling -Wimplicit-fallthrough, mark switch cases
where we are expecting to fall through.

Addresses-Coverity-ID: 115090 ("Missing break in switch")
Addresses-Coverity-ID: 115091 ("Missing break in switch")
Addresses-Coverity-ID: 114700 ("Missing break in switch")
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
---
 kernel/debug/kdb/kdb_main.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/kernel/debug/kdb/kdb_main.c b/kernel/debug/kdb/kdb_main.c
index 2ddfce8..2249645 100644
--- a/kernel/debug/kdb/kdb_main.c
+++ b/kernel/debug/kdb/kdb_main.c
@@ -1545,13 +1545,16 @@ static void kdb_md_line(const char *fmtstr, unsigned long addr,
 				*c++ = printable_char(*cp++);
 				*c++ = printable_char(*cp++);
 				addr += 4;
+				/* fall through */
 			case 4:
 				*c++ = printable_char(*cp++);
 				*c++ = printable_char(*cp++);
 				addr += 2;
+				/* fall through */
 			case 2:
 				*c++ = printable_char(*cp++);
 				addr++;
+				/* fall through */
 			case 1:
 				*c++ = printable_char(*cp++);
 				addr++;
-- 
2.7.4

Re: [PATCH] kdb: kdb_main: mark expected switch fall-throughs

[Daniel Thompson]

On 05/08/18 05:14, Gustavo A. R. Silva wrote:
> In preparation to enabling -Wimplicit-fallthrough, mark switch cases
> where we are expecting to fall through.
> 
> Addresses-Coverity-ID: 115090 ("Missing break in switch")
> Addresses-Coverity-ID: 115091 ("Missing break in switch")
> Addresses-Coverity-ID: 114700 ("Missing break in switch")
> Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>

Adding fall through isn't wrong but its reasonable to ask why there is a 
complex hand unrolled loop here in the first place (and doubly so 
without a comment). The whole switch statement would be much clear 
expressed as:

	for (j=0; j<bytesperword; j++)
		*c++ = printable_char(*cp++);
	addr += bytesperword;


Daniel.


> ---
>   kernel/debug/kdb/kdb_main.c | 3 +++
>   1 file changed, 3 insertions(+)
> 
> diff --git a/kernel/debug/kdb/kdb_main.c b/kernel/debug/kdb/kdb_main.c
> index 2ddfce8..2249645 100644
> --- a/kernel/debug/kdb/kdb_main.c
> +++ b/kernel/debug/kdb/kdb_main.c
> @@ -1545,13 +1545,16 @@ static void kdb_md_line(const char *fmtstr, unsigned long addr,
>   				*c++ = printable_char(*cp++);
>   				*c++ = printable_char(*cp++);
>   				addr += 4;
> +				/* fall through */
>   			case 4:
>   				*c++ = printable_char(*cp++);
>   				*c++ = printable_char(*cp++);
>   				addr += 2;
> +				/* fall through */
>   			case 2:
>   				*c++ = printable_char(*cp++);
>   				addr++;
> +				/* fall through */
>   			case 1:
>   				*c++ = printable_char(*cp++);
>   				addr++;
> 

Re: [PATCH] kdb: kdb_main: mark expected switch fall-throughs

[Gustavo A. R. Silva]

Hi Daniel,

On 8/15/18 9:34 AM, Daniel Thompson wrote:
> On 05/08/18 05:14, Gustavo A. R. Silva wrote:
>> In preparation to enabling -Wimplicit-fallthrough, mark switch cases
>> where we are expecting to fall through.
>>
>> Addresses-Coverity-ID: 115090 ("Missing break in switch")
>> Addresses-Coverity-ID: 115091 ("Missing break in switch")
>> Addresses-Coverity-ID: 114700 ("Missing break in switch")
>> Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
> 
> Adding fall through isn't wrong but its reasonable to ask why there is a complex hand unrolled loop here in the first place (and doubly so without a comment). The whole switch statement would be much clear expressed as:
> 
>     for (j=0; j<bytesperword; j++)
>         *c++ = printable_char(*cp++);
>     addr += bytesperword;
> 

Yeah, I agree. I can send a patch for that.

Thanks for the feedback.
--
Gustavo

> 
> Daniel.
> 
> 
>> ---
>>   kernel/debug/kdb/kdb_main.c | 3 +++
>>   1 file changed, 3 insertions(+)
>>
>> diff --git a/kernel/debug/kdb/kdb_main.c b/kernel/debug/kdb/kdb_main.c
>> index 2ddfce8..2249645 100644
>> --- a/kernel/debug/kdb/kdb_main.c
>> +++ b/kernel/debug/kdb/kdb_main.c
>> @@ -1545,13 +1545,16 @@ static void kdb_md_line(const char *fmtstr, unsigned long addr,
>>                   *c++ = printable_char(*cp++);
>>                   *c++ = printable_char(*cp++);
>>                   addr += 4;
>> +                /* fall through */
>>               case 4:
>>                   *c++ = printable_char(*cp++);
>>                   *c++ = printable_char(*cp++);
>>                   addr += 2;
>> +                /* fall through */
>>               case 2:
>>                   *c++ = printable_char(*cp++);
>>                   addr++;
>> +                /* fall through */
>>               case 1:
>>                   *c++ = printable_char(*cp++);
>>                   addr++;
>>
>