[PATCH] rds: send: mark expected switch fall-through in rds_rm_size

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

Addresses-Coverity-ID: 1465362 ("Missing break in switch")
Signed-off-by: Gustavo A. R. Silva <redacted>
---
 net/rds/send.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/net/rds/send.c b/net/rds/send.c
index 028ab59..79d158b 100644
--- a/net/rds/send.c
+++ b/net/rds/send.c

@@ -902,6 +902,8 @@ static int rds_rm_size(struct msghdr *msg, int num_sgs)
 
 		case RDS_CMSG_ZCOPY_COOKIE:
 			zcopy_cookie = true;
+			/* fall through */
+
 		case RDS_CMSG_RDMA_DEST:
 		case RDS_CMSG_RDMA_MAP:
 			cmsg_groups |= 2;

-- 
2.7.4

On (02/19/18 12:10), Gustavo A. R. Silva wrote:

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

Acked-by:  Sowmini Varadhan <redacted>

Hi,

2/19/2018 10:10 AM, Gustavo A. R. Silva wrote:

So coverity greps for commet as "fall through" for
-Wimplicit-fallthrough build ?

Adding that comments itself if fine but was curious
about it if some one makes a spell error in this
comment what happens ;-)

For patch itself,
Acked-by: Santosh Shilimkar <redacted>

From: Santosh Shilimkar <redacted>
Date: Tue, 20 Feb 2018 09:54:09 -0800

So coverity greps for commet as "fall through" for
-Wimplicit-fallthrough build ?

From what I understand, 'gcc' does in the latest versions.  Coverity

might as well, I don't know.

Hi Santosh,

On 02/20/2018 11:54 AM, Santosh Shilimkar wrote:

Hi,

2/19/2018 10:10 AM, Gustavo A. R. Silva wrote:

quoted

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

Addresses-Coverity-ID: 1465362 ("Missing break in switch")
Signed-off-by: Gustavo A. R. Silva <redacted>
---
  net/rds/send.c | 2 ++
  1 file changed, 2 insertions(+)

diff --git a/net/rds/send.c b/net/rds/send.c
index 028ab59..79d158b 100644
--- a/net/rds/send.c
+++ b/net/rds/send.c

@@ -902,6 +902,8 @@ static int rds_rm_size(struct msghdr *msg, int 

num_sgs)
          case RDS_CMSG_ZCOPY_COOKIE:
              zcopy_cookie = true;
+            /* fall through */
+
          case RDS_CMSG_RDMA_DEST:
          case RDS_CMSG_RDMA_MAP:
              cmsg_groups |= 2;

So coverity greps for commet as "fall through" for
-Wimplicit-fallthrough build ?

No. Basically, Coverity only reports cases in which a break, return or 
continue statement is missing.

Now, if the statements I mention above are missing and if you add the 
following line to your Makefile:

KBUILD_CFLAGS  += $(call cc-option,-Wimplicit-fallthrough)

You will get a warning if a fall-through comment is missing.

Adding that comments itself if fine but was curious
about it if some one makes a spell error in this
comment what happens ;-)

In this case, Coverity would still report the same "Missing break in 
switch" error, but you'll get a GCC warning.

For patch itself,
Acked-by: Santosh Shilimkar <redacted>

--
Gustavo

On 02/20/2018 12:01 PM, David Miller wrote:

From: Santosh Shilimkar <redacted>
Date: Tue, 20 Feb 2018 09:54:09 -0800

quoted

So coverity greps for commet as "fall through" for
-Wimplicit-fallthrough build ?

 From what I understand, 'gcc' does in the latest versions.  Coverity
might as well, I don't know.

Yeah, the one that reports those warnings is GCC.

Coverity only knows about missing break, return and continue.

--
Gustavo

On 2/20/2018 10:01 AM, David Miller wrote:

From: Santosh Shilimkar <redacted>
Date: Tue, 20 Feb 2018 09:54:09 -0800

quoted

So coverity greps for commet as "fall through" for
-Wimplicit-fallthrough build ?

 From what I understand, 'gcc' does in the latest versions.  Coverity
might as well, I don't know.

Good to know about 'gcc' adding such option. Thanks !!

On 2/20/2018 10:05 AM, Gustavo A. R. Silva wrote:

Hi Santosh,

On 02/20/2018 11:54 AM, Santosh Shilimkar wrote:

quoted

Hi,

2/19/2018 10:10 AM, Gustavo A. R. Silva wrote:

quoted

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

Addresses-Coverity-ID: 1465362 ("Missing break in switch")
Signed-off-by: Gustavo A. R. Silva <redacted>
---
  net/rds/send.c | 2 ++
  1 file changed, 2 insertions(+)

diff --git a/net/rds/send.c b/net/rds/send.c
index 028ab59..79d158b 100644
--- a/net/rds/send.c
+++ b/net/rds/send.c

@@ -902,6 +902,8 @@ static int rds_rm_size(struct msghdr *msg, int 

num_sgs)
          case RDS_CMSG_ZCOPY_COOKIE:
              zcopy_cookie = true;
+            /* fall through */
+
          case RDS_CMSG_RDMA_DEST:
          case RDS_CMSG_RDMA_MAP:
              cmsg_groups |= 2;

So coverity greps for commet as "fall through" for
-Wimplicit-fallthrough build ?

No. Basically, Coverity only reports cases in which a break, return or 
continue statement is missing.

Now, if the statements I mention above are missing and if you add the 
following line to your Makefile:

KBUILD_CFLAGS  += $(call cc-option,-Wimplicit-fallthrough)

You will get a warning if a fall-through comment is missing.

That make sense.

quoted

Adding that comments itself if fine but was curious
about it if some one makes a spell error in this
comment what happens ;-)

In this case, Coverity would still report the same "Missing break in 
switch" error, but you'll get a GCC warning.

Got it. Thanks !!

From: "Gustavo A. R. Silva" <redacted>
Date: Mon, 19 Feb 2018 12:10:20 -0600

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

Addresses-Coverity-ID: 1465362 ("Missing break in switch")
Signed-off-by: Gustavo A. R. Silva <redacted>

Applied.