Re: [PATCH] carl9170: Fix error return -EAGAIN if not started

From: Christian Lamparter
Date: Fri Oct 08 2021 - 11:15:44 EST


Hello,

On 08/10/2021 09:31, Colin Ian King wrote:
On 08/10/2021 06:58, Dan Carpenter wrote:
On Fri, Oct 08, 2021 at 01:15:58AM +0100, Colin King wrote:
From: Colin Ian King <colin.king@xxxxxxxxxxxxx>

There is an error return path where the error return is being
assigned to err rather than count and the error exit path does
not return -EAGAIN as expected. Fix this by setting the error
return to variable count as this is the value that is returned
at the end of the function.

Addresses-Coverity: ("Unused value")
Fixes: 00c4da27a421 ("carl9170: firmware parser and debugfs code")
Signed-off-by: Colin Ian King <colin.king@xxxxxxxxxxxxx>
---
  drivers/net/wireless/ath/carl9170/debug.c | 2 +-
  1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/net/wireless/ath/carl9170/debug.c b/drivers/net/wireless/ath/carl9170/debug.c
index bb40889d7c72..f163c6bdac8f 100644
--- a/drivers/net/wireless/ath/carl9170/debug.c
+++ b/drivers/net/wireless/ath/carl9170/debug.c
@@ -628,7 +628,7 @@ static ssize_t carl9170_debugfs_bug_write(struct ar9170 *ar, const char *buf,
      case 'R':
          if (!IS_STARTED(ar)) {
-            err = -EAGAIN;
+            count = -EAGAIN;
              goto out;

This is ugly.  The bug wouldn't have happened with a direct return, it's
only the goto out which causes it.  Better to replace all the error
paths with direct returns.  There are two other direct returns so it's
not like a new thing...

Yep, I agree it was ugly, I was trying to keep to the coding style and reduce the patch delta size. I can do a V2 if the maintainers deem it's a cleaner solution.

Hm? I don't think there's any need to stick to a particular
coding style. This file hasn't been touched a lot since 2010.
Things moved on and replacing the gotos with straight return
is totally fine.

(It has to pass the build checkers of course. However I don't
think this will be a problem here...)

Cheers,
Christian