Re: IPA_STATUS_SIZE, commit b8dc7d0eea5a7709bb534f1b3ca70d2d7de0b42c

[Bert Karwatzki <spasswolf@web.de>]

Am Mittwoch, dem 17.05.2023 um 16:35 -0500 schrieb Alex Elder:
> On 5/12/23 8:04 AM, Bert Karwatzki wrote:
> > commit b8dc7d0eea5a7709bb534f1b3ca70d2d7de0b42c
> > Author: Alex Elder <elder@linaro.org>
> > Date:   Wed Jan 25 14:45:39 2023 -0600
> > 
> >      net: ipa: stop using sizeof(status)
> >      
> >      The IPA packet status structure changes in IPA v5.0 in ways
> > that
> > are
> >      difficult to represent cleanly.  As a small step toward
> > redefining
> >      it as a parsed block of data, use a constant to define its
> > size,
> >      rather than the size of the IPA status structure type.
> >      
> >      Signed-off-by: Alex Elder <elder@linaro.org>
> >      Signed-off-by: David S. Miller <davem@davemloft.net>
> > 
> > introduced the IPA_STATUS_SIZE constant as a replacent for
> > sizeof(struct ipa_status). IPA_STATUS_SIZE is defined as
> > sizeof(__le32[4]), but sizeof(struct ipa_status) =
> > sizeof(__le32[8])
> > and the newly introducded ipa_status_extract operates on 8 __le32
> > words, so I wondered if IPA_STATUS_SIZE is correct.
> 
> You are right to wonder about this.  I think you have identified
> a bug.  It is a bug that most likely almost never matters (because
> the status size is always proper--and not too small), but it is
> a bug nevertheless.
> 
> Would you like to provide a patch to fix this?  Otherwise I can
> do that, and I'll provide credit to you:
> 
>      Reported-by: Bert Karwatzki <spasswolf@web.de>
> 
> Please let me know.  Thanks for inquiring about/reporting this.
> 
>                                         -Alex
> 
> > 
> > Bert Karwatzki
> 

Here's the patch that addresse the issue (if there's a > in front of
the first From, that seems to be a quirk of evolution ...)


From 583f35b3d91f048d413fc4f6a3b9237fc9d7efb2 Mon Sep 17 00:00:00 2001
From: Bert Karwatzki <spasswolf@web.de>
Date: Fri, 19 May 2023 00:02:55 +0200
Subject: [PATCH] Make IPA_STATUS_SIZE equal to the size of the remove
struct
 ipa_status.

---
 drivers/net/ipa/ipa_endpoint.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/net/ipa/ipa_endpoint.c
b/drivers/net/ipa/ipa_endpoint.c
index 2ee80ed140b7..afa1d56d9095 100644
--- a/drivers/net/ipa/ipa_endpoint.c
+++ b/drivers/net/ipa/ipa_endpoint.c
@@ -119,7 +119,7 @@ enum ipa_status_field_id {
 };
 
 /* Size in bytes of an IPA packet status structure */
-#define IPA_STATUS_SIZE			sizeof(__le32[4])
+#define IPA_STATUS_SIZE			sizeof(__le32[8])
 
 /* IPA status structure decoder; looks up field values for a structure
*/
 static u32 ipa_status_extract(struct ipa *ipa, const void *data,
-- 
2.40.1

Bert Karwatzki