The netdevsim IPsec debugfs file (used by selftests/net/rtnetlink.sh's
ipsec_offload subtest) prints the SA salt and key in host CPU byte
order instead of network byte order, because nsim_sa.key[]/salt are
typed as plain u32 and printed directly with "%08x". This makes the
reported values differ between little-endian and big-endian hosts for
the same underlying key material, and breaks the selftest on
big-endian (e.g. s390x), which hardcodes the little-endian output.

A driver-side fix was proposed in 2022 but stalled in review: keeping
the fields as plain u32 meant sparse could not validate the added
ntohl()/be32_to_cpu() conversions.

  https://lore.kernel.org/netdev/20220308135106.890270-1-kleber.souza@canonical.com/

This series:

  1/2 retypes nsim_sa.key[]/salt to __be32 (matching the existing
      __be32 ipaddr[] field) and converts with be32_to_cpu() before
      printing, so the debugfs output is now network-order on every
      host, independent of endianness.

  2/2 updates the selftest's expected output to match the new,
      endianness-independent values. It depends on 1/2: applied on
      its own it would regress little-endian hosts (though it happens
      to have no effect on big-endian hosts, whose old host-order
      output already matched the new expected values).

Tested on real booted kernels, both patches applied:
  - x86_64 (little-endian): PASS: ipsec_offload
  - s390x (big-endian):     PASS: ipsec_offload

checkpatch.pl --strict and sparse (make C=2) are clean on both patches.

Andrei Gherzan (2):
  netdevsim: print IPsec salt/key in network byte order
  selftests: rtnetlink: update ipsec_offload expected output

 drivers/net/netdevsim/ipsec.c            | 10 +++++-----
 drivers/net/netdevsim/netdevsim.h        |  4 ++--
 tools/testing/selftests/net/rtnetlink.sh |  8 ++++----
 3 files changed, 11 insertions(+), 11 deletions(-)

-- 
2.43.0

On 26/09/08 03:03PM, Andrei Gherzan wrote:
> The netdevsim IPsec debugfs file (used by selftests/net/rtnetlink.sh's
> ipsec_offload subtest) prints the SA salt and key in host CPU byte
> order instead of network byte order, because nsim_sa.key[]/salt are
> typed as plain u32 and printed directly with "%08x". This makes the
> reported values differ between little-endian and big-endian hosts for
> the same underlying key material, and breaks the selftest on
> big-endian (e.g. s390x), which hardcodes the little-endian output.
> 
> A driver-side fix was proposed in 2022 but stalled in review: keeping
> the fields as plain u32 meant sparse could not validate the added
> ntohl()/be32_to_cpu() conversions.
> 
>   https://lore.kernel.org/netdev/20220308135106.890270-1-kleber.souza@canonical.com/
> 
> This series:
> 
>   1/2 retypes nsim_sa.key[]/salt to __be32 (matching the existing
>       __be32 ipaddr[] field) and converts with be32_to_cpu() before
>       printing, so the debugfs output is now network-order on every
>       host, independent of endianness.
> 
>   2/2 updates the selftest's expected output to match the new,
>       endianness-independent values. It depends on 1/2: applied on
>       its own it would regress little-endian hosts (though it happens
>       to have no effect on big-endian hosts, whose old host-order
>       output already matched the new expected values).
> 

I forgot to add Cc: stable@vger.kernel.org to these patches. Should I
send a v2 for that, given patch 2/2 only makes sense together with
patch 1/2 (applying just one regresses the test on one endianness or
the other)?

> Tested on real booted kernels, both patches applied:
>   - x86_64 (little-endian): PASS: ipsec_offload
>   - s390x (big-endian):     PASS: ipsec_offload
> 
> checkpatch.pl --strict and sparse (make C=2) are clean on both patches.
> 
> Andrei Gherzan (2):
>   netdevsim: print IPsec salt/key in network byte order
>   selftests: rtnetlink: update ipsec_offload expected output
> 
>  drivers/net/netdevsim/ipsec.c            | 10 +++++-----
>  drivers/net/netdevsim/netdevsim.h        |  4 ++--
>  tools/testing/selftests/net/rtnetlink.sh |  8 ++++----
>  3 files changed, 11 insertions(+), 11 deletions(-)

-- 
Andrei Gherzan
gpg: rsa4096/D4D94F67AD0E9640

On Wed, 9 Sep 2026 14:37:41 +0100 Andrei Gherzan wrote:
> I forgot to add Cc: stable@vger.kernel.org to these patches. 

We don't generally send documentation and test fixes to stable in netdev
Especially now that stable is busy enough with all the AI-found bugs
In fact I'm stripping the Fixes tags, too.

> Should I send a v2 for that, given patch 2/2 only makes sense
> together with patch 1/2 (applying just one regresses the test on one
> endianness or the other)?

No need.

Thanks for the changes!