Re: [PATCH bpf-next 0/6] Error handling when map lookup isn't supported

Re: [PATCH bpf-next 0/6] Error handling when map lookup isn't supported

[Alexei Starovoitov]

On Fri, Oct 05, 2018 at 12:35:55PM +0900, Prashant Bhole wrote:
> Currently when map a lookup fails, user space API can not make any
> distinction whether given key was not found or lookup is not supported
> by particular map.
> 
> In this series we modify return value of maps which do not support
> lookup. Lookup on such map implementation will return -EOPNOTSUPP.
> bpf() syscall with BPF_MAP_LOOKUP_ELEM command will set EOPNOTSUPP
> errno. We also handle this error in bpftool to print appropriate
> message.
> 
> Patch 1: adds handling of BPF_MAP_LOOKUP ELEM command of bpf syscall
> such that errno will set to EOPNOTSUPP when map doesn't support lookup
> 
> Patch 2: Modifies the return value of map_lookup_elem() to EOPNOTSUPP
> for maps which do not support lookup
> 
> Patch 3: Splits do_dump() in bpftool/map.c. Element printing code is
> moved out into new function dump_map_elem(). This was done in order to
> reduce deep indentation and accomodate further changes.
> 
> Patch 4: Changes in bpftool to print strerror() message when lookup
> error is occured. This will result in appropriate message like
> "Operation not supported" when map doesn't support lookup.
> 
> Patch 5: test_verifier: change fixup map naming convention as
> suggested by Alexei
> 
> Patch 6: Added verifier tests to check whether verifier rejects call 
> to bpf_map_lookup_elem from bpf program. For all map types those
> do not support map lookup.

for the set:
Acked-by: Alexei Starovoitov <ast@kernel.org>

Re: [PATCH bpf-next 0/6] Error handling when map lookup isn't supported

[Prashant Bhole]

On 10/6/2018 3:35 AM, Alexei Starovoitov wrote:
> On Fri, Oct 05, 2018 at 12:35:55PM +0900, Prashant Bhole wrote:
>> Currently when map a lookup fails, user space API can not make any
>> distinction whether given key was not found or lookup is not supported
>> by particular map.
>>
>> In this series we modify return value of maps which do not support
>> lookup. Lookup on such map implementation will return -EOPNOTSUPP.
>> bpf() syscall with BPF_MAP_LOOKUP_ELEM command will set EOPNOTSUPP
>> errno. We also handle this error in bpftool to print appropriate
>> message.
>>
>> Patch 1: adds handling of BPF_MAP_LOOKUP ELEM command of bpf syscall
>> such that errno will set to EOPNOTSUPP when map doesn't support lookup
>>
>> Patch 2: Modifies the return value of map_lookup_elem() to EOPNOTSUPP
>> for maps which do not support lookup
>>
>> Patch 3: Splits do_dump() in bpftool/map.c. Element printing code is
>> moved out into new function dump_map_elem(). This was done in order to
>> reduce deep indentation and accomodate further changes.
>>
>> Patch 4: Changes in bpftool to print strerror() message when lookup
>> error is occured. This will result in appropriate message like
>> "Operation not supported" when map doesn't support lookup.
>>
>> Patch 5: test_verifier: change fixup map naming convention as
>> suggested by Alexei
>>
>> Patch 6: Added verifier tests to check whether verifier rejects call
>> to bpf_map_lookup_elem from bpf program. For all map types those
>> do not support map lookup.
> 
> for the set:
> Acked-by: Alexei Starovoitov <ast@kernel.org>

Thanks. Is there any reason this series did not get posted on 
netdev-list and can not be seen in the patchwork?

Re: [PATCH bpf-next 0/6] Error handling when map lookup isn't supported

[Daniel Borkmann]

On 10/09/2018 02:02 AM, Prashant Bhole wrote:
> On 10/6/2018 3:35 AM, Alexei Starovoitov wrote:
>> On Fri, Oct 05, 2018 at 12:35:55PM +0900, Prashant Bhole wrote:
>>> Currently when map a lookup fails, user space API can not make any
>>> distinction whether given key was not found or lookup is not supported
>>> by particular map.
>>>
>>> In this series we modify return value of maps which do not support
>>> lookup. Lookup on such map implementation will return -EOPNOTSUPP.
>>> bpf() syscall with BPF_MAP_LOOKUP_ELEM command will set EOPNOTSUPP
>>> errno. We also handle this error in bpftool to print appropriate
>>> message.
>>>
>>> Patch 1: adds handling of BPF_MAP_LOOKUP ELEM command of bpf syscall
>>> such that errno will set to EOPNOTSUPP when map doesn't support lookup
>>>
>>> Patch 2: Modifies the return value of map_lookup_elem() to EOPNOTSUPP
>>> for maps which do not support lookup
>>>
>>> Patch 3: Splits do_dump() in bpftool/map.c. Element printing code is
>>> moved out into new function dump_map_elem(). This was done in order to
>>> reduce deep indentation and accomodate further changes.
>>>
>>> Patch 4: Changes in bpftool to print strerror() message when lookup
>>> error is occured. This will result in appropriate message like
>>> "Operation not supported" when map doesn't support lookup.
>>>
>>> Patch 5: test_verifier: change fixup map naming convention as
>>> suggested by Alexei
>>>
>>> Patch 6: Added verifier tests to check whether verifier rejects call
>>> to bpf_map_lookup_elem from bpf program. For all map types those
>>> do not support map lookup.
>>
>> for the set:
>> Acked-by: Alexei Starovoitov <ast@kernel.org>
> 
> Thanks. Is there any reason this series did not get posted on netdev-list and can not be seen in the patchwork?

Hmm, could you repost to netdev? Perhaps a netdev or patchwork issue that
it did not land there. I just double-checked and it's indeed not present.

Thanks,
Daniel

Re: [PATCH bpf-next 0/6] Error handling when map lookup isn't supported

[Prashant Bhole]

On 10/9/2018 9:43 AM, Daniel Borkmann wrote:
> On 10/09/2018 02:02 AM, Prashant Bhole wrote:
>> On 10/6/2018 3:35 AM, Alexei Starovoitov wrote:
>>> On Fri, Oct 05, 2018 at 12:35:55PM +0900, Prashant Bhole wrote:
>>>> Currently when map a lookup fails, user space API can not make any
>>>> distinction whether given key was not found or lookup is not supported
>>>> by particular map.
>>>>
>>>> In this series we modify return value of maps which do not support
>>>> lookup. Lookup on such map implementation will return -EOPNOTSUPP.
>>>> bpf() syscall with BPF_MAP_LOOKUP_ELEM command will set EOPNOTSUPP
>>>> errno. We also handle this error in bpftool to print appropriate
>>>> message.
>>>>
>>>> Patch 1: adds handling of BPF_MAP_LOOKUP ELEM command of bpf syscall
>>>> such that errno will set to EOPNOTSUPP when map doesn't support lookup
>>>>
>>>> Patch 2: Modifies the return value of map_lookup_elem() to EOPNOTSUPP
>>>> for maps which do not support lookup
>>>>
>>>> Patch 3: Splits do_dump() in bpftool/map.c. Element printing code is
>>>> moved out into new function dump_map_elem(). This was done in order to
>>>> reduce deep indentation and accomodate further changes.
>>>>
>>>> Patch 4: Changes in bpftool to print strerror() message when lookup
>>>> error is occured. This will result in appropriate message like
>>>> "Operation not supported" when map doesn't support lookup.
>>>>
>>>> Patch 5: test_verifier: change fixup map naming convention as
>>>> suggested by Alexei
>>>>
>>>> Patch 6: Added verifier tests to check whether verifier rejects call
>>>> to bpf_map_lookup_elem from bpf program. For all map types those
>>>> do not support map lookup.
>>>
>>> for the set:
>>> Acked-by: Alexei Starovoitov <ast@kernel.org>
>>
>> Thanks. Is there any reason this series did not get posted on netdev-list and can not be seen in the patchwork?
> 
> Hmm, could you repost to netdev? Perhaps a netdev or patchwork issue that
> it did not land there. I just double-checked and it's indeed not present.
> 

Shall I repost with the same version and Alexei's Acked-by for the series?

-Prashant

Re: [PATCH bpf-next 0/6] Error handling when map lookup isn't supported

[Alexei Starovoitov]

On Tue, Oct 9, 2018 at 12:48 AM Prashant Bhole
<bhole_prashant_q7@lab.ntt.co.jp> wrote:
>
> Shall I repost with the same version and Alexei's Acked-by for the series?

yes. please repost as-is and add my Ack to all patches.
Thanks!

Re: [PATCH bpf-next 0/6] Error handling when map lookup isn't supported

[David Miller]

From: Prashant Bhole <bhole_prashant_q7@lab.ntt.co.jp>
Date: Tue, 9 Oct 2018 09:02:15 +0900

> Thanks. Is there any reason this series did not get posted on
> netdev-list and can not be seen in the patchwork?

Bad timing.  I did something stupid on vger.kernel.org, it ran out of
disk space while the postings were being processed, and thus they were
lost.

Re: [PATCH bpf-next 0/6] Error handling when map lookup isn't supported

[Alexei Starovoitov]

On Tue, Oct 09, 2018 at 10:04:48AM +0900, Prashant Bhole wrote:
> Currently when map a lookup fails, user space API can not make any
> distinction whether given key was not found or lookup is not supported
> by particular map.
> 
> In this series we modify return value of maps which do not support
> lookup. Lookup on such map implementation will return -EOPNOTSUPP.
> bpf() syscall with BPF_MAP_LOOKUP_ELEM command will set EOPNOTSUPP
> errno. We also handle this error in bpftool to print appropriate
> message.
> 
> Patch 1: adds handling of BPF_MAP_LOOKUP ELEM command of bpf syscall
> such that errno will set to EOPNOTSUPP when map doesn't support lookup
> 
> Patch 2: Modifies the return value of map_lookup_elem() to EOPNOTSUPP
> for maps which do not support lookup
> 
> Patch 3: Splits do_dump() in bpftool/map.c. Element printing code is
> moved out into new function dump_map_elem(). This was done in order to
> reduce deep indentation and accomodate further changes.
> 
> Patch 4: Changes in bpftool to print strerror() message when lookup
> error is occured. This will result in appropriate message like
> "Operation not supported" when map doesn't support lookup.
> 
> Patch 5: test_verifier: change fixup map naming convention as
> suggested by Alexei
> 
> Patch 6: Added verifier tests to check whether verifier rejects call 
> to bpf_map_lookup_elem from bpf program. For all map types those
> do not support map lookup.

Applied, Thanks

[PATCH bpf-next 0/6] Error handling when map lookup isn't supported

[Prashant Bhole]

Currently when map a lookup fails, user space API can not make any
distinction whether given key was not found or lookup is not supported
by particular map.

In this series we modify return value of maps which do not support
lookup. Lookup on such map implementation will return -EOPNOTSUPP.
bpf() syscall with BPF_MAP_LOOKUP_ELEM command will set EOPNOTSUPP
errno. We also handle this error in bpftool to print appropriate
message.

Patch 1: adds handling of BPF_MAP_LOOKUP ELEM command of bpf syscall
such that errno will set to EOPNOTSUPP when map doesn't support lookup

Patch 2: Modifies the return value of map_lookup_elem() to EOPNOTSUPP
for maps which do not support lookup

Patch 3: Splits do_dump() in bpftool/map.c. Element printing code is
moved out into new function dump_map_elem(). This was done in order to
reduce deep indentation and accomodate further changes.

Patch 4: Changes in bpftool to print strerror() message when lookup
error is occured. This will result in appropriate message like
"Operation not supported" when map doesn't support lookup.

Patch 5: test_verifier: change fixup map naming convention as
suggested by Alexei

Patch 6: Added verifier tests to check whether verifier rejects call 
to bpf_map_lookup_elem from bpf program. For all map types those
do not support map lookup.

Prashant Bhole (6):
  bpf: error handling when map_lookup_elem isn't supported
  bpf: return EOPNOTSUPP when map lookup isn't supported
  tools/bpf: bpftool, split the function do_dump()
  tools/bpf: bpftool, print strerror when map lookup error occurs
  selftests/bpf: test_verifier, change names of fixup maps
  selftests/bpf: test_verifier, check bpf_map_lookup_elem access in bpf
    prog

 kernel/bpf/arraymap.c                       |   2 +-
 kernel/bpf/sockmap.c                        |   2 +-
 kernel/bpf/stackmap.c                       |   2 +-
 kernel/bpf/syscall.c                        |   9 +-
 kernel/bpf/xskmap.c                         |   2 +-
 tools/bpf/bpftool/map.c                     | 102 ++--
 tools/testing/selftests/bpf/test_verifier.c | 501 ++++++++++++--------
 7 files changed, 389 insertions(+), 231 deletions(-)

-- 
2.17.1