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

From: Daniel Borkmann <daniel@iogearbox.net>
To: Prashant Bhole <bhole_prashant_q7@lab.ntt.co.jp>,
	Alexei Starovoitov <alexei.starovoitov@gmail.com>
Cc: Alexei Starovoitov <ast@kernel.org>,
	Jakub Kicinski <jakub.kicinski@netronome.com>,
	"David S . Miller" <davem@davemloft.net>,
	Quentin Monnet <quentin.monnet@netronome.com>,
	netdev@vger.kernel.org
Subject: Re: [PATCH bpf-next 0/6] Error handling when map lookup isn't supported
Date: Tue, 9 Oct 2018 02:43:46 +0200	[thread overview]
Message-ID: <5029a2fe-10f8-116a-428d-e02790ec8366@iogearbox.net> (raw)
In-Reply-To: <49b6c6b1-d66b-db0d-d866-9720b269c1a2@lab.ntt.co.jp>

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