Re: [PATCH] selftests/bpf: Add bpf_probe_read_str to bpf_helpers.h

From: Daniel Borkmann
Date: Wed Feb 28 2018 - 16:31:48 EST


On 02/28/2018 10:28 PM, Tushar Dave wrote:
> On 02/28/2018 08:57 AM, Daniel Borkmann wrote:
>> Hi Tushar,
>>
>> On 02/28/2018 01:33 AM, Tushar Dave wrote:
>>> Using bpf_probe_read_str() from samples/bpf causes compiler warning.
>>> e.g.
>>> warning: implicit declaration of function 'bpf_probe_read_str' is invalid in C99
>>> ÂÂÂÂÂÂ [-Wimplicit-function-declaration]
>>> ÂÂÂÂÂÂÂÂ num = bpf_probe_read_str(buf, sizeof(buf), ctx->di);
>>> ÂÂÂÂÂÂÂÂÂÂÂÂÂÂ ^
>>> 1 warning generated.
>>>
>>> Add bpf_probe_read_str() to bpf_helpers.h so it can be used by
>>> samples/bpf programs.
>>>
>>> Signed-off-by: Tushar Dave <tushar.n.dave@xxxxxxxxxx>
>>
>> In general no objections to it, but it would need an in-tree
>> user first:
>>
>> $ git grep -n bpf_probe_read_str tools/
>> tools/include/uapi/linux/bpf.h:596: * int bpf_probe_read_str(void *dst, int size, const void *unsafe_ptr)
>> $
>>
>> Why not adding this along with a sample?
> Okay, I will send new patch along with new sample or add usage of
> bpf_probe_read_str() in one of our exiting sample :)

Sounds great, the latter is totally fine as well. :-)

Thanks,
Daniel