Re: [PATCH bpf-next v6 06/12] libbpf: Add support for global percpu data

[Leon Hwang <leon.hwang@linux.dev>]

On 15/6/26 23:41, sashiko-bot@kernel.org wrote:
[...]
> 
>> @@ -1198,6 +1198,7 @@ void bpf_gen__map_update_elem(struct bpf_gen *gen, int map_idx, void *pvalue,
>>  	int zero = 0;
>>  
>>  	memset(&attr, 0, attr_size);
>> +	attr.flags = flags;
> 
> [Severity: High]
> Does this assignment need to use tgt_endian() to support cross-compilation?
> 
> When libbpf generates a skeleton loader for a target architecture with a
> different endianness than the host, fields populated into the union bpf_attr
> blob usually need to be converted to the target byte order.
> 
> For global percpu data maps, this flag will be BPF_F_ALL_CPUS (0x10). If a
> little-endian host generates a skeleton for a big-endian target, a direct
> assignment of the 64-bit value could result in it being interpreted as
> 0x1000000000000000 by the target kernel, which would cause the sys_bpf
> call to fail with -EINVAL.
> 
Will use tgt_endian() in the next revision.

Thanks,
Leon