On Wed, Sep 7, 2022 at 7:35 PM Vincent Li <vincent.mc.li@xxxxxxxxx> wrote:
>
> Hi,
>
> I see some verifier log examples with error like:
>
> R4 invalid mem access 'inv'
>
> It looks like invalid mem access errors occur in two places below,
> does it make sense to make the error message slightly different so for
> new eBPF programmers like me to tell the first invalid mem access is
> maybe the memory is NULL? and the second invalid mem access is because
> the register type does not match any valid memory pointer? or this
> won't help identifying problems and don't bother ?
>
> 4772 } else if (base_type(reg->type) == PTR_TO_MEM) {
>
> 4773 bool rdonly_mem = type_is_rdonly_mem(reg->type);
>
> 4774
>
> 4775 if (type_may_be_null(reg->type)) {
>
> 4776 verbose(env, "R%d invalid mem access
> '%s'\n", regno,
>
> 4777 reg_type_str(env, reg->type));
>
> 4778 return -EACCES;
>
> 4779 }
>
> and
>
> 4924 } else {
>
> 4925 verbose(env, "R%d invalid mem access '%s'\n", regno,
>
> 4926 reg_type_str(env, reg->type));
>
> 4927 return -EACCES;
>
> 4928 }
sorry I should read the code more carefully, I guess the "inv" already
says it is invalid memory access, not NULL, right?
