Re: [PATCH v5 bpf-next] Small BPF verifier log improvements

[Daniel Borkmann <daniel@xxxxxxxxxxxxx>]

On 3/2/22 10:23 PM, Alexei Starovoitov wrote:
> On Tue, Mar 01, 2022 at 02:27:45PM -0800, Mykola Lysenko wrote:
> >   		.prog_type = BPF_PROG_TYPE_SCHED_CLS,
> >   		.matches = {
> > -			{6, "R3_w=inv(id=0,umax_value=255,var_off=(0x0; 0xff))"},
> > -			{7, "R4_w=inv(id=1,umax_value=255,var_off=(0x0; 0xff))"},
> > -			{8, "R4_w=inv(id=0,umax_value=255,var_off=(0x0; 0xff))"},
> > -			{9, "R4_w=inv(id=1,umax_value=255,var_off=(0x0; 0xff))"},
> > -			{10, "R4_w=inv(id=0,umax_value=510,var_off=(0x0; 0x1fe))"},
> > -			{11, "R4_w=inv(id=1,umax_value=255,var_off=(0x0; 0xff))"},
> > -			{12, "R4_w=inv(id=0,umax_value=1020,var_off=(0x0; 0x3fc))"},
> > -			{13, "R4_w=inv(id=1,umax_value=255,var_off=(0x0; 0xff))"},
> > -			{14, "R4_w=inv(id=0,umax_value=2040,var_off=(0x0; 0x7f8))"},
> > -			{15, "R4_w=inv(id=0,umax_value=4080,var_off=(0x0; 0xff0))"},
> > +			{6, "R3_w=scalar(umax=255,var_off=(0x0; 0xff))"},
> > +			{7, "R4_w=scalar(id=1,umax=255,var_off=(0x0; 0xff))"},
> > +			{8, "R4_w=scalar(umax=255,var_off=(0x0; 0xff))"},
> > +			{9, "R4_w=scalar(id=1,umax=255,var_off=(0x0; 0xff))"},
> > +			{10, "R4_w=scalar(umax=510,var_off=(0x0; 0x1fe))"},
> > +			{11, "R4_w=scalar(id=1,umax=255,var_off=(0x0; 0xff))"},
> > +			{12, "R4_w=scalar(umax=1020,var_off=(0x0; 0x3fc))"},
> > +			{13, "R4_w=scalar(id=1,umax=255,var_off=(0x0; 0xff))"},
> > +			{14, "R4_w=scalar(umax=2040,var_off=(0x0; 0x7f8))"},
> > +			{15, "R4_w=scalar(umax=4080,var_off=(0x0; 0xff0))"},
>
> Sorry for the later review.
> Would "int" be more precise and less verbose than "scalar"?

Could work as well, although in many places today we make use of the term "scalar",
so developers might be more familiar with it (and more consistent towards the
verifier type internals).

Thanks,
Daniel