Re: [PATCH] arm64: bpf: fix div-by-zero case

[Shi, Yang]

On 11/3/2015 11:04 PM, Xi Wang wrote:
> On Tue, Nov 3, 2015 at 10:56 PM, Zi Shen Lim <zlim.lnx@xxxxxxxxx> wrote:
> >          case BPF_ALU | BPF_DIV | BPF_X:
> >          case BPF_ALU64 | BPF_DIV | BPF_X:
> > +       {
> > +               const u8 r0 = bpf2a64[BPF_REG_0];
> > +
> > +               /* if (src == 0) return 0 */
> > +               jmp_offset = 3; /* skip ahead to else path */
> > +               check_imm19(jmp_offset);
> > +               emit(A64_CBNZ(is64, src, jmp_offset), ctx);
> > +               emit(A64_MOVZ(1, r0, 0, 0), ctx);
> > +               jmp_offset = epilogue_offset(ctx);
> > +               check_imm26(jmp_offset);
> > +               emit(A64_B(jmp_offset), ctx);
> > +               /* else */
> >                  emit(A64_UDIV(is64, dst, dst, src), ctx);
> >                  break;
> > +       }
> >          case BPF_ALU | BPF_MOD | BPF_X:
> >          case BPF_ALU64 | BPF_MOD | BPF_X:
>
> BPF_MOD might need the same fix.

Agreed, and we may need add one more test cases in test_bpf module to 
cover MOD?

Yang

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