Messages in this thread | | | Date | Wed, 4 Nov 2015 10:25:05 -0800 | Subject | Re: [PATCH] arm64: bpf: fix div-by-zero case | From | Z Lim <> |
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On Wed, Nov 4, 2015 at 10:21 AM, Shi, Yang <yang.shi@linaro.org> wrote: > On 11/3/2015 11:04 PM, Xi Wang wrote: >> >> On Tue, Nov 3, 2015 at 10:56 PM, Zi Shen Lim <zlim.lnx@gmail.com> 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.
I'll post a fix for this case as well.
> > > Agreed, and we may need add one more test cases in test_bpf module to cover > MOD?
Let me know if you have a test case ready :)
> > Yang > >> >> _______________________________________________ >> linux-arm-kernel mailing list >> linux-arm-kernel@lists.infradead.org >> http://lists.infradead.org/mailman/listinfo/linux-arm-kernel >> >
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