From: yang.shi@linaro.org (Shi, Yang)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH] arm64: bpf: fix div-by-zero case
Date: Wed, 04 Nov 2015 10:21:14 -0800 [thread overview]
Message-ID: <563A4C9A.7000002@linaro.org> (raw)
In-Reply-To: <CAKU6vyZu5KNAipSVUMg8ASnRXztVwh57weKXxXOXkqAJ3erDBQ@mail.gmail.com>
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.
Agreed, and we may need add one more test cases in test_bpf module to
cover MOD?
Yang
>
> _______________________________________________
> linux-arm-kernel mailing list
> linux-arm-kernel at lists.infradead.org
> http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
>
next prev parent reply other threads:[~2015-11-04 18:21 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-11-04 6:56 [PATCH] arm64: bpf: fix div-by-zero case Zi Shen Lim
2015-11-04 7:04 ` Xi Wang
2015-11-04 18:21 ` Shi, Yang [this message]
2015-11-04 18:25 ` Z Lim
2015-11-04 18:41 ` Shi, Yang
2015-11-04 19:39 ` Daniel Borkmann
2015-11-04 18:03 ` Shi, Yang
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