From nobody Sun Dec 28 17:32:19 2025 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id E4EC3C4167B for ; Thu, 7 Dec 2023 03:30:14 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229536AbjLGDaF (ORCPT ); Wed, 6 Dec 2023 22:30:05 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:57168 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229460AbjLGD36 (ORCPT ); Wed, 6 Dec 2023 22:29:58 -0500 Received: from mail.loongson.cn (mail.loongson.cn [114.242.206.163]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id 1D31819E for ; Wed, 6 Dec 2023 19:30:02 -0800 (PST) Received: from loongson.cn (unknown [113.200.148.30]) by gateway (Coremail) with SMTP id _____8CxfOo4PHFl+oQ_AA--.34214S3; Thu, 07 Dec 2023 11:30:00 +0800 (CST) Received: from linux.localdomain (unknown [113.200.148.30]) by localhost.localdomain (Coremail) with SMTP id AQAAf8Ax3tw0PHFlBCFXAA--.60649S3; Thu, 07 Dec 2023 11:29:59 +0800 (CST) From: Tiezhu Yang To: Huacai Chen Cc: Hengqi Chen , loongarch@lists.linux.dev, linux-kernel@vger.kernel.org Subject: [PATCH v1 1/2] LoongArch: BPF: Fix sign-extension mov instructions Date: Thu, 7 Dec 2023 11:29:50 +0800 Message-ID: <20231207032951.16334-2-yangtiezhu@loongson.cn> X-Mailer: git-send-email 2.42.0 In-Reply-To: <20231207032951.16334-1-yangtiezhu@loongson.cn> References: <20231207032951.16334-1-yangtiezhu@loongson.cn> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-CM-TRANSID: AQAAf8Ax3tw0PHFlBCFXAA--.60649S3 X-CM-SenderInfo: p1dqw3xlh2x3gn0dqz5rrqw2lrqou0/ X-Coremail-Antispam: 1Uk129KBj93XoW7Ar48Xr47uw47ZF15Xw4kKrX_yoW8WF1rpr s8Crs5KrWxX3yI9a4kA3y7XF4qkFs5Gr13Ga4aqay8WwsxXryUXF1xKw1Utan5JrZYvFW8 ua4Skwn09a4kXagCm3ZEXasCq-sJn29KB7ZKAUJUUUU5529EdanIXcx71UUUUU7KY7ZEXa sCq-sGcSsGvfJ3Ic02F40EFcxC0VAKzVAqx4xG6I80ebIjqfuFe4nvWSU5nxnvy29KBjDU 0xBIdaVrnRJUUUkYb4IE77IF4wAFF20E14v26r1j6r4UM7CY07I20VC2zVCF04k26cxKx2 IYs7xG6rWj6s0DM7CIcVAFz4kK6r126r13M28lY4IEw2IIxxk0rwA2F7IY1VAKz4vEj48v e4kI8wA2z4x0Y4vE2Ix0cI8IcVAFwI0_Gr0_Xr1l84ACjcxK6xIIjxv20xvEc7CjxVAFwI 0_Gr0_Cr1l84ACjcxK6I8E87Iv67AKxVWxJVW8Jr1l84ACjcxK6I8E87Iv6xkF7I0E14v2 6r4UJVWxJr1le2I262IYc4CY6c8Ij28IcVAaY2xG8wAqjxCEc2xF0cIa020Ex4CE44I27w Aqx4xG64xvF2IEw4CE5I8CrVC2j2WlYx0E2Ix0cI8IcVAFwI0_JF0_Jw1lYx0Ex4A2jsIE 14v26r1j6r4UMcvjeVCFs4IE7xkEbVWUJVW8JwACjcxG0xvY0x0EwIxGrwCF04k20xvY0x 0EwIxGrwCFx2IqxVCFs4IE7xkEbVWUJVW8JwC20s026c02F40E14v26r1j6r18MI8I3I0E 7480Y4vE14v26r106r1rMI8E67AF67kF1VAFwI0_JF0_Jw1lIxkGc2Ij64vIr41lIxAIcV C0I7IYx2IY67AKxVWUJVWUCwCI42IY6xIIjxv20xvEc7CjxVAFwI0_Jr0_Gr1lIxAIcVCF 04k26cxKx2IYs7xG6r1j6r1xMIIF0xvEx4A2jsIE14v26r1j6r4UMIIF0xvEx4A2jsIEc7 CjxVAFwI0_Jr0_GrUvcSsGvfC2KfnxnUUI43ZEXa7IU8niSPUUUUU== Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" We can see that "Short form of movsx, dst_reg =3D (s8,s16,s32)src_reg" in include/linux/filter.h, additionally, for BPF_ALU64 the value of the destination register is unchanged whereas for BPF_ALU the upper 32 bits of the destination register are zeroed, so it should clear the upper 32 bits for BPF_ALU. [root@linux fedora]# echo 1 > /proc/sys/net/core/bpf_jit_enable [root@linux fedora]# modprobe test_bpf Before: test_bpf: #81 ALU_MOVSX | BPF_B jited:1 ret 2 !=3D 1 (0x2 !=3D 0x1)FAIL (1 = times) test_bpf: #82 ALU_MOVSX | BPF_H jited:1 ret 2 !=3D 1 (0x2 !=3D 0x1)FAIL (1 = times) After: test_bpf: #81 ALU_MOVSX | BPF_B jited:1 6 PASS test_bpf: #82 ALU_MOVSX | BPF_H jited:1 6 PASS By the way, the bpf selftest case "./test_progs -t verifier_movsx" can also be fixed with this patch. Fixes: f48012f16150 ("LoongArch: BPF: Support sign-extension mov instructio= ns") Signed-off-by: Tiezhu Yang Acked-by: Hengqi Chen --- arch/loongarch/net/bpf_jit.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/arch/loongarch/net/bpf_jit.c b/arch/loongarch/net/bpf_jit.c index 169ff8b3915e..8c907c2c42f7 100644 --- a/arch/loongarch/net/bpf_jit.c +++ b/arch/loongarch/net/bpf_jit.c @@ -480,10 +480,12 @@ static int build_insn(const struct bpf_insn *insn, st= ruct jit_ctx *ctx, bool ext case 8: move_reg(ctx, t1, src); emit_insn(ctx, extwb, dst, t1); + emit_zext_32(ctx, dst, is32); break; case 16: move_reg(ctx, t1, src); emit_insn(ctx, extwh, dst, t1); + emit_zext_32(ctx, dst, is32); break; case 32: emit_insn(ctx, addw, dst, src, LOONGARCH_GPR_ZERO); --=20 2.42.0