From nobody Sun Dec 28 15:39:22 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 From nobody Sun Dec 28 15:39:22 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 58E82C4167B for ; Thu, 7 Dec 2023 03:30:11 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229530AbjLGDaB (ORCPT ); Wed, 6 Dec 2023 22:30:01 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:57158 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229459AbjLGD35 (ORCPT ); Wed, 6 Dec 2023 22:29:57 -0500 Received: from mail.loongson.cn (mail.loongson.cn [114.242.206.163]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id 07F7018D 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 _____8Cxrus5PHFl_YQ_AA--.58501S3; Thu, 07 Dec 2023 11:30:01 +0800 (CST) Received: from linux.localdomain (unknown [113.200.148.30]) by localhost.localdomain (Coremail) with SMTP id AQAAf8Ax3tw0PHFlBCFXAA--.60649S4; Thu, 07 Dec 2023 11:30:00 +0800 (CST) From: Tiezhu Yang To: Huacai Chen Cc: Hengqi Chen , loongarch@lists.linux.dev, linux-kernel@vger.kernel.org Subject: [PATCH v1 2/2] LoongArch: BPF: Fix unconditional bswap instructions Date: Thu, 7 Dec 2023 11:29:51 +0800 Message-ID: <20231207032951.16334-3-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--.60649S4 X-CM-SenderInfo: p1dqw3xlh2x3gn0dqz5rrqw2lrqou0/ X-Coremail-Antispam: 1Uk129KBj93XoW7Zw45KrW7Gw4DJr1DWw1fZrc_yoW8Ww1Dpr sFyrs5KrW0gFy7Xa4UX3yxJr4jkan5A3WUJF1av34rGa9Fqw1UWF18Kw1YvasIy3yvva40 qa1jkFnIgF1UuagCm3ZEXasCq-sJn29KB7ZKAUJUUUU5529EdanIXcx71UUUUU7KY7ZEXa sCq-sGcSsGvfJ3Ic02F40EFcxC0VAKzVAqx4xG6I80ebIjqfuFe4nvWSU5nxnvy29KBjDU 0xBIdaVrnRJUUUkYb4IE77IF4wAFF20E14v26r1j6r4UM7CY07I20VC2zVCF04k26cxKx2 IYs7xG6rWj6s0DM7CIcVAFz4kK6r126r13M28lY4IEw2IIxxk0rwA2F7IY1VAKz4vEj48v e4kI8wA2z4x0Y4vE2Ix0cI8IcVAFwI0_Xr0_Ar1l84ACjcxK6xIIjxv20xvEc7CjxVAFwI 0_Gr0_Cr1l84ACjcxK6I8E87Iv67AKxVWxJVW8Jr1l84ACjcxK6I8E87Iv6xkF7I0E14v2 6r4UJVWxJr1le2I262IYc4CY6c8Ij28IcVAaY2xG8wAqjxCEc2xF0cIa020Ex4CE44I27w Aqx4xG64xvF2IEw4CE5I8CrVC2j2WlYx0E2Ix0cI8IcVAFwI0_Jw0_WrylYx0Ex4A2jsIE 14v26r4j6F4UMcvjeVCFs4IE7xkEbVWUJVW8JwACjcxG0xvY0x0EwIxGrwCF04k20xvY0x 0EwIxGrwCFx2IqxVCFs4IE7xkEbVWUJVW8JwC20s026c02F40E14v26r1j6r18MI8I3I0E 7480Y4vE14v26r106r1rMI8E67AF67kF1VAFwI0_JF0_Jw1lIxkGc2Ij64vIr41lIxAIcV C0I7IYx2IY67AKxVWUCVW8JwCI42IY6xIIjxv20xvEc7CjxVAFwI0_Jr0_Gr1lIxAIcVCF 04k26cxKx2IYs7xG6r1j6r1xMIIF0xvEx4A2jsIE14v26r1j6r4UMIIF0xvEx4A2jsIEc7 CjxVAFwI0_Jr0_GrUvcSsGvfC2KfnxnUUI43ZEXa7IU8gAw7UUUUU== Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" We can see that "bswap32: Takes an unsigned 32-bit number in either big- or little-endian format and returns the equivalent number with the same bit width but opposite endianness" in BPF Instruction Set Specification, so it should clear the upper 32 bits in the case 32 for BPF_ALU and BPF_ALU64. [root@linux fedora]# echo 1 > /proc/sys/net/core/bpf_jit_enable [root@linux fedora]# modprobe test_bpf Before: test_bpf: #313 BSWAP 32: 0x0123456789abcdef -> 0xefcdab89 jited:1 ret 14608= 50314 !=3D -271733879 (0x5712ce8a !=3D 0xefcdab89)FAIL (1 times) test_bpf: #317 BSWAP 32: 0xfedcba9876543210 -> 0x10325476 jited:1 ret -1460= 850316 !=3D 271733878 (0xa8ed3174 !=3D 0x10325476)FAIL (1 times) After: test_bpf: #313 BSWAP 32: 0x0123456789abcdef -> 0xefcdab89 jited:1 4 PASS test_bpf: #317 BSWAP 32: 0xfedcba9876543210 -> 0x10325476 jited:1 4 PASS Fixes: 4ebf9216e7df ("LoongArch: BPF: Support unconditional bswap instructi= ons") Signed-off-by: Tiezhu Yang Acked-by: Hengqi Chen --- arch/loongarch/net/bpf_jit.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/arch/loongarch/net/bpf_jit.c b/arch/loongarch/net/bpf_jit.c index 8c907c2c42f7..da48398e8794 100644 --- a/arch/loongarch/net/bpf_jit.c +++ b/arch/loongarch/net/bpf_jit.c @@ -774,8 +774,8 @@ static int build_insn(const struct bpf_insn *insn, stru= ct jit_ctx *ctx, bool ext break; case 32: emit_insn(ctx, revb2w, dst, dst); - /* zero-extend 32 bits into 64 bits */ - emit_zext_32(ctx, dst, is32); + /* clear the upper 32 bits */ + emit_zext_32(ctx, dst, true); break; case 64: emit_insn(ctx, revbd, dst, dst); --=20 2.42.0