From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-pl1-f173.google.com (mail-pl1-f173.google.com [209.85.214.173]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 6E2A71DED40 for ; Tue, 14 Jul 2026 00:26:43 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.214.173 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1783988804; cv=none; b=FchHZDA1AzcGy/ECIBh5Hajw17H3i8r02At8RPHCGg+SqTPyV7SQwlm7LaPP3DrdaUTHjxxc+jkiFloWlK0VZbvWsAgsqdOE/qRrbn+Kq/Y7XCIPKD73e4mT+qapMI2sIzWIoen871lmIWQrQ4ekEyzXI2H+dNllIyRcag55bgg= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1783988804; c=relaxed/simple; bh=r+kaBAfu+hKvqErDjZHt/uZYexn2mom/mH68FSlhKfo=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=V4RMqQ0N2/e+F9FPNu2syjFAGM8XVXRt7P8fpicNzj0Kf1xDLvXdaTTMGljum3tRcNi3zWIUNgAtIfjTB63546bR/ErKsjWwv5n1aTfmXk4gXi+FEozrtr4/8wbsQkDAZoUCveVbS/1HSPlxL0JkVPlaRYXVdA8Opl5JnIfIK2Y= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com; spf=pass smtp.mailfrom=gmail.com; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b=p1rj5n9k; arc=none smtp.client-ip=209.85.214.173 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=gmail.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="p1rj5n9k" Received: by mail-pl1-f173.google.com with SMTP id d9443c01a7336-2ce98cb8165so4515645ad.1 for ; Mon, 13 Jul 2026 17:26:43 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20251104; t=1783988803; x=1784593603; darn=vger.kernel.org; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to:content-type; bh=Fcmn/mUzmVUL+DoQNyIpH9sLS8JVVLYSWdiiiJ0QKdQ=; b=p1rj5n9kTipY3utX52KDqvwrBl80/vdKDKGO/sHO2HdCp/d62n+ln7fUEUlpkN6R7X ZcBwIog2BlcDxky2YpoL6orfNanTyGGEIzjxohzk1Un46T3W4vyzZ3TdZpq1Tsde9TEt 0sZ+v43Lsk38VS0p513p4vBjv7KqQSQXWpxIDjZ51h2DtMm6qta4TMVXahJFyWCb7ZRo 7L9UyX3JbvlLS/5zfMvT53NGiKkrVF6LV60dC6TmI+d0diXg1xFKnjZcRK7Do9PAsc/d 6ppHvLhLWHCGZyzpxt+tZUxBUd1vvIS9QCPuqp1uedrlGy6BelBf0Mm7ifJZF48ytwVo +bDg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1783988803; x=1784593603; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-gg:x-gm-message-state:from :to:cc:subject:date:message-id:reply-to:content-type; bh=Fcmn/mUzmVUL+DoQNyIpH9sLS8JVVLYSWdiiiJ0QKdQ=; b=EogYkhuIoTfcfMQEK+R3d9Lxrb+1tjCCxN+cvceB6FfvV2bpTbwzTnxfklcm8ljksU 4PqwRC24aXpnCFd+plLxPAt+EqFpQLPcSbLBAj/A2mFntyspFuCYGuKhPkoIsnQtoau1 BkHPN1M+hTR9Vr+v0MtUJbo6WVP1vuHnedRMhfuAefwQzzJBvGpVsyCxugl+yNuhNQ4w kt0JKToyu9s0RMWEyjBRYvwzFvDkS7p4yfDiw4D9JtSRg3fEWGCUtTpVyFF5hVw9oOgJ K6r6nVLtL+iQD7g1ZFdQI2VtWvH5ImgZu37rXlQLFwFzGZeB0GCYWekcVJSAbLo/Dw+9 /YGg== X-Forwarded-Encrypted: i=1; AHgh+RpEXsLPq+awV7iYta4FVKOCDlvnWTvv2hCRCywUvzuBZ8O/47r8bo/JR52rc2z/sIUIZiE=@vger.kernel.org X-Gm-Message-State: AOJu0YwJik3CVosTL+dlLvDQBwxM+bDOXcfo3Ylwn9E8qBubOhMrQZzb +HVbD/oadav65b6s+kpHZ6b48T2vA4yfnRIU6vZX6eGNO7ZoN3I062Ic X-Gm-Gg: AfdE7cn9p3gAW5GiCw6VTUXZaqWB2yd060mSntk54JmMw2IR31zgaxFxZwwfrZJ3J8E 3QdTVDJYoA+ckcyGjxNsfJ1hqRptwVTeUWwMBY/DC3QRtZdXhSdbQxl9fmvBm0CZJTdstG7HrcZ YF5jeEbLiajsU1i9FkUYK2BALGnKC7u5H2Q4j/uy62TTVwg5xSrBpMS/oSRjRTUxQLaEn2DArxw ychuvVSmrS8o0I0OpVzsFdWMyFDZGGQ+b+6k76tDmKydOFHAkYfhkV6N0aHmSaopblfRVTbMgYT iRyZ/BK9WZJgARWk8iY/758aQrQVjp7s3CXbbKiP+qT2joxeiwNQCvQOSYJ72rJ2FrDzheFwMRV OB1gCOaGYknTEOXyleDeonDhZe/7xMpK2LxZVfxmxCuLeVD48tQ8fs57UYOwG+CDvIcSENALvyg zGDn0cYZXcz6zG0O2AW8yngvefd7jeZAXhM7xNYmT0O158k5fIWqbOZ6XKN4YzyKI8MzT67lQ/t DimgTBhUWTWW04= X-Received: by 2002:a17:903:2406:b0:2c7:c385:c5a7 with SMTP id d9443c01a7336-2ce8297869amr137544225ad.26.1783988802746; Mon, 13 Jul 2026 17:26:42 -0700 (PDT) Received: from visitorckw-work01.c.googlers.com.com (131.197.81.34.bc.googleusercontent.com. [34.81.197.131]) by smtp.gmail.com with ESMTPSA id d9443c01a7336-2ccc9d1edb0sm105796545ad.53.2026.07.13.17.26.36 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 13 Jul 2026 17:26:42 -0700 (PDT) From: Kuan-Wei Chiu To: ast@kernel.org, daniel@iogearbox.net, andrii@kernel.org, eddyz87@gmail.com, memxor@gmail.com, luke.r.nels@gmail.com, xi.wang@gmail.com, pjw@kernel.org, palmer@dabbelt.com, aou@eecs.berkeley.edu, pulehui@huawei.com Cc: martin.lau@linux.dev, song@kernel.org, yonghong.song@linux.dev, jolsa@kernel.org, emil@etsalapatis.com, alex@ghiti.fr, jserv@ccns.ncku.edu.tw, eleanor15x@gmail.com, marscheng@google.com, bpf@vger.kernel.org, linux-riscv@lists.infradead.org, linux-kernel@vger.kernel.org, Kuan-Wei Chiu Subject: [PATCH bpf-next v4 2/3] riscv, bpf: Add support for BPF_MOVSX in RV32 JIT Date: Tue, 14 Jul 2026 00:24:50 +0000 Message-ID: <20260714002451.4091139-3-visitorckw@gmail.com> X-Mailer: git-send-email 2.55.0.795.g602f6c329a-goog In-Reply-To: <20260714002451.4091139-1-visitorckw@gmail.com> References: <20260714002451.4091139-1-visitorckw@gmail.com> Precedence: bulk X-Mailing-List: bpf@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit The current rv32 bpf jit compiler incorrectly treats BPF_MOVSX as a standard zero-extended move operation. The bpf instruction set allows sign-extension moves by reusing the BPF_MOV opcode with the instruction offset set to 8, 16, or 32. Update the bpf_jit_emit_insn() function to check the offset field for both ALU and ALU64 MOV operations. If the offset is non-zero, emit the correct slli and srai instructions to perform the sign extension. Before this patch: [ 19.549705] test_bpf: #82 ALU_MOVSX | BPF_B jited:1 ret 2 != 1 (0x2 != 0x1)FAIL (1 times) [ 19.551354] test_bpf: #83 ALU_MOVSX | BPF_H jited:1 ret 2 != 1 (0x2 != 0x1)FAIL (1 times) [ 19.552576] test_bpf: #84 ALU64_MOVSX | BPF_B jited:1 ret 2 != 1 (0x2 != 0x1)FAIL (1 times) [ 19.553542] test_bpf: #85 ALU64_MOVSX | BPF_H jited:1 ret 2 != 1 (0x2 != 0x1)FAIL (1 times) [ 19.554807] test_bpf: #86 ALU64_MOVSX | BPF_W jited:1 ret 2 != 1 (0x2 != 0x1)FAIL (1 times) After this patch: [ 17.931172] test_bpf: #82 ALU_MOVSX | BPF_B jited:1 125 PASS [ 17.932198] test_bpf: #83 ALU_MOVSX | BPF_H jited:1 124 PASS [ 17.933039] test_bpf: #84 ALU64_MOVSX | BPF_B jited:1 124 PASS [ 17.933918] test_bpf: #85 ALU64_MOVSX | BPF_H jited:1 124 PASS [ 17.934751] test_bpf: #86 ALU64_MOVSX | BPF_W jited:1 122 PASS Signed-off-by: Kuan-Wei Chiu Reviewed-by: Pu Lehui --- arch/riscv/net/bpf_jit_comp32.c | 32 ++++++++++++++++++++++++++++++++ 1 file changed, 32 insertions(+) diff --git a/arch/riscv/net/bpf_jit_comp32.c b/arch/riscv/net/bpf_jit_comp32.c index 89153946a4e4..39e2b0b907dc 100644 --- a/arch/riscv/net/bpf_jit_comp32.c +++ b/arch/riscv/net/bpf_jit_comp32.c @@ -972,6 +972,24 @@ int bpf_jit_emit_insn(const struct bpf_insn *insn, struct rv_jit_context *ctx, switch (code) { case BPF_ALU64 | BPF_MOV | BPF_X: + if (insn->off != 0) { + const s8 *rd = bpf_get_reg64(dst, tmp1, ctx); + const s8 *rs = bpf_get_reg64(src, tmp2, ctx); + + if (insn->off == 8) { + emit(rv_slli(lo(rd), lo(rs), 24), ctx); + emit(rv_srai(lo(rd), lo(rd), 24), ctx); + } else if (insn->off == 16) { + emit(rv_slli(lo(rd), lo(rs), 16), ctx); + emit(rv_srai(lo(rd), lo(rd), 16), ctx); + } else { + emit(rv_addi(lo(rd), lo(rs), 0), ctx); + } + emit(rv_srai(hi(rd), lo(rd), 31), ctx); + bpf_put_reg64(dst, rd, ctx); + break; + } + fallthrough; case BPF_ALU64 | BPF_ADD | BPF_X: case BPF_ALU64 | BPF_ADD | BPF_K: @@ -1022,6 +1040,20 @@ int bpf_jit_emit_insn(const struct bpf_insn *insn, struct rv_jit_context *ctx, emit_zext64(dst, ctx); break; } + if (insn->off != 0) { + const s8 *rd = bpf_get_reg32(dst, tmp1, ctx); + const s8 *rs = bpf_get_reg32(src, tmp2, ctx); + + if (insn->off == 8) { + emit(rv_slli(lo(rd), lo(rs), 24), ctx); + emit(rv_srai(lo(rd), lo(rd), 24), ctx); + } else if (insn->off == 16) { + emit(rv_slli(lo(rd), lo(rs), 16), ctx); + emit(rv_srai(lo(rd), lo(rd), 16), ctx); + } + bpf_put_reg32(dst, rd, ctx); + break; + } fallthrough; case BPF_ALU | BPF_ADD | BPF_X: -- 2.55.0.795.g602f6c329a-goog