From patchwork Thu Oct 17 22:32:09 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Yonghong Song X-Patchwork-Id: 13840889 X-Patchwork-Delegate: bpf@iogearbox.net Received: from 66-220-155-178.mail-mxout.facebook.com (66-220-155-178.mail-mxout.facebook.com [66.220.155.178]) (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 2EEFF1D86CB for ; Thu, 17 Oct 2024 22:32:22 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=66.220.155.178 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1729204348; cv=none; b=JLF9ezSsNBIHGtFjkazBTgD0fYDpEHwHzhjjhJfrMVDMeKxS148eW0Cwfre5uO8FgiBvp4UX7U42rKOgpXaCVr5QCr+l5OZ6zUhkfXKopFFT1cETMIiqgjk7zNtF52AjxE+0TYM+yLFC6tlXBZjtevn1QDKdzLtb7oUYsagD0QA= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1729204348; c=relaxed/simple; bh=GpSmPbQXUavgPZYJFod3hh5zOpeJZo+P04PkrivsCME=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=gitOzUBQcfFyPWUd98WU2qKvBuXBlmQSoQ8tHMCtFkuKkpEllvRHhc9/yk1CG080J54fEVzPII+DStorJ8WGNZssZ1sHwbE2PxzCVF4z+ZzkVYw2adfS+SOUr3oi1dLq9kFfa5lOok0oD+tajEf35Bkq64vw5yVncab0L9Xu04s= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=fail (p=none dis=none) header.from=linux.dev; spf=fail smtp.mailfrom=linux.dev; arc=none smtp.client-ip=66.220.155.178 Authentication-Results: smtp.subspace.kernel.org; dmarc=fail (p=none dis=none) header.from=linux.dev Authentication-Results: smtp.subspace.kernel.org; spf=fail smtp.mailfrom=linux.dev Received: by devbig309.ftw3.facebook.com (Postfix, from userid 128203) id 74898A2F0835; Thu, 17 Oct 2024 15:32:09 -0700 (PDT) From: Yonghong Song To: bpf@vger.kernel.org Cc: Alexei Starovoitov , Andrii Nakryiko , Daniel Borkmann , kernel-team@fb.com, Martin KaFai Lau , Tejun Heo Subject: [PATCH bpf-next v5 6/9] bpf, x86: Create a helper for certain "reg = imm" operations Date: Thu, 17 Oct 2024 15:32:09 -0700 Message-ID: <20241017223209.3177719-1-yonghong.song@linux.dev> X-Mailer: git-send-email 2.43.5 In-Reply-To: <20241017223138.3175885-1-yonghong.song@linux.dev> References: <20241017223138.3175885-1-yonghong.song@linux.dev> Precedence: bulk X-Mailing-List: bpf@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Patchwork-Delegate: bpf@iogearbox.net Create a helper to generate jited codes for certain "reg = imm" operations where operations are for add/sub/and/or/xor. This helper will be used in the subsequent patch. Signed-off-by: Yonghong Song --- arch/x86/net/bpf_jit_comp.c | 82 +++++++++++++++++++++---------------- 1 file changed, 46 insertions(+), 36 deletions(-) diff --git a/arch/x86/net/bpf_jit_comp.c b/arch/x86/net/bpf_jit_comp.c index 6d24389e58a1..6be8c739c3c2 100644 --- a/arch/x86/net/bpf_jit_comp.c +++ b/arch/x86/net/bpf_jit_comp.c @@ -1406,6 +1406,51 @@ static void emit_shiftx(u8 **pprog, u32 dst_reg, u8 src_reg, bool is64, u8 op) *pprog = prog; } +/* emit ADD/SUB/AND/OR/XOR 'reg = imm' operations */ +static void emit_alu_imm(u8 **pprog, u8 insn_code, u32 dst_reg, s32 imm32) +{ + u8 b2 = 0, b3 = 0; + u8 *prog = *pprog; + + maybe_emit_1mod(&prog, dst_reg, BPF_CLASS(insn_code) == BPF_ALU64); + + /* + * b3 holds 'normal' opcode, b2 short form only valid + * in case dst is eax/rax. + */ + switch (BPF_OP(insn_code)) { + case BPF_ADD: + b3 = 0xC0; + b2 = 0x05; + break; + case BPF_SUB: + b3 = 0xE8; + b2 = 0x2D; + break; + case BPF_AND: + b3 = 0xE0; + b2 = 0x25; + break; + case BPF_OR: + b3 = 0xC8; + b2 = 0x0D; + break; + case BPF_XOR: + b3 = 0xF0; + b2 = 0x35; + break; + } + + if (is_imm8(imm32)) + EMIT3(0x83, add_1reg(b3, dst_reg), imm32); + else if (is_axreg(dst_reg)) + EMIT1_off32(b2, imm32); + else + EMIT2_off32(0x81, add_1reg(b3, dst_reg), imm32); + + *pprog = prog; +} + #define INSN_SZ_DIFF (((addrs[i] - addrs[i - 1]) - (prog - temp))) #define __LOAD_TCC_PTR(off) \ @@ -1567,42 +1612,7 @@ static int do_jit(struct bpf_prog *bpf_prog, int *addrs, u8 *image, u8 *rw_image case BPF_ALU64 | BPF_AND | BPF_K: case BPF_ALU64 | BPF_OR | BPF_K: case BPF_ALU64 | BPF_XOR | BPF_K: - maybe_emit_1mod(&prog, dst_reg, - BPF_CLASS(insn->code) == BPF_ALU64); - - /* - * b3 holds 'normal' opcode, b2 short form only valid - * in case dst is eax/rax. - */ - switch (BPF_OP(insn->code)) { - case BPF_ADD: - b3 = 0xC0; - b2 = 0x05; - break; - case BPF_SUB: - b3 = 0xE8; - b2 = 0x2D; - break; - case BPF_AND: - b3 = 0xE0; - b2 = 0x25; - break; - case BPF_OR: - b3 = 0xC8; - b2 = 0x0D; - break; - case BPF_XOR: - b3 = 0xF0; - b2 = 0x35; - break; - } - - if (is_imm8(imm32)) - EMIT3(0x83, add_1reg(b3, dst_reg), imm32); - else if (is_axreg(dst_reg)) - EMIT1_off32(b2, imm32); - else - EMIT2_off32(0x81, add_1reg(b3, dst_reg), imm32); + emit_alu_imm(&prog, insn->code, dst_reg, imm32); break; case BPF_ALU64 | BPF_MOV | BPF_K: