From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-10.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 16461C5DF61 for ; Thu, 7 Nov 2019 05:47:19 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id DEAF52166E for ; Thu, 7 Nov 2019 05:47:18 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1573105638; bh=pXs2PdMP1vwN9jqqtxb4Q8/IGWYgnvCD1P9T+u6rnfY=; h=From:To:CC:Subject:Date:In-Reply-To:References:List-ID:From; b=JGNuT9zOkdLpjcwEyg9dTMLdRcBatddUbM4z6Bbg1AOSoKOe4oMcpwWtUVnaD5nPf gHg3mlrofLwXcWWRX9M9csPtxliY7ePNw/D+JbCGvzq7t4XxqZO2tY+ONGUNHlxkrj DrVjSlKO/ERW9ahC5QOaRScOxhZctUhXBi/tVsHQ= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1725763AbfKGFrS convert rfc822-to-8bit (ORCPT ); Thu, 7 Nov 2019 00:47:18 -0500 Received: from mx0a-00082601.pphosted.com ([67.231.145.42]:54578 "EHLO mx0a-00082601.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726871AbfKGFrS (ORCPT ); Thu, 7 Nov 2019 00:47:18 -0500 Received: from pps.filterd (m0044012.ppops.net [127.0.0.1]) by mx0a-00082601.pphosted.com (8.16.0.42/8.16.0.42) with SMTP id xA75jPQM001836 for ; Wed, 6 Nov 2019 21:47:17 -0800 Received: from mail.thefacebook.com (mailout.thefacebook.com [199.201.64.23]) by mx0a-00082601.pphosted.com with ESMTP id 2w41un3gmx-15 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-SHA384 bits=256 verify=NOT) for ; Wed, 06 Nov 2019 21:47:17 -0800 Received: from 2401:db00:2050:5102:face:0:3b:0 (2620:10d:c081:10::13) by mail.thefacebook.com (2620:10d:c081:35::129) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA) id 15.1.1713.5; Wed, 6 Nov 2019 21:46:50 -0800 Received: by devbig007.ftw2.facebook.com (Postfix, from userid 572438) id 33701760BC0; Wed, 6 Nov 2019 21:46:46 -0800 (PST) Smtp-Origin-Hostprefix: devbig From: Alexei Starovoitov Smtp-Origin-Hostname: devbig007.ftw2.facebook.com To: CC: , , , , Smtp-Origin-Cluster: ftw2c04 Subject: [PATCH v2 bpf-next 01/17] bpf: refactor x86 JIT into helpers Date: Wed, 6 Nov 2019 21:46:28 -0800 Message-ID: <20191107054644.1285697-2-ast@kernel.org> X-Mailer: git-send-email 2.23.0 In-Reply-To: <20191107054644.1285697-1-ast@kernel.org> References: <20191107054644.1285697-1-ast@kernel.org> MIME-Version: 1.0 Content-Transfer-Encoding: 8BIT X-FB-Internal: Safe Content-Type: text/plain X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:6.0.95,18.0.572 definitions=2019-11-06_09:2019-11-06,2019-11-06 signatures=0 X-Proofpoint-Spam-Details: rule=fb_default_notspam policy=fb_default score=0 phishscore=0 bulkscore=0 mlxscore=0 spamscore=0 suspectscore=1 impostorscore=0 mlxlogscore=554 lowpriorityscore=0 clxscore=1034 malwarescore=0 priorityscore=1501 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-1910280000 definitions=main-1911070060 X-FB-Internal: deliver Sender: bpf-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org Refactor x86 JITing of LDX, STX, CALL instructions into separate helper functions. No functional changes in LDX and STX helpers. There is a minor change in CALL helper. It will populate target address correctly on the first pass of JIT instead of second pass. That won't reduce total number of JIT passes though. Signed-off-by: Alexei Starovoitov --- arch/x86/net/bpf_jit_comp.c | 153 +++++++++++++++++++++++------------- 1 file changed, 99 insertions(+), 54 deletions(-) diff --git a/arch/x86/net/bpf_jit_comp.c b/arch/x86/net/bpf_jit_comp.c index 8cd23d8309bf..0399b1f83c23 100644 --- a/arch/x86/net/bpf_jit_comp.c +++ b/arch/x86/net/bpf_jit_comp.c @@ -198,6 +198,8 @@ struct jit_context { /* Maximum number of bytes emitted while JITing one eBPF insn */ #define BPF_MAX_INSN_SIZE 128 #define BPF_INSN_SAFETY 64 +/* number of bytes emit_call() needs to generate call instruction */ +#define X86_CALL_SIZE 5 #define PROLOGUE_SIZE 20 @@ -390,6 +392,100 @@ static void emit_mov_reg(u8 **pprog, bool is64, u32 dst_reg, u32 src_reg) *pprog = prog; } +/* LDX: dst_reg = *(u8*)(src_reg + off) */ +static void emit_ldx(u8 **pprog, u32 size, u32 dst_reg, u32 src_reg, int off) +{ + u8 *prog = *pprog; + int cnt = 0; + + switch (size) { + case BPF_B: + /* Emit 'movzx rax, byte ptr [rax + off]' */ + EMIT3(add_2mod(0x48, src_reg, dst_reg), 0x0F, 0xB6); + break; + case BPF_H: + /* Emit 'movzx rax, word ptr [rax + off]' */ + EMIT3(add_2mod(0x48, src_reg, dst_reg), 0x0F, 0xB7); + break; + case BPF_W: + /* Emit 'mov eax, dword ptr [rax+0x14]' */ + if (is_ereg(dst_reg) || is_ereg(src_reg)) + EMIT2(add_2mod(0x40, src_reg, dst_reg), 0x8B); + else + EMIT1(0x8B); + break; + case BPF_DW: + /* Emit 'mov rax, qword ptr [rax+0x14]' */ + EMIT2(add_2mod(0x48, src_reg, dst_reg), 0x8B); + break; + } + /* + * If insn->off == 0 we can save one extra byte, but + * special case of x86 R13 which always needs an offset + * is not worth the hassle + */ + if (is_imm8(off)) + EMIT2(add_2reg(0x40, src_reg, dst_reg), off); + else + EMIT1_off32(add_2reg(0x80, src_reg, dst_reg), off); + *pprog = prog; +} + +/* STX: *(u8*)(dst_reg + off) = src_reg */ +static void emit_stx(u8 **pprog, u32 size, u32 dst_reg, u32 src_reg, int off) +{ + u8 *prog = *pprog; + int cnt = 0; + + switch (size) { + case BPF_B: + /* Emit 'mov byte ptr [rax + off], al' */ + if (is_ereg(dst_reg) || is_ereg(src_reg) || + /* We have to add extra byte for x86 SIL, DIL regs */ + src_reg == BPF_REG_1 || src_reg == BPF_REG_2) + EMIT2(add_2mod(0x40, dst_reg, src_reg), 0x88); + else + EMIT1(0x88); + break; + case BPF_H: + if (is_ereg(dst_reg) || is_ereg(src_reg)) + EMIT3(0x66, add_2mod(0x40, dst_reg, src_reg), 0x89); + else + EMIT2(0x66, 0x89); + break; + case BPF_W: + if (is_ereg(dst_reg) || is_ereg(src_reg)) + EMIT2(add_2mod(0x40, dst_reg, src_reg), 0x89); + else + EMIT1(0x89); + break; + case BPF_DW: + EMIT2(add_2mod(0x48, dst_reg, src_reg), 0x89); + break; + } + if (is_imm8(off)) + EMIT2(add_2reg(0x40, dst_reg, src_reg), off); + else + EMIT1_off32(add_2reg(0x80, dst_reg, src_reg), + off); + *pprog = prog; +} + +static int emit_call(u8 **pprog, void *func, void *ip) +{ + u8 *prog = *pprog; + int cnt = 0; + s64 offset; + + offset = func - (ip + X86_CALL_SIZE); + if (!is_simm32(offset)) { + pr_err("Target call %p is out of range\n", func); + return -EINVAL; + } + EMIT1_off32(0xE8, offset); + *pprog = prog; + return 0; +} static bool ex_handler_bpf(const struct exception_table_entry *x, struct pt_regs *regs, int trapnr, @@ -773,68 +869,22 @@ st: if (is_imm8(insn->off)) /* STX: *(u8*)(dst_reg + off) = src_reg */ case BPF_STX | BPF_MEM | BPF_B: - /* Emit 'mov byte ptr [rax + off], al' */ - if (is_ereg(dst_reg) || is_ereg(src_reg) || - /* We have to add extra byte for x86 SIL, DIL regs */ - src_reg == BPF_REG_1 || src_reg == BPF_REG_2) - EMIT2(add_2mod(0x40, dst_reg, src_reg), 0x88); - else - EMIT1(0x88); - goto stx; case BPF_STX | BPF_MEM | BPF_H: - if (is_ereg(dst_reg) || is_ereg(src_reg)) - EMIT3(0x66, add_2mod(0x40, dst_reg, src_reg), 0x89); - else - EMIT2(0x66, 0x89); - goto stx; case BPF_STX | BPF_MEM | BPF_W: - if (is_ereg(dst_reg) || is_ereg(src_reg)) - EMIT2(add_2mod(0x40, dst_reg, src_reg), 0x89); - else - EMIT1(0x89); - goto stx; case BPF_STX | BPF_MEM | BPF_DW: - EMIT2(add_2mod(0x48, dst_reg, src_reg), 0x89); -stx: if (is_imm8(insn->off)) - EMIT2(add_2reg(0x40, dst_reg, src_reg), insn->off); - else - EMIT1_off32(add_2reg(0x80, dst_reg, src_reg), - insn->off); + emit_stx(&prog, BPF_SIZE(insn->code), dst_reg, src_reg, insn->off); break; /* LDX: dst_reg = *(u8*)(src_reg + off) */ case BPF_LDX | BPF_MEM | BPF_B: case BPF_LDX | BPF_PROBE_MEM | BPF_B: - /* Emit 'movzx rax, byte ptr [rax + off]' */ - EMIT3(add_2mod(0x48, src_reg, dst_reg), 0x0F, 0xB6); - goto ldx; case BPF_LDX | BPF_MEM | BPF_H: case BPF_LDX | BPF_PROBE_MEM | BPF_H: - /* Emit 'movzx rax, word ptr [rax + off]' */ - EMIT3(add_2mod(0x48, src_reg, dst_reg), 0x0F, 0xB7); - goto ldx; case BPF_LDX | BPF_MEM | BPF_W: case BPF_LDX | BPF_PROBE_MEM | BPF_W: - /* Emit 'mov eax, dword ptr [rax+0x14]' */ - if (is_ereg(dst_reg) || is_ereg(src_reg)) - EMIT2(add_2mod(0x40, src_reg, dst_reg), 0x8B); - else - EMIT1(0x8B); - goto ldx; case BPF_LDX | BPF_MEM | BPF_DW: case BPF_LDX | BPF_PROBE_MEM | BPF_DW: - /* Emit 'mov rax, qword ptr [rax+0x14]' */ - EMIT2(add_2mod(0x48, src_reg, dst_reg), 0x8B); -ldx: /* - * If insn->off == 0 we can save one extra byte, but - * special case of x86 R13 which always needs an offset - * is not worth the hassle - */ - if (is_imm8(insn->off)) - EMIT2(add_2reg(0x40, src_reg, dst_reg), insn->off); - else - EMIT1_off32(add_2reg(0x80, src_reg, dst_reg), - insn->off); + emit_ldx(&prog, BPF_SIZE(insn->code), dst_reg, src_reg, insn->off); if (BPF_MODE(insn->code) == BPF_PROBE_MEM) { struct exception_table_entry *ex; u8 *_insn = image + proglen; @@ -899,13 +949,8 @@ xadd: if (is_imm8(insn->off)) /* call */ case BPF_JMP | BPF_CALL: func = (u8 *) __bpf_call_base + imm32; - jmp_offset = func - (image + addrs[i]); - if (!imm32 || !is_simm32(jmp_offset)) { - pr_err("unsupported BPF func %d addr %p image %p\n", - imm32, func, image); + if (!imm32 || emit_call(&prog, func, image + addrs[i - 1])) return -EINVAL; - } - EMIT1_off32(0xE8, jmp_offset); break; case BPF_JMP | BPF_TAIL_CALL: -- 2.23.0