From patchwork Wed Nov 30 03:38:06 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Pu Lehui X-Patchwork-Id: 27574 Return-Path: Delivered-To: ouuuleilei@gmail.com Received: by 2002:adf:f944:0:0:0:0:0 with SMTP id q4csp710846wrr; Tue, 29 Nov 2022 19:44:44 -0800 (PST) X-Google-Smtp-Source: AA0mqf7fgm+PlXTRmEswXdpqvx6nu4D3ZIco6ThWrPgKwj78czDAyqA+Xd6SjNWE++hJlsp9vkXq X-Received: by 2002:aa7:c986:0:b0:46b:b010:3f43 with SMTP id c6-20020aa7c986000000b0046bb0103f43mr1453531edt.215.1669779884540; Tue, 29 Nov 2022 19:44:44 -0800 (PST) ARC-Seal: i=1; a=rsa-sha256; t=1669779884; cv=none; d=google.com; s=arc-20160816; b=II5cTJQmUKorA1NSAcDquZSy+lv2p3zEe6rSgh22hx3CrbS9NW9nEGSU9OESyt9Vve LAj+FMy5rBreWGR6aG9lsiBlEDI6jCgm/7Q9CIEpCjQFyDnAiKEnwz8yf8pGlVhlnG5i 1YA+YeGAVGIPTmjMmeY4X6a/09/+xUEswhjk0vlW932AaOaDeUw38yw50KPF+HfF4rEr Tb4SxZiBQXZ5Mwf8Fnk4j+9oUtOJM5S6smCC8riFrBeEY2EpwH2BynmNXZeDqGM8/GNS YqGBz7qSZ+ve4rJJniTNfE1U6hN/PoDGCDu+Da+qHJCgAC9S0O9/6Uc377/texLQes/Z Nf5w== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:content-transfer-encoding:mime-version :message-id:date:subject:cc:to:from; bh=46MPWjUXiGqLNkf0XSq5OYBXa3ui25QzUetY8yQU0pk=; b=zuTaIBL1ALR4NNam0FPnNzn97ONikWPhKNcXW0K7MqQyM9L1RV87wfWQQfSkuebHI3 ijz6rs99J9vEEAshqwwrwiybp5Upv071nYHo4wRFZpZgkgfRdkm6Q8pthGcJfNT5TcBO b0op3CUxHq7qdlh9CixDVjVCKGayR/Vr1Pr5YNjap4NWBDZo0YOkkH0BB21d3lWSV79F ThEGV6hyWmlt24gwMzhI2TdBHOnotRACtCLV4qmWNe9w4btlpbl5wv/LLEqcCSX1qPlm MP3JtlMHAcacjS047dlCBB/aw8Lsg41D3Q9qkgU495x93F/iwW8uSOlOl+12Xu5H2A8J vwdg== ARC-Authentication-Results: i=1; mx.google.com; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: from out1.vger.email (out1.vger.email. [2620:137:e000::1:20]) by mx.google.com with ESMTP id hs30-20020a1709073e9e00b0078e11a20640si454869ejc.2.2022.11.29.19.44.21; Tue, 29 Nov 2022 19:44:44 -0800 (PST) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20; Authentication-Results: mx.google.com; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232859AbiK3Dhc (ORCPT + 99 others); Tue, 29 Nov 2022 22:37:32 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:53816 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232827AbiK3Dh2 (ORCPT ); Tue, 29 Nov 2022 22:37:28 -0500 Received: from dggsgout12.his.huawei.com (dggsgout12.his.huawei.com [45.249.212.56]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id A276D73BBF; Tue, 29 Nov 2022 19:37:25 -0800 (PST) Received: from mail02.huawei.com (unknown [172.30.67.169]) by dggsgout12.his.huawei.com (SkyGuard) with ESMTP id 4NMPz41THGz4f3mS4; Wed, 30 Nov 2022 11:37:20 +0800 (CST) Received: from localhost.localdomain (unknown [10.67.175.61]) by APP2 (Coremail) with SMTP id Syh0CgBHXrnyz4ZjLguABQ--.10963S2; Wed, 30 Nov 2022 11:37:22 +0800 (CST) From: Pu Lehui To: bpf@vger.kernel.org, linux-riscv@lists.infradead.org, linux-kernel@vger.kernel.org Cc: =?utf-8?b?QmrDtnJuIFTDtnBlbA==?= , Alexei Starovoitov , Daniel Borkmann , Andrii Nakryiko , Martin KaFai Lau , Song Liu , Yonghong Song , John Fastabend , KP Singh , Stanislav Fomichev , Hao Luo , Jiri Olsa , Paul Walmsley , Palmer Dabbelt , Albert Ou , Pu Lehui , Pu Lehui Subject: [PATCH bpf] riscv, bpf: Emit fixed-length imm64 for BPF_PSEUDO_FUNC Date: Wed, 30 Nov 2022 11:38:06 +0800 Message-Id: <20221130033806.2967822-1-pulehui@huaweicloud.com> X-Mailer: git-send-email 2.25.1 MIME-Version: 1.0 X-CM-TRANSID: Syh0CgBHXrnyz4ZjLguABQ--.10963S2 X-Coremail-Antispam: 1UD129KBjvJXoW7CFy5AFyxuryDur4UCF1DAwb_yoW8tFy5pr WUKr4fCFZ2qr1S9rnxtr1rXr15CF40qFsIgry3Way5Ga12qrsF93WDKw4Yka98ZFy8Gr15 XFyUKF9xua4Dt3DanT9S1TB71UUUUU7qnTZGkaVYY2UrUUUUjbIjqfuFe4nvWSU5nxnvy2 9KBjDU0xBIdaVrnRJUUUvF14x267AKxVW5JVWrJwAFc2x0x2IEx4CE42xK8VAvwI8IcIk0 rVWrJVCq3wAFIxvE14AKwVWUJVWUGwA2ocxC64kIII0Yj41l84x0c7CEw4AK67xGY2AK02 1l84ACjcxK6xIIjxv20xvE14v26w1j6s0DM28EF7xvwVC0I7IYx2IY6xkF7I0E14v26r4U JVWxJr1l84ACjcxK6I8E87Iv67AKxVW0oVCq3wA2z4x0Y4vEx4A2jsIEc7CjxVAFwI0_Gc CE3s1le2I262IYc4CY6c8Ij28IcVAaY2xG8wAqx4xG64xvF2IEw4CE5I8CrVC2j2WlYx0E 2Ix0cI8IcVAFwI0_JrI_JrylYx0Ex4A2jsIE14v26r1j6r4UMcvjeVCFs4IE7xkEbVWUJV W8JwACjcxG0xvY0x0EwIxGrwACjI8F5VA0II8E6IAqYI8I648v4I1lFIxGxcIEc7CjxVA2 Y2ka0xkIwI1l42xK82IYc2Ij64vIr41l4I8I3I0E4IkC6x0Yz7v_Jr0_Gr1lx2IqxVAqx4 xG67AKxVWUJVWUGwC20s026x8GjcxK67AKxVWUGVWUWwC2zVAF1VAY17CE14v26r4a6rW5 MIIYrxkI7VAKI48JMIIF0xvE2Ix0cI8IcVAFwI0_Jr0_JF4lIxAIcVC0I7IYx2IY6xkF7I 0E14v26r4j6F4UMIIF0xvE42xK8VAvwI8IcIk0rVWrJr0_WFyUJwCI42IY6I8E87Iv67AK xVWUJVW8JwCI42IY6I8E87Iv6xkF7I0E14v26r4j6r4UJbIYCTnIWIevJa73UjIFyTuYvj fUF0eHDUUUU X-CM-SenderInfo: psxovxtxl6x35dzhxuhorxvhhfrp/ X-CFilter-Loop: Reflected X-Spam-Status: No, score=-1.9 required=5.0 tests=BAYES_00,SPF_HELO_NONE, SPF_NONE autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on lindbergh.monkeyblade.net Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org X-getmail-retrieved-from-mailbox: =?utf-8?q?INBOX?= X-GMAIL-THRID: =?utf-8?q?1750891112075573982?= X-GMAIL-MSGID: =?utf-8?q?1750891112075573982?= From: Pu Lehui For BPF_PSEUDO_FUNC instruction, verifier will refill imm with correct addresses of bpf_calls and then run last pass of JIT. Since the emit_imm of RV64 is variable-length, which will emit appropriate length instructions accorroding to the imm, it may broke ctx->offset, and lead to unpredictable problem, such as inaccurate jump. So let's fix it with fixed-length imm64 insns. Fixes: 69c087ba6225 ("bpf: Add bpf_for_each_map_elem() helper") Signed-off-by: Pu Lehui --- arch/riscv/net/bpf_jit_comp64.c | 31 ++++++++++++++++++++++++++++++- 1 file changed, 30 insertions(+), 1 deletion(-) diff --git a/arch/riscv/net/bpf_jit_comp64.c b/arch/riscv/net/bpf_jit_comp64.c index eb99df41fa33..f984d5fa014b 100644 --- a/arch/riscv/net/bpf_jit_comp64.c +++ b/arch/riscv/net/bpf_jit_comp64.c @@ -139,6 +139,30 @@ static bool in_auipc_jalr_range(s64 val) val < ((1L << 31) - (1L << 11)); } +/* Emit fixed-length instructions for 32-bit imm */ +static void emit_fixed_imm32(u8 rd, s32 val, struct rv_jit_context *ctx) +{ + s32 upper = (val + (1U << 11)) >> 12; + s32 lower = ((val & 0xfff) << 20) >> 20; + + emit(rv_lui(rd, upper), ctx); + emit(rv_addi(rd, rd, lower), ctx); +} + +/* Emit fixed-length instructions for 64-bit imm */ +static void emit_fixed_imm64(u8 rd, s64 val, struct rv_jit_context *ctx) +{ + /* Compensation for sign-extension of rv_addi */ + s32 imm_hi = (val + (1U << 31)) >> 32; + s32 imm_lo = val; + + emit_fixed_imm32(rd, imm_hi, ctx); + emit_fixed_imm32(RV_REG_T1, imm_lo, ctx); + emit(rv_slli(rd, rd, 32), ctx); + emit(rv_add(rd, rd, RV_REG_T1), ctx); +} + +/* Emit variable-length instructions for 32-bit and 64-bit imm */ static void emit_imm(u8 rd, s64 val, struct rv_jit_context *ctx) { /* Note that the immediate from the add is sign-extended, @@ -1053,7 +1077,12 @@ int bpf_jit_emit_insn(const struct bpf_insn *insn, struct rv_jit_context *ctx, u64 imm64; imm64 = (u64)insn1.imm << 32 | (u32)imm; - emit_imm(rd, imm64, ctx); + if (bpf_pseudo_func(insn)) + /* fixed-length insns for extra jit pass */ + emit_fixed_imm64(rd, imm64, ctx); + else + emit_imm(rd, imm64, ctx); + return 1; }