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=unavailable 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 00365C2D0C6 for ; Fri, 27 Dec 2019 17:42:30 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id CEC8E222C3 for ; Fri, 27 Dec 2019 17:42:30 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1577468550; bh=sA28e4/Vn28o0eBK2OtFILC07rU4A36VwG070Roqi1Y=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=VBGCe9rW5ECJqVy1cR4Ic+ufObMQCMZAt+J3iZPz0S5d2lNALJlVxQk1M1XAa9pWH FCPYONXoyOw6LVrM4RMLsReRwRpXPyaWhvelJSDsw22KojhYI9FClg299r2A2XfanE 3V7s1UXw31Qi1mYIpprjFxTIZBh5zJdSff+UHd7U= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727868AbfL0Rm3 (ORCPT ); Fri, 27 Dec 2019 12:42:29 -0500 Received: from mail.kernel.org ([198.145.29.99]:39252 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727456AbfL0RmX (ORCPT ); Fri, 27 Dec 2019 12:42:23 -0500 Received: from sasha-vm.mshome.net (c-73-47-72-35.hsd1.nh.comcast.net [73.47.72.35]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 836E624656; Fri, 27 Dec 2019 17:42:21 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1577468542; bh=sA28e4/Vn28o0eBK2OtFILC07rU4A36VwG070Roqi1Y=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=TiKHpEc6CjWZYqHnTSwrNT6baXTcn23/DRReuzfA9XS8TZUMxmDmnBH5smo1ha96M ehPvzrdCkn1N0u2vCUI6ia6pA8vZCNYLNODmvK+ehrpI7xlOCdF3zGXDsaubdsgEdu d+76EAmFFcvYvSbQs3m1aOdCaEKFlLWSLbIiE72Q= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Paul Chaignon , Mahshid Khezri , Daniel Borkmann , =?UTF-8?q?Bj=C3=B6rn=20T=C3=B6pel?= , Martin KaFai Lau , Sasha Levin , netdev@vger.kernel.org, linux-riscv@lists.infradead.org, bpf@vger.kernel.org Subject: [PATCH AUTOSEL 5.4 071/187] bpf, riscv: Limit to 33 tail calls Date: Fri, 27 Dec 2019 12:38:59 -0500 Message-Id: <20191227174055.4923-71-sashal@kernel.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20191227174055.4923-1-sashal@kernel.org> References: <20191227174055.4923-1-sashal@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Paul Chaignon [ Upstream commit 96bc4432f5ade1045521f3b247f516b1478166bd ] All BPF JIT compilers except RISC-V's and MIPS' enforce a 33-tail calls limit at runtime. In addition, a test was recently added, in tailcalls2, to check this limit. This patch updates the tail call limit in RISC-V's JIT compiler to allow 33 tail calls. I tested it using the above selftest on an emulated RISCV64. Fixes: 2353ecc6f91f ("bpf, riscv: add BPF JIT for RV64G") Reported-by: Mahshid Khezri Signed-off-by: Paul Chaignon Signed-off-by: Daniel Borkmann Acked-by: Björn Töpel Acked-by: Martin KaFai Lau Link: https://lore.kernel.org/bpf/966fe384383bf23a0ee1efe8d7291c78a3fb832b.1575916815.git.paul.chaignon@gmail.com Signed-off-by: Sasha Levin --- arch/riscv/net/bpf_jit_comp.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/arch/riscv/net/bpf_jit_comp.c b/arch/riscv/net/bpf_jit_comp.c index 5451ef3845f2..7fbf56aab661 100644 --- a/arch/riscv/net/bpf_jit_comp.c +++ b/arch/riscv/net/bpf_jit_comp.c @@ -631,14 +631,14 @@ static int emit_bpf_tail_call(int insn, struct rv_jit_context *ctx) return -1; emit(rv_bgeu(RV_REG_A2, RV_REG_T1, off >> 1), ctx); - /* if (--TCC < 0) + /* if (TCC-- < 0) * goto out; */ emit(rv_addi(RV_REG_T1, tcc, -1), ctx); off = (tc_ninsn - (ctx->ninsns - start_insn)) << 2; if (is_13b_check(off, insn)) return -1; - emit(rv_blt(RV_REG_T1, RV_REG_ZERO, off >> 1), ctx); + emit(rv_blt(tcc, RV_REG_ZERO, off >> 1), ctx); /* prog = array->ptrs[index]; * if (!prog) -- 2.20.1