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=-6.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,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 CACE9C352A3 for ; Mon, 10 Feb 2020 13:02:45 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 95ACD20708 for ; Mon, 10 Feb 2020 13:02:45 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1581339765; bh=m+U00sw7e0xmBxIhKSkjHZxP8XgULJD6o0SKO1wayGA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=Ax8+1V/eY8G2nu23Ovx6M51lYB082nvnScEysDgtT+f7WlauTHfvWBPmVz8mveuG2 YMG+1KYdCh9446L1hSf0YOXJugy6GGGUXBSwLXaNwPbs37CpEISnUVVSEnfsZIcsb1 NYD8Jz5T4LmnxF/15gRO/Nz4qf5sWRmiFtz9oEOE= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730641AbgBJNCp (ORCPT ); Mon, 10 Feb 2020 08:02:45 -0500 Received: from mail.kernel.org ([198.145.29.99]:40726 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729001AbgBJMkb (ORCPT ); Mon, 10 Feb 2020 07:40:31 -0500 Received: from localhost (unknown [209.37.97.194]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 3852C208C4; Mon, 10 Feb 2020 12:40:31 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1581338431; bh=m+U00sw7e0xmBxIhKSkjHZxP8XgULJD6o0SKO1wayGA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=F3SmhTtIrhaBpVnzr2KK9b6Cc64Nq71uv87HPb3LTcx0aMmGpCc4leML9Xl0hfgZY wPlmnmkxM7337q+DiwIFfAgLi8y1T1vPbba4lZZgfJqCxgux0GQu90eGthRI6eH/+u m4fbSNpdF3pBWOz6o9kryQdnJMf5KV2fLETWzx+M= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, =?UTF-8?q?Bj=C3=B6rn=20T=C3=B6pel?= , Daniel Borkmann Subject: [PATCH 5.5 157/367] riscv, bpf: Fix broken BPF tail calls Date: Mon, 10 Feb 2020 04:31:10 -0800 Message-Id: <20200210122439.322516249@linuxfoundation.org> X-Mailer: git-send-email 2.25.0 In-Reply-To: <20200210122423.695146547@linuxfoundation.org> References: <20200210122423.695146547@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Björn Töpel commit f1003b787c00fbaa4b11619c6b23a885bfce8f07 upstream. The BPF JIT incorrectly clobbered the a0 register, and did not flag usage of s5 register when BPF stack was being used. Fixes: 2353ecc6f91f ("bpf, riscv: add BPF JIT for RV64G") Signed-off-by: Björn Töpel Signed-off-by: Daniel Borkmann Link: https://lore.kernel.org/bpf/20191216091343.23260-2-bjorn.topel@gmail.com Signed-off-by: Greg Kroah-Hartman --- arch/riscv/net/bpf_jit_comp.c | 13 +++++++++++-- 1 file changed, 11 insertions(+), 2 deletions(-) --- a/arch/riscv/net/bpf_jit_comp.c +++ b/arch/riscv/net/bpf_jit_comp.c @@ -120,6 +120,11 @@ static bool seen_reg(int reg, struct rv_ return false; } +static void mark_fp(struct rv_jit_context *ctx) +{ + __set_bit(RV_CTX_F_SEEN_S5, &ctx->flags); +} + static void mark_call(struct rv_jit_context *ctx) { __set_bit(RV_CTX_F_SEEN_CALL, &ctx->flags); @@ -596,7 +601,8 @@ static void __build_epilogue(u8 reg, str emit(rv_addi(RV_REG_SP, RV_REG_SP, stack_adjust), ctx); /* Set return value. */ - emit(rv_addi(RV_REG_A0, RV_REG_A5, 0), ctx); + if (reg == RV_REG_RA) + emit(rv_addi(RV_REG_A0, RV_REG_A5, 0), ctx); emit(rv_jalr(RV_REG_ZERO, reg, 0), ctx); } @@ -1426,6 +1432,10 @@ static void build_prologue(struct rv_jit { int stack_adjust = 0, store_offset, bpf_stack_adjust; + bpf_stack_adjust = round_up(ctx->prog->aux->stack_depth, 16); + if (bpf_stack_adjust) + mark_fp(ctx); + if (seen_reg(RV_REG_RA, ctx)) stack_adjust += 8; stack_adjust += 8; /* RV_REG_FP */ @@ -1443,7 +1453,6 @@ static void build_prologue(struct rv_jit stack_adjust += 8; stack_adjust = round_up(stack_adjust, 16); - bpf_stack_adjust = round_up(ctx->prog->aux->stack_depth, 16); stack_adjust += bpf_stack_adjust; store_offset = stack_adjust - 8;