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=-9.6 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,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 B4F67C43603 for ; Mon, 9 Dec 2019 17:31:52 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 8DC942080D for ; Mon, 9 Dec 2019 17:31:52 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="JG/Fdtoa" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726647AbfLIRbw (ORCPT ); Mon, 9 Dec 2019 12:31:52 -0500 Received: from mail-pj1-f66.google.com ([209.85.216.66]:34896 "EHLO mail-pj1-f66.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726230AbfLIRbv (ORCPT ); Mon, 9 Dec 2019 12:31:51 -0500 Received: by mail-pj1-f66.google.com with SMTP id w23so6193277pjd.2; Mon, 09 Dec 2019 09:31:51 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=bYazlit0M4yBFQMfwCbOmC5g6AIzkoA/91yiEDZt7b0=; b=JG/FdtoaT1PdHdeb1nQSG3n58INhw4WAwPx4fgf/iNqq6+YukonnT/Te2EfrJCYbwS BA839prSyM9HNh1zIq1Y6mtGIkk9Hb+UVfTCxDxX7jXyY2CwmcHbybwq+G5REvSl/X40 P9Rh91X5SyPVRrqmh9uS5XjMdub94pM7M0MD5oQtO/gb4wKcvuCcLgwXIQ2VOyXkAC1b q22mSGWXKWS6XeieReZpy5r+4wkmjv+esiy9JZkyXkCJRjbFGxTYAPCdvNaLN6VVjfK2 0Gua8XtVNUIyFq0HqEyNqTgudqrWWL9uHE+hGO7h/IaBfuYzgCqRMBV0akFCO4kKU77v 2YZA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=bYazlit0M4yBFQMfwCbOmC5g6AIzkoA/91yiEDZt7b0=; b=EczPqMI39UG+7Y0mks3KMJQYhgOmc+7fb4qjye+hVN5xrSXvZZvQYJgtZ5sda4VxvG Kxuff/uKmH/DQN9t8Cp8xfL+eI5wHy6YVCpVCYDkE2PBNbzKm7uX2F2lSwMGHlKqmSRq fStgyWe4zvD281M1BZEP1edEFwPwlULWRVAEQLFd/VmWt8YIHBvCs3F4I/XqpRZHInE8 kDetjlykcgwdJrOE07ONmvHFgKfC+G59YfxgmvmJLMufqcm7oAwVOTzpq+Ndt7YIwdtY NFDLxt1kbsiTYingpBoCwpa+nEDtKJBxhc+D5HFph1gH8ZXEX3j9XxfZzXDQlYIlrHYg NCTg== X-Gm-Message-State: APjAAAUFExxkM0uAVax6v+jCm6W4W7aPKDWCJcBdPYP4/QhJb/l359Lc 6H4pVDSXlRNqlD6OoMDH6Tc= X-Google-Smtp-Source: APXvYqwrSC1AJl671lj66BCLyGpEOq1PPz3mWlePEUYhbgIUczUyAsdnUS2TdGA2AA3b+CVw6LGv2Q== X-Received: by 2002:a17:902:6502:: with SMTP id b2mr30307947plk.182.1575912710989; Mon, 09 Dec 2019 09:31:50 -0800 (PST) Received: from btopel-mobl.ger.intel.com ([192.55.55.41]) by smtp.gmail.com with ESMTPSA id d23sm54943pfo.176.2019.12.09.09.31.48 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 09 Dec 2019 09:31:50 -0800 (PST) From: =?UTF-8?q?Bj=C3=B6rn=20T=C3=B6pel?= To: daniel@iogearbox.net, ast@kernel.org, netdev@vger.kernel.org Cc: =?UTF-8?q?Bj=C3=B6rn=20T=C3=B6pel?= , linux-riscv@lists.infradead.org, bpf@vger.kernel.org Subject: [PATCH bpf-next 1/8] riscv, bpf: fix broken BPF tail calls Date: Mon, 9 Dec 2019 18:31:29 +0100 Message-Id: <20191209173136.29615-2-bjorn.topel@gmail.com> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20191209173136.29615-1-bjorn.topel@gmail.com> References: <20191209173136.29615-1-bjorn.topel@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: bpf-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org 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 --- arch/riscv/net/bpf_jit_comp.c | 13 +++++++++++-- 1 file changed, 11 insertions(+), 2 deletions(-) diff --git a/arch/riscv/net/bpf_jit_comp.c b/arch/riscv/net/bpf_jit_comp.c index 5451ef3845f2..1606ebd49666 100644 --- 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_jit_context *ctx) 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, struct rv_jit_context *ctx) 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_context *ctx) { 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_context *ctx) 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; -- 2.20.1