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 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 6A203CF8840 for ; Fri, 4 Oct 2024 18:19:47 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To: Message-ID:Date:Subject:Cc:To:From:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=F752wb2iyzTsxGbyI8aRZCQ8SDjpDxVNzzedvVTcUsI=; b=hco+otE+F3deQ6 712Jlo1XZN6YY4wO2k1lEs+TwE3QOW83JWMl9pebXlha/LNIHovNO/XguEDl58Ab5u1uEd0MB0oho XKkRTfJauLfYaEQqEGg6gV3MFfQwL/eIuD+9hDHCeWck7Qv2qveueHLHuLXYBx2ll7g5gnAvRiP7U 49db2C3bJio1qbsHl0Yypdety9Jg8UtcyKYM5KOton02tB71P+1OHn7BJ3NCC2L9qVDd0LQUQo0g2 Zs9Ia3CbdVhiYzG/HC3P6KwHEJRR3t3DAlHcdouQYcubiHV/nTf/uB5+6pelb3pyqMiSMCf88PuD8 whfA5MroItWEGocTifww==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98 #2 (Red Hat Linux)) id 1swmu0-0000000Df7z-2WZW; Fri, 04 Oct 2024 18:19:44 +0000 Received: from dfw.source.kernel.org ([2604:1380:4641:c500::1]) by bombadil.infradead.org with esmtps (Exim 4.98 #2 (Red Hat Linux)) id 1swmty-0000000Df6p-16Kf for linux-riscv@lists.infradead.org; Fri, 04 Oct 2024 18:19:43 +0000 Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by dfw.source.kernel.org (Postfix) with ESMTP id 9AF3B5C5DCD; Fri, 4 Oct 2024 18:19:37 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id AC948C4CECC; Fri, 4 Oct 2024 18:19:39 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1728065981; bh=/B2Gc/EMzBDQckZ37mMVoHmmOAbe4wh83yczyv1hib4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=QRpR0qAH6GYeq6glzx9ToEMJfToDw4n7+EdDkIbcHzr1A/OQgVsXzRf9AooKXMkRU TTZJJp9qwPAS2sHtJ9t7PXSpmWUZqKLPI8vzZB//wlNdmqho4LIPvZd4PtaZX1xAK/ icGetN0JwzyZn4AVy6XBJfkyAy8wCbKb5FrXEBUBwH5dOdOHNAtERiSpNJX+6NIrDT sxJQlBXnVkXIMQ9V1A/hDRegPYPqBj1XVykte4eSHwN4flwHir97fm/d8NPQYaSAHG DGTyHaUVMJNFGJUrYlcQooc7t5s7LztOwCgYPpNvS00rEqqCui0DGnC96kMryY4dwX t7hz8u2rzGpOA== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Jisheng Zhang , Cyril Bur , Palmer Dabbelt , Sasha Levin , paul.walmsley@sifive.com, palmer@dabbelt.com, aou@eecs.berkeley.edu, samitolvanen@google.com, cleger@rivosinc.com, guoren@kernel.org, namcaov@gmail.com, debug@rivosinc.com, antonb@tenstorrent.com, andy.chiu@sifive.com, linux-riscv@lists.infradead.org Subject: [PATCH AUTOSEL 6.11 38/76] riscv: avoid Imbalance in RAS Date: Fri, 4 Oct 2024 14:16:55 -0400 Message-ID: <20241004181828.3669209-38-sashal@kernel.org> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20241004181828.3669209-1-sashal@kernel.org> References: <20241004181828.3669209-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore X-stable-base: Linux 6.11.2 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20241004_111942_368901_4CE36A91 X-CRM114-Status: UNSURE ( 8.91 ) X-CRM114-Notice: Please train this message. X-BeenThere: linux-riscv@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-riscv" Errors-To: linux-riscv-bounces+linux-riscv=archiver.kernel.org@lists.infradead.org From: Jisheng Zhang [ Upstream commit 8f1534e7440382d118c3d655d3a6014128b2086d ] Inspired by[1], modify the code to remove the code of modifying ra to avoid imbalance RAS (return address stack) which may lead to incorret predictions on return. Link: https://lore.kernel.org/linux-riscv/20240607061335.2197383-1-cyrilbur@tenstorrent.com/ [1] Signed-off-by: Jisheng Zhang Reviewed-by: Cyril Bur Link: https://lore.kernel.org/r/20240720170659.1522-1-jszhang@kernel.org Signed-off-by: Palmer Dabbelt Signed-off-by: Sasha Levin --- arch/riscv/kernel/entry.S | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/arch/riscv/kernel/entry.S b/arch/riscv/kernel/entry.S index ac2e908d4418d..fefb8e7d957a0 100644 --- a/arch/riscv/kernel/entry.S +++ b/arch/riscv/kernel/entry.S @@ -239,8 +239,8 @@ SYM_CODE_START(ret_from_fork) jalr s0 1: move a0, sp /* pt_regs */ - la ra, ret_from_exception - tail syscall_exit_to_user_mode + call syscall_exit_to_user_mode + j ret_from_exception SYM_CODE_END(ret_from_fork) #ifdef CONFIG_IRQ_STACKS -- 2.43.0 _______________________________________________ linux-riscv mailing list linux-riscv@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-riscv