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 E4F1CCF885A for ; Fri, 4 Oct 2024 19:32:10 +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=y2ouNHSQtEYK9n4bhs1liiXSGmts3t3XWE56q9Id30E=; b=vG4NisaO7+xLWg gSX7uK3JC/GZiLUS7YiTZWPmHrsMHo08BRWkEb0g2sdY/ekffHcGgpvkzLIrs/Rbyb12gUQvEqvts xaX7RYrJs6A2bb+nXt04C3cwEVvpY+nkA+omegW17pOeP6PME1wt83fs0coJ8PxO6nJl3tZ7o9Xe/ x4Oaatpw5sjrQUVsQ0P/f4RnU5dNSxykvo5ze0c8Vu8qI3AVNvHW9NZsM4ZyUFJUuLfHM3GrP7Ow7 /UDuwVnl/DIV2jqNISXIbNCZjZDVsEvKKisC8R3dTkm+iA4NuT5D79DF2HIFi6shkzEhU/sg8Dl+Q SMinsg1d8JX40e3kULZA==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98 #2 (Red Hat Linux)) id 1swo22-0000000DueY-39kQ; Fri, 04 Oct 2024 19:32:06 +0000 Received: from dfw.source.kernel.org ([139.178.84.217]) by bombadil.infradead.org with esmtps (Exim 4.98 #2 (Red Hat Linux)) id 1swn05-0000000DhGF-2bwz for linux-riscv@lists.infradead.org; Fri, 04 Oct 2024 18:26:02 +0000 Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by dfw.source.kernel.org (Postfix) with ESMTP id EF5DE5C12A9; Fri, 4 Oct 2024 18:25:56 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 288A7C4CECC; Fri, 4 Oct 2024 18:25:59 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1728066360; bh=KEHGx5ZxOwmv3mqRRP4gulTwHNAd9PJT3vm70lAVmY4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=GMhwOui6NifvV0XMnaswzCogywNQ3ugAmVOhFFYu19hf2Da/RyF6pVYdUOqniqVs8 wsaC0GjhyE0JQzKY+BqE5dzv2nVK++UZgYbbbMVuc38HMgS/uu60Djcv2Yxl1iNSvX ReVrBu6ZUHgOXWcK46C3XkrC40mcACe3RoRH3FAaydjHTM8z4lKCa3QnMq5gogPRGv KBG8IIxkTLWvlDpFLB10CksvOjSByYhaShfirlZ7FzFtCWRbpdJlIIIZ5sqEYw0dQ5 DweFebealMUilmhzrk0XVQS+9iRKGDImPA7jDMGyWOYoZRyZrTTLYI7e052jmIJPkh Z8EomJy/lpF7w== 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, antonb@tenstorrent.com, debug@rivosinc.com, andy.chiu@sifive.com, linux-riscv@lists.infradead.org Subject: [PATCH AUTOSEL 6.6 32/58] riscv: avoid Imbalance in RAS Date: Fri, 4 Oct 2024 14:24:05 -0400 Message-ID: <20241004182503.3672477-32-sashal@kernel.org> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20241004182503.3672477-1-sashal@kernel.org> References: <20241004182503.3672477-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore X-stable-base: Linux 6.6.54 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20241004_112601_727695_10FCEE2F X-CRM114-Status: UNSURE ( 9.60 ) 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 ed7baf2cf7e87..1f90fee24a8ba 100644 --- a/arch/riscv/kernel/entry.S +++ b/arch/riscv/kernel/entry.S @@ -219,8 +219,8 @@ 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) /* -- 2.43.0 _______________________________________________ linux-riscv mailing list linux-riscv@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-riscv