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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 78B66C77B76 for ; Tue, 18 Apr 2023 12:39:55 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231295AbjDRMjy (ORCPT ); Tue, 18 Apr 2023 08:39:54 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:56364 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231839AbjDRMjv (ORCPT ); Tue, 18 Apr 2023 08:39:51 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 652584699 for ; Tue, 18 Apr 2023 05:39:50 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id F40B2632F5 for ; Tue, 18 Apr 2023 12:39:49 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 10E50C4339B; Tue, 18 Apr 2023 12:39:48 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1681821589; bh=zRLMH/4M1S3OWNZU5MIgZLHkKCAM3Htt2XONDBZDETI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=hVcmRLaqNqCdh4bMzppkw/2MkhMe0KHko3w+YWy/3FWxbQ+DdiajKEA+5m1Y2b2RZ NcJT1mtmjw7h95ostVz29QgJ1Ay60JreWQuuUqzc3O/5Vi63spfdW4LGgNp7aHUKsZ /mlDj+9bju6XFwqONBUMoZ8/o060nBz7K4fOcsL0= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Mathis Salmen , Palmer Dabbelt Subject: [PATCH 5.15 58/91] riscv: add icache flush for nommu sigreturn trampoline Date: Tue, 18 Apr 2023 14:22:02 +0200 Message-Id: <20230418120307.611756567@linuxfoundation.org> X-Mailer: git-send-email 2.40.0 In-Reply-To: <20230418120305.520719816@linuxfoundation.org> References: <20230418120305.520719816@linuxfoundation.org> User-Agent: quilt/0.67 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Mathis Salmen commit 8d736482749f6d350892ef83a7a11d43cd49981e upstream. In a NOMMU kernel, sigreturn trampolines are generated on the user stack by setup_rt_frame. Currently, these trampolines are not instruction fenced, thus their visibility to ifetch is not guaranteed. This patch adds a flush_icache_range in setup_rt_frame to fix this problem. Signed-off-by: Mathis Salmen Fixes: 6bd33e1ece52 ("riscv: add nommu support") Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/20230406101130.82304-1-mathis.salmen@matsal.de Signed-off-by: Palmer Dabbelt Signed-off-by: Greg Kroah-Hartman --- arch/riscv/kernel/signal.c | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-) --- a/arch/riscv/kernel/signal.c +++ b/arch/riscv/kernel/signal.c @@ -16,6 +16,7 @@ #include #include #include +#include extern u32 __user_rt_sigreturn[2]; @@ -178,6 +179,7 @@ static int setup_rt_frame(struct ksignal { struct rt_sigframe __user *frame; long err = 0; + unsigned long __maybe_unused addr; frame = get_sigframe(ksig, regs, sizeof(*frame)); if (!access_ok(frame, sizeof(*frame))) @@ -206,7 +208,12 @@ static int setup_rt_frame(struct ksignal if (copy_to_user(&frame->sigreturn_code, __user_rt_sigreturn, sizeof(frame->sigreturn_code))) return -EFAULT; - regs->ra = (unsigned long)&frame->sigreturn_code; + + addr = (unsigned long)&frame->sigreturn_code; + /* Make sure the two instructions are pushed to icache. */ + flush_icache_range(addr, addr + sizeof(frame->sigreturn_code)); + + regs->ra = addr; #endif /* CONFIG_MMU */ /*