From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 5F2C32572 for ; Tue, 18 Apr 2023 12:46:04 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id D5177C433EF; Tue, 18 Apr 2023 12:46:03 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1681821964; bh=L2qpSYZN89yg6JT/x90oJp6boUmemheD0VU0QcLFxgE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=yI9CsRTZLiaoRWEf2Ev1bBZUbpzxcbKVj+6iWd1w1Gpb3yBpFk0ZHr94n2JUkfF8F 9KAN72FpSwoGaQNnvp+mpny9FJmfzG2Oa6xAZ4vHo7dmxLNKVdYWNdSvTsknVWMyIy d/GNbdRYbq9RgxReallfFf6pQr0u0qtDzjIKBKYY= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Mathis Salmen , Palmer Dabbelt Subject: [PATCH 6.1 104/134] riscv: add icache flush for nommu sigreturn trampoline Date: Tue, 18 Apr 2023 14:22:40 +0200 Message-Id: <20230418120316.817971546@linuxfoundation.org> X-Mailer: git-send-email 2.40.0 In-Reply-To: <20230418120313.001025904@linuxfoundation.org> References: <20230418120313.001025904@linuxfoundation.org> User-Agent: quilt/0.67 Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 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 @@ -19,6 +19,7 @@ #include #include #include +#include extern u32 __user_rt_sigreturn[2]; @@ -181,6 +182,7 @@ 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))) @@ -209,7 +211,12 @@ 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 */ /*