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 E791CC433FE for ; Thu, 7 Apr 2022 01:20:25 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S238997AbiDGBWQ (ORCPT ); Wed, 6 Apr 2022 21:22:16 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:60920 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S240237AbiDGBTw (ORCPT ); Wed, 6 Apr 2022 21:19:52 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 197D51B7606; Wed, 6 Apr 2022 18:15:33 -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 F2BC061DCF; Thu, 7 Apr 2022 01:15:32 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 831F7C385A1; Thu, 7 Apr 2022 01:15:31 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1649294132; bh=JGTxfCZOOghgkyjf3BWnR1x9TbNLIoiVYqZlPvou4Fk=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=IfTDA8yfdQTolKfp3k0/nbj3lclzidaZ5ajH+HnR+XSHs0I1Om8jfWyahgX3yqw3k imL6CYHFYRKxk43NtCv/QBqlVEGFqYXZnDlvKfmrZEQ2E0VOHgA9DAsMhActimu6z8 7GgG2o//RJPG9DUFZdu6AordA7E+DPwB9LLD/UqX5fC7smBPQcngqHVUGVycMb8MTk uwnuxzQIYmgAma8IR4fB38dvaamD6U8RgMbT4/4vyU+Qow3Tz0T4vJCYwydA0SYIZZ qQHzbTxUL7CThkVaq6m4pIddMMbM4sYtsFCNp+/CFGNtw8JPGClhT+Tj+AmoEVI+Zc xHRaZiJwfwHkA== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Glenn Washburn , Richard Weinberger , Sasha Levin , anton.ivanov@cambridgegreys.com, johannes@sipsolutions.net, linux-um@lists.infradead.org Subject: [PATCH AUTOSEL 5.4 04/17] um: port_user: Improve error handling when port-helper is not found Date: Wed, 6 Apr 2022 21:15:08 -0400 Message-Id: <20220407011521.115014-4-sashal@kernel.org> X-Mailer: git-send-email 2.35.1 In-Reply-To: <20220407011521.115014-1-sashal@kernel.org> References: <20220407011521.115014-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Glenn Washburn [ Upstream commit 3cb5a7f167c620a8b0e38b0446df2e024d2243dc ] Check if port-helper exists and is executable. If not, write an error message to the kernel log with information to help the user diagnose the issue and exit with an error. If UML_PORT_HELPER was not set, write a message suggesting that the user set it. This makes it easier to understand why telneting to the UML instance is failing and what can be done to fix it. Signed-off-by: Glenn Washburn Signed-off-by: Richard Weinberger Signed-off-by: Sasha Levin --- arch/um/drivers/port_user.c | 12 ++++++++++++ 1 file changed, 12 insertions(+) diff --git a/arch/um/drivers/port_user.c b/arch/um/drivers/port_user.c index 5b5b64cb1071..133ca7bf2d91 100644 --- a/arch/um/drivers/port_user.c +++ b/arch/um/drivers/port_user.c @@ -5,6 +5,7 @@ #include #include +#include #include #include #include @@ -175,6 +176,17 @@ int port_connection(int fd, int *socket, int *pid_out) if (new < 0) return -errno; + err = os_access(argv[2], X_OK); + if (err < 0) { + printk(UM_KERN_ERR "port_connection : error accessing port-helper " + "executable at %s: %s\n", argv[2], strerror(-err)); + if (env == NULL) + printk(UM_KERN_ERR "Set UML_PORT_HELPER environment " + "variable to path to uml-utilities port-helper " + "binary\n"); + goto out_close; + } + err = os_pipe(socket, 0, 0); if (err < 0) goto out_close; -- 2.35.1