From patchwork Wed Oct 19 14:55:42 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: John Ogness X-Patchwork-Id: 1692044 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@legolas.ozlabs.org Authentication-Results: legolas.ozlabs.org; spf=none (no SPF record) smtp.mailfrom=lists.infradead.org (client-ip=2607:7c80:54:3::133; helo=bombadil.infradead.org; envelope-from=linux-um-bounces+incoming=patchwork.ozlabs.org@lists.infradead.org; receiver=) Authentication-Results: legolas.ozlabs.org; dkim=pass (2048-bit key; secure) header.d=lists.infradead.org header.i=@lists.infradead.org header.a=rsa-sha256 header.s=bombadil.20210309 header.b=dVvqqN5a; dkim=fail reason="signature verification failed" (2048-bit key; secure) header.d=linutronix.de header.i=@linutronix.de header.a=rsa-sha256 header.s=2020 header.b=s+uK2CVy; dkim=fail reason="signature verification failed" header.d=linutronix.de header.i=@linutronix.de header.a=ed25519-sha256 header.s=2020e header.b=o+Tf43pK; dkim-atps=neutral Received: from bombadil.infradead.org (bombadil.infradead.org [IPv6:2607:7c80:54:3::133]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-384) server-digest SHA384) (No client certificate requested) by legolas.ozlabs.org (Postfix) with ESMTPS id 4MsvN42Rfpz23kb for ; Thu, 20 Oct 2022 02:12:04 +1100 (AEDT) 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=e24APktF5KaoM+SW3308/XRqLdr+eBbVqgmqZEN3tCU=; b=dVvqqN5azZLJ2F hNcdlsge8TsZ0rxwpnfY4th18SR2hipkjGPUYjelnvVnqPO6KvusEksHddx+O769kh+c22QvjnMbm 5KBoxfdBwE2vX0a1Mer1AWn/vFVayYlxecbzBCrkbH6vWq+X1Avkt4EmY9DY0hhs5r/D/WmGHt+IB 7KkaIPPzmGKeqF1JTU1731eAFsrL2DyzoX5Ts+bhN79oPitspiEjIoIfT5w+yHKHiYHmSds+J0PLO zAoE9PfQmd9e/TWV7Ji8++8mKyJC0YuPOQwr2E3yFUnJt9fY7LlMVeuyl3rdSh3pqkwgQWobUCt5H w9bG3l4ulOmpro9o/8zQ==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1olAja-0036Uy-41; Wed, 19 Oct 2022 15:11:54 +0000 Received: from galois.linutronix.de ([2a0a:51c0:0:12e:550::1]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1olAUQ-002wcx-Ir for linux-um@lists.infradead.org; Wed, 19 Oct 2022 14:56:16 +0000 From: John Ogness DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1666191373; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=2RcyNuvhxtc3XAp6KUXXBEZGfBTKoyRNmah0KdJRqUM=; b=s+uK2CVyfeRWS2SM8ONtEm3ezF4TKCfBKPBHIwbQeW7/3EKdt2DXK8Se8xiredxeNeCSkY ZKidWJ9kOFMnJ+GDRhqzajlfU0p4AFkX17OY/4V8RDFxWqEJS/1ZvxtBmCOcbU/4l2IV5+ uARnYyoVv6Nyvh9wOtzsxW1T3vJw5LOkY1LuXAHyxPLMVW6YaxF14EZEX4gyzIy+5CXUjS vS1F3O108Xc1xgSipOJuPxZcLQ/qV1jeZloh/cC1xGCqj2wAIwT9zN8nuby6knA2dC3umy BQvb2BMGIRylFs6NDquzoIBMVcnZI7H6sM7m8P0T/FddSctNfiRBDKDOqpiRPg== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1666191373; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=2RcyNuvhxtc3XAp6KUXXBEZGfBTKoyRNmah0KdJRqUM=; b=o+Tf43pKW3jb3K3SYt/Uyhx64JMO0G2cG8/ulnFuahJncjT6ev9pQxCcwgJEpI8Oeo5SuX YSUluQ/obMklGtAg== To: Petr Mladek Cc: Sergey Senozhatsky , Steven Rostedt , Thomas Gleixner , linux-kernel@vger.kernel.org, Richard Weinberger , Anton Ivanov , Johannes Berg , linux-um@lists.infradead.org Subject: [PATCH printk v2 20/38] um: kmsg_dumper: use srcu console list iterator Date: Wed, 19 Oct 2022 17:01:42 +0206 Message-Id: <20221019145600.1282823-21-john.ogness@linutronix.de> In-Reply-To: <20221019145600.1282823-1-john.ogness@linutronix.de> References: <20221019145600.1282823-1-john.ogness@linutronix.de> MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20221019_075614_810331_E53864DB X-CRM114-Status: UNSURE ( 9.06 ) X-CRM114-Notice: Please train this message. X-Spam-Score: -1.9 (-) X-Spam-Report: Spam detection software, running on the system "bombadil.infradead.org", has NOT identified this incoming email as spam. The original message has been attached to this so you can view it or label similar future email. If you have any questions, see the administrator of that system for details. Content preview: Rather than using the console_lock to guarantee safe console list traversal, use srcu console list iteration. Signed-off-by: John Ogness --- arch/um/kernel/kmsg_dump.c | 11 ++++------- 1 file changed, 4 insertions(+), 7 deletions(-) Content analysis details: (-1.9 points, 5.0 required) pts rule name description ---- ---------------------- -------------------------------------------------- -2.3 RCVD_IN_DNSWL_MED RBL: Sender listed at https://www.dnswl.org/, medium trust [2a0a:51c0:0:12e:550:0:0:1 listed in] [list.dnswl.org] 0.6 INVALID_DATE_TZ_ABSURD Invalid Date: header (timezone does not exist) -0.0 SPF_PASS SPF: sender matches SPF record 0.0 SPF_HELO_NONE SPF: HELO does not publish an SPF Record -0.1 DKIM_VALID_AU Message has a valid DKIM or DK signature from author's domain -0.1 DKIM_VALID Message has at least one valid DKIM or DK signature 0.1 DKIM_SIGNED Message has a DKIM or DK signature, not necessarily valid -0.1 DKIM_VALID_EF Message has a valid DKIM or DK signature from envelope-from domain X-BeenThere: linux-um@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-um" Errors-To: linux-um-bounces+incoming=patchwork.ozlabs.org@lists.infradead.org Rather than using the console_lock to guarantee safe console list traversal, use srcu console list iteration. Signed-off-by: John Ogness --- arch/um/kernel/kmsg_dump.c | 11 ++++------- 1 file changed, 4 insertions(+), 7 deletions(-) diff --git a/arch/um/kernel/kmsg_dump.c b/arch/um/kernel/kmsg_dump.c index 3a3bbbb22090..44a418dec919 100644 --- a/arch/um/kernel/kmsg_dump.c +++ b/arch/um/kernel/kmsg_dump.c @@ -16,20 +16,17 @@ static void kmsg_dumper_stdout(struct kmsg_dumper *dumper, struct console *con; unsigned long flags; size_t len = 0; + int cookie; /* only dump kmsg when no console is available */ - if (!console_trylock()) - return; - - for_each_console(con) { + cookie = console_srcu_read_lock(); + for_each_console_srcu(con) { if (strcmp(con->name, "tty") == 0 && (console_is_enabled(con) || (con->flags & CON_CONSDEV))) { break; } } - - console_unlock(); - + console_srcu_read_unlock(cookie); if (con) return;