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 X-Spam-Level: X-Spam-Status: No, score=-10.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 16DC2C433E0 for ; Mon, 8 Jun 2020 23:59:17 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id DC0F920659 for ; Mon, 8 Jun 2020 23:59:16 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1591660756; bh=gwHOTiEwrXbrhoFntqQY0pMO4V4hlL1dCJ8i+b9GK68=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=aBS/lWjy0DKk+S3hyVM37ZOfGDSb4hor92e+ZW5l/kKQ+VgbC4+vUWsn8K/ZCIexr ma1QY1a8ave22hQDSyAFbauW9m1Jdd8QM0rqILpcfI+SDDIN/VVVcyVlbY9pFIZu9L SpAcHzTMJ3YLsub8dazz+oIujWuXf4z6bmySMC60= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732739AbgFHX7P (ORCPT ); Mon, 8 Jun 2020 19:59:15 -0400 Received: from mail.kernel.org ([198.145.29.99]:47936 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730212AbgFHXXA (ORCPT ); Mon, 8 Jun 2020 19:23:00 -0400 Received: from sasha-vm.mshome.net (c-73-47-72-35.hsd1.nh.comcast.net [73.47.72.35]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 1086C20842; Mon, 8 Jun 2020 23:22:59 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1591658580; bh=gwHOTiEwrXbrhoFntqQY0pMO4V4hlL1dCJ8i+b9GK68=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=bayEzrATFAzGgDtKbhAOUCxfRwTm4KcOvfY+7l36f6d1QZ3c77vZ7rgc0cyd0f7Oo ikwbPvnk5HKDCWLfJd4NupP7aJfcHP4HSW1zZFKDIgU4WOCkFNlTbM+B9X3fXZpaoX PXLS1A1khn3y7bNQbp66ny0HTlplq2Cs3o73jdI8= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Douglas Anderson , Greg Kroah-Hartman , Daniel Thompson , Sasha Levin , kgdb-bugreport@lists.sourceforge.net Subject: [PATCH AUTOSEL 4.19 018/106] kgdb: Disable WARN_CONSOLE_UNLOCKED for all kgdb Date: Mon, 8 Jun 2020 19:21:10 -0400 Message-Id: <20200608232238.3368589-18-sashal@kernel.org> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20200608232238.3368589-1-sashal@kernel.org> References: <20200608232238.3368589-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Douglas Anderson [ Upstream commit 202164fbfa2b2ffa3e66b504e0f126ba9a745006 ] In commit 81eaadcae81b ("kgdboc: disable the console lock when in kgdb") we avoided the WARN_CONSOLE_UNLOCKED() yell when we were in kgdboc. That still works fine, but it turns out that we get a similar yell when using other I/O drivers. One example is the "I/O driver" for the kgdb test suite (kgdbts). When I enabled that I again got the same yells. Even though "kgdbts" doesn't actually interact with the user over the console, using it still causes kgdb to print to the consoles. That trips the same warning: con_is_visible+0x60/0x68 con_scroll+0x110/0x1b8 lf+0x4c/0xc8 vt_console_print+0x1b8/0x348 vkdb_printf+0x320/0x89c kdb_printf+0x68/0x90 kdb_main_loop+0x190/0x860 kdb_stub+0x2cc/0x3ec kgdb_cpu_enter+0x268/0x744 kgdb_handle_exception+0x1a4/0x200 kgdb_compiled_brk_fn+0x34/0x44 brk_handler+0x7c/0xb8 do_debug_exception+0x1b4/0x228 Let's increment/decrement the "ignore_console_lock_warning" variable all the time when we enter the debugger. This will allow us to later revert commit 81eaadcae81b ("kgdboc: disable the console lock when in kgdb"). Signed-off-by: Douglas Anderson Reviewed-by: Greg Kroah-Hartman Reviewed-by: Daniel Thompson Link: https://lore.kernel.org/r/20200507130644.v4.1.Ied2b058357152ebcc8bf68edd6f20a11d98d7d4e@changeid Signed-off-by: Daniel Thompson Signed-off-by: Sasha Levin --- kernel/debug/debug_core.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/kernel/debug/debug_core.c b/kernel/debug/debug_core.c index 94aa9ae0007a..d2799767aab8 100644 --- a/kernel/debug/debug_core.c +++ b/kernel/debug/debug_core.c @@ -577,6 +577,8 @@ static int kgdb_cpu_enter(struct kgdb_state *ks, struct pt_regs *regs, if (kgdb_skipexception(ks->ex_vector, ks->linux_regs)) goto kgdb_restore; + atomic_inc(&ignore_console_lock_warning); + /* Call the I/O driver's pre_exception routine */ if (dbg_io_ops->pre_exception) dbg_io_ops->pre_exception(); @@ -649,6 +651,8 @@ static int kgdb_cpu_enter(struct kgdb_state *ks, struct pt_regs *regs, if (dbg_io_ops->post_exception) dbg_io_ops->post_exception(); + atomic_dec(&ignore_console_lock_warning); + if (!kgdb_single_step) { raw_spin_unlock(&dbg_slave_lock); /* Wait till all the CPUs have quit from the debugger. */ -- 2.25.1