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 6E8D4C433DF for ; Mon, 8 Jun 2020 23:44:58 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 5031B2078D for ; Mon, 8 Jun 2020 23:44:58 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1591659898; bh=/YRsKm+UuUQSjVNhO4o+amEOfE2Aw0EN2Skl2Q46c+Q=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=VOtc3Hfoi59Le3kob9f9xF0NhAFarJTSNrE7p/V1HX7sIS6fCoicsS9YFntTktADo 7dCjFuehpREzlykbPhuOJO9U9m+nuOgzSs7+mEWZpB3YB02vh7P99Mw/GXVh29wGya uLG6aZSDCaAIjuOzReUTcCBLgtN5E6F71nM2fYVY= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731466AbgFHXo4 (ORCPT ); Mon, 8 Jun 2020 19:44:56 -0400 Received: from mail.kernel.org ([198.145.29.99]:54762 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1732042AbgFHX0u (ORCPT ); Mon, 8 Jun 2020 19:26:50 -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 9B4762072F; Mon, 8 Jun 2020 23:26:49 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1591658810; bh=/YRsKm+UuUQSjVNhO4o+amEOfE2Aw0EN2Skl2Q46c+Q=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=lx0VLFRJ2a312UGj1WC3l1BfOJIlbn9yCNFuk3difwrH23LSRXP7yfZjgY8VOmGCt cyTGq0RuP+OWYgum4DS6CIU/3mGiWeWLtLAvUpbgRSwDRpv4N6Yl8brewx5F9sYQmI iQtGvp0E2KZk7GvH/yD97c3tEwhP+VjvnyKPSeWI= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Douglas Anderson , Daniel Thompson , Sasha Levin , kgdb-bugreport@lists.sourceforge.net Subject: [PATCH AUTOSEL 4.9 08/50] kgdb: Prevent infinite recursive entries to the debugger Date: Mon, 8 Jun 2020 19:25:58 -0400 Message-Id: <20200608232640.3370262-8-sashal@kernel.org> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20200608232640.3370262-1-sashal@kernel.org> References: <20200608232640.3370262-1-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 3ca676e4ca60d1834bb77535dafe24169cadacef ] If we detect that we recursively entered the debugger we should hack our I/O ops to NULL so that the panic() in the next line won't actually cause another recursion into the debugger. The first line of kgdb_panic() will check this and return. Signed-off-by: Douglas Anderson Reviewed-by: Daniel Thompson Link: https://lore.kernel.org/r/20200507130644.v4.6.I89de39f68736c9de610e6f241e68d8dbc44bc266@changeid Signed-off-by: Daniel Thompson Signed-off-by: Sasha Levin --- kernel/debug/debug_core.c | 1 + 1 file changed, 1 insertion(+) diff --git a/kernel/debug/debug_core.c b/kernel/debug/debug_core.c index 79517e5549f1..9c939c6bf21c 100644 --- a/kernel/debug/debug_core.c +++ b/kernel/debug/debug_core.c @@ -443,6 +443,7 @@ static int kgdb_reenter_check(struct kgdb_state *ks) if (exception_level > 1) { dump_stack(); + kgdb_io_module_registered = false; panic("Recursive entry to debugger"); } -- 2.25.1