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,URIBL_BLOCKED,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 5B89ECA9EAB for ; Fri, 18 Oct 2019 22:25:42 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 25849205C9 for ; Fri, 18 Oct 2019 22:25:42 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1571437542; bh=d/6zc+tZJQ0l59lFjH5IKUXNkBz2OQ9GKqznhzOEnoA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=F17ZlN+nf3dcokrYzlMSp124x6YooVEKm7toKjdU4PbCQAgA7j202509vomI1nWHm COkMMZeunUxL8jQFfBmnucocVvUhjdX9xIiuDNZnBUeqjNEsCjW2g5t0VUv1FWYg8O pBTSKdSv84GNGwI23uC7Vk+/vky5yKkOXc22HmHw= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728319AbfJRWZl (ORCPT ); Fri, 18 Oct 2019 18:25:41 -0400 Received: from mail.kernel.org ([198.145.29.99]:36258 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728314AbfJRWEd (ORCPT ); Fri, 18 Oct 2019 18:04:33 -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 9F3A6222CC; Fri, 18 Oct 2019 22:04:32 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1571436273; bh=d/6zc+tZJQ0l59lFjH5IKUXNkBz2OQ9GKqznhzOEnoA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=XV6zvPvZKq2mDapBa8Eg5nDYTtjfwT3evZnCkwNwOxRlgKsjY4XDWpyGPeCjIkcRG /uyTqfhvej73GzkelNEFeX0NNyW2WcPUGGL+ipr17BmtX/aX1MVdQBtXf4TsnFgxpf 9lkK3zIHpqBEl5nkGlyGlWNIOzhO1i7Pj9qR2V+E= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Vincent Chen , Christoph Hellwig , Paul Walmsley , Sasha Levin Subject: [PATCH AUTOSEL 5.3 52/89] riscv: avoid kernel hangs when trapped in BUG() Date: Fri, 18 Oct 2019 18:02:47 -0400 Message-Id: <20191018220324.8165-52-sashal@kernel.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20191018220324.8165-1-sashal@kernel.org> References: <20191018220324.8165-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Vincent Chen [ Upstream commit 8b04825ed205da38754f86f4c07ea8600d8c2a65 ] When the CONFIG_GENERIC_BUG is disabled by disabling CONFIG_BUG, if a kernel thread is trapped by BUG(), the whole system will be in the loop that infinitely handles the ebreak exception instead of entering the die function. To fix this problem, the do_trap_break() will always call the die() to deal with the break exception as the type of break is BUG_TRAP_TYPE_BUG. Signed-off-by: Vincent Chen Reviewed-by: Christoph Hellwig Signed-off-by: Paul Walmsley Signed-off-by: Sasha Levin --- arch/riscv/kernel/traps.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/arch/riscv/kernel/traps.c b/arch/riscv/kernel/traps.c index 424eb72d56b10..055a937aca70a 100644 --- a/arch/riscv/kernel/traps.c +++ b/arch/riscv/kernel/traps.c @@ -124,23 +124,23 @@ static inline unsigned long get_break_insn_length(unsigned long pc) asmlinkage void do_trap_break(struct pt_regs *regs) { -#ifdef CONFIG_GENERIC_BUG if (!user_mode(regs)) { enum bug_trap_type type; type = report_bug(regs->sepc, regs); switch (type) { +#ifdef CONFIG_GENERIC_BUG case BUG_TRAP_TYPE_NONE: break; case BUG_TRAP_TYPE_WARN: regs->sepc += get_break_insn_length(regs->sepc); break; case BUG_TRAP_TYPE_BUG: +#endif /* CONFIG_GENERIC_BUG */ + default: die(regs, "Kernel BUG"); } } -#endif /* CONFIG_GENERIC_BUG */ - force_sig_fault(SIGTRAP, TRAP_BRKPT, (void __user *)(regs->sepc)); } -- 2.20.1