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 lists.ozlabs.org (lists.ozlabs.org [112.213.38.117]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id D665BC433EF for ; Mon, 17 Jan 2022 17:31:24 +0000 (UTC) Received: from boromir.ozlabs.org (localhost [IPv6:::1]) by lists.ozlabs.org (Postfix) with ESMTP id 4JczTl24P2z3hD9 for ; Tue, 18 Jan 2022 04:31:23 +1100 (AEDT) Authentication-Results: lists.ozlabs.org; dkim=fail reason="signature verification failed" (2048-bit key; unprotected) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20201202 header.b=pLziprGx; dkim-atps=neutral Authentication-Results: lists.ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=kernel.org (client-ip=145.40.68.75; helo=ams.source.kernel.org; envelope-from=sashal@kernel.org; receiver=) Authentication-Results: lists.ozlabs.org; dkim=pass (2048-bit key; unprotected) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20201202 header.b=pLziprGx; dkim-atps=neutral Received: from ams.source.kernel.org (ams.source.kernel.org [145.40.68.75]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 4Jcyw12H1yz3f0G for ; Tue, 18 Jan 2022 04:05:37 +1100 (AEDT) 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 ams.source.kernel.org (Postfix) with ESMTPS id D7905B81151; Mon, 17 Jan 2022 17:05:34 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 20FA3C36AE3; Mon, 17 Jan 2022 17:05:32 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1642439133; bh=+4Y45NR2lyzG41zk6KY232Sml1e0lHoiQZKzYnmhRPk=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=pLziprGxrKUiYk7EzhHcRRlIkZRUfXWlj8ksd2f/RLRhxOHITAmPD4ukTd2SDxYjT TmqEOzo08QkrWWo49akd81plKomM66R1BaiXF3LbspcJQ1mjjnvdmGr/oELpZGjESi 9pW4uNltA6LdZ3/gRWms4FwPZtQPXo2d5m1lSK5e9LGvSV++BSS0T80r59rVep3kzS AGzv+agCXQCwlxCEDUDXYyRQfAv9D2ry1rYtNwP+7TSktqPbyNGFvr2jsMBtlFw/fm hQPieDyfSpgXGuEikfp+f8uKXX7uOjGo0GvtGcfCXMWnmgSfhAwjq9xH4eAwgY+EMl mI6HAdCovJwLg== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Subject: [PATCH AUTOSEL 5.4 16/21] powerpc: handle kdump appropriately with crash_kexec_post_notifiers option Date: Mon, 17 Jan 2022 12:04:48 -0500 Message-Id: <20220117170454.1472347-16-sashal@kernel.org> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20220117170454.1472347-1-sashal@kernel.org> References: <20220117170454.1472347-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit X-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Sasha Levin , ego@linux.vnet.ibm.com, kernel test robot , parth@linux.ibm.com, linuxppc-dev@lists.ozlabs.org, npiggin@gmail.com, clg@kaod.org, yukuai3@huawei.com, robh@kernel.org, valentin.schneider@arm.com, Hari Bathini , srikar@linux.vnet.ibm.com Errors-To: linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Sender: "Linuxppc-dev" From: Hari Bathini [ Upstream commit 219572d2fc4135b5ce65c735d881787d48b10e71 ] Kdump can be triggered after panic_notifers since commit f06e5153f4ae2 ("kernel/panic.c: add "crash_kexec_post_notifiers" option for kdump after panic_notifers") introduced crash_kexec_post_notifiers option. But using this option would mean smp_send_stop(), that marks all other CPUs as offline, gets called before kdump is triggered. As a result, kdump routines fail to save other CPUs' registers. To fix this, kdump friendly crash_smp_send_stop() function was introduced with kernel commit 0ee59413c967 ("x86/panic: replace smp_send_stop() with kdump friendly version in panic path"). Override this kdump friendly weak function to handle crash_kexec_post_notifiers option appropriately on powerpc. Reported-by: kernel test robot Signed-off-by: Hari Bathini [Fixed signature of crash_stop_this_cpu() - reported by lkp@intel.com] Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20211207103719.91117-1-hbathini@linux.ibm.com Signed-off-by: Sasha Levin --- arch/powerpc/kernel/smp.c | 30 ++++++++++++++++++++++++++++++ 1 file changed, 30 insertions(+) diff --git a/arch/powerpc/kernel/smp.c b/arch/powerpc/kernel/smp.c index 82dff003a7fd6..4de63ec2e1551 100644 --- a/arch/powerpc/kernel/smp.c +++ b/arch/powerpc/kernel/smp.c @@ -582,6 +582,36 @@ void crash_send_ipi(void (*crash_ipi_callback)(struct pt_regs *)) } #endif +#ifdef CONFIG_NMI_IPI +static void crash_stop_this_cpu(struct pt_regs *regs) +#else +static void crash_stop_this_cpu(void *dummy) +#endif +{ + /* + * Just busy wait here and avoid marking CPU as offline to ensure + * register data is captured appropriately. + */ + while (1) + cpu_relax(); +} + +void crash_smp_send_stop(void) +{ + static bool stopped = false; + + if (stopped) + return; + + stopped = true; + +#ifdef CONFIG_NMI_IPI + smp_send_nmi_ipi(NMI_IPI_ALL_OTHERS, crash_stop_this_cpu, 1000000); +#else + smp_call_function(crash_stop_this_cpu, NULL, 0); +#endif /* CONFIG_NMI_IPI */ +} + #ifdef CONFIG_NMI_IPI static void nmi_stop_this_cpu(struct pt_regs *regs) { -- 2.34.1