From patchwork Fri May 8 12:30:24 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg KH X-Patchwork-Id: 226296 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=-6.8 required=3.0 tests=DKIMWL_WL_HIGH, DKIM_SIGNED, DKIM_VALID, HEADER_FROM_DIFFERENT_DOMAINS, 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 A1351C38A2A for ; Fri, 8 May 2020 12:37:22 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 81F9824959 for ; Fri, 8 May 2020 12:37:22 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1588941442; bh=St1aqTSXUcoikltNALu5tsbQlVhuyMmsI6shkvrXr8g=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=rMlT26qwMERVrP0MKHJx6Zz5j6fHtYH72tztQRwUsBvxNixCq7K4vBUst6HuTv6P4 5Qt2eUz7xqep77eBTLyuBDGNp79NGNRC3mbPO9AGSmCmSvIQxXUYDI5nQpU5esLY4U 2aJpAjutdmHBJPqAwydzddaq9vzdHzCJfFDGWfIM= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728089AbgEHMhV (ORCPT ); Fri, 8 May 2020 08:37:21 -0400 Received: from mail.kernel.org ([198.145.29.99]:51658 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728083AbgEHMhU (ORCPT ); Fri, 8 May 2020 08:37:20 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 65248207DD; Fri, 8 May 2020 12:37:19 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1588941440; bh=St1aqTSXUcoikltNALu5tsbQlVhuyMmsI6shkvrXr8g=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=XhC3EdcjKBsTttTG3+Zb/fbA1t+ek9mpNyQZ4QKjGGqxCg+WAYbEqHym+Gr+mWPGO XVwWn5g1pklEGLZgCWXHRUDJNksX9D1GZXiaDlnxzIbbPfeA6B9vLm+p/1Ls1YlOfS l2R+w/JLuaSk2XICa03Xd5CbfnAunlN3GVhzZ6Jo= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Hidehiro Kawai , Daniel Walker , Dave Young , Baoquan He , Vivek Goyal , Eric Biederman , Masami Hiramatsu , Xunlei Pang , Thomas Gleixner , Ingo Molnar , "H. Peter Anvin" , Borislav Petkov , David Vrabel , Toshi Kani , Ralf Baechle , David Daney , Aaro Koskinen , "Steven J. Hill" , Corey Minyard , Andrew Morton , Linus Torvalds Subject: [PATCH 4.4 033/312] mips/panic: replace smp_send_stop() with kdump friendly version in panic path Date: Fri, 8 May 2020 14:30:24 +0200 Message-Id: <20200508123126.809500098@linuxfoundation.org> X-Mailer: git-send-email 2.26.2 In-Reply-To: <20200508123124.574959822@linuxfoundation.org> References: <20200508123124.574959822@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Hidehiro Kawai commit 54c721b857fd45f3ad3bda695ee4f472518db02a upstream. Daniel Walker reported problems which happens when crash_kexec_post_notifiers kernel option is enabled (https://lkml.org/lkml/2015/6/24/44). In that case, smp_send_stop() is called before entering kdump routines which assume other CPUs are still online. As the result, kdump routines fail to save other CPUs' registers. Additionally for MIPS OCTEON, it misses to stop the watchdog timer. To fix this problem, call a new kdump friendly function, crash_smp_send_stop(), instead of the smp_send_stop() when crash_kexec_post_notifiers is enabled. crash_smp_send_stop() is a weak function, and it just call smp_send_stop(). Architecture codes should override it so that kdump can work appropriately. This patch provides MIPS version. Fixes: f06e5153f4ae (kernel/panic.c: add "crash_kexec_post_notifiers" option) Link: http://lkml.kernel.org/r/20160810080950.11028.28000.stgit@sysi4-13.yrl.intra.hitachi.co.jp Signed-off-by: Hidehiro Kawai Reported-by: Daniel Walker Cc: Dave Young Cc: Baoquan He Cc: Vivek Goyal Cc: Eric Biederman Cc: Masami Hiramatsu Cc: Daniel Walker Cc: Xunlei Pang Cc: Thomas Gleixner Cc: Ingo Molnar Cc: "H. Peter Anvin" Cc: Borislav Petkov Cc: David Vrabel Cc: Toshi Kani Cc: Ralf Baechle Cc: David Daney Cc: Aaro Koskinen Cc: "Steven J. Hill" Cc: Corey Minyard Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman --- arch/mips/cavium-octeon/setup.c | 14 ++++++++++++++ arch/mips/include/asm/kexec.h | 1 + arch/mips/kernel/crash.c | 18 +++++++++++++++++- arch/mips/kernel/machine_kexec.c | 1 + 4 files changed, 33 insertions(+), 1 deletion(-) --- a/arch/mips/cavium-octeon/setup.c +++ b/arch/mips/cavium-octeon/setup.c @@ -251,6 +251,17 @@ static void octeon_crash_shutdown(struct default_machine_crash_shutdown(regs); } +#ifdef CONFIG_SMP +void octeon_crash_smp_send_stop(void) +{ + int cpu; + + /* disable watchdogs */ + for_each_online_cpu(cpu) + cvmx_write_csr(CVMX_CIU_WDOGX(cpu_logical_map(cpu)), 0); +} +#endif + #endif /* CONFIG_KEXEC */ #ifdef CONFIG_CAVIUM_RESERVE32 @@ -864,6 +875,9 @@ void __init prom_init(void) _machine_kexec_shutdown = octeon_shutdown; _machine_crash_shutdown = octeon_crash_shutdown; _machine_kexec_prepare = octeon_kexec_prepare; +#ifdef CONFIG_SMP + _crash_smp_send_stop = octeon_crash_smp_send_stop; +#endif #endif octeon_user_io_init(); --- a/arch/mips/include/asm/kexec.h +++ b/arch/mips/include/asm/kexec.h @@ -45,6 +45,7 @@ extern const unsigned char kexec_smp_wai extern unsigned long secondary_kexec_args[4]; extern void (*relocated_kexec_smp_wait) (void *); extern atomic_t kexec_ready_to_reboot; +extern void (*_crash_smp_send_stop)(void); #endif #endif --- a/arch/mips/kernel/crash.c +++ b/arch/mips/kernel/crash.c @@ -50,9 +50,14 @@ static void crash_shutdown_secondary(voi static void crash_kexec_prepare_cpus(void) { + static int cpus_stopped; unsigned int msecs; + unsigned int ncpus; - unsigned int ncpus = num_online_cpus() - 1;/* Excluding the panic cpu */ + if (cpus_stopped) + return; + + ncpus = num_online_cpus() - 1;/* Excluding the panic cpu */ dump_send_ipi(crash_shutdown_secondary); smp_wmb(); @@ -67,6 +72,17 @@ static void crash_kexec_prepare_cpus(voi cpu_relax(); mdelay(1); } + + cpus_stopped = 1; +} + +/* Override the weak function in kernel/panic.c */ +void crash_smp_send_stop(void) +{ + if (_crash_smp_send_stop) + _crash_smp_send_stop(); + + crash_kexec_prepare_cpus(); } #else /* !defined(CONFIG_SMP) */ --- a/arch/mips/kernel/machine_kexec.c +++ b/arch/mips/kernel/machine_kexec.c @@ -25,6 +25,7 @@ void (*_machine_crash_shutdown)(struct p #ifdef CONFIG_SMP void (*relocated_kexec_smp_wait) (void *); atomic_t kexec_ready_to_reboot = ATOMIC_INIT(0); +void (*_crash_smp_send_stop)(void) = NULL; #endif int