From patchwork Thu Aug 11 07:41:45 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Xianting Tian X-Patchwork-Id: 12941212 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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (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 132BCC25B0C for ; Thu, 11 Aug 2022 07:42:32 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:MIME-Version:List-Subscribe:List-Help: List-Post:List-Archive:List-Unsubscribe:List-Id:References:In-Reply-To: Message-Id:Date:Subject:Cc:To:From:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=uVPx8cl15OMdC/5DjMk0t//7HY32xKBJoV07V607lKw=; b=LjulvmxsQhLImO eMyO0Wq59/GznuowGBkyiks59zftqQh8TtC3iQncz1Rdalvk0SSDQ/LN1zMmoEFrdKtjAwRdEOtrP Sbee5usR7MI39j2eEW0yOCnYZjs9YROZ9BRzKniMH+0URrTCIAvtFeP/uy4OGZmB3NCzlCnLZSQzt +nTUS63lwJ0eLn4N+Om0inEiduq3NYMyOAbBBwMfSXzUhBDAc0fVe3nLTP/fZDCTJKAAgQWnh3f2I cgxmpmluhj0Ycs/+4intt2+VRMUsIlrhuqK9dZzyJfKgMTCREqS+G61VD3ES4ygvGOAJC9MTlo8JD 70UAFHgxE5n99TY+oxag==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1oM2pe-009m2S-D4; Thu, 11 Aug 2022 07:42:18 +0000 Received: from out30-54.freemail.mail.aliyun.com ([115.124.30.54]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1oM2pN-009lcS-7G; Thu, 11 Aug 2022 07:42:03 +0000 X-Alimail-AntiSpam: AC=PASS;BC=-1|-1;BR=01201311R191e4;CH=green;DM=||false|;DS=||;FP=0|-1|-1|-1|0|-1|-1|-1;HT=ay29a033018045192;MF=xianting.tian@linux.alibaba.com;NM=1;PH=DS;RN=23;SR=0;TI=SMTPD_---0VLyMVg9_1660203714; Received: from localhost(mailfrom:xianting.tian@linux.alibaba.com fp:SMTPD_---0VLyMVg9_1660203714) by smtp.aliyun-inc.com; Thu, 11 Aug 2022 15:41:55 +0800 From: Xianting Tian To: paul.walmsley@sifive.com, palmer@dabbelt.com, aou@eecs.berkeley.edu, anup@brainfault.org, heiko@sntech.de, guoren@kernel.org, mick@ics.forth.gr, alexandre.ghiti@canonical.com, bhe@redhat.com, vgoyal@redhat.com, dyoung@redhat.com, corbet@lwn.net, Conor.Dooley@microchip.com Cc: kexec@lists.infradead.org, linux-doc@vger.kernel.org, linux-riscv@lists.infradead.org, linux-kernel@vger.kernel.org, crash-utility@redhat.com, heinrich.schuchardt@canonical.com, k-hagio-ab@nec.com, hschauhan@nulltrace.org, yixun.lan@gmail.com, Xianting Tian Subject: [PATCH V6 1/6] RISC-V: kexec: Fixup use of smp_processor_id() in preemptible context Date: Thu, 11 Aug 2022 15:41:45 +0800 Message-Id: <20220811074150.3020189-2-xianting.tian@linux.alibaba.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20220811074150.3020189-1-xianting.tian@linux.alibaba.com> References: <20220811074150.3020189-1-xianting.tian@linux.alibaba.com> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20220811_004201_511829_7AEB756D X-CRM114-Status: UNSURE ( 8.80 ) X-CRM114-Notice: Please train this message. X-BeenThere: linux-riscv@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Sender: "linux-riscv" Errors-To: linux-riscv-bounces+linux-riscv=archiver.kernel.org@lists.infradead.org Use __smp_processor_id() to avoid check the preemption context when CONFIG_DEBUG_PREEMPT enabled, as we will enter crash kernel and no return. Without the patch, [ 103.781044] sysrq: Trigger a crash [ 103.784625] Kernel panic - not syncing: sysrq triggered crash [ 103.837634] CPU1: off [ 103.889668] CPU2: off [ 103.933479] CPU3: off [ 103.939424] Starting crashdump kernel... [ 103.943442] BUG: using smp_processor_id() in preemptible [00000000] code: sh/346 [ 103.950884] caller is debug_smp_processor_id+0x1c/0x26 [ 103.956051] CPU: 0 PID: 346 Comm: sh Kdump: loaded Not tainted 5.10.113-00002-gce03f03bf4ec-dirty #149 [ 103.965355] Call Trace: [ 103.967805] [] walk_stackframe+0x0/0xa2 [ 103.973206] [] show_stack+0x32/0x3e [ 103.978258] [] dump_stack_lvl+0x72/0x8e [ 103.983655] [] dump_stack+0x14/0x1c [ 103.988705] [] check_preemption_disabled+0x9e/0xaa [ 103.995057] [] debug_smp_processor_id+0x1c/0x26 [ 104.001150] [] machine_kexec+0x22/0xd0 [ 104.006463] [] __crash_kexec+0x6a/0xa4 [ 104.011774] [] panic+0xfc/0x2b0 [ 104.016480] [] sysrq_reset_seq_param_set+0x0/0x70 [ 104.022745] [] __handle_sysrq+0x8c/0x154 [ 104.028229] [] write_sysrq_trigger+0x5a/0x6a [ 104.034061] [] proc_reg_write+0x58/0xd4 [ 104.039459] [] vfs_write+0x7e/0x254 [ 104.044509] [] ksys_write+0x58/0xbe [ 104.049558] [] sys_write+0xe/0x16 [ 104.054434] [] ret_from_syscall+0x0/0x2 [ 104.067863] Will call new kernel at ecc00000 from hart id 0 [ 104.074939] FDT image at fc5ee000 [ 104.079523] Bye... With the patch we can got clear output, [ 67.740553] sysrq: Trigger a crash [ 67.744166] Kernel panic - not syncing: sysrq triggered crash [ 67.809123] CPU1: off [ 67.865210] CPU2: off [ 67.909075] CPU3: off [ 67.919123] Starting crashdump kernel... [ 67.924900] Will call new kernel at ecc00000 from hart id 0 [ 67.932045] FDT image at fc5ee000 [ 67.935560] Bye... Fixes: 0e105f1d0037 ("riscv: use hart id instead of cpu id on machine_kexec") Reviewed-by: Guo Ren Reviewed-by: Heiko Stuebner Reviewed-by: Atish Patra Signed-off-by: Xianting Tian --- arch/riscv/kernel/machine_kexec.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/riscv/kernel/machine_kexec.c b/arch/riscv/kernel/machine_kexec.c index df8e24559035..86d1b5f9dfb5 100644 --- a/arch/riscv/kernel/machine_kexec.c +++ b/arch/riscv/kernel/machine_kexec.c @@ -171,7 +171,7 @@ machine_kexec(struct kimage *image) struct kimage_arch *internal = &image->arch; unsigned long jump_addr = (unsigned long) image->start; unsigned long first_ind_entry = (unsigned long) &image->head; - unsigned long this_cpu_id = smp_processor_id(); + unsigned long this_cpu_id = __smp_processor_id(); unsigned long this_hart_id = cpuid_to_hartid_map(this_cpu_id); unsigned long fdt_addr = internal->fdt_addr; void *control_code_buffer = page_address(image->control_code_page);