From patchwork Wed Jan 24 05:12:40 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Baoquan He X-Patchwork-Id: 13528561 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id D2C6CE54E for ; Wed, 24 Jan 2024 05:13:10 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=170.10.133.124 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1706073192; cv=none; b=dF8LsAT0JTh50FtLjm9Qpf51x7RQBee4noiGqdEK0GEVgjRSA1UNOUNNZr3fyJvsze5wxaRdsMJlVDLWXG6B91EdCvKXvqoVqsDIPeWpAJ4Gwy9wL7nkWr5Xy9RhFZthF3YbF7KjZM6i4hJPFM4cWA/nnQrbkrG+tqMWieJNLyM= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1706073192; c=relaxed/simple; bh=8IRILIHbZzm7JiU2AP+iQrJP86mAIlHIlBV5y0BJ124=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version:Content-type; b=XL9vpg1CEW5frGCZ2hWaVLaE2qIWnCZ150vztHvxXCF18cFMaEK7ruWynvGWXQl7pEHpK6XUenwReiflAHodDAfGgLzE+mb/vBihjuTzZZ8249+RAdKigzNehLYAUASQU9bD6Cnl/r03cgI5VlT5xXkqz7nr22sMFZlTCW3O0Ik= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=redhat.com; spf=pass smtp.mailfrom=redhat.com; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b=C2aci20w; arc=none smtp.client-ip=170.10.133.124 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=redhat.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=redhat.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="C2aci20w" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1706073189; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding; bh=hMrXo75T+RiZg6Ni6slGNp8f5iS89iUB0hhC0nnqkcg=; b=C2aci20wdMV5Vi5o20yvJ1F9+BoiGIJQ9Y5Iqgi36orCFSZLRjxkg1wSE+WvBFXMs4uGCw ZFYF7J+8m2CfYSm6vJc7aAdpSvspYO39clem30gT0RPp8NW6YjVnfkKpFti00mYtNoxV0d d5N60CHKf/Ld2UyOeqfIhXQgoi4uFjU= Received: from mimecast-mx02.redhat.com (mx-ext.redhat.com [66.187.233.73]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-272-wtN1dBuqPpKMsbqqxC-a1w-1; Wed, 24 Jan 2024 00:13:05 -0500 X-MC-Unique: wtN1dBuqPpKMsbqqxC-a1w-1 Received: from smtp.corp.redhat.com (int-mx07.intmail.prod.int.rdu2.redhat.com [10.11.54.7]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 2B2E81C04348; Wed, 24 Jan 2024 05:13:05 +0000 (UTC) Received: from MiWiFi-R3L-srv.redhat.com (unknown [10.72.116.117]) by smtp.corp.redhat.com (Postfix) with ESMTP id 417FF1C060AF; Wed, 24 Jan 2024 05:12:57 +0000 (UTC) From: Baoquan He To: linux-kernel@vger.kernel.org Cc: kexec@lists.infradead.org, x86@kernel.org, linux-arm-kernel@lists.infradead.org, linuxppc-dev@lists.ozlabs.org, linux-s390@vger.kernel.org, linux-sh@vger.kernel.org, linux-mips@vger.kernel.org, linux-riscv@lists.infradead.org, loongarch@lists.linux.dev, akpm@linux-foundation.org, ebiederm@xmission.com, hbathini@linux.ibm.com, piliu@redhat.com, viro@zeniv.linux.org.uk, Baoquan He Subject: [PATCH linux-next v3 00/14] Split crash out from kexec and clean up related config items Date: Wed, 24 Jan 2024 13:12:40 +0800 Message-ID: <20240124051254.67105-1-bhe@redhat.com> Precedence: bulk X-Mailing-List: linux-sh@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-type: text/plain X-Scanned-By: MIMEDefang 3.4.1 on 10.11.54.7 Motivation: ============= Previously, LKP reported a building error. When investigating, it can't be resolved reasonablly with the present messy kdump config items. https://lore.kernel.org/oe-kbuild-all/202312182200.Ka7MzifQ-lkp@intel.com/ The kdump (crash dumping) related config items could causes confusions: Firstly, --- CRASH_CORE enables codes including - crashkernel reservation; - elfcorehdr updating; - vmcoreinfo exporting; - crash hotplug handling; Now fadump of powerpc, kcore dynamic debugging and kdump all selects CRASH_CORE, while fadump - fadump needs crashkernel parsing, vmcoreinfo exporting, and accessing global variable 'elfcorehdr_addr'; - kcore only needs vmcoreinfo exporting; - kdump needs all of the current kernel/crash_core.c. So only enabling PROC_CORE or FA_DUMP will enable CRASH_CORE, this mislead people that we enable crash dumping, actual it's not. Secondly, --- It's not reasonable to allow KEXEC_CORE select CRASH_CORE. Because KEXEC_CORE enables codes which allocate control pages, copy kexec/kdump segments, and prepare for switching. These codes are shared by both kexec reboot and kdump. We could want kexec reboot, but disable kdump. In that case, CRASH_CORE should not be selected. -------------------- CONFIG_CRASH_CORE=y CONFIG_KEXEC_CORE=y CONFIG_KEXEC=y CONFIG_KEXEC_FILE=y --------------------- Thirdly, --- It's not reasonable to allow CRASH_DUMP select KEXEC_CORE. That could make KEXEC_CORE, CRASH_DUMP are enabled independently from KEXEC or KEXEC_FILE. However, w/o KEXEC or KEXEC_FILE, the KEXEC_CORE code built in doesn't make any sense because no kernel loading or switching will happen to utilize the KEXEC_CORE code. --------------------- CONFIG_CRASH_CORE=y CONFIG_KEXEC_CORE=y CONFIG_CRASH_DUMP=y --------------------- In this case, what is worse, on arch sh and arm, KEXEC relies on MMU, while CRASH_DUMP can still be enabled when !MMU, then compiling error is seen as the lkp test robot reported in above link. ------arch/sh/Kconfig------ config ARCH_SUPPORTS_KEXEC def_bool MMU config ARCH_SUPPORTS_CRASH_DUMP def_bool BROKEN_ON_SMP --------------------------- Changes: =========== 1, split out crash_reserve.c from crash_core.c; 2, split out vmcore_infoc. from crash_core.c; 3, move crash related codes in kexec_core.c into crash_core.c; 4, remove dependency of FA_DUMP on CRASH_DUMP; 5, clean up kdump related config items; 6, wrap up crash codes in crash related ifdefs on all 8 arch-es which support crash dumping, except of ppc; Achievement: =========== With above changes, I can rearrange the config item logic as below (the right item depends on or is selected by the left item): PROC_KCORE -----------> VMCORE_INFO |----------> VMCORE_INFO FA_DUMP----| |----------> CRASH_RESERVE ---->VMCORE_INFO / |---->CRASH_RESERVE KEXEC --| /| |--> KEXEC_CORE--> CRASH_DUMP-->/-|---->PROC_VMCORE KEXEC_FILE --| \ | \---->CRASH_HOTPLUG KEXEC --| |--> KEXEC_CORE (for kexec reboot only) KEXEC_FILE --| Test ======== On all 8 architectures, including x86_64, arm64, s390x, sh, arm, mips, riscv, loongarch, I did below three cases of config item setting and building all passed. Take configs on x86_64 as exampmle here: (1) Both CONFIG_KEXEC and KEXEC_FILE is unset, then all kexec/kdump items are unset automatically: # Kexec and crash features # CONFIG_KEXEC is not set # CONFIG_KEXEC_FILE is not set # end of Kexec and crash features (2) set CONFIG_KEXEC_FILE and 'make olddefconfig': --------------- # Kexec and crash features CONFIG_CRASH_RESERVE=y CONFIG_VMCORE_INFO=y CONFIG_KEXEC_CORE=y CONFIG_KEXEC_FILE=y CONFIG_CRASH_DUMP=y CONFIG_CRASH_HOTPLUG=y CONFIG_CRASH_MAX_MEMORY_RANGES=8192 # end of Kexec and crash features --------------- (3) unset CONFIG_CRASH_DUMP in case 2 and execute 'make olddefconfig': ------------------------ # Kexec and crash features CONFIG_KEXEC_CORE=y CONFIG_KEXEC_FILE=y # end of Kexec and crash features ------------------------ Note: For ppc, it needs investigation to make clear how to split out crash code in arch folder. Hope Hari and Pingfan can help have a look, see if it's doable. Now, I make it either have both kexec and crash enabled, or disable both of them altogether. Changelog ========== v2->v3: - In patch 2, there's conflict when rebasing to linux-next in kernel/crash_core.c because of below commits from Uladzislau: - commit 699d9351822e ("mm: vmalloc: Fix a warning in the crash_save_vmcoreinfo_init()") - commit 5f4c0c1e2a51 (:mm/vmalloc: remove vmap_area_list") - In patch 13, fix the lkp reported issue by using CONFIG_CRASH_RESERVE ifdef, giving up the earlier IS_ENABLED(CONFIG_CRASH_RESERVE) checking in v2. - In patch 14, update code change after below commit merged into mainline: - commit 78de91b45860 ("LoongArch: Use generic interface to support crashkernel=X,[high,low]") Baoquan He (14): kexec: split crashkernel reservation code out from crash_core.c crash: split vmcoreinfo exporting code out from crash_core.c crash: remove dependency of FA_DUMP on CRASH_DUMP crash: split crash dumping code out from kexec_core.c crash: clean up kdump related config items x86, crash: wrap crash dumping code into crash related ifdefs arm64, crash: wrap crash dumping code into crash related ifdefs ppc, crash: enforce KEXEC and KEXEC_FILE to select CRASH_DUMP s390, crash: wrap crash dumping code into crash related ifdefs sh, crash: wrap crash dumping code into crash related ifdefs mips, crash: wrap crash dumping code into crash related ifdefs riscv, crash: wrap crash dumping code into crash related ifdefs arm, crash: wrap crash dumping code into crash related ifdefs loongarch, crash: wrap crash dumping code into crash related ifdefs arch/arm/kernel/setup.c | 4 +- arch/arm64/Kconfig | 2 +- .../asm/{crash_core.h => crash_reserve.h} | 4 +- arch/arm64/include/asm/kexec.h | 2 +- arch/arm64/kernel/Makefile | 2 +- arch/arm64/kernel/machine_kexec.c | 2 +- arch/arm64/kernel/machine_kexec_file.c | 10 +- .../kernel/{crash_core.c => vmcore_info.c} | 2 +- arch/arm64/mm/init.c | 2 +- arch/loongarch/kernel/setup.c | 2 +- arch/mips/kernel/setup.c | 17 +- arch/powerpc/Kconfig | 9 +- arch/powerpc/kernel/setup-common.c | 2 +- arch/powerpc/mm/nohash/kaslr_booke.c | 4 +- arch/powerpc/platforms/powernv/opal-core.c | 2 +- arch/riscv/Kconfig | 2 +- .../asm/{crash_core.h => crash_reserve.h} | 4 +- arch/riscv/kernel/Makefile | 2 +- arch/riscv/kernel/elf_kexec.c | 9 +- .../kernel/{crash_core.c => vmcore_info.c} | 2 +- arch/riscv/mm/init.c | 2 +- arch/s390/kernel/kexec_elf.c | 2 + arch/s390/kernel/kexec_image.c | 2 + arch/s390/kernel/machine_kexec_file.c | 10 + arch/sh/kernel/machine_kexec.c | 3 + arch/sh/kernel/setup.c | 2 +- arch/x86/Kconfig | 2 +- .../asm/{crash_core.h => crash_reserve.h} | 6 +- arch/x86/kernel/Makefile | 6 +- arch/x86/kernel/cpu/mshyperv.c | 4 + arch/x86/kernel/kexec-bzimage64.c | 4 + arch/x86/kernel/kvm.c | 4 +- arch/x86/kernel/machine_kexec_64.c | 3 + arch/x86/kernel/reboot.c | 2 +- arch/x86/kernel/setup.c | 2 +- arch/x86/kernel/smp.c | 2 +- .../{crash_core_32.c => vmcore_info_32.c} | 2 +- .../{crash_core_64.c => vmcore_info_64.c} | 2 +- arch/x86/xen/enlighten_hvm.c | 4 + drivers/base/cpu.c | 6 +- drivers/firmware/qemu_fw_cfg.c | 14 +- fs/proc/Kconfig | 2 +- fs/proc/kcore.c | 2 +- include/linux/buildid.h | 2 +- include/linux/crash_core.h | 152 ++-- include/linux/crash_reserve.h | 48 ++ include/linux/kexec.h | 47 +- include/linux/vmcore_info.h | 81 ++ init/initramfs.c | 2 +- kernel/Kconfig.kexec | 12 +- kernel/Makefile | 5 +- kernel/crash_core.c | 762 +++++------------- kernel/crash_reserve.c | 464 +++++++++++ kernel/{crash_dump.c => elfcorehdr.c} | 0 kernel/kexec.c | 11 +- kernel/kexec_core.c | 250 +----- kernel/kexec_file.c | 13 +- kernel/kexec_internal.h | 2 + kernel/ksysfs.c | 10 +- kernel/printk/printk.c | 4 +- kernel/vmcore_info.c | 231 ++++++ lib/buildid.c | 2 +- 62 files changed, 1228 insertions(+), 1043 deletions(-) rename arch/arm64/include/asm/{crash_core.h => crash_reserve.h} (81%) rename arch/arm64/kernel/{crash_core.c => vmcore_info.c} (97%) rename arch/riscv/include/asm/{crash_core.h => crash_reserve.h} (78%) rename arch/riscv/kernel/{crash_core.c => vmcore_info.c} (96%) rename arch/x86/include/asm/{crash_core.h => crash_reserve.h} (92%) rename arch/x86/kernel/{crash_core_32.c => vmcore_info_32.c} (90%) rename arch/x86/kernel/{crash_core_64.c => vmcore_info_64.c} (94%) create mode 100644 include/linux/crash_reserve.h create mode 100644 include/linux/vmcore_info.h create mode 100644 kernel/crash_reserve.c rename kernel/{crash_dump.c => elfcorehdr.c} (100%) create mode 100644 kernel/vmcore_info.c