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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 4D0A9C433FE for ; Mon, 17 Oct 2022 19:54:40 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229765AbiJQTyj (ORCPT ); Mon, 17 Oct 2022 15:54:39 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:54068 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229949AbiJQTyi (ORCPT ); Mon, 17 Oct 2022 15:54:38 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 9101E10FF6; Mon, 17 Oct 2022 12:54:37 -0700 (PDT) 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 dfw.source.kernel.org (Postfix) with ESMTPS id 2BB6461219; Mon, 17 Oct 2022 19:54:37 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 0CF7CC433D7; Mon, 17 Oct 2022 19:54:31 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1666036476; bh=RjBn26b54Qi9hFzWIH/n9PJ/ByfUPuIEutsDV4SvCtQ=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=r2RTCDdWs6UFggXb3K1bjDM1eF7gIH+o00GFyEI3o6+eiVahUtptyD6IHMINLEsWi 0KOmf1XXtv/HDz5Y8qRmDvOD0PbR+4BWl56eNEtKtaYE1XJpviwXu6GuH3XFXGZLW8 5U8MxpQVRcXBcheWjwC9vurSJhUxVRho2nEHTREKcAnzJYPQtmeml7BSYRbbgsnA/t DXeOxcX7Cr3ZtI2KOfPkVHZyal9qM0I9dtSczyeyEO2Nt6l0PieRDuQisCVo4Wr3D6 MWCBZ00RgKMjIbqmkjrqZ9rc+W81g7lW01kd7jVEHaKDeAkanf99OxClmxj27gyGiy 9ZWx0u5faSFWg== Date: Mon, 17 Oct 2022 20:54:29 +0100 From: Conor Dooley To: Xianting Tian Cc: 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, bagasdotme@gmail.com, 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 Subject: Re: [PATCH V2 1/2] RISC-V: Add arch_crash_save_vmcoreinfo support Message-ID: References: <20221014134139.5151-1-xianting.tian@linux.alibaba.com> <20221014134139.5151-2-xianting.tian@linux.alibaba.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20221014134139.5151-2-xianting.tian@linux.alibaba.com> Precedence: bulk List-ID: X-Mailing-List: linux-doc@vger.kernel.org On Fri, Oct 14, 2022 at 09:41:38PM +0800, Xianting Tian wrote: > Add arch_crash_save_vmcoreinfo(), which exports VM layout(MODULES, VMALLOC, > VMEMMAP and KERNEL_LINK_ADDR ranges), va bits and ram base for vmcore. > > Default pagetable levels and PAGE_OFFSET aren't same for different kernel > version as below. For default pagetable levels, it sets sv57 on defaultly > in latest kernel and do fallback to try to set sv48 on boot time if sv57 > is not supported in current hardware. nit: This would read better as "it sets sv57 by default and falls back to setting sv48 at boot time if sv57 is not supported by the hardware". > > For ram base, the default value is 0x80200000 for qemu riscv64 env, 0x200000 > for riscv64 SoC platform(eg, SoC platform of RISC-V XuanTie 910 CPU). The second part of this sentence I'm not really sure that that is true, I think you should reword it to something like "...for qemu riscv64 and, for example, is 0x200000 on the XuanTie 910 CPU." and avoid applying that number blanketly for other SoCs. > > * Linux Kernel 5.18 ~ > * PGTABLE_LEVELS = 5 > * PAGE_OFFSET = 0xff60000000000000 > * Linux Kernel 5.17 ~ > * PGTABLE_LEVELS = 4 > * PAGE_OFFSET = 0xffffaf8000000000 > * Linux Kernel 4.19 ~ > * PGTABLE_LEVELS = 3 > * PAGE_OFFSET = 0xffffffe000000000 > > Since these configurations change from time to time and version to version, > it is preferable to export them via vmcoreinfo than to change the crash's > code frequently, it can simplify the development of crash tool. > > Signed-off-by: Xianting Tian > --- > arch/riscv/kernel/Makefile | 1 + > arch/riscv/kernel/crash_core.c | 29 +++++++++++++++++++++++++++++ > 2 files changed, 30 insertions(+) > create mode 100644 arch/riscv/kernel/crash_core.c > > diff --git a/arch/riscv/kernel/Makefile b/arch/riscv/kernel/Makefile > index db6e4b1294ba..4cf303a779ab 100644 > --- a/arch/riscv/kernel/Makefile > +++ b/arch/riscv/kernel/Makefile > @@ -81,6 +81,7 @@ obj-$(CONFIG_KGDB) += kgdb.o > obj-$(CONFIG_KEXEC_CORE) += kexec_relocate.o crash_save_regs.o machine_kexec.o > obj-$(CONFIG_KEXEC_FILE) += elf_kexec.o machine_kexec_file.o > obj-$(CONFIG_CRASH_DUMP) += crash_dump.o > +obj-$(CONFIG_CRASH_CORE) += crash_core.o > > obj-$(CONFIG_JUMP_LABEL) += jump_label.o > > diff --git a/arch/riscv/kernel/crash_core.c b/arch/riscv/kernel/crash_core.c > new file mode 100644 > index 000000000000..8d7f5ff108da > --- /dev/null > +++ b/arch/riscv/kernel/crash_core.c > @@ -0,0 +1,29 @@ > +// SPDX-License-Identifier: GPL-2.0-only > + > +#include > +#include > + > +void arch_crash_save_vmcoreinfo(void) > +{ > + VMCOREINFO_NUMBER(VA_BITS); > + VMCOREINFO_NUMBER(phys_ram_base); > + > + vmcoreinfo_append_str("NUMBER(PAGE_OFFSET)=0x%lx\n", PAGE_OFFSET); > + vmcoreinfo_append_str("NUMBER(VMALLOC_START)=0x%lx\n", VMALLOC_START); > + vmcoreinfo_append_str("NUMBER(VMALLOC_END)=0x%lx\n", VMALLOC_END); > + vmcoreinfo_append_str("NUMBER(VMEMMAP_START)=0x%lx\n", VMEMMAP_START); > + vmcoreinfo_append_str("NUMBER(VMEMMAP_END)=0x%lx\n", VMEMMAP_END); > +#ifdef CONFIG_64BIT > + vmcoreinfo_append_str("NUMBER(MODULES_VADDR)=0x%lx\n", MODULES_VADDR); > + vmcoreinfo_append_str("NUMBER(MODULES_END)=0x%lx\n", MODULES_END); > +#endif > + > + if (IS_ENABLED(CONFIG_64BIT)) { You've already got a #ifdef CONFIG_64BIT above, is there a reason why you'd use the IS_ENABLED here rather than merge this with the above section? I'm a big fan of IS_ENABLED but I'm not sure what it adds here, maybe you can show me the light :) Thanks, Conor. > +#ifdef CONFIG_KASAN > + vmcoreinfo_append_str("NUMBER(KASAN_SHADOW_START)=0x%lx\n", KASAN_SHADOW_START); > + vmcoreinfo_append_str("NUMBER(KASAN_SHADOW_END)=0x%lx\n", KASAN_SHADOW_END); > +#endif > + vmcoreinfo_append_str("NUMBER(KERNEL_LINK_ADDR)=0x%lx\n", KERNEL_LINK_ADDR); > + vmcoreinfo_append_str("NUMBER(ADDRESS_SPACE_END)=0x%lx\n", ADDRESS_SPACE_END); > + } > +} > -- > 2.17.1 > >