From: Conor Dooley <conor@kernel.org>
To: Xianting Tian <xianting.tian@linux.alibaba.com>
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
Date: Mon, 17 Oct 2022 20:54:29 +0100 [thread overview]
Message-ID: <Y02y9eN1TNJteTw6@spud> (raw)
In-Reply-To: <20221014134139.5151-2-xianting.tian@linux.alibaba.com>
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 <xianting.tian@linux.alibaba.com>
> ---
> 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 <linux/crash_core.h>
> +#include <linux/pagemap.h>
> +
> +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
>
>
next prev parent reply other threads:[~2022-10-17 19:54 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-10-14 13:41 [PATCH V2 0/2] Support VMCOREINFO export for RISCV64 Xianting Tian
2022-10-14 13:41 ` [PATCH V2 1/2] RISC-V: Add arch_crash_save_vmcoreinfo support Xianting Tian
2022-10-17 19:54 ` Conor Dooley [this message]
[not found] ` <78420277-215f-55d0-67b8-fbf9208b3d22@linux.alibaba.com>
2022-10-18 7:19 ` Conor.Dooley
2022-10-18 8:01 ` Xianting Tian
2022-10-14 13:41 ` [PATCH V2 2/2] Documentation: kdump: describe VMCOREINFO export for RISCV64 Xianting Tian
2022-10-17 19:40 ` Conor Dooley
2022-10-18 2:41 ` Xianting Tian
2022-10-18 7:13 ` Conor Dooley
2022-10-18 3:19 ` Bagas Sanjaya
2022-10-18 5:32 ` Xianting Tian
2022-10-18 6:06 ` Xianting Tian
2022-10-18 7:20 ` Bagas Sanjaya
-- strict thread matches above, loose matches on Subject: below --
2022-07-14 2:58 [PATCH V2 0/2] Improve vmcoreinfo and memory layout dump Xianting Tian
2022-07-14 2:59 ` [PATCH V2 1/2] RISC-V: Add arch_crash_save_vmcoreinfo support Xianting Tian
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=Y02y9eN1TNJteTw6@spud \
--to=conor@kernel.org \
--cc=Conor.Dooley@microchip.com \
--cc=alexandre.ghiti@canonical.com \
--cc=anup@brainfault.org \
--cc=aou@eecs.berkeley.edu \
--cc=bagasdotme@gmail.com \
--cc=bhe@redhat.com \
--cc=corbet@lwn.net \
--cc=crash-utility@redhat.com \
--cc=dyoung@redhat.com \
--cc=guoren@kernel.org \
--cc=heiko@sntech.de \
--cc=heinrich.schuchardt@canonical.com \
--cc=hschauhan@nulltrace.org \
--cc=k-hagio-ab@nec.com \
--cc=kexec@lists.infradead.org \
--cc=linux-doc@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-riscv@lists.infradead.org \
--cc=mick@ics.forth.gr \
--cc=palmer@dabbelt.com \
--cc=paul.walmsley@sifive.com \
--cc=vgoyal@redhat.com \
--cc=xianting.tian@linux.alibaba.com \
--cc=yixun.lan@gmail.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).