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From: "Rafael J. Wysocki" <rafael@kernel.org>
Date: Mon, 27 May 2024 12:52:19 +0200
Message-ID: <CAJZ5v0gcyZM7PZPrKccLhNtNDhHvqrZsgD-+Xx+W9WesD3yhyw@mail.gmail.com>
Subject: Re: [PATCH] fix kdump kernel cannot find ACPI RSDP
To: Chunjie Zhu <chunjie.zhu@cloud.com>
Cc: "Rafael J. Wysocki" <rafael@kernel.org>, Len Brown <lenb@kernel.org>, linux-acpi@vger.kernel.org, 
	linux-kernel@vger.kernel.org
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On Fri, May 24, 2024 at 11:43=E2=80=AFAM Chunjie Zhu <chunjie.zhu@cloud.com=
> wrote:
>
> kexec/kdump must pass acpi_rsdp (physical address of ACPI RSDP table) to =
the
> crash kernel, especially in EFI case, otherwise, the crash kernel fails t=
o
> locate ACPI RSDP table. Consequently, ACPI init runs into error, and APIC
> mmio read page fault happens, finally crash kernel gets stuck.

Fair enough.

So has this ever worked before?  Presumably it has, in which case it
has regressed and so it would be prudent to say when it broke and why
and explain why the proposed change is the right one to make.

> Signed-off-by: Chunjie Zhu <chunjie.zhu@cloud.com>
> ---
>  drivers/acpi/osl.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/acpi/osl.c b/drivers/acpi/osl.c
> index f725813d0cce..39474468dba1 100644
> --- a/drivers/acpi/osl.c
> +++ b/drivers/acpi/osl.c
> @@ -174,7 +174,7 @@ void acpi_os_vprintf(const char *fmt, va_list args)
>  #endif
>  }
>
> -#ifdef CONFIG_KEXEC
> +#ifdef CONFIG_KEXEC_CORE
>  static unsigned long acpi_rsdp;
>  static int __init setup_acpi_rsdp(char *arg)
>  {
> @@ -187,7 +187,7 @@ acpi_physical_address __init acpi_os_get_root_pointer=
(void)
>  {
>         acpi_physical_address pa;
>
> -#ifdef CONFIG_KEXEC
> +#ifdef CONFIG_KEXEC_CORE
>         /*
>          * We may have been provided with an RSDP on the command line,
>          * but if a malicious user has done so they may be pointing us
> --
> 2.34.1
>