LKML Archive on lore.kernel.org
help / color / mirror / Atom feed
From: Baoquan He <bhe@redhat.com>
To: Borislav Petkov <bp@alien8.de>
Cc: j-nomura@ce.jp.nec.com, kasong@redhat.com, dyoung@redhat.com,
	fanc.fnst@cn.fujitsu.com, x86@kernel.org,
	kexec@lists.infradead.org, linux-kernel@vger.kernel.org,
	hpa@zytor.com, tglx@linutronix.de
Subject: Re: [PATCH v6 1/2] x86/kexec: Build identity mapping for EFI systab and ACPI tables
Date: Mon, 13 May 2019 09:43:05 +0800	[thread overview]
Message-ID: <20190513014248.GA16774@MiWiFi-R3L-srv> (raw)
In-Reply-To: <20190429135536.GC2324@zn.tnic>

Hi Boris,

On 04/29/19 at 03:55pm, Borislav Petkov wrote:
> From: Kairui Song <kasong@redhat.com>
> Date: Mon, 29 Apr 2019 08:23:18 +0800
> Subject: [PATCH] x86/kexec: Add the EFI system tables and ACPI tables to the ident map

> 
> Currently, only the whole physical memory is identity-mapped for the
> kexec kernel and the regions reserved by firmware are ignored.
> 
> However, the recent addition of RSDP parsing in the decompression stage
> and especially:
> 
>   33f0df8d843d ("x86/boot: Search for RSDP in the EFI tables")
> 
> which tries to access EFI system tables and to dig out the RDSP address
> from there, becomes a problem because in certain configurations, they
> might not be mapped in the kexec'ed kernel's address space.
> 
> What is more, this problem doesn't appear on all systems because the
> kexec kernel uses gigabyte pages to build the identity mapping. And
> the EFI system tables and ACPI tables can, depending on the system
> configuration, end up being mapped as part of all physical memory, if
> they share the same 1 GB area with the physical memory.
> 
> Therefore, make sure they're always mapped.
> 
>  [ bp: productize half-baked patch:
>    - rewrite commit message.
>    - s/init_acpi_pgtable/map_acpi_tables/ in the !ACPI case. ]

Can this patchset be merged, or picked into tip?

Thanks
Baoquan

> Signed-off-by: Kairui Song <kasong@redhat.com>
> Signed-off-by: Baoquan He <bhe@redhat.com>
> Signed-off-by: Borislav Petkov <bp@suse.de>
> Cc: dyoung@redhat.com
> Cc: fanc.fnst@cn.fujitsu.com
> Cc: "H. Peter Anvin" <hpa@zytor.com>
> Cc: Ingo Molnar <mingo@redhat.com>
> Cc: j-nomura@ce.jp.nec.com
> Cc: kexec@lists.infradead.org
> Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
> Cc: Lianbo Jiang <lijiang@redhat.com>
> Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
> Cc: Thomas Gleixner <tglx@linutronix.de>
> Cc: x86-ml <x86@kernel.org>
> Link: https://lkml.kernel.org/r/20190429002318.GA25400@MiWiFi-R3L-srv
> ---
>  arch/x86/kernel/machine_kexec_64.c | 75 ++++++++++++++++++++++++++++++
>  1 file changed, 75 insertions(+)
> 
> diff --git a/arch/x86/kernel/machine_kexec_64.c b/arch/x86/kernel/machine_kexec_64.c
> index ceba408ea982..3c77bdf7b32a 100644
> --- a/arch/x86/kernel/machine_kexec_64.c
> +++ b/arch/x86/kernel/machine_kexec_64.c
> @@ -18,6 +18,7 @@
>  #include <linux/io.h>
>  #include <linux/suspend.h>
>  #include <linux/vmalloc.h>
> +#include <linux/efi.h>
>  
>  #include <asm/init.h>
>  #include <asm/pgtable.h>
> @@ -29,6 +30,43 @@
>  #include <asm/setup.h>
>  #include <asm/set_memory.h>
>  
> +#ifdef CONFIG_ACPI
> +/*
> + * Used while adding mapping for ACPI tables.
> + * Can be reused when other iomem regions need be mapped
> + */
> +struct init_pgtable_data {
> +	struct x86_mapping_info *info;
> +	pgd_t *level4p;
> +};
> +
> +static int mem_region_callback(struct resource *res, void *arg)
> +{
> +	struct init_pgtable_data *data = arg;
> +	unsigned long mstart, mend;
> +
> +	mstart = res->start;
> +	mend = mstart + resource_size(res) - 1;
> +
> +	return kernel_ident_mapping_init(data->info, data->level4p, mstart, mend);
> +}
> +
> +static int
> +map_acpi_tables(struct x86_mapping_info *info, pgd_t *level4p)
> +{
> +	unsigned long flags = IORESOURCE_MEM | IORESOURCE_BUSY;
> +	struct init_pgtable_data data;
> +
> +	data.info = info;
> +	data.level4p = level4p;
> +	flags = IORESOURCE_MEM | IORESOURCE_BUSY;
> +	return walk_iomem_res_desc(IORES_DESC_ACPI_TABLES, flags, 0, -1,
> +				   &data, mem_region_callback);
> +}
> +#else
> +static int map_acpi_tables(struct x86_mapping_info *info, pgd_t *level4p) { return 0; }
> +#endif
> +
>  #ifdef CONFIG_KEXEC_FILE
>  const struct kexec_file_ops * const kexec_file_loaders[] = {
>  		&kexec_bzImage64_ops,
> @@ -36,6 +74,31 @@ const struct kexec_file_ops * const kexec_file_loaders[] = {
>  };
>  #endif
>  
> +static int
> +map_efi_systab(struct x86_mapping_info *info, pgd_t *level4p)
> +{
> +#ifdef CONFIG_EFI
> +	unsigned long mstart, mend;
> +
> +	if (!efi_enabled(EFI_BOOT))
> +		return 0;
> +
> +	mstart = (boot_params.efi_info.efi_systab |
> +			((u64)boot_params.efi_info.efi_systab_hi<<32));
> +
> +	if (efi_enabled(EFI_64BIT))
> +		mend = mstart + sizeof(efi_system_table_64_t);
> +	else
> +		mend = mstart + sizeof(efi_system_table_32_t);
> +
> +	if (!mstart)
> +		return 0;
> +
> +	return kernel_ident_mapping_init(info, level4p, mstart, mend);
> +#endif
> +	return 0;
> +}
> +
>  static void free_transition_pgtable(struct kimage *image)
>  {
>  	free_page((unsigned long)image->arch.p4d);
> @@ -159,6 +222,18 @@ static int init_pgtable(struct kimage *image, unsigned long start_pgtable)
>  			return result;
>  	}
>  
> +	/*
> +	 * Prepare EFI systab and ACPI tables for kexec kernel since they are
> +	 * not covered by pfn_mapped.
> +	 */
> +	result = map_efi_systab(&info, level4p);
> +	if (result)
> +		return result;
> +
> +	result = map_acpi_tables(&info, level4p);
> +	if (result)
> +		return result;
> +
>  	return init_transition_pgtable(image, level4p);
>  }
>  
> -- 
> 2.21.0
> 
> -- 
> Regards/Gruss,
>     Boris.
> 
> Good mailing practices for 400: avoid top-posting and trim the reply.

  parent reply	other threads:[~2019-05-13  1:43 UTC|newest]

Thread overview: 42+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-04-24  9:29 [PATCH v5 0/2] x86/boot: Use efi_setup_data for searching RSDP on kexec-ed kernel Baoquan He
2019-04-24  9:29 ` [PATCH v5 1/2] x86/kexec: Build identity mapping for EFI systab and ACPI tables Baoquan He
2019-04-27 16:11   ` Borislav Petkov
2019-04-28  5:41     ` Baoquan He
2019-04-29 12:50       ` Borislav Petkov
2019-04-29  0:23   ` [PATCH v6 " Baoquan He
2019-04-29 13:55     ` Borislav Petkov
2019-04-29 14:16       ` Baoquan He
2019-05-13  1:43       ` Baoquan He [this message]
2019-05-13  7:07         ` Borislav Petkov
2019-05-13  7:32           ` Baoquan He
2019-05-13  7:50             ` Borislav Petkov
2019-05-13  8:02               ` Baoquan He
2019-05-15  5:17                 ` Junichi Nomura
2019-05-15  6:58                   ` Borislav Petkov
2019-05-15  7:09                     ` Junichi Nomura
2019-05-21  9:02                       ` Kairui Song
2019-05-21 10:43                         ` Junichi Nomura
2019-05-21 18:09                         ` Borislav Petkov
2019-05-28  2:49                           ` Kairui Song
2019-06-06 19:20                             ` Borislav Petkov
2019-05-13  8:06               ` Baoquan He
2019-05-14  3:22                 ` Dave Young
2019-05-14  3:33                   ` Baoquan He
2019-05-21 21:53                     ` Dirk van der Merwe
2019-05-21 23:04                       ` Borislav Petkov
2019-05-14  8:48                   ` Dave Young
2019-05-14 11:18                     ` Kairui Song
2019-05-14 11:38                     ` Peter Zijlstra
2019-05-14 12:58                       ` Dave Young
2019-05-14 13:54                         ` Peter Zijlstra
2019-05-14 14:09                         ` Ingo Molnar
2019-05-15  1:08                           ` Dave Young
2019-05-15  6:43                             ` Junichi Nomura
2019-05-17 13:41                   ` Borislav Petkov
2019-05-17 13:50                     ` [PATCH] x86/boot: Call get_rsdp_addr() after console_init() Borislav Petkov
2019-05-21  9:28                       ` Baoquan He
2019-06-06 19:22     ` [tip:x86/boot] x86/kexec: Add the EFI system tables and ACPI tables to the ident map tip-bot for Kairui Song
2019-04-24  9:29 ` [PATCH v5 2/2] x86/boot: Use efi_setup_data for searching RSDP on kexec-ed kernels Baoquan He
2019-04-24  9:33   ` Baoquan He
2019-04-24  9:38 ` [PATCH v5 0/2] x86/boot: Use efi_setup_data for searching RSDP on kexec-ed kernel Borislav Petkov
2019-04-24 10:00   ` Baoquan He

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=20190513014248.GA16774@MiWiFi-R3L-srv \
    --to=bhe@redhat.com \
    --cc=bp@alien8.de \
    --cc=dyoung@redhat.com \
    --cc=fanc.fnst@cn.fujitsu.com \
    --cc=hpa@zytor.com \
    --cc=j-nomura@ce.jp.nec.com \
    --cc=kasong@redhat.com \
    --cc=kexec@lists.infradead.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=tglx@linutronix.de \
    --cc=x86@kernel.org \
    --subject='Re: [PATCH v6 1/2] x86/kexec: Build identity mapping for EFI systab and ACPI tables' \
    /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

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).