diff mbox series

[RESEND] arm64: acpi,efi: fix alignment fault in accessing ACPI tables at kdump

Message ID 20180425063527.29763-1-takahiro.akashi@linaro.org
State New
Headers show
Series [RESEND] arm64: acpi,efi: fix alignment fault in accessing ACPI tables at kdump | expand

Commit Message

AKASHI Takahiro April 25, 2018, 6:35 a.m. UTC 
This is a fix against the issue that crash dump kernel may hang up
during booting, which can happen on any ACPI-based system with "ACPI
Reclaim Memory."

(kernel messages after panic kicked off kdump)
	   (snip...)
	Bye!
	   (snip...)
	ACPI: Core revision 20170728
	pud=000000002e7d0003, *pmd=000000002e7c0003, *pte=00e8000039710707
	Internal error: Oops: 96000021 [#1] SMP
	Modules linked in:
	CPU: 0 PID: 0 Comm: swapper/0 Not tainted 4.14.0-rc6 #1
	task: ffff000008d05180 task.stack: ffff000008cc0000
	PC is at acpi_ns_lookup+0x25c/0x3c0
	LR is at acpi_ds_load1_begin_op+0xa4/0x294
	   (snip...)
	Process swapper/0 (pid: 0, stack limit = 0xffff000008cc0000)
	Call trace:
	   (snip...)
	[<ffff0000084a6764>] acpi_ns_lookup+0x25c/0x3c0
	[<ffff00000849b4f8>] acpi_ds_load1_begin_op+0xa4/0x294
	[<ffff0000084ad4ac>] acpi_ps_build_named_op+0xc4/0x198
	[<ffff0000084ad6cc>] acpi_ps_create_op+0x14c/0x270
	[<ffff0000084acfa8>] acpi_ps_parse_loop+0x188/0x5c8
	[<ffff0000084ae048>] acpi_ps_parse_aml+0xb0/0x2b8
	[<ffff0000084a8e10>] acpi_ns_one_complete_parse+0x144/0x184
	[<ffff0000084a8e98>] acpi_ns_parse_table+0x48/0x68
	[<ffff0000084a82cc>] acpi_ns_load_table+0x4c/0xdc
	[<ffff0000084b32f8>] acpi_tb_load_namespace+0xe4/0x264
	[<ffff000008baf9b4>] acpi_load_tables+0x48/0xc0
	[<ffff000008badc20>] acpi_early_init+0x9c/0xd0
	[<ffff000008b70d50>] start_kernel+0x3b4/0x43c
	Code: b9008fb9 2a000318 36380054 32190318 (b94002c0)
	---[ end trace c46ed37f9651c58e ]---
	Kernel panic - not syncing: Fatal exception
	Rebooting in 10 seconds..

(diagnosis)
* This fault is a data abort, alignment fault (ESR=0x96000021)
  during reading out ACPI table.
* Initial ACPI tables are normally stored in system ram and marked as
  "ACPI Reclaim memory" by the firmware.
* After the commit f56ab9a5b73c ("efi/arm: Don't mark ACPI reclaim
  memory as MEMBLOCK_NOMAP"), those regions are differently handled
  as they are "memblock-reserved", without NOMAP bit.
* So they are now excluded from device tree's "usable-memory-range"
  which kexec-tools determines based on a current view of /proc/iomem.
* When crash dump kernel boots up, it tries to accesses ACPI tables by
  mapping them with ioremap(), not ioremap_cache(), in acpi_os_ioremap()
  since they are no longer part of mapped system ram.
* Given that ACPI accessor/helper functions are compiled in without
  unaligned access support (ACPI_MISALIGNMENT_NOT_SUPPORTED),
  any unaligned access to ACPI tables can cause a fatal panic.

With this patch, acpi_os_ioremap() always honors a memory attribute
provided by the firmware (efi). Hence retaining cacheability in said cases
allows the kernel safe access to ACPI tables.

Please note that arm_enable_runtime_services(), which is renamed to
efi_enter_virtual_mode() due to the similarity to x86's, is now called
earlier before acpi_early_init() since efi_mem_attributes() relies on
efi.memmap being mapped.

Signed-off-by: AKASHI Takahiro <takahiro.akashi@linaro.org>

Suggested-by: James Morse <james.morse@arm.com>
Suggested-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Reported-by and Tested-by: Bhupesh Sharma <bhsharma@redhat.com>
---
 arch/arm64/include/asm/acpi.h      | 23 ++++++++++++++++-------
 arch/arm64/kernel/acpi.c           | 11 +++--------
 drivers/firmware/efi/arm-runtime.c | 15 ++++++---------
 init/main.c                        |  3 +++
 4 files changed, 28 insertions(+), 24 deletions(-)

-- 
2.17.0

Comments

Ard Biesheuvel April 25, 2018, 8:09 a.m. UTC | #1 
On 25 April 2018 at 08:35, AKASHI Takahiro <takahiro.akashi@linaro.org> wrote:
> This is a fix against the issue that crash dump kernel may hang up

> during booting, which can happen on any ACPI-based system with "ACPI

> Reclaim Memory."

>

> (kernel messages after panic kicked off kdump)

>            (snip...)

>         Bye!

>            (snip...)

>         ACPI: Core revision 20170728

>         pud=000000002e7d0003, *pmd=000000002e7c0003, *pte=00e8000039710707

>         Internal error: Oops: 96000021 [#1] SMP

>         Modules linked in:

>         CPU: 0 PID: 0 Comm: swapper/0 Not tainted 4.14.0-rc6 #1

>         task: ffff000008d05180 task.stack: ffff000008cc0000

>         PC is at acpi_ns_lookup+0x25c/0x3c0

>         LR is at acpi_ds_load1_begin_op+0xa4/0x294

>            (snip...)

>         Process swapper/0 (pid: 0, stack limit = 0xffff000008cc0000)

>         Call trace:

>            (snip...)

>         [<ffff0000084a6764>] acpi_ns_lookup+0x25c/0x3c0

>         [<ffff00000849b4f8>] acpi_ds_load1_begin_op+0xa4/0x294

>         [<ffff0000084ad4ac>] acpi_ps_build_named_op+0xc4/0x198

>         [<ffff0000084ad6cc>] acpi_ps_create_op+0x14c/0x270

>         [<ffff0000084acfa8>] acpi_ps_parse_loop+0x188/0x5c8

>         [<ffff0000084ae048>] acpi_ps_parse_aml+0xb0/0x2b8

>         [<ffff0000084a8e10>] acpi_ns_one_complete_parse+0x144/0x184

>         [<ffff0000084a8e98>] acpi_ns_parse_table+0x48/0x68

>         [<ffff0000084a82cc>] acpi_ns_load_table+0x4c/0xdc

>         [<ffff0000084b32f8>] acpi_tb_load_namespace+0xe4/0x264

>         [<ffff000008baf9b4>] acpi_load_tables+0x48/0xc0

>         [<ffff000008badc20>] acpi_early_init+0x9c/0xd0

>         [<ffff000008b70d50>] start_kernel+0x3b4/0x43c

>         Code: b9008fb9 2a000318 36380054 32190318 (b94002c0)

>         ---[ end trace c46ed37f9651c58e ]---

>         Kernel panic - not syncing: Fatal exception

>         Rebooting in 10 seconds..

>

> (diagnosis)

> * This fault is a data abort, alignment fault (ESR=0x96000021)

>   during reading out ACPI table.

> * Initial ACPI tables are normally stored in system ram and marked as

>   "ACPI Reclaim memory" by the firmware.

> * After the commit f56ab9a5b73c ("efi/arm: Don't mark ACPI reclaim

>   memory as MEMBLOCK_NOMAP"), those regions are differently handled

>   as they are "memblock-reserved", without NOMAP bit.

> * So they are now excluded from device tree's "usable-memory-range"

>   which kexec-tools determines based on a current view of /proc/iomem.

> * When crash dump kernel boots up, it tries to accesses ACPI tables by

>   mapping them with ioremap(), not ioremap_cache(), in acpi_os_ioremap()

>   since they are no longer part of mapped system ram.

> * Given that ACPI accessor/helper functions are compiled in without

>   unaligned access support (ACPI_MISALIGNMENT_NOT_SUPPORTED),

>   any unaligned access to ACPI tables can cause a fatal panic.

>

> With this patch, acpi_os_ioremap() always honors a memory attribute

> provided by the firmware (efi). Hence retaining cacheability in said cases

> allows the kernel safe access to ACPI tables.

>

> Please note that arm_enable_runtime_services(), which is renamed to

> efi_enter_virtual_mode() due to the similarity to x86's, is now called

> earlier before acpi_early_init() since efi_mem_attributes() relies on

> efi.memmap being mapped.

>

> Signed-off-by: AKASHI Takahiro <takahiro.akashi@linaro.org>

> Suggested-by: James Morse <james.morse@arm.com>

> Suggested-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>

> Reported-by and Tested-by: Bhupesh Sharma <bhsharma@redhat.com>

> ---

>  arch/arm64/include/asm/acpi.h      | 23 ++++++++++++++++-------

>  arch/arm64/kernel/acpi.c           | 11 +++--------

>  drivers/firmware/efi/arm-runtime.c | 15 ++++++---------

>  init/main.c                        |  3 +++

>  4 files changed, 28 insertions(+), 24 deletions(-)

>

> diff --git a/arch/arm64/include/asm/acpi.h b/arch/arm64/include/asm/acpi.h

> index 32f465a80e4e..d53c95f4e1a9 100644

> --- a/arch/arm64/include/asm/acpi.h

> +++ b/arch/arm64/include/asm/acpi.h

> @@ -12,10 +12,12 @@

>  #ifndef _ASM_ACPI_H

>  #define _ASM_ACPI_H

>

> +#include <linux/efi.h>

>  #include <linux/memblock.h>

>  #include <linux/psci.h>

>

>  #include <asm/cputype.h>

> +#include <asm/io.h>

>  #include <asm/smp_plat.h>

>  #include <asm/tlbflush.h>

>

> @@ -29,18 +31,22 @@

>

>  /* Basic configuration for ACPI */

>  #ifdef CONFIG_ACPI

> +pgprot_t __acpi_get_mem_attribute(phys_addr_t addr);

> +

>  /* ACPI table mapping after acpi_permanent_mmap is set */

>  static inline void __iomem *acpi_os_ioremap(acpi_physical_address phys,

>                                             acpi_size size)

>  {

> +       /* For normal memory we already have a cacheable mapping. */

> +       if (memblock_is_map_memory(phys))

> +               return (void __iomem *)__phys_to_virt(phys);

> +

>         /*

> -        * EFI's reserve_regions() call adds memory with the WB attribute

> -        * to memblock via early_init_dt_add_memory_arch().

> +        * We should still honor the memory's attribute here because

> +        * crash dump kernel possibly excludes some ACPI (reclaim)

> +        * regions from memblock list.

>          */

> -       if (!memblock_is_memory(phys))

> -               return ioremap(phys, size);

> -

> -       return ioremap_cache(phys, size);

> +       return __ioremap(phys, size, __acpi_get_mem_attribute(phys));

>  }

>  #define acpi_os_ioremap acpi_os_ioremap

>

> @@ -125,7 +131,10 @@ static inline const char *acpi_get_enable_method(int cpu)

>   * for compatibility.

>   */

>  #define acpi_disable_cmcff 1

> -pgprot_t arch_apei_get_mem_attribute(phys_addr_t addr);

> +static inline pgprot_t arch_apei_get_mem_attribute(phys_addr_t addr)

> +{

> +       return __acpi_get_mem_attribute(addr);

> +}

>  #endif /* CONFIG_ACPI_APEI */

>

>  #ifdef CONFIG_ACPI_NUMA

> diff --git a/arch/arm64/kernel/acpi.c b/arch/arm64/kernel/acpi.c

> index 7b09487ff8fb..7880076c1cf0 100644

> --- a/arch/arm64/kernel/acpi.c

> +++ b/arch/arm64/kernel/acpi.c

> @@ -18,6 +18,7 @@

>  #include <linux/acpi.h>

>  #include <linux/bootmem.h>

>  #include <linux/cpumask.h>

> +# include <linux/efi.h>


Please drop the space after #

>  #include <linux/efi-bgrt.h>

>  #include <linux/init.h>

>  #include <linux/irq.h>

> @@ -29,12 +30,8 @@

>

>  #include <asm/cputype.h>

>  #include <asm/cpu_ops.h>

> -#include <asm/smp_plat.h>

> -

> -#ifdef CONFIG_ACPI_APEI

> -# include <linux/efi.h>

>  # include <asm/pgtable.h>


And here

> -#endif

> +#include <asm/smp_plat.h>

>

>  int acpi_noirq = 1;            /* skip ACPI IRQ initialization */

>  int acpi_disabled = 1;

> @@ -239,8 +236,7 @@ void __init acpi_boot_table_init(void)

>         }

>  }

>

> -#ifdef CONFIG_ACPI_APEI

> -pgprot_t arch_apei_get_mem_attribute(phys_addr_t addr)

> +pgprot_t __acpi_get_mem_attribute(phys_addr_t addr)

>  {

>         /*

>          * According to "Table 8 Map: EFI memory types to AArch64 memory

> @@ -261,4 +257,3 @@ pgprot_t arch_apei_get_mem_attribute(phys_addr_t addr)

>                 return __pgprot(PROT_NORMAL_NC);

>         return __pgprot(PROT_DEVICE_nGnRnE);

>  }

> -#endif

> diff --git a/drivers/firmware/efi/arm-runtime.c b/drivers/firmware/efi/arm-runtime.c

> index 5889cbea60b8..1148ea5a0faa 100644

> --- a/drivers/firmware/efi/arm-runtime.c

> +++ b/drivers/firmware/efi/arm-runtime.c

> @@ -106,23 +106,23 @@ static bool __init efi_virtmap_init(void)

>   * non-early mapping of the UEFI system table and virtual mappings for all

>   * EFI_MEMORY_RUNTIME regions.

>   */

> -static int __init arm_enable_runtime_services(void)

> +void __init efi_enter_virtual_mode(void)

>  {

>         u64 mapsize;

>

>         if (!efi_enabled(EFI_BOOT)) {

>                 pr_info("EFI services will not be available.\n");

> -               return 0;

> +               return;

>         }

>

>         if (efi_runtime_disabled()) {

>                 pr_info("EFI runtime services will be disabled.\n");

> -               return 0;

> +               return;

>         }

>


This is a problem. If you are booting using efi=noruntime, the routine
exits early and never sets up the mapping for the EFI memory map.
So the efi_memmap_init_late() call should be moved before the
efi_runtime_disabled() check, everything else can stay as is afaict

Could you please move the changes to this file and init/main.c into a
separate patch?

>         if (efi_enabled(EFI_RUNTIME_SERVICES)) {

>                 pr_info("EFI runtime services access via paravirt.\n");

> -               return 0;

> +               return;

>         }

>

>         pr_info("Remapping and enabling EFI services.\n");

> @@ -131,21 +131,18 @@ static int __init arm_enable_runtime_services(void)

>

>         if (efi_memmap_init_late(efi.memmap.phys_map, mapsize)) {

>                 pr_err("Failed to remap EFI memory map\n");

> -               return -ENOMEM;

> +               return;

>         }

>

>         if (!efi_virtmap_init()) {

>                 pr_err("UEFI virtual mapping missing or invalid -- runtime services will not be available\n");

> -               return -ENOMEM;

> +               return;

>         }

>

>         /* Set up runtime services function pointers */

>         efi_native_runtime_setup();

>         set_bit(EFI_RUNTIME_SERVICES, &efi.flags);

> -

> -       return 0;

>  }

> -early_initcall(arm_enable_runtime_services);

>

>  void efi_virtmap_load(void)

>  {

> diff --git a/init/main.c b/init/main.c

> index b795aa341a3a..40d05b63960f 100644

> --- a/init/main.c

> +++ b/init/main.c

> @@ -693,6 +693,9 @@ asmlinkage __visible void __init start_kernel(void)

>         debug_objects_mem_init();

>         setup_per_cpu_pageset();

>         numa_policy_init();

> +       if (IS_ENABLED(CONFIG_EFI) &&

> +           (IS_ENABLED(CONFIG_ARM64) || IS_ENABLED(CONFIG_ARM)))

> +               efi_enter_virtual_mode();

>         acpi_early_init();

>         if (late_time_init)

>                 late_time_init();

> --

> 2.17.0

>
AKASHI Takahiro April 25, 2018, 9:06 a.m. UTC | #2 
Ard,

On Wed, Apr 25, 2018 at 10:09:26AM +0200, Ard Biesheuvel wrote:
> On 25 April 2018 at 08:35, AKASHI Takahiro <takahiro.akashi@linaro.org> wrote:

> > This is a fix against the issue that crash dump kernel may hang up

> > during booting, which can happen on any ACPI-based system with "ACPI

> > Reclaim Memory."

> >

> > (kernel messages after panic kicked off kdump)

> >            (snip...)

> >         Bye!

> >            (snip...)

> >         ACPI: Core revision 20170728

> >         pud=000000002e7d0003, *pmd=000000002e7c0003, *pte=00e8000039710707

> >         Internal error: Oops: 96000021 [#1] SMP

> >         Modules linked in:

> >         CPU: 0 PID: 0 Comm: swapper/0 Not tainted 4.14.0-rc6 #1

> >         task: ffff000008d05180 task.stack: ffff000008cc0000

> >         PC is at acpi_ns_lookup+0x25c/0x3c0

> >         LR is at acpi_ds_load1_begin_op+0xa4/0x294

> >            (snip...)

> >         Process swapper/0 (pid: 0, stack limit = 0xffff000008cc0000)

> >         Call trace:

> >            (snip...)

> >         [<ffff0000084a6764>] acpi_ns_lookup+0x25c/0x3c0

> >         [<ffff00000849b4f8>] acpi_ds_load1_begin_op+0xa4/0x294

> >         [<ffff0000084ad4ac>] acpi_ps_build_named_op+0xc4/0x198

> >         [<ffff0000084ad6cc>] acpi_ps_create_op+0x14c/0x270

> >         [<ffff0000084acfa8>] acpi_ps_parse_loop+0x188/0x5c8

> >         [<ffff0000084ae048>] acpi_ps_parse_aml+0xb0/0x2b8

> >         [<ffff0000084a8e10>] acpi_ns_one_complete_parse+0x144/0x184

> >         [<ffff0000084a8e98>] acpi_ns_parse_table+0x48/0x68

> >         [<ffff0000084a82cc>] acpi_ns_load_table+0x4c/0xdc

> >         [<ffff0000084b32f8>] acpi_tb_load_namespace+0xe4/0x264

> >         [<ffff000008baf9b4>] acpi_load_tables+0x48/0xc0

> >         [<ffff000008badc20>] acpi_early_init+0x9c/0xd0

> >         [<ffff000008b70d50>] start_kernel+0x3b4/0x43c

> >         Code: b9008fb9 2a000318 36380054 32190318 (b94002c0)

> >         ---[ end trace c46ed37f9651c58e ]---

> >         Kernel panic - not syncing: Fatal exception

> >         Rebooting in 10 seconds..

> >

> > (diagnosis)

> > * This fault is a data abort, alignment fault (ESR=0x96000021)

> >   during reading out ACPI table.

> > * Initial ACPI tables are normally stored in system ram and marked as

> >   "ACPI Reclaim memory" by the firmware.

> > * After the commit f56ab9a5b73c ("efi/arm: Don't mark ACPI reclaim

> >   memory as MEMBLOCK_NOMAP"), those regions are differently handled

> >   as they are "memblock-reserved", without NOMAP bit.

> > * So they are now excluded from device tree's "usable-memory-range"

> >   which kexec-tools determines based on a current view of /proc/iomem.

> > * When crash dump kernel boots up, it tries to accesses ACPI tables by

> >   mapping them with ioremap(), not ioremap_cache(), in acpi_os_ioremap()

> >   since they are no longer part of mapped system ram.

> > * Given that ACPI accessor/helper functions are compiled in without

> >   unaligned access support (ACPI_MISALIGNMENT_NOT_SUPPORTED),

> >   any unaligned access to ACPI tables can cause a fatal panic.

> >

> > With this patch, acpi_os_ioremap() always honors a memory attribute

> > provided by the firmware (efi). Hence retaining cacheability in said cases

> > allows the kernel safe access to ACPI tables.

> >

> > Please note that arm_enable_runtime_services(), which is renamed to

> > efi_enter_virtual_mode() due to the similarity to x86's, is now called

> > earlier before acpi_early_init() since efi_mem_attributes() relies on

> > efi.memmap being mapped.

> >

> > Signed-off-by: AKASHI Takahiro <takahiro.akashi@linaro.org>

> > Suggested-by: James Morse <james.morse@arm.com>

> > Suggested-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>

> > Reported-by and Tested-by: Bhupesh Sharma <bhsharma@redhat.com>

> > ---

> >  arch/arm64/include/asm/acpi.h      | 23 ++++++++++++++++-------

> >  arch/arm64/kernel/acpi.c           | 11 +++--------

> >  drivers/firmware/efi/arm-runtime.c | 15 ++++++---------

> >  init/main.c                        |  3 +++

> >  4 files changed, 28 insertions(+), 24 deletions(-)

> >

> > diff --git a/arch/arm64/include/asm/acpi.h b/arch/arm64/include/asm/acpi.h

> > index 32f465a80e4e..d53c95f4e1a9 100644

> > --- a/arch/arm64/include/asm/acpi.h

> > +++ b/arch/arm64/include/asm/acpi.h

> > @@ -12,10 +12,12 @@

> >  #ifndef _ASM_ACPI_H

> >  #define _ASM_ACPI_H

> >

> > +#include <linux/efi.h>

> >  #include <linux/memblock.h>

> >  #include <linux/psci.h>

> >

> >  #include <asm/cputype.h>

> > +#include <asm/io.h>

> >  #include <asm/smp_plat.h>

> >  #include <asm/tlbflush.h>

> >

> > @@ -29,18 +31,22 @@

> >

> >  /* Basic configuration for ACPI */

> >  #ifdef CONFIG_ACPI

> > +pgprot_t __acpi_get_mem_attribute(phys_addr_t addr);

> > +

> >  /* ACPI table mapping after acpi_permanent_mmap is set */

> >  static inline void __iomem *acpi_os_ioremap(acpi_physical_address phys,

> >                                             acpi_size size)

> >  {

> > +       /* For normal memory we already have a cacheable mapping. */

> > +       if (memblock_is_map_memory(phys))

> > +               return (void __iomem *)__phys_to_virt(phys);

> > +

> >         /*

> > -        * EFI's reserve_regions() call adds memory with the WB attribute

> > -        * to memblock via early_init_dt_add_memory_arch().

> > +        * We should still honor the memory's attribute here because

> > +        * crash dump kernel possibly excludes some ACPI (reclaim)

> > +        * regions from memblock list.

> >          */

> > -       if (!memblock_is_memory(phys))

> > -               return ioremap(phys, size);

> > -

> > -       return ioremap_cache(phys, size);

> > +       return __ioremap(phys, size, __acpi_get_mem_attribute(phys));

> >  }

> >  #define acpi_os_ioremap acpi_os_ioremap

> >

> > @@ -125,7 +131,10 @@ static inline const char *acpi_get_enable_method(int cpu)

> >   * for compatibility.

> >   */

> >  #define acpi_disable_cmcff 1

> > -pgprot_t arch_apei_get_mem_attribute(phys_addr_t addr);

> > +static inline pgprot_t arch_apei_get_mem_attribute(phys_addr_t addr)

> > +{

> > +       return __acpi_get_mem_attribute(addr);

> > +}

> >  #endif /* CONFIG_ACPI_APEI */

> >

> >  #ifdef CONFIG_ACPI_NUMA

> > diff --git a/arch/arm64/kernel/acpi.c b/arch/arm64/kernel/acpi.c

> > index 7b09487ff8fb..7880076c1cf0 100644

> > --- a/arch/arm64/kernel/acpi.c

> > +++ b/arch/arm64/kernel/acpi.c

> > @@ -18,6 +18,7 @@

> >  #include <linux/acpi.h>

> >  #include <linux/bootmem.h>

> >  #include <linux/cpumask.h>

> > +# include <linux/efi.h>

> 

> Please drop the space after #


Oops, will fix.

> >  #include <linux/efi-bgrt.h>

> >  #include <linux/init.h>

> >  #include <linux/irq.h>

> > @@ -29,12 +30,8 @@

> >

> >  #include <asm/cputype.h>

> >  #include <asm/cpu_ops.h>

> > -#include <asm/smp_plat.h>

> > -

> > -#ifdef CONFIG_ACPI_APEI

> > -# include <linux/efi.h>

> >  # include <asm/pgtable.h>

> 

> And here


Yes, but it's not my change ...

> > -#endif

> > +#include <asm/smp_plat.h>

> >

> >  int acpi_noirq = 1;            /* skip ACPI IRQ initialization */

> >  int acpi_disabled = 1;

> > @@ -239,8 +236,7 @@ void __init acpi_boot_table_init(void)

> >         }

> >  }

> >

> > -#ifdef CONFIG_ACPI_APEI

> > -pgprot_t arch_apei_get_mem_attribute(phys_addr_t addr)

> > +pgprot_t __acpi_get_mem_attribute(phys_addr_t addr)

> >  {

> >         /*

> >          * According to "Table 8 Map: EFI memory types to AArch64 memory

> > @@ -261,4 +257,3 @@ pgprot_t arch_apei_get_mem_attribute(phys_addr_t addr)

> >                 return __pgprot(PROT_NORMAL_NC);

> >         return __pgprot(PROT_DEVICE_nGnRnE);

> >  }

> > -#endif

> > diff --git a/drivers/firmware/efi/arm-runtime.c b/drivers/firmware/efi/arm-runtime.c

> > index 5889cbea60b8..1148ea5a0faa 100644

> > --- a/drivers/firmware/efi/arm-runtime.c

> > +++ b/drivers/firmware/efi/arm-runtime.c

> > @@ -106,23 +106,23 @@ static bool __init efi_virtmap_init(void)

> >   * non-early mapping of the UEFI system table and virtual mappings for all

> >   * EFI_MEMORY_RUNTIME regions.

> >   */

> > -static int __init arm_enable_runtime_services(void)

> > +void __init efi_enter_virtual_mode(void)

> >  {

> >         u64 mapsize;

> >

> >         if (!efi_enabled(EFI_BOOT)) {

> >                 pr_info("EFI services will not be available.\n");

> > -               return 0;

> > +               return;

> >         }

> >

> >         if (efi_runtime_disabled()) {

> >                 pr_info("EFI runtime services will be disabled.\n");

> > -               return 0;

> > +               return;

> >         }

> >

> 

> This is a problem. If you are booting using efi=noruntime, the routine

> exits early and never sets up the mapping for the EFI memory map.

> So the efi_memmap_init_late() call should be moved before the

> efi_runtime_disabled() check, everything else can stay as is afaict

> 

> Could you please move the changes to this file and init/main.c into a

> separate patch?


Okay.

Thank you for your reviewing.

-Takahiro AKASHI


> >         if (efi_enabled(EFI_RUNTIME_SERVICES)) {

> >                 pr_info("EFI runtime services access via paravirt.\n");

> > -               return 0;

> > +               return;

> >         }

> >

> >         pr_info("Remapping and enabling EFI services.\n");

> > @@ -131,21 +131,18 @@ static int __init arm_enable_runtime_services(void)

> >

> >         if (efi_memmap_init_late(efi.memmap.phys_map, mapsize)) {

> >                 pr_err("Failed to remap EFI memory map\n");

> > -               return -ENOMEM;

> > +               return;

> >         }

> >

> >         if (!efi_virtmap_init()) {

> >                 pr_err("UEFI virtual mapping missing or invalid -- runtime services will not be available\n");

> > -               return -ENOMEM;

> > +               return;

> >         }

> >

> >         /* Set up runtime services function pointers */

> >         efi_native_runtime_setup();

> >         set_bit(EFI_RUNTIME_SERVICES, &efi.flags);

> > -

> > -       return 0;

> >  }

> > -early_initcall(arm_enable_runtime_services);

> >

> >  void efi_virtmap_load(void)

> >  {

> > diff --git a/init/main.c b/init/main.c

> > index b795aa341a3a..40d05b63960f 100644

> > --- a/init/main.c

> > +++ b/init/main.c

> > @@ -693,6 +693,9 @@ asmlinkage __visible void __init start_kernel(void)

> >         debug_objects_mem_init();

> >         setup_per_cpu_pageset();

> >         numa_policy_init();

> > +       if (IS_ENABLED(CONFIG_EFI) &&

> > +           (IS_ENABLED(CONFIG_ARM64) || IS_ENABLED(CONFIG_ARM)))

> > +               efi_enter_virtual_mode();

> >         acpi_early_init();

> >         if (late_time_init)

> >                 late_time_init();

> > --

> > 2.17.0

> >
Ard Biesheuvel April 25, 2018, 9:07 a.m. UTC | #3 
On 25 April 2018 at 11:06, AKASHI Takahiro <takahiro.akashi@linaro.org> wrote:
> Ard,

>

> On Wed, Apr 25, 2018 at 10:09:26AM +0200, Ard Biesheuvel wrote:

>> On 25 April 2018 at 08:35, AKASHI Takahiro <takahiro.akashi@linaro.org> wrote:

>> > This is a fix against the issue that crash dump kernel may hang up

>> > during booting, which can happen on any ACPI-based system with "ACPI

>> > Reclaim Memory."

>> >

>> > (kernel messages after panic kicked off kdump)

>> >            (snip...)

>> >         Bye!

>> >            (snip...)

>> >         ACPI: Core revision 20170728

>> >         pud=000000002e7d0003, *pmd=000000002e7c0003, *pte=00e8000039710707

>> >         Internal error: Oops: 96000021 [#1] SMP

>> >         Modules linked in:

>> >         CPU: 0 PID: 0 Comm: swapper/0 Not tainted 4.14.0-rc6 #1

>> >         task: ffff000008d05180 task.stack: ffff000008cc0000

>> >         PC is at acpi_ns_lookup+0x25c/0x3c0

>> >         LR is at acpi_ds_load1_begin_op+0xa4/0x294

>> >            (snip...)

>> >         Process swapper/0 (pid: 0, stack limit = 0xffff000008cc0000)

>> >         Call trace:

>> >            (snip...)

>> >         [<ffff0000084a6764>] acpi_ns_lookup+0x25c/0x3c0

>> >         [<ffff00000849b4f8>] acpi_ds_load1_begin_op+0xa4/0x294

>> >         [<ffff0000084ad4ac>] acpi_ps_build_named_op+0xc4/0x198

>> >         [<ffff0000084ad6cc>] acpi_ps_create_op+0x14c/0x270

>> >         [<ffff0000084acfa8>] acpi_ps_parse_loop+0x188/0x5c8

>> >         [<ffff0000084ae048>] acpi_ps_parse_aml+0xb0/0x2b8

>> >         [<ffff0000084a8e10>] acpi_ns_one_complete_parse+0x144/0x184

>> >         [<ffff0000084a8e98>] acpi_ns_parse_table+0x48/0x68

>> >         [<ffff0000084a82cc>] acpi_ns_load_table+0x4c/0xdc

>> >         [<ffff0000084b32f8>] acpi_tb_load_namespace+0xe4/0x264

>> >         [<ffff000008baf9b4>] acpi_load_tables+0x48/0xc0

>> >         [<ffff000008badc20>] acpi_early_init+0x9c/0xd0

>> >         [<ffff000008b70d50>] start_kernel+0x3b4/0x43c

>> >         Code: b9008fb9 2a000318 36380054 32190318 (b94002c0)

>> >         ---[ end trace c46ed37f9651c58e ]---

>> >         Kernel panic - not syncing: Fatal exception

>> >         Rebooting in 10 seconds..

>> >

>> > (diagnosis)

>> > * This fault is a data abort, alignment fault (ESR=0x96000021)

>> >   during reading out ACPI table.

>> > * Initial ACPI tables are normally stored in system ram and marked as

>> >   "ACPI Reclaim memory" by the firmware.

>> > * After the commit f56ab9a5b73c ("efi/arm: Don't mark ACPI reclaim

>> >   memory as MEMBLOCK_NOMAP"), those regions are differently handled

>> >   as they are "memblock-reserved", without NOMAP bit.

>> > * So they are now excluded from device tree's "usable-memory-range"

>> >   which kexec-tools determines based on a current view of /proc/iomem.

>> > * When crash dump kernel boots up, it tries to accesses ACPI tables by

>> >   mapping them with ioremap(), not ioremap_cache(), in acpi_os_ioremap()

>> >   since they are no longer part of mapped system ram.

>> > * Given that ACPI accessor/helper functions are compiled in without

>> >   unaligned access support (ACPI_MISALIGNMENT_NOT_SUPPORTED),

>> >   any unaligned access to ACPI tables can cause a fatal panic.

>> >

>> > With this patch, acpi_os_ioremap() always honors a memory attribute

>> > provided by the firmware (efi). Hence retaining cacheability in said cases

>> > allows the kernel safe access to ACPI tables.

>> >

>> > Please note that arm_enable_runtime_services(), which is renamed to

>> > efi_enter_virtual_mode() due to the similarity to x86's, is now called

>> > earlier before acpi_early_init() since efi_mem_attributes() relies on

>> > efi.memmap being mapped.

>> >

>> > Signed-off-by: AKASHI Takahiro <takahiro.akashi@linaro.org>

>> > Suggested-by: James Morse <james.morse@arm.com>

>> > Suggested-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>

>> > Reported-by and Tested-by: Bhupesh Sharma <bhsharma@redhat.com>

>> > ---

>> >  arch/arm64/include/asm/acpi.h      | 23 ++++++++++++++++-------

>> >  arch/arm64/kernel/acpi.c           | 11 +++--------

>> >  drivers/firmware/efi/arm-runtime.c | 15 ++++++---------

>> >  init/main.c                        |  3 +++

>> >  4 files changed, 28 insertions(+), 24 deletions(-)

>> >

>> > diff --git a/arch/arm64/include/asm/acpi.h b/arch/arm64/include/asm/acpi.h

>> > index 32f465a80e4e..d53c95f4e1a9 100644

>> > --- a/arch/arm64/include/asm/acpi.h

>> > +++ b/arch/arm64/include/asm/acpi.h

>> > @@ -12,10 +12,12 @@

>> >  #ifndef _ASM_ACPI_H

>> >  #define _ASM_ACPI_H

>> >

>> > +#include <linux/efi.h>

>> >  #include <linux/memblock.h>

>> >  #include <linux/psci.h>

>> >

>> >  #include <asm/cputype.h>

>> > +#include <asm/io.h>

>> >  #include <asm/smp_plat.h>

>> >  #include <asm/tlbflush.h>

>> >

>> > @@ -29,18 +31,22 @@

>> >

>> >  /* Basic configuration for ACPI */

>> >  #ifdef CONFIG_ACPI

>> > +pgprot_t __acpi_get_mem_attribute(phys_addr_t addr);

>> > +

>> >  /* ACPI table mapping after acpi_permanent_mmap is set */

>> >  static inline void __iomem *acpi_os_ioremap(acpi_physical_address phys,

>> >                                             acpi_size size)

>> >  {

>> > +       /* For normal memory we already have a cacheable mapping. */

>> > +       if (memblock_is_map_memory(phys))

>> > +               return (void __iomem *)__phys_to_virt(phys);

>> > +

>> >         /*

>> > -        * EFI's reserve_regions() call adds memory with the WB attribute

>> > -        * to memblock via early_init_dt_add_memory_arch().

>> > +        * We should still honor the memory's attribute here because

>> > +        * crash dump kernel possibly excludes some ACPI (reclaim)

>> > +        * regions from memblock list.

>> >          */

>> > -       if (!memblock_is_memory(phys))

>> > -               return ioremap(phys, size);

>> > -

>> > -       return ioremap_cache(phys, size);

>> > +       return __ioremap(phys, size, __acpi_get_mem_attribute(phys));

>> >  }

>> >  #define acpi_os_ioremap acpi_os_ioremap

>> >

>> > @@ -125,7 +131,10 @@ static inline const char *acpi_get_enable_method(int cpu)

>> >   * for compatibility.

>> >   */

>> >  #define acpi_disable_cmcff 1

>> > -pgprot_t arch_apei_get_mem_attribute(phys_addr_t addr);

>> > +static inline pgprot_t arch_apei_get_mem_attribute(phys_addr_t addr)

>> > +{

>> > +       return __acpi_get_mem_attribute(addr);

>> > +}

>> >  #endif /* CONFIG_ACPI_APEI */

>> >

>> >  #ifdef CONFIG_ACPI_NUMA

>> > diff --git a/arch/arm64/kernel/acpi.c b/arch/arm64/kernel/acpi.c

>> > index 7b09487ff8fb..7880076c1cf0 100644

>> > --- a/arch/arm64/kernel/acpi.c

>> > +++ b/arch/arm64/kernel/acpi.c

>> > @@ -18,6 +18,7 @@

>> >  #include <linux/acpi.h>

>> >  #include <linux/bootmem.h>

>> >  #include <linux/cpumask.h>

>> > +# include <linux/efi.h>

>>

>> Please drop the space after #

>

> Oops, will fix.

>

>> >  #include <linux/efi-bgrt.h>

>> >  #include <linux/init.h>

>> >  #include <linux/irq.h>

>> > @@ -29,12 +30,8 @@

>> >

>> >  #include <asm/cputype.h>

>> >  #include <asm/cpu_ops.h>

>> > -#include <asm/smp_plat.h>

>> > -

>> > -#ifdef CONFIG_ACPI_APEI

>> > -# include <linux/efi.h>

>> >  # include <asm/pgtable.h>

>>

>> And here

>

> Yes, but it's not my change ...

>


The space is there because of the #ifdef, which you remove ...

>> > -#endif

>> > +#include <asm/smp_plat.h>

>> >

>> >  int acpi_noirq = 1;            /* skip ACPI IRQ initialization */

>> >  int acpi_disabled = 1;

>> > @@ -239,8 +236,7 @@ void __init acpi_boot_table_init(void)

>> >         }

>> >  }

>> >

>> > -#ifdef CONFIG_ACPI_APEI

>> > -pgprot_t arch_apei_get_mem_attribute(phys_addr_t addr)

>> > +pgprot_t __acpi_get_mem_attribute(phys_addr_t addr)

>> >  {

>> >         /*

>> >          * According to "Table 8 Map: EFI memory types to AArch64 memory

>> > @@ -261,4 +257,3 @@ pgprot_t arch_apei_get_mem_attribute(phys_addr_t addr)

>> >                 return __pgprot(PROT_NORMAL_NC);

>> >         return __pgprot(PROT_DEVICE_nGnRnE);

>> >  }

>> > -#endif

>> > diff --git a/drivers/firmware/efi/arm-runtime.c b/drivers/firmware/efi/arm-runtime.c

>> > index 5889cbea60b8..1148ea5a0faa 100644

>> > --- a/drivers/firmware/efi/arm-runtime.c

>> > +++ b/drivers/firmware/efi/arm-runtime.c

>> > @@ -106,23 +106,23 @@ static bool __init efi_virtmap_init(void)

>> >   * non-early mapping of the UEFI system table and virtual mappings for all

>> >   * EFI_MEMORY_RUNTIME regions.

>> >   */

>> > -static int __init arm_enable_runtime_services(void)

>> > +void __init efi_enter_virtual_mode(void)

>> >  {

>> >         u64 mapsize;

>> >

>> >         if (!efi_enabled(EFI_BOOT)) {

>> >                 pr_info("EFI services will not be available.\n");

>> > -               return 0;

>> > +               return;

>> >         }

>> >

>> >         if (efi_runtime_disabled()) {

>> >                 pr_info("EFI runtime services will be disabled.\n");

>> > -               return 0;

>> > +               return;

>> >         }

>> >

>>

>> This is a problem. If you are booting using efi=noruntime, the routine

>> exits early and never sets up the mapping for the EFI memory map.

>> So the efi_memmap_init_late() call should be moved before the

>> efi_runtime_disabled() check, everything else can stay as is afaict

>>

>> Could you please move the changes to this file and init/main.c into a

>> separate patch?

>

> Okay.

>

> Thank you for your reviewing.

>

> -Takahiro AKASHI

>

>

>> >         if (efi_enabled(EFI_RUNTIME_SERVICES)) {

>> >                 pr_info("EFI runtime services access via paravirt.\n");

>> > -               return 0;

>> > +               return;

>> >         }

>> >

>> >         pr_info("Remapping and enabling EFI services.\n");

>> > @@ -131,21 +131,18 @@ static int __init arm_enable_runtime_services(void)

>> >

>> >         if (efi_memmap_init_late(efi.memmap.phys_map, mapsize)) {

>> >                 pr_err("Failed to remap EFI memory map\n");

>> > -               return -ENOMEM;

>> > +               return;

>> >         }

>> >

>> >         if (!efi_virtmap_init()) {

>> >                 pr_err("UEFI virtual mapping missing or invalid -- runtime services will not be available\n");

>> > -               return -ENOMEM;

>> > +               return;

>> >         }

>> >

>> >         /* Set up runtime services function pointers */

>> >         efi_native_runtime_setup();

>> >         set_bit(EFI_RUNTIME_SERVICES, &efi.flags);

>> > -

>> > -       return 0;

>> >  }

>> > -early_initcall(arm_enable_runtime_services);

>> >

>> >  void efi_virtmap_load(void)

>> >  {

>> > diff --git a/init/main.c b/init/main.c

>> > index b795aa341a3a..40d05b63960f 100644

>> > --- a/init/main.c

>> > +++ b/init/main.c

>> > @@ -693,6 +693,9 @@ asmlinkage __visible void __init start_kernel(void)

>> >         debug_objects_mem_init();

>> >         setup_per_cpu_pageset();

>> >         numa_policy_init();

>> > +       if (IS_ENABLED(CONFIG_EFI) &&

>> > +           (IS_ENABLED(CONFIG_ARM64) || IS_ENABLED(CONFIG_ARM)))

>> > +               efi_enter_virtual_mode();

>> >         acpi_early_init();

>> >         if (late_time_init)

>> >                 late_time_init();

>> > --

>> > 2.17.0

>> >
diff mbox series

Patch

diff --git a/arch/arm64/include/asm/acpi.h b/arch/arm64/include/asm/acpi.h
index 32f465a80e4e..d53c95f4e1a9 100644
--- a/arch/arm64/include/asm/acpi.h
+++ b/arch/arm64/include/asm/acpi.h
@@ -12,10 +12,12 @@ 
 #ifndef _ASM_ACPI_H
 #define _ASM_ACPI_H
 
+#include <linux/efi.h>
 #include <linux/memblock.h>
 #include <linux/psci.h>
 
 #include <asm/cputype.h>
+#include <asm/io.h>
 #include <asm/smp_plat.h>
 #include <asm/tlbflush.h>
 
@@ -29,18 +31,22 @@ 
 
 /* Basic configuration for ACPI */
 #ifdef	CONFIG_ACPI
+pgprot_t __acpi_get_mem_attribute(phys_addr_t addr);
+
 /* ACPI table mapping after acpi_permanent_mmap is set */
 static inline void __iomem *acpi_os_ioremap(acpi_physical_address phys,
 					    acpi_size size)
 {
+	/* For normal memory we already have a cacheable mapping. */
+	if (memblock_is_map_memory(phys))
+		return (void __iomem *)__phys_to_virt(phys);
+
 	/*
-	 * EFI's reserve_regions() call adds memory with the WB attribute
-	 * to memblock via early_init_dt_add_memory_arch().
+	 * We should still honor the memory's attribute here because
+	 * crash dump kernel possibly excludes some ACPI (reclaim)
+	 * regions from memblock list.
 	 */
-	if (!memblock_is_memory(phys))
-		return ioremap(phys, size);
-
-	return ioremap_cache(phys, size);
+	return __ioremap(phys, size, __acpi_get_mem_attribute(phys));
 }
 #define acpi_os_ioremap acpi_os_ioremap
 
@@ -125,7 +131,10 @@  static inline const char *acpi_get_enable_method(int cpu)
  * for compatibility.
  */
 #define acpi_disable_cmcff 1
-pgprot_t arch_apei_get_mem_attribute(phys_addr_t addr);
+static inline pgprot_t arch_apei_get_mem_attribute(phys_addr_t addr)
+{
+	return __acpi_get_mem_attribute(addr);
+}
 #endif /* CONFIG_ACPI_APEI */
 
 #ifdef CONFIG_ACPI_NUMA
diff --git a/arch/arm64/kernel/acpi.c b/arch/arm64/kernel/acpi.c
index 7b09487ff8fb..7880076c1cf0 100644
--- a/arch/arm64/kernel/acpi.c
+++ b/arch/arm64/kernel/acpi.c
@@ -18,6 +18,7 @@ 
 #include <linux/acpi.h>
 #include <linux/bootmem.h>
 #include <linux/cpumask.h>
+# include <linux/efi.h>
 #include <linux/efi-bgrt.h>
 #include <linux/init.h>
 #include <linux/irq.h>
@@ -29,12 +30,8 @@ 
 
 #include <asm/cputype.h>
 #include <asm/cpu_ops.h>
-#include <asm/smp_plat.h>
-
-#ifdef CONFIG_ACPI_APEI
-# include <linux/efi.h>
 # include <asm/pgtable.h>
-#endif
+#include <asm/smp_plat.h>
 
 int acpi_noirq = 1;		/* skip ACPI IRQ initialization */
 int acpi_disabled = 1;
@@ -239,8 +236,7 @@  void __init acpi_boot_table_init(void)
 	}
 }
 
-#ifdef CONFIG_ACPI_APEI
-pgprot_t arch_apei_get_mem_attribute(phys_addr_t addr)
+pgprot_t __acpi_get_mem_attribute(phys_addr_t addr)
 {
 	/*
 	 * According to "Table 8 Map: EFI memory types to AArch64 memory
@@ -261,4 +257,3 @@  pgprot_t arch_apei_get_mem_attribute(phys_addr_t addr)
 		return __pgprot(PROT_NORMAL_NC);
 	return __pgprot(PROT_DEVICE_nGnRnE);
 }
-#endif
diff --git a/drivers/firmware/efi/arm-runtime.c b/drivers/firmware/efi/arm-runtime.c
index 5889cbea60b8..1148ea5a0faa 100644
--- a/drivers/firmware/efi/arm-runtime.c
+++ b/drivers/firmware/efi/arm-runtime.c
@@ -106,23 +106,23 @@  static bool __init efi_virtmap_init(void)
  * non-early mapping of the UEFI system table and virtual mappings for all
  * EFI_MEMORY_RUNTIME regions.
  */
-static int __init arm_enable_runtime_services(void)
+void __init efi_enter_virtual_mode(void)
 {
 	u64 mapsize;
 
 	if (!efi_enabled(EFI_BOOT)) {
 		pr_info("EFI services will not be available.\n");
-		return 0;
+		return;
 	}
 
 	if (efi_runtime_disabled()) {
 		pr_info("EFI runtime services will be disabled.\n");
-		return 0;
+		return;
 	}
 
 	if (efi_enabled(EFI_RUNTIME_SERVICES)) {
 		pr_info("EFI runtime services access via paravirt.\n");
-		return 0;
+		return;
 	}
 
 	pr_info("Remapping and enabling EFI services.\n");
@@ -131,21 +131,18 @@  static int __init arm_enable_runtime_services(void)
 
 	if (efi_memmap_init_late(efi.memmap.phys_map, mapsize)) {
 		pr_err("Failed to remap EFI memory map\n");
-		return -ENOMEM;
+		return;
 	}
 
 	if (!efi_virtmap_init()) {
 		pr_err("UEFI virtual mapping missing or invalid -- runtime services will not be available\n");
-		return -ENOMEM;
+		return;
 	}
 
 	/* Set up runtime services function pointers */
 	efi_native_runtime_setup();
 	set_bit(EFI_RUNTIME_SERVICES, &efi.flags);
-
-	return 0;
 }
-early_initcall(arm_enable_runtime_services);
 
 void efi_virtmap_load(void)
 {
diff --git a/init/main.c b/init/main.c
index b795aa341a3a..40d05b63960f 100644
--- a/init/main.c
+++ b/init/main.c
@@ -693,6 +693,9 @@  asmlinkage __visible void __init start_kernel(void)
 	debug_objects_mem_init();
 	setup_per_cpu_pageset();
 	numa_policy_init();
+	if (IS_ENABLED(CONFIG_EFI) &&
+	    (IS_ENABLED(CONFIG_ARM64) || IS_ENABLED(CONFIG_ARM)))
+		efi_enter_virtual_mode();
 	acpi_early_init();
 	if (late_time_init)
 		late_time_init();