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

Message ID 20180425063527.29763-1-takahiro.akashi@linaro.org
State New, archived
Headers show

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(-)

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
>> >

Patch
diff mbox

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();