diff mbox series

[v2,4/4] arm64: acpi: fix alignment fault in accessing ACPI

Message ID 20180619064424.6642-5-takahiro.akashi@linaro.org
State Superseded
Headers show
Series arm64: kexec,kdump: fix boot failures on acpi-only system | expand

Commit Message

AKASHI Takahiro June 19, 2018, 6:44 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 memory attribute
information provided by the firmware (EFI) and retaining cacheability
allows the kernel safe access to ACPI tables.

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 +++--------
 2 files changed, 19 insertions(+), 15 deletions(-)

-- 
2.17.0

Comments

James Morse June 28, 2018, 5:28 p.m. UTC | #1 
Hi Akashi,

On 19/06/18 07:44, AKASHI Takahiro 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 memory attribute

> information provided by the firmware (EFI) and retaining cacheability

> allows the kernel safe access to ACPI tables.


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



Thanks,

James
Ard Biesheuvel July 5, 2018, 10:27 p.m. UTC | #2 
On 19 June 2018 at 08:44, 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 memory attribute

> information provided by the firmware (EFI) and retaining cacheability

> allows the kernel safe access to ACPI tables.

>

> 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>


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


> ---

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

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

>  2 files changed, 19 insertions(+), 15 deletions(-)

>

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

> index 0db62a4cbce2..68bc18cb2b85 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

>

> @@ -129,7 +135,10 @@ 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..ed46dc188b22 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>

> @@ -29,13 +30,9 @@

>

>  #include <asm/cputype.h>

>  #include <asm/cpu_ops.h>

> +#include <asm/pgtable.h>

>  #include <asm/smp_plat.h>

>

> -#ifdef CONFIG_ACPI_APEI

> -# include <linux/efi.h>

> -# include <asm/pgtable.h>

> -#endif

> -

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

>  int acpi_disabled = 1;

>  EXPORT_SYMBOL(acpi_disabled);

> @@ -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

> --

> 2.17.0

>
diff mbox series

Patch

diff --git a/arch/arm64/include/asm/acpi.h b/arch/arm64/include/asm/acpi.h
index 0db62a4cbce2..68bc18cb2b85 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
 
@@ -129,7 +135,10 @@  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..ed46dc188b22 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>
@@ -29,13 +30,9 @@ 
 
 #include <asm/cputype.h>
 #include <asm/cpu_ops.h>
+#include <asm/pgtable.h>
 #include <asm/smp_plat.h>
 
-#ifdef CONFIG_ACPI_APEI
-# include <linux/efi.h>
-# include <asm/pgtable.h>
-#endif
-
 int acpi_noirq = 1;		/* skip ACPI IRQ initialization */
 int acpi_disabled = 1;
 EXPORT_SYMBOL(acpi_disabled);
@@ -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