| Message ID | 20180619064424.6642-5-takahiro.akashi@linaro.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
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
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 --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
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(-)