| Message ID | 20180425063527.29763-1-takahiro.akashi@linaro.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
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 >
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 > >
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 --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();
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(-)