diff --git a/arch/x86/include/asm/efi.h b/arch/x86/include/asm/efi.h index c98f78330b0920200d870f43a4a6901df4cc5d56..4b7706ddd8b60175048be49e1146db31bfee929d 100644 --- a/arch/x86/include/asm/efi.h +++ b/arch/x86/include/asm/efi.h @@ -150,7 +150,7 @@ extern void __init efi_apply_memmap_quirks(void); extern int __init efi_reuse_config(u64 tables, int nr_tables); extern void efi_delete_dummy_variable(void); extern void efi_switch_mm(struct mm_struct *mm); -extern void efi_recover_from_page_fault(unsigned long phys_addr); +extern void efi_crash_gracefully_on_page_fault(unsigned long phys_addr); extern void efi_free_boot_services(void); /* kexec external ABI */ diff --git a/arch/x86/mm/fault.c b/arch/x86/mm/fault.c index 1c3054bb4a5b244ab038530077287459a2ce0e57..7b3a125e1e984ac8c796f50977ac96ef67a490e8 100644 --- a/arch/x86/mm/fault.c +++ b/arch/x86/mm/fault.c @@ -16,7 +16,7 @@ #include <linux/prefetch.h> /* prefetchw */ #include <linux/context_tracking.h> /* exception_enter(), ... */ #include <linux/uaccess.h> /* faulthandler_disabled() */ -#include <linux/efi.h> /* efi_recover_from_page_fault()*/ +#include <linux/efi.h> /* efi_crash_gracefully_on_page_fault()*/ #include <linux/mm_types.h> #include <asm/cpufeature.h> /* boot_cpu_has, ... */ @@ -25,7 +25,7 @@ #include <asm/vsyscall.h> /* emulate_vsyscall */ #include <asm/vm86.h> /* struct vm86 */ #include <asm/mmu_context.h> /* vma_pkey() */ -#include <asm/efi.h> /* efi_recover_from_page_fault()*/ +#include <asm/efi.h> /* efi_crash_gracefully_on_page_fault()*/ #include <asm/desc.h> /* store_idt(), ... */ #include <asm/cpu_entry_area.h> /* exception stack */ #include <asm/pgtable_areas.h> /* VMALLOC_START, ... */ @@ -701,11 +701,12 @@ page_fault_oops(struct pt_regs *regs, unsigned long error_code, #endif /* - * Buggy firmware could access regions which might page fault, try to - * recover from such faults. + * Buggy firmware could access regions which might page fault. If + * this happens, EFI has a special OOPS path that will try to + * avoid hanging the system. */ if (IS_ENABLED(CONFIG_EFI)) - efi_recover_from_page_fault(address); + efi_crash_gracefully_on_page_fault(address); oops: /* diff --git a/arch/x86/platform/efi/quirks.c b/arch/x86/platform/efi/quirks.c index 5a40fe411ebda0fedbf65d9de0f9c1f0ba92abee..67d93a243c353c5aad59a65910f529928d10c5d8 100644 --- a/arch/x86/platform/efi/quirks.c +++ b/arch/x86/platform/efi/quirks.c @@ -687,15 +687,25 @@ int efi_capsule_setup_info(struct capsule_info *cap_info, void *kbuff, * @return: Returns, if the page fault is not handled. This function * will never return if the page fault is handled successfully. */ -void efi_recover_from_page_fault(unsigned long phys_addr) +void efi_crash_gracefully_on_page_fault(unsigned long phys_addr) { if (!IS_ENABLED(CONFIG_X86_64)) return; + /* + * If we get an interrupt/NMI while processing an EFI runtime service + * then this is a regular OOPS, not an EFI failure. + */ + if (in_interrupt()) + return; + /* * Make sure that an efi runtime service caused the page fault. + * READ_ONCE() because we might be OOPSing in a different thread, + * and we don't want to trip KTSAN while trying to OOPS. */ - if (efi_rts_work.efi_rts_id == EFI_NONE) + if (READ_ONCE(efi_rts_work.efi_rts_id) == EFI_NONE || + current_work() != &efi_rts_work.work) return; /* @@ -747,6 +757,4 @@ void efi_recover_from_page_fault(unsigned long phys_addr) set_current_state(TASK_IDLE); schedule(); } - - return; }