diff options
Diffstat (limited to 'arch/x86/platform/efi')
| -rw-r--r-- | arch/x86/platform/efi/efi_64.c | 52 | ||||
| -rw-r--r-- | arch/x86/platform/efi/efi_thunk_64.S | 6 | ||||
| -rw-r--r-- | arch/x86/platform/efi/quirks.c | 16 |
3 files changed, 35 insertions, 39 deletions
diff --git a/arch/x86/platform/efi/efi_64.c b/arch/x86/platform/efi/efi_64.c index e1e8d4e3a213..1b82d77019b1 100644 --- a/arch/x86/platform/efi/efi_64.c +++ b/arch/x86/platform/efi/efi_64.c @@ -54,10 +54,7 @@ * 0xffff_ffff_0000_0000 and limit EFI VA mapping space to 64G. */ static u64 efi_va = EFI_VA_START; - -struct efi_scratch efi_scratch; - -EXPORT_SYMBOL_GPL(efi_mm); +static struct mm_struct *efi_prev_mm; /* * We need our own copy of the higher levels of the page tables @@ -115,31 +112,12 @@ void efi_sync_low_kernel_mappings(void) pud_t *pud_k, *pud_efi; pgd_t *efi_pgd = efi_mm.pgd; - /* - * We can share all PGD entries apart from the one entry that - * covers the EFI runtime mapping space. - * - * Make sure the EFI runtime region mappings are guaranteed to - * only span a single PGD entry and that the entry also maps - * other important kernel regions. - */ - MAYBE_BUILD_BUG_ON(pgd_index(EFI_VA_END) != pgd_index(MODULES_END)); - MAYBE_BUILD_BUG_ON((EFI_VA_START & PGDIR_MASK) != - (EFI_VA_END & PGDIR_MASK)); - pgd_efi = efi_pgd + pgd_index(PAGE_OFFSET); pgd_k = pgd_offset_k(PAGE_OFFSET); num_entries = pgd_index(EFI_VA_END) - pgd_index(PAGE_OFFSET); memcpy(pgd_efi, pgd_k, sizeof(pgd_t) * num_entries); - /* - * As with PGDs, we share all P4D entries apart from the one entry - * that covers the EFI runtime mapping space. - */ - BUILD_BUG_ON(p4d_index(EFI_VA_END) != p4d_index(MODULES_END)); - BUILD_BUG_ON((EFI_VA_START & P4D_MASK) != (EFI_VA_END & P4D_MASK)); - pgd_efi = efi_pgd + pgd_index(EFI_VA_END); pgd_k = pgd_offset_k(EFI_VA_END); p4d_efi = p4d_offset(pgd_efi, 0); @@ -256,7 +234,7 @@ int __init efi_setup_page_tables(unsigned long pa_memmap, unsigned num_pages) return 1; } - efi_scratch.phys_stack = page_to_phys(page + 1); /* stack grows down */ + efi_mixed_mode_stack_pa = page_to_phys(page + 1); /* stack grows down */ npages = (_etext - _text) >> PAGE_SHIFT; text = __pa(_text); @@ -481,11 +459,17 @@ void __init efi_dump_pagetable(void) * can not change under us. * It should be ensured that there are no concurent calls to this function. */ -void efi_switch_mm(struct mm_struct *mm) +void efi_enter_mm(void) +{ + efi_prev_mm = current->active_mm; + current->active_mm = &efi_mm; + switch_mm(efi_prev_mm, &efi_mm, NULL); +} + +void efi_leave_mm(void) { - efi_scratch.prev_mm = current->active_mm; - current->active_mm = mm; - switch_mm(efi_scratch.prev_mm, mm, NULL); + current->active_mm = efi_prev_mm; + switch_mm(&efi_mm, efi_prev_mm, NULL); } static DEFINE_SPINLOCK(efi_runtime_lock); @@ -549,12 +533,12 @@ efi_thunk_set_virtual_address_map(unsigned long memory_map_size, efi_sync_low_kernel_mappings(); local_irq_save(flags); - efi_switch_mm(&efi_mm); + efi_enter_mm(); status = __efi_thunk(set_virtual_address_map, memory_map_size, descriptor_size, descriptor_version, virtual_map); - efi_switch_mm(efi_scratch.prev_mm); + efi_leave_mm(); local_irq_restore(flags); return status; @@ -848,9 +832,9 @@ efi_set_virtual_address_map(unsigned long memory_map_size, descriptor_size, descriptor_version, virtual_map); - efi_switch_mm(&efi_mm); + efi_enter_mm(); - kernel_fpu_begin(); + efi_fpu_begin(); /* Disable interrupts around EFI calls: */ local_irq_save(flags); @@ -859,12 +843,12 @@ efi_set_virtual_address_map(unsigned long memory_map_size, descriptor_version, virtual_map); local_irq_restore(flags); - kernel_fpu_end(); + efi_fpu_end(); /* grab the virtually remapped EFI runtime services table pointer */ efi.runtime = READ_ONCE(systab->runtime); - efi_switch_mm(efi_scratch.prev_mm); + efi_leave_mm(); return status; } diff --git a/arch/x86/platform/efi/efi_thunk_64.S b/arch/x86/platform/efi/efi_thunk_64.S index 26f0da238c1c..fd3dd1708eba 100644 --- a/arch/x86/platform/efi/efi_thunk_64.S +++ b/arch/x86/platform/efi/efi_thunk_64.S @@ -33,7 +33,7 @@ SYM_CODE_START(__efi64_thunk) * Switch to 1:1 mapped 32-bit stack pointer. */ movq %rsp, %rax - movq efi_scratch(%rip), %rsp + movq efi_mixed_mode_stack_pa(%rip), %rsp push %rax /* @@ -70,3 +70,7 @@ SYM_CODE_START(__efi64_thunk) pushl %ebp lret SYM_CODE_END(__efi64_thunk) + + .bss + .balign 8 +SYM_DATA(efi_mixed_mode_stack_pa, .quad 0) diff --git a/arch/x86/platform/efi/quirks.c b/arch/x86/platform/efi/quirks.c index 5a40fe411ebd..67d93a243c35 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; } |