| .. | .. |
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| 619 | 619 | |
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| 620 | 620 | /* |
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| 621 | 621 | * Makes the calling thread switch to/from efi_mm context. Can be used |
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| 622 | | - * for SetVirtualAddressMap() i.e. current->active_mm == init_mm as well |
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| 623 | | - * as during efi runtime calls i.e current->active_mm == current_mm. |
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| 624 | | - * We are not mm_dropping()/mm_grabbing() any mm, because we are not |
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| 625 | | - * losing/creating any references. |
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| 622 | + * in a kernel thread and user context. Preemption needs to remain disabled |
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| 623 | + * while the EFI-mm is borrowed. mmgrab()/mmdrop() is not used because the mm |
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| 624 | + * can not change under us. |
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| 625 | + * It should be ensured that there are no concurent calls to this function. |
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| 626 | 626 | */ |
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| 627 | 627 | void efi_switch_mm(struct mm_struct *mm) |
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| 628 | 628 | { |
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| 629 | | - task_lock(current); |
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| 630 | 629 | efi_scratch.prev_mm = current->active_mm; |
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| 631 | 630 | current->active_mm = mm; |
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| 632 | 631 | switch_mm(efi_scratch.prev_mm, mm, NULL); |
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| 633 | | - task_unlock(current); |
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| 634 | 632 | } |
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| 635 | 633 | |
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| 636 | 634 | #ifdef CONFIG_EFI_MIXED |
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