diff options
| -rw-r--r-- | arch/arm64/include/asm/efi.h | 13 | ||||
| -rw-r--r-- | arch/arm64/kernel/efi.c | 18 |
2 files changed, 21 insertions, 10 deletions
diff --git a/arch/arm64/include/asm/efi.h b/arch/arm64/include/asm/efi.h index bcd5622aa096..aa91165ca140 100644 --- a/arch/arm64/include/asm/efi.h +++ b/arch/arm64/include/asm/efi.h @@ -126,21 +126,14 @@ static inline void efi_set_pgd(struct mm_struct *mm) if (mm != current->active_mm) { /* * Update the current thread's saved ttbr0 since it is - * restored as part of a return from exception. Enable - * access to the valid TTBR0_EL1 and invoke the errata - * workaround directly since there is no return from - * exception when invoking the EFI run-time services. + * restored as part of a return from exception. */ update_saved_ttbr0(current, mm); - uaccess_ttbr0_enable(); - post_ttbr_update_workaround(); } else { /* - * Defer the switch to the current thread's TTBR0_EL1 - * until uaccess_enable(). Restore the current - * thread's saved ttbr0 corresponding to its active_mm + * Restore the current thread's saved ttbr0 + * corresponding to its active_mm */ - uaccess_ttbr0_disable(); update_saved_ttbr0(current, current->active_mm); } } diff --git a/arch/arm64/kernel/efi.c b/arch/arm64/kernel/efi.c index 0094f5938ba6..85f65d5c863c 100644 --- a/arch/arm64/kernel/efi.c +++ b/arch/arm64/kernel/efi.c @@ -169,12 +169,30 @@ void arch_efi_call_virt_setup(void) { efi_runtime_assert_lock_held(); efi_virtmap_load(); + + /* + * Enable access to the valid TTBR0_EL1 and invoke the errata + * workaround directly since there is no return from exception when + * invoking the EFI run-time services. + */ + uaccess_ttbr0_enable(); + post_ttbr_update_workaround(); + __efi_fpsimd_begin(); } void arch_efi_call_virt_teardown(void) { __efi_fpsimd_end(); + + /* + * Defer the switch to the current thread's TTBR0_EL1 until + * uaccess_enable(). Do so before efi_virtmap_unload() updates the + * saved TTBR0 value, so the userland page tables are not activated + * inadvertently over the back of an exception. + */ + uaccess_ttbr0_disable(); + efi_virtmap_unload(); } |