diff options
| -rw-r--r-- | arch/arm64/kernel/efi.c | 23 |
1 files changed, 21 insertions, 2 deletions
diff --git a/arch/arm64/kernel/efi.c b/arch/arm64/kernel/efi.c index 85f65d5c863c..a81cb4aa4738 100644 --- a/arch/arm64/kernel/efi.c +++ b/arch/arm64/kernel/efi.c @@ -10,6 +10,7 @@ #include <linux/efi.h> #include <linux/init.h> #include <linux/kmemleak.h> +#include <linux/kthread.h> #include <linux/screen_info.h> #include <linux/vmalloc.h> @@ -168,7 +169,20 @@ asmlinkage efi_status_t efi_handle_corrupted_x18(efi_status_t s, const char *f) void arch_efi_call_virt_setup(void) { efi_runtime_assert_lock_held(); - efi_virtmap_load(); + + if (preemptible() && (current->flags & PF_KTHREAD)) { + /* + * Disable migration to ensure that a preempted EFI runtime + * service call will be resumed on the same CPU. This avoids + * potential issues with EFI runtime calls that are preempted + * while polling for an asynchronous completion of a secure + * firmware call, which may not permit the CPU to change. + */ + migrate_disable(); + kthread_use_mm(&efi_mm); + } else { + efi_virtmap_load(); + } /* * Enable access to the valid TTBR0_EL1 and invoke the errata @@ -193,7 +207,12 @@ void arch_efi_call_virt_teardown(void) */ uaccess_ttbr0_disable(); - efi_virtmap_unload(); + if (preemptible() && (current->flags & PF_KTHREAD)) { + kthread_unuse_mm(&efi_mm); + migrate_enable(); + } else { + efi_virtmap_unload(); + } } asmlinkage u64 *efi_rt_stack_top __ro_after_init; |