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-rw-r--r--arch/arm64/include/asm/efi.h4
-rw-r--r--arch/arm64/include/asm/mmu_context.h22
2 files changed, 14 insertions, 12 deletions
diff --git a/arch/arm64/include/asm/efi.h b/arch/arm64/include/asm/efi.h
index 650344d01124..c4cd5081d78b 100644
--- a/arch/arm64/include/asm/efi.h
+++ b/arch/arm64/include/asm/efi.h
@@ -132,11 +132,9 @@ static inline void efi_set_pgd(struct mm_struct *mm)
* 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
- * (if different from init_mm).
*/
cpu_set_reserved_ttbr0();
- if (current->active_mm != &init_mm)
- update_saved_ttbr0(current, current->active_mm);
+ update_saved_ttbr0(current, current->active_mm);
}
}
}
diff --git a/arch/arm64/include/asm/mmu_context.h b/arch/arm64/include/asm/mmu_context.h
index 3257895a9b5e..f7773f90546e 100644
--- a/arch/arm64/include/asm/mmu_context.h
+++ b/arch/arm64/include/asm/mmu_context.h
@@ -174,11 +174,17 @@ enter_lazy_tlb(struct mm_struct *mm, struct task_struct *tsk)
static inline void update_saved_ttbr0(struct task_struct *tsk,
struct mm_struct *mm)
{
- if (system_uses_ttbr0_pan()) {
- BUG_ON(mm->pgd == swapper_pg_dir);
- task_thread_info(tsk)->ttbr0 =
- virt_to_phys(mm->pgd) | ASID(mm) << 48;
- }
+ u64 ttbr;
+
+ if (!system_uses_ttbr0_pan())
+ return;
+
+ if (mm == &init_mm)
+ ttbr = __pa_symbol(empty_zero_page);
+ else
+ ttbr = virt_to_phys(mm->pgd) | ASID(mm) << 48;
+
+ task_thread_info(tsk)->ttbr0 = ttbr;
}
#else
static inline void update_saved_ttbr0(struct task_struct *tsk,
@@ -214,11 +220,9 @@ switch_mm(struct mm_struct *prev, struct mm_struct *next,
* Update the saved TTBR0_EL1 of the scheduled-in task as the previous
* value may have not been initialised yet (activate_mm caller) or the
* ASID has changed since the last run (following the context switch
- * of another thread of the same process). Avoid setting the reserved
- * TTBR0_EL1 to swapper_pg_dir (init_mm; e.g. via idle_task_exit).
+ * of another thread of the same process).
*/
- if (next != &init_mm)
- update_saved_ttbr0(tsk, next);
+ update_saved_ttbr0(tsk, next);
}
#define deactivate_mm(tsk,mm) do { } while (0)