diff options
| -rw-r--r-- | arch/arm64/include/asm/efi.h | 4 | ||||
| -rw-r--r-- | arch/arm64/include/asm/mmu_context.h | 22 | ||||
| -rw-r--r-- | arch/arm64/include/asm/uaccess.h | 2 |
3 files changed, 15 insertions, 13 deletions
diff --git a/arch/arm64/include/asm/efi.h b/arch/arm64/include/asm/efi.h index 3a405dccb6cf..4e7eec79cbc8 100644 --- a/arch/arm64/include/asm/efi.h +++ b/arch/arm64/include/asm/efi.h @@ -93,11 +93,9 @@ 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 0363fe80455c..3cc41837e181 100644 --- a/arch/arm64/include/asm/mmu_context.h +++ b/arch/arm64/include/asm/mmu_context.h @@ -168,11 +168,17 @@ 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, @@ -208,11 +214,9 @@ 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) diff --git a/arch/arm64/include/asm/uaccess.h b/arch/arm64/include/asm/uaccess.h index 6986f56cfa88..d26750ca6e06 100644 --- a/arch/arm64/include/asm/uaccess.h +++ b/arch/arm64/include/asm/uaccess.h @@ -188,7 +188,7 @@ do { \ #define __uaccess_enable(alt) \ do { \ - if (uaccess_ttbr0_enable()) \ + if (!uaccess_ttbr0_enable()) \ asm(ALTERNATIVE("nop", SET_PSTATE_PAN(0), alt, \ CONFIG_ARM64_PAN)); \ } while (0) |