diff options
Diffstat (limited to 'arch/arm64/mm')
| -rw-r--r-- | arch/arm64/mm/cache.S | 41 | ||||
| -rw-r--r-- | arch/arm64/mm/copypage.c | 9 | ||||
| -rw-r--r-- | arch/arm64/mm/dma-mapping.c | 19 | ||||
| -rw-r--r-- | arch/arm64/mm/extable.c | 10 | ||||
| -rw-r--r-- | arch/arm64/mm/fault.c | 1 | ||||
| -rw-r--r-- | arch/arm64/mm/hugetlbpage.c | 10 | ||||
| -rw-r--r-- | arch/arm64/mm/init.c | 4 | ||||
| -rw-r--r-- | arch/arm64/mm/ioremap.c | 90 | ||||
| -rw-r--r-- | arch/arm64/mm/mmu.c | 23 | ||||
| -rw-r--r-- | arch/arm64/mm/mteswap.c | 9 | ||||
| -rw-r--r-- | arch/arm64/mm/proc.S | 173 |
11 files changed, 124 insertions, 265 deletions
diff --git a/arch/arm64/mm/cache.S b/arch/arm64/mm/cache.S index 21c907987080..081058d4e436 100644 --- a/arch/arm64/mm/cache.S +++ b/arch/arm64/mm/cache.S @@ -194,44 +194,3 @@ SYM_FUNC_START(__pi_dcache_clean_pop) ret SYM_FUNC_END(__pi_dcache_clean_pop) SYM_FUNC_ALIAS(dcache_clean_pop, __pi_dcache_clean_pop) - -/* - * __dma_flush_area(start, size) - * - * clean & invalidate D / U line - * - * - start - virtual start address of region - * - size - size in question - */ -SYM_FUNC_START(__pi___dma_flush_area) - add x1, x0, x1 - dcache_by_line_op civac, sy, x0, x1, x2, x3 - ret -SYM_FUNC_END(__pi___dma_flush_area) -SYM_FUNC_ALIAS(__dma_flush_area, __pi___dma_flush_area) - -/* - * __dma_map_area(start, size, dir) - * - start - kernel virtual start address - * - size - size of region - * - dir - DMA direction - */ -SYM_FUNC_START(__pi___dma_map_area) - add x1, x0, x1 - b __pi_dcache_clean_poc -SYM_FUNC_END(__pi___dma_map_area) -SYM_FUNC_ALIAS(__dma_map_area, __pi___dma_map_area) - -/* - * __dma_unmap_area(start, size, dir) - * - start - kernel virtual start address - * - size - size of region - * - dir - DMA direction - */ -SYM_FUNC_START(__pi___dma_unmap_area) - add x1, x0, x1 - cmp w2, #DMA_TO_DEVICE - b.ne __pi_dcache_inval_poc - ret -SYM_FUNC_END(__pi___dma_unmap_area) -SYM_FUNC_ALIAS(__dma_unmap_area, __pi___dma_unmap_area) diff --git a/arch/arm64/mm/copypage.c b/arch/arm64/mm/copypage.c index 0dea80bf6de4..24913271e898 100644 --- a/arch/arm64/mm/copypage.c +++ b/arch/arm64/mm/copypage.c @@ -23,15 +23,6 @@ void copy_highpage(struct page *to, struct page *from) if (system_supports_mte() && test_bit(PG_mte_tagged, &from->flags)) { set_bit(PG_mte_tagged, &to->flags); - page_kasan_tag_reset(to); - /* - * We need smp_wmb() in between setting the flags and clearing the - * tags because if another thread reads page->flags and builds a - * tagged address out of it, there is an actual dependency to the - * memory access, but on the current thread we do not guarantee that - * the new page->flags are visible before the tags were updated. - */ - smp_wmb(); mte_copy_page_tags(kto, kfrom); } } diff --git a/arch/arm64/mm/dma-mapping.c b/arch/arm64/mm/dma-mapping.c index 6099c81b9322..599cf81f5685 100644 --- a/arch/arm64/mm/dma-mapping.c +++ b/arch/arm64/mm/dma-mapping.c @@ -14,20 +14,29 @@ #include <asm/xen/xen-ops.h> void arch_sync_dma_for_device(phys_addr_t paddr, size_t size, - enum dma_data_direction dir) + enum dma_data_direction dir) { - __dma_map_area(phys_to_virt(paddr), size, dir); + unsigned long start = (unsigned long)phys_to_virt(paddr); + + dcache_clean_poc(start, start + size); } void arch_sync_dma_for_cpu(phys_addr_t paddr, size_t size, - enum dma_data_direction dir) + enum dma_data_direction dir) { - __dma_unmap_area(phys_to_virt(paddr), size, dir); + unsigned long start = (unsigned long)phys_to_virt(paddr); + + if (dir == DMA_TO_DEVICE) + return; + + dcache_inval_poc(start, start + size); } void arch_dma_prep_coherent(struct page *page, size_t size) { - __dma_flush_area(page_address(page), size); + unsigned long start = (unsigned long)page_address(page); + + dcache_clean_inval_poc(start, start + size); } #ifdef CONFIG_IOMMU_DMA diff --git a/arch/arm64/mm/extable.c b/arch/arm64/mm/extable.c index 489455309695..228d681a8715 100644 --- a/arch/arm64/mm/extable.c +++ b/arch/arm64/mm/extable.c @@ -16,13 +16,6 @@ get_ex_fixup(const struct exception_table_entry *ex) return ((unsigned long)&ex->fixup + ex->fixup); } -static bool ex_handler_fixup(const struct exception_table_entry *ex, - struct pt_regs *regs) -{ - regs->pc = get_ex_fixup(ex); - return true; -} - static bool ex_handler_uaccess_err_zero(const struct exception_table_entry *ex, struct pt_regs *regs) { @@ -72,11 +65,10 @@ bool fixup_exception(struct pt_regs *regs) return false; switch (ex->type) { - case EX_TYPE_FIXUP: - return ex_handler_fixup(ex, regs); case EX_TYPE_BPF: return ex_handler_bpf(ex, regs); case EX_TYPE_UACCESS_ERR_ZERO: + case EX_TYPE_KACCESS_ERR_ZERO: return ex_handler_uaccess_err_zero(ex, regs); case EX_TYPE_LOAD_UNALIGNED_ZEROPAD: return ex_handler_load_unaligned_zeropad(ex, regs); diff --git a/arch/arm64/mm/fault.c b/arch/arm64/mm/fault.c index c5e11768e5c1..cdf3ffa0c223 100644 --- a/arch/arm64/mm/fault.c +++ b/arch/arm64/mm/fault.c @@ -927,6 +927,5 @@ struct page *alloc_zeroed_user_highpage_movable(struct vm_area_struct *vma, void tag_clear_highpage(struct page *page) { mte_zero_clear_page_tags(page_address(page)); - page_kasan_tag_reset(page); set_bit(PG_mte_tagged, &page->flags); } diff --git a/arch/arm64/mm/hugetlbpage.c b/arch/arm64/mm/hugetlbpage.c index e2a5ec9fdc0d..8eab05367549 100644 --- a/arch/arm64/mm/hugetlbpage.c +++ b/arch/arm64/mm/hugetlbpage.c @@ -100,16 +100,6 @@ int pud_huge(pud_t pud) #endif } -/* - * Select all bits except the pfn - */ -static inline pgprot_t pte_pgprot(pte_t pte) -{ - unsigned long pfn = pte_pfn(pte); - - return __pgprot(pte_val(pfn_pte(pfn, __pgprot(0))) ^ pte_val(pte)); -} - static int find_num_contig(struct mm_struct *mm, unsigned long addr, pte_t *ptep, size_t *pgsize) { diff --git a/arch/arm64/mm/init.c b/arch/arm64/mm/init.c index 339ee84e5a61..b6ef26fc8ebe 100644 --- a/arch/arm64/mm/init.c +++ b/arch/arm64/mm/init.c @@ -389,7 +389,7 @@ void __init arm64_memblock_init(void) early_init_fdt_scan_reserved_mem(); - if (!IS_ENABLED(CONFIG_ZONE_DMA) && !IS_ENABLED(CONFIG_ZONE_DMA32)) + if (!defer_reserve_crashkernel()) reserve_crashkernel(); high_memory = __va(memblock_end_of_DRAM() - 1) + 1; @@ -438,7 +438,7 @@ void __init bootmem_init(void) * request_standard_resources() depends on crashkernel's memory being * reserved, so do it here. */ - if (IS_ENABLED(CONFIG_ZONE_DMA) || IS_ENABLED(CONFIG_ZONE_DMA32)) + if (defer_reserve_crashkernel()) reserve_crashkernel(); memblock_dump_all(); diff --git a/arch/arm64/mm/ioremap.c b/arch/arm64/mm/ioremap.c index b21f91cd830d..c5af103d4ad4 100644 --- a/arch/arm64/mm/ioremap.c +++ b/arch/arm64/mm/ioremap.c @@ -1,96 +1,22 @@ // SPDX-License-Identifier: GPL-2.0-only -/* - * Based on arch/arm/mm/ioremap.c - * - * (C) Copyright 1995 1996 Linus Torvalds - * Hacked for ARM by Phil Blundell <philb@gnu.org> - * Hacked to allow all architectures to build, and various cleanups - * by Russell King - * Copyright (C) 2012 ARM Ltd. - */ -#include <linux/export.h> #include <linux/mm.h> -#include <linux/vmalloc.h> #include <linux/io.h> -#include <asm/fixmap.h> -#include <asm/tlbflush.h> - -static void __iomem *__ioremap_caller(phys_addr_t phys_addr, size_t size, - pgprot_t prot, void *caller) +bool ioremap_allowed(phys_addr_t phys_addr, size_t size, unsigned long prot) { - unsigned long last_addr; - unsigned long offset = phys_addr & ~PAGE_MASK; - int err; - unsigned long addr; - struct vm_struct *area; + unsigned long last_addr = phys_addr + size - 1; - /* - * Page align the mapping address and size, taking account of any - * offset. - */ - phys_addr &= PAGE_MASK; - size = PAGE_ALIGN(size + offset); + /* Don't allow outside PHYS_MASK */ + if (last_addr & ~PHYS_MASK) + return false; - /* - * Don't allow wraparound, zero size or outside PHYS_MASK. - */ - last_addr = phys_addr + size - 1; - if (!size || last_addr < phys_addr || (last_addr & ~PHYS_MASK)) - return NULL; - - /* - * Don't allow RAM to be mapped. - */ + /* Don't allow RAM to be mapped. */ if (WARN_ON(pfn_is_map_memory(__phys_to_pfn(phys_addr)))) - return NULL; - - area = get_vm_area_caller(size, VM_IOREMAP, caller); - if (!area) - return NULL; - addr = (unsigned long)area->addr; - area->phys_addr = phys_addr; - - err = ioremap_page_range(addr, addr + size, phys_addr, prot); - if (err) { - vunmap((void *)addr); - return NULL; - } - - return (void __iomem *)(offset + addr); -} - -void __iomem *__ioremap(phys_addr_t phys_addr, size_t size, pgprot_t prot) -{ - return __ioremap_caller(phys_addr, size, prot, - __builtin_return_address(0)); -} -EXPORT_SYMBOL(__ioremap); - -void iounmap(volatile void __iomem *io_addr) -{ - unsigned long addr = (unsigned long)io_addr & PAGE_MASK; - - /* - * We could get an address outside vmalloc range in case - * of ioremap_cache() reusing a RAM mapping. - */ - if (is_vmalloc_addr((void *)addr)) - vunmap((void *)addr); -} -EXPORT_SYMBOL(iounmap); - -void __iomem *ioremap_cache(phys_addr_t phys_addr, size_t size) -{ - /* For normal memory we already have a cacheable mapping. */ - if (pfn_is_map_memory(__phys_to_pfn(phys_addr))) - return (void __iomem *)__phys_to_virt(phys_addr); + return false; - return __ioremap_caller(phys_addr, size, __pgprot(PROT_NORMAL), - __builtin_return_address(0)); + return true; } -EXPORT_SYMBOL(ioremap_cache); /* * Must be called after early_fixmap_init diff --git a/arch/arm64/mm/mmu.c b/arch/arm64/mm/mmu.c index 05d77f2342a9..db7c4e6ae57b 100644 --- a/arch/arm64/mm/mmu.c +++ b/arch/arm64/mm/mmu.c @@ -400,6 +400,13 @@ static void __create_pgd_mapping(pgd_t *pgdir, phys_addr_t phys, } while (pgdp++, addr = next, addr != end); } +#ifdef CONFIG_UNMAP_KERNEL_AT_EL0 +extern __alias(__create_pgd_mapping) +void create_kpti_ng_temp_pgd(pgd_t *pgdir, phys_addr_t phys, unsigned long virt, + phys_addr_t size, pgprot_t prot, + phys_addr_t (*pgtable_alloc)(int), int flags); +#endif + static phys_addr_t __pgd_pgtable_alloc(int shift) { void *ptr = (void *)__get_free_page(GFP_PGTABLE_KERNEL); @@ -541,8 +548,7 @@ static void __init map_mem(pgd_t *pgdp) #ifdef CONFIG_KEXEC_CORE if (crash_mem_map) { - if (IS_ENABLED(CONFIG_ZONE_DMA) || - IS_ENABLED(CONFIG_ZONE_DMA32)) + if (defer_reserve_crashkernel()) flags |= NO_BLOCK_MAPPINGS | NO_CONT_MAPPINGS; else if (crashk_res.end) memblock_mark_nomap(crashk_res.start, @@ -583,8 +589,7 @@ static void __init map_mem(pgd_t *pgdp) * through /sys/kernel/kexec_crash_size interface. */ #ifdef CONFIG_KEXEC_CORE - if (crash_mem_map && - !IS_ENABLED(CONFIG_ZONE_DMA) && !IS_ENABLED(CONFIG_ZONE_DMA32)) { + if (crash_mem_map && !defer_reserve_crashkernel()) { if (crashk_res.end) { __map_memblock(pgdp, crashk_res.start, crashk_res.end + 1, @@ -677,13 +682,9 @@ static int __init map_entry_trampoline(void) __set_fixmap(FIX_ENTRY_TRAMP_TEXT1 - i, pa_start + i * PAGE_SIZE, prot); - if (IS_ENABLED(CONFIG_RANDOMIZE_BASE)) { - extern char __entry_tramp_data_start[]; - - __set_fixmap(FIX_ENTRY_TRAMP_DATA, - __pa_symbol(__entry_tramp_data_start), - PAGE_KERNEL_RO); - } + if (IS_ENABLED(CONFIG_RELOCATABLE)) + __set_fixmap(FIX_ENTRY_TRAMP_TEXT1 - i, + pa_start + i * PAGE_SIZE, PAGE_KERNEL_RO); return 0; } diff --git a/arch/arm64/mm/mteswap.c b/arch/arm64/mm/mteswap.c index a9e50e930484..4334dec93bd4 100644 --- a/arch/arm64/mm/mteswap.c +++ b/arch/arm64/mm/mteswap.c @@ -53,15 +53,6 @@ bool mte_restore_tags(swp_entry_t entry, struct page *page) if (!tags) return false; - page_kasan_tag_reset(page); - /* - * We need smp_wmb() in between setting the flags and clearing the - * tags because if another thread reads page->flags and builds a - * tagged address out of it, there is an actual dependency to the - * memory access, but on the current thread we do not guarantee that - * the new page->flags are visible before the tags were updated. - */ - smp_wmb(); mte_restore_page_tags(page_address(page), tags); return true; diff --git a/arch/arm64/mm/proc.S b/arch/arm64/mm/proc.S index 9eb490effb7f..7837a69524c5 100644 --- a/arch/arm64/mm/proc.S +++ b/arch/arm64/mm/proc.S @@ -14,6 +14,7 @@ #include <asm/asm-offsets.h> #include <asm/asm_pointer_auth.h> #include <asm/hwcap.h> +#include <asm/kernel-pgtable.h> #include <asm/pgtable-hwdef.h> #include <asm/cpufeature.h> #include <asm/alternative.h> @@ -200,25 +201,51 @@ SYM_FUNC_END(idmap_cpu_replace_ttbr1) .popsection #ifdef CONFIG_UNMAP_KERNEL_AT_EL0 + +#define KPTI_NG_PTE_FLAGS (PTE_ATTRINDX(MT_NORMAL) | SWAPPER_PTE_FLAGS) + .pushsection ".idmap.text", "awx" - .macro __idmap_kpti_get_pgtable_ent, type - dc cvac, cur_\()\type\()p // Ensure any existing dirty - dmb sy // lines are written back before - ldr \type, [cur_\()\type\()p] // loading the entry - tbz \type, #0, skip_\()\type // Skip invalid and - tbnz \type, #11, skip_\()\type // non-global entries + .macro kpti_mk_tbl_ng, type, num_entries + add end_\type\()p, cur_\type\()p, #\num_entries * 8 +.Ldo_\type: + ldr \type, [cur_\type\()p] // Load the entry + tbz \type, #0, .Lnext_\type // Skip invalid and + tbnz \type, #11, .Lnext_\type // non-global entries + orr \type, \type, #PTE_NG // Same bit for blocks and pages + str \type, [cur_\type\()p] // Update the entry + .ifnc \type, pte + tbnz \type, #1, .Lderef_\type + .endif +.Lnext_\type: + add cur_\type\()p, cur_\type\()p, #8 + cmp cur_\type\()p, end_\type\()p + b.ne .Ldo_\type .endm - .macro __idmap_kpti_put_pgtable_ent_ng, type - orr \type, \type, #PTE_NG // Same bit for blocks and pages - str \type, [cur_\()\type\()p] // Update the entry and ensure - dmb sy // that it is visible to all - dc civac, cur_\()\type\()p // CPUs. + /* + * Dereference the current table entry and map it into the temporary + * fixmap slot associated with the current level. + */ + .macro kpti_map_pgtbl, type, level + str xzr, [temp_pte, #8 * (\level + 1)] // break before make + dsb nshst + add pte, temp_pte, #PAGE_SIZE * (\level + 1) + lsr pte, pte, #12 + tlbi vaae1, pte + dsb nsh + isb + + phys_to_pte pte, cur_\type\()p + add cur_\type\()p, temp_pte, #PAGE_SIZE * (\level + 1) + orr pte, pte, pte_flags + str pte, [temp_pte, #8 * (\level + 1)] + dsb nshst .endm /* - * void __kpti_install_ng_mappings(int cpu, int num_cpus, phys_addr_t swapper) + * void __kpti_install_ng_mappings(int cpu, int num_secondaries, phys_addr_t temp_pgd, + * unsigned long temp_pte_va) * * Called exactly once from stop_machine context by each CPU found during boot. */ @@ -228,8 +255,10 @@ SYM_DATA(__idmap_kpti_flag, .long 1) SYM_FUNC_START(idmap_kpti_install_ng_mappings) cpu .req w0 + temp_pte .req x0 num_cpus .req w1 - swapper_pa .req x2 + pte_flags .req x1 + temp_pgd_phys .req x2 swapper_ttb .req x3 flag_ptr .req x4 cur_pgdp .req x5 @@ -237,16 +266,15 @@ SYM_FUNC_START(idmap_kpti_install_ng_mappings) pgd .req x7 cur_pudp .req x8 end_pudp .req x9 - pud .req x10 cur_pmdp .req x11 end_pmdp .req x12 - pmd .req x13 cur_ptep .req x14 end_ptep .req x15 pte .req x16 + valid .req x17 + mov x5, x3 // preserve temp_pte arg mrs swapper_ttb, ttbr1_el1 - restore_ttbr1 swapper_ttb adr_l flag_ptr, __idmap_kpti_flag cbnz cpu, __idmap_kpti_secondary @@ -258,98 +286,71 @@ SYM_FUNC_START(idmap_kpti_install_ng_mappings) eor w17, w17, num_cpus cbnz w17, 1b - /* We need to walk swapper, so turn off the MMU. */ - pre_disable_mmu_workaround - mrs x17, sctlr_el1 - bic x17, x17, #SCTLR_ELx_M - msr sctlr_el1, x17 + /* Switch to the temporary page tables on this CPU only */ + __idmap_cpu_set_reserved_ttbr1 x8, x9 + offset_ttbr1 temp_pgd_phys, x8 + msr ttbr1_el1, temp_pgd_phys isb + mov temp_pte, x5 + mov pte_flags, #KPTI_NG_PTE_FLAGS + /* Everybody is enjoying the idmap, so we can rewrite swapper. */ /* PGD */ - mov cur_pgdp, swapper_pa - add end_pgdp, cur_pgdp, #(PTRS_PER_PGD * 8) -do_pgd: __idmap_kpti_get_pgtable_ent pgd - tbnz pgd, #1, walk_puds -next_pgd: - __idmap_kpti_put_pgtable_ent_ng pgd -skip_pgd: - add cur_pgdp, cur_pgdp, #8 - cmp cur_pgdp, end_pgdp - b.ne do_pgd - - /* Publish the updated tables and nuke all the TLBs */ - dsb sy - tlbi vmalle1is - dsb ish - isb + adrp cur_pgdp, swapper_pg_dir + kpti_map_pgtbl pgd, 0 + kpti_mk_tbl_ng pgd, PTRS_PER_PGD - /* We're done: fire up the MMU again */ - mrs x17, sctlr_el1 - orr x17, x17, #SCTLR_ELx_M - set_sctlr_el1 x17 + /* Ensure all the updated entries are visible to secondary CPUs */ + dsb ishst + + /* We're done: fire up swapper_pg_dir again */ + __idmap_cpu_set_reserved_ttbr1 x8, x9 + msr ttbr1_el1, swapper_ttb + isb /* Set the flag to zero to indicate that we're all done */ str wzr, [flag_ptr] ret +.Lderef_pgd: /* PUD */ -walk_puds: - .if CONFIG_PGTABLE_LEVELS > 3 + .if CONFIG_PGTABLE_LEVELS > 3 + pud .req x10 pte_to_phys cur_pudp, pgd - add end_pudp, cur_pudp, #(PTRS_PER_PUD * 8) -do_pud: __idmap_kpti_get_pgtable_ent pud - tbnz pud, #1, walk_pmds -next_pud: - __idmap_kpti_put_pgtable_ent_ng pud -skip_pud: - add cur_pudp, cur_pudp, 8 - cmp cur_pudp, end_pudp - b.ne do_pud - b next_pgd - .else /* CONFIG_PGTABLE_LEVELS <= 3 */ - mov pud, pgd - b walk_pmds -next_pud: - b next_pgd + kpti_map_pgtbl pud, 1 + kpti_mk_tbl_ng pud, PTRS_PER_PUD + b .Lnext_pgd + .else /* CONFIG_PGTABLE_LEVELS <= 3 */ + pud .req pgd + .set .Lnext_pud, .Lnext_pgd .endif +.Lderef_pud: /* PMD */ -walk_pmds: - .if CONFIG_PGTABLE_LEVELS > 2 + .if CONFIG_PGTABLE_LEVELS > 2 + pmd .req x13 pte_to_phys cur_pmdp, pud - add end_pmdp, cur_pmdp, #(PTRS_PER_PMD * 8) -do_pmd: __idmap_kpti_get_pgtable_ent pmd - tbnz pmd, #1, walk_ptes -next_pmd: - __idmap_kpti_put_pgtable_ent_ng pmd -skip_pmd: - add cur_pmdp, cur_pmdp, #8 - cmp cur_pmdp, end_pmdp - b.ne do_pmd - b next_pud - .else /* CONFIG_PGTABLE_LEVELS <= 2 */ - mov pmd, pud - b walk_ptes -next_pmd: - b next_pud + kpti_map_pgtbl pmd, 2 + kpti_mk_tbl_ng pmd, PTRS_PER_PMD + b .Lnext_pud + .else /* CONFIG_PGTABLE_LEVELS <= 2 */ + pmd .req pgd + .set .Lnext_pmd, .Lnext_pgd .endif +.Lderef_pmd: /* PTE */ -walk_ptes: pte_to_phys cur_ptep, pmd - add end_ptep, cur_ptep, #(PTRS_PER_PTE * 8) -do_pte: __idmap_kpti_get_pgtable_ent pte - __idmap_kpti_put_pgtable_ent_ng pte -skip_pte: - add cur_ptep, cur_ptep, #8 - cmp cur_ptep, end_ptep - b.ne do_pte - b next_pmd + kpti_map_pgtbl pte, 3 + kpti_mk_tbl_ng pte, PTRS_PER_PTE + b .Lnext_pmd .unreq cpu + .unreq temp_pte .unreq num_cpus - .unreq swapper_pa + .unreq pte_flags + .unreq temp_pgd_phys .unreq cur_pgdp .unreq end_pgdp .unreq pgd @@ -362,6 +363,7 @@ skip_pte: .unreq cur_ptep .unreq end_ptep .unreq pte + .unreq valid /* Secondary CPUs end up here */ __idmap_kpti_secondary: @@ -381,7 +383,6 @@ __idmap_kpti_secondary: cbnz w16, 1b /* All done, act like nothing happened */ - offset_ttbr1 swapper_ttb, x16 msr ttbr1_el1, swapper_ttb isb ret |