diff options
Diffstat (limited to 'arch/arm64/mm/mmu.c')
| -rw-r--r-- | arch/arm64/mm/mmu.c | 76 |
1 files changed, 58 insertions, 18 deletions
diff --git a/arch/arm64/mm/mmu.c b/arch/arm64/mm/mmu.c index a374e4f51a62..e7fbc6275329 100644 --- a/arch/arm64/mm/mmu.c +++ b/arch/arm64/mm/mmu.c @@ -290,18 +290,19 @@ static void alloc_init_pud(pgd_t *pgdp, unsigned long addr, unsigned long end, { unsigned long next; pud_t *pudp; - pgd_t pgd = READ_ONCE(*pgdp); + p4d_t *p4dp = p4d_offset(pgdp, addr); + p4d_t p4d = READ_ONCE(*p4dp); - if (pgd_none(pgd)) { + if (p4d_none(p4d)) { phys_addr_t pud_phys; BUG_ON(!pgtable_alloc); pud_phys = pgtable_alloc(PUD_SHIFT); - __pgd_populate(pgdp, pud_phys, PUD_TYPE_TABLE); - pgd = READ_ONCE(*pgdp); + __p4d_populate(p4dp, pud_phys, PUD_TYPE_TABLE); + p4d = READ_ONCE(*p4dp); } - BUG_ON(pgd_bad(pgd)); + BUG_ON(p4d_bad(p4d)); - pudp = pud_set_fixmap_offset(pgdp, addr); + pudp = pud_set_fixmap_offset(p4dp, addr); do { pud_t old_pud = READ_ONCE(*pudp); @@ -610,6 +611,22 @@ core_initcall(map_entry_trampoline); #endif /* + * Open coded check for BTI, only for use to determine configuration + * for early mappings for before the cpufeature code has run. + */ +static bool arm64_early_this_cpu_has_bti(void) +{ + u64 pfr1; + + if (!IS_ENABLED(CONFIG_ARM64_BTI_KERNEL)) + return false; + + pfr1 = read_sysreg_s(SYS_ID_AA64PFR1_EL1); + return cpuid_feature_extract_unsigned_field(pfr1, + ID_AA64PFR1_BT_SHIFT); +} + +/* * Create fine-grained mappings for the kernel. */ static void __init map_kernel(pgd_t *pgdp) @@ -625,6 +642,14 @@ static void __init map_kernel(pgd_t *pgdp) pgprot_t text_prot = rodata_enabled ? PAGE_KERNEL_ROX : PAGE_KERNEL_EXEC; /* + * If we have a CPU that supports BTI and a kernel built for + * BTI then mark the kernel executable text as guarded pages + * now so we don't have to rewrite the page tables later. + */ + if (arm64_early_this_cpu_has_bti()) + text_prot = __pgprot_modify(text_prot, PTE_GP, PTE_GP); + + /* * Only rodata will be remapped with different permissions later on, * all other segments are allowed to use contiguous mappings. */ @@ -648,6 +673,7 @@ static void __init map_kernel(pgd_t *pgdp) READ_ONCE(*pgd_offset_k(FIXADDR_START))); } else if (CONFIG_PGTABLE_LEVELS > 3) { pgd_t *bm_pgdp; + p4d_t *bm_p4dp; pud_t *bm_pudp; /* * The fixmap shares its top level pgd entry with the kernel @@ -657,7 +683,8 @@ static void __init map_kernel(pgd_t *pgdp) */ BUG_ON(!IS_ENABLED(CONFIG_ARM64_16K_PAGES)); bm_pgdp = pgd_offset_raw(pgdp, FIXADDR_START); - bm_pudp = pud_set_fixmap_offset(bm_pgdp, FIXADDR_START); + bm_p4dp = p4d_offset(bm_pgdp, FIXADDR_START); + bm_pudp = pud_set_fixmap_offset(bm_p4dp, FIXADDR_START); pud_populate(&init_mm, bm_pudp, lm_alias(bm_pmd)); pud_clear_fixmap(); } else { @@ -691,6 +718,7 @@ void __init paging_init(void) int kern_addr_valid(unsigned long addr) { pgd_t *pgdp; + p4d_t *p4dp; pud_t *pudp, pud; pmd_t *pmdp, pmd; pte_t *ptep, pte; @@ -702,7 +730,11 @@ int kern_addr_valid(unsigned long addr) if (pgd_none(READ_ONCE(*pgdp))) return 0; - pudp = pud_offset(pgdp, addr); + p4dp = p4d_offset(pgdp, addr); + if (p4d_none(READ_ONCE(*p4dp))) + return 0; + + pudp = pud_offset(p4dp, addr); pud = READ_ONCE(*pudp); if (pud_none(pud)) return 0; @@ -1045,6 +1077,7 @@ int __meminit vmemmap_populate(unsigned long start, unsigned long end, int node, unsigned long addr = start; unsigned long next; pgd_t *pgdp; + p4d_t *p4dp; pud_t *pudp; pmd_t *pmdp; @@ -1055,7 +1088,11 @@ int __meminit vmemmap_populate(unsigned long start, unsigned long end, int node, if (!pgdp) return -ENOMEM; - pudp = vmemmap_pud_populate(pgdp, addr, node); + p4dp = vmemmap_p4d_populate(pgdp, addr, node); + if (!p4dp) + return -ENOMEM; + + pudp = vmemmap_pud_populate(p4dp, addr, node); if (!pudp) return -ENOMEM; @@ -1090,11 +1127,12 @@ void vmemmap_free(unsigned long start, unsigned long end, static inline pud_t * fixmap_pud(unsigned long addr) { pgd_t *pgdp = pgd_offset_k(addr); - pgd_t pgd = READ_ONCE(*pgdp); + p4d_t *p4dp = p4d_offset(pgdp, addr); + p4d_t p4d = READ_ONCE(*p4dp); - BUG_ON(pgd_none(pgd) || pgd_bad(pgd)); + BUG_ON(p4d_none(p4d) || p4d_bad(p4d)); - return pud_offset_kimg(pgdp, addr); + return pud_offset_kimg(p4dp, addr); } static inline pmd_t * fixmap_pmd(unsigned long addr) @@ -1120,25 +1158,27 @@ static inline pte_t * fixmap_pte(unsigned long addr) */ void __init early_fixmap_init(void) { - pgd_t *pgdp, pgd; + pgd_t *pgdp; + p4d_t *p4dp, p4d; pud_t *pudp; pmd_t *pmdp; unsigned long addr = FIXADDR_START; pgdp = pgd_offset_k(addr); - pgd = READ_ONCE(*pgdp); + p4dp = p4d_offset(pgdp, addr); + p4d = READ_ONCE(*p4dp); if (CONFIG_PGTABLE_LEVELS > 3 && - !(pgd_none(pgd) || pgd_page_paddr(pgd) == __pa_symbol(bm_pud))) { + !(p4d_none(p4d) || p4d_page_paddr(p4d) == __pa_symbol(bm_pud))) { /* * We only end up here if the kernel mapping and the fixmap * share the top level pgd entry, which should only happen on * 16k/4 levels configurations. */ BUG_ON(!IS_ENABLED(CONFIG_ARM64_16K_PAGES)); - pudp = pud_offset_kimg(pgdp, addr); + pudp = pud_offset_kimg(p4dp, addr); } else { - if (pgd_none(pgd)) - __pgd_populate(pgdp, __pa_symbol(bm_pud), PUD_TYPE_TABLE); + if (p4d_none(p4d)) + __p4d_populate(p4dp, __pa_symbol(bm_pud), PUD_TYPE_TABLE); pudp = fixmap_pud(addr); } if (pud_none(READ_ONCE(*pudp))) |