diff options
Diffstat (limited to 'arch/arm64/kernel/cpufeature.c')
| -rw-r--r-- | arch/arm64/kernel/cpufeature.c | 120 |
1 files changed, 16 insertions, 104 deletions
diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c index 3917ad897801..42b182cfa404 100644 --- a/arch/arm64/kernel/cpufeature.c +++ b/arch/arm64/kernel/cpufeature.c @@ -95,6 +95,7 @@ #include <asm/vectors.h> #include <asm/virt.h> +#include <asm/spectre.h> /* Kernel representation of AT_HWCAP and AT_HWCAP2 */ static DECLARE_BITMAP(elf_hwcap, MAX_CPU_FEATURES) __read_mostly; @@ -1002,7 +1003,7 @@ static void __init sort_ftr_regs(void) /* * Initialise the CPU feature register from Boot CPU values. - * Also initiliases the strict_mask for the register. + * Also initialises the strict_mask for the register. * Any bits that are not covered by an arm64_ftr_bits entry are considered * RES0 for the system-wide value, and must strictly match. */ @@ -1941,104 +1942,6 @@ static bool has_pmuv3(const struct arm64_cpu_capabilities *entry, int scope) } #endif -#ifdef CONFIG_UNMAP_KERNEL_AT_EL0 -#define KPTI_NG_TEMP_VA (-(1UL << PMD_SHIFT)) - -extern -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)(enum pgtable_type), int flags); - -static phys_addr_t __initdata kpti_ng_temp_alloc; - -static phys_addr_t __init kpti_ng_pgd_alloc(enum pgtable_type type) -{ - kpti_ng_temp_alloc -= PAGE_SIZE; - return kpti_ng_temp_alloc; -} - -static int __init __kpti_install_ng_mappings(void *__unused) -{ - typedef void (kpti_remap_fn)(int, int, phys_addr_t, unsigned long); - extern kpti_remap_fn idmap_kpti_install_ng_mappings; - kpti_remap_fn *remap_fn; - - int cpu = smp_processor_id(); - int levels = CONFIG_PGTABLE_LEVELS; - int order = order_base_2(levels); - u64 kpti_ng_temp_pgd_pa = 0; - pgd_t *kpti_ng_temp_pgd; - u64 alloc = 0; - - if (levels == 5 && !pgtable_l5_enabled()) - levels = 4; - else if (levels == 4 && !pgtable_l4_enabled()) - levels = 3; - - remap_fn = (void *)__pa_symbol(idmap_kpti_install_ng_mappings); - - if (!cpu) { - alloc = __get_free_pages(GFP_ATOMIC | __GFP_ZERO, order); - kpti_ng_temp_pgd = (pgd_t *)(alloc + (levels - 1) * PAGE_SIZE); - kpti_ng_temp_alloc = kpti_ng_temp_pgd_pa = __pa(kpti_ng_temp_pgd); - - // - // Create a minimal page table hierarchy that permits us to map - // the swapper page tables temporarily as we traverse them. - // - // The physical pages are laid out as follows: - // - // +--------+-/-------+-/------ +-/------ +-\\\--------+ - // : PTE[] : | PMD[] : | PUD[] : | P4D[] : ||| PGD[] : - // +--------+-\-------+-\------ +-\------ +-///--------+ - // ^ - // The first page is mapped into this hierarchy at a PMD_SHIFT - // aligned virtual address, so that we can manipulate the PTE - // level entries while the mapping is active. The first entry - // covers the PTE[] page itself, the remaining entries are free - // to be used as a ad-hoc fixmap. - // - create_kpti_ng_temp_pgd(kpti_ng_temp_pgd, __pa(alloc), - KPTI_NG_TEMP_VA, PAGE_SIZE, PAGE_KERNEL, - kpti_ng_pgd_alloc, 0); - } - - cpu_install_idmap(); - remap_fn(cpu, num_online_cpus(), kpti_ng_temp_pgd_pa, KPTI_NG_TEMP_VA); - cpu_uninstall_idmap(); - - if (!cpu) { - free_pages(alloc, order); - arm64_use_ng_mappings = true; - } - - return 0; -} - -static void __init kpti_install_ng_mappings(void) -{ - /* Check whether KPTI is going to be used */ - if (!arm64_kernel_unmapped_at_el0()) - return; - - /* - * We don't need to rewrite the page-tables if either we've done - * it already or we have KASLR enabled and therefore have not - * created any global mappings at all. - */ - if (arm64_use_ng_mappings) - return; - - init_idmap_kpti_bbml2_flag(); - stop_machine(__kpti_install_ng_mappings, NULL, cpu_online_mask); -} - -#else -static inline void kpti_install_ng_mappings(void) -{ -} -#endif /* CONFIG_UNMAP_KERNEL_AT_EL0 */ - static void cpu_enable_kpti(struct arm64_cpu_capabilities const *cap) { if (__this_cpu_read(this_cpu_vector) == vectors) { @@ -2067,7 +1970,7 @@ static struct cpumask dbm_cpus __read_mostly; static inline void __cpu_enable_hw_dbm(void) { - u64 tcr = read_sysreg(tcr_el1) | TCR_HD; + u64 tcr = read_sysreg(tcr_el1) | TCR_EL1_HD; write_sysreg(tcr, tcr_el1); isb(); @@ -2353,7 +2256,7 @@ static bool has_generic_auth(const struct arm64_cpu_capabilities *entry, static void cpu_enable_e0pd(struct arm64_cpu_capabilities const *cap) { if (this_cpu_has_cap(ARM64_HAS_E0PD)) - sysreg_clear_set(tcr_el1, 0, TCR_E0PD1); + sysreg_clear_set(tcr_el1, 0, TCR_EL1_E0PD1); } #endif /* CONFIG_ARM64_E0PD */ @@ -2419,17 +2322,21 @@ static void bti_enable(const struct arm64_cpu_capabilities *__unused) #ifdef CONFIG_ARM64_MTE static void cpu_enable_mte(struct arm64_cpu_capabilities const *cap) { + static bool cleared_zero_page = false; + sysreg_clear_set(sctlr_el1, 0, SCTLR_ELx_ATA | SCTLR_EL1_ATA0); mte_cpu_setup(); /* * Clear the tags in the zero page. This needs to be done via the - * linear map which has the Tagged attribute. + * linear map which has the Tagged attribute. Since this page is + * always mapped as pte_special(), set_pte_at() will not attempt to + * clear the tags or set PG_mte_tagged. */ - if (try_page_mte_tagging(ZERO_PAGE(0))) { + if (!cleared_zero_page) { + cleared_zero_page = true; mte_clear_page_tags(lm_alias(empty_zero_page)); - set_page_mte_tagged(ZERO_PAGE(0)); } kasan_init_hw_tags_cpu(); @@ -3969,6 +3876,11 @@ static void __init setup_system_capabilities(void) */ if (system_uses_ttbr0_pan()) pr_info("emulated: Privileged Access Never (PAN) using TTBR0_EL1 switching\n"); + + /* + * Report Spectre mitigations status. + */ + spectre_print_disabled_mitigations(); } void __init setup_system_features(void) |