diff options
| -rw-r--r-- | arch/x86/include/asm/qspinlock.h | 12 | ||||
| -rw-r--r-- | arch/x86/kernel/acpi/madt_wakeup.c | 2 | ||||
| -rw-r--r-- | arch/x86/kernel/cpu/mtrr/mtrr.c | 2 | ||||
| -rw-r--r-- | arch/x86/kernel/paravirt.c | 7 | ||||
| -rw-r--r-- | arch/x86/mm/pti.c | 45 |
5 files changed, 41 insertions, 27 deletions
diff --git a/arch/x86/include/asm/qspinlock.h b/arch/x86/include/asm/qspinlock.h index a053c1293975..68da67df304d 100644 --- a/arch/x86/include/asm/qspinlock.h +++ b/arch/x86/include/asm/qspinlock.h @@ -66,13 +66,15 @@ static inline bool vcpu_is_preempted(long cpu) #ifdef CONFIG_PARAVIRT /* - * virt_spin_lock_key - enables (by default) the virt_spin_lock() hijack. + * virt_spin_lock_key - disables by default the virt_spin_lock() hijack. * - * Native (and PV wanting native due to vCPU pinning) should disable this key. - * It is done in this backwards fashion to only have a single direction change, - * which removes ordering between native_pv_spin_init() and HV setup. + * Native (and PV wanting native due to vCPU pinning) should keep this key + * disabled. Native does not touch the key. + * + * When in a guest then native_pv_lock_init() enables the key first and + * KVM/XEN might conditionally disable it later in the boot process again. */ -DECLARE_STATIC_KEY_TRUE(virt_spin_lock_key); +DECLARE_STATIC_KEY_FALSE(virt_spin_lock_key); /* * Shortcut for the queued_spin_lock_slowpath() function that allows diff --git a/arch/x86/kernel/acpi/madt_wakeup.c b/arch/x86/kernel/acpi/madt_wakeup.c index 6cfe762be28b..d5ef6215583b 100644 --- a/arch/x86/kernel/acpi/madt_wakeup.c +++ b/arch/x86/kernel/acpi/madt_wakeup.c @@ -19,7 +19,7 @@ static u64 acpi_mp_wake_mailbox_paddr __ro_after_init; /* Virtual address of the Multiprocessor Wakeup Structure mailbox */ -static struct acpi_madt_multiproc_wakeup_mailbox *acpi_mp_wake_mailbox __ro_after_init; +static struct acpi_madt_multiproc_wakeup_mailbox *acpi_mp_wake_mailbox; static u64 acpi_mp_pgd __ro_after_init; static u64 acpi_mp_reset_vector_paddr __ro_after_init; diff --git a/arch/x86/kernel/cpu/mtrr/mtrr.c b/arch/x86/kernel/cpu/mtrr/mtrr.c index 767bf1c71aad..2a2fc14955cd 100644 --- a/arch/x86/kernel/cpu/mtrr/mtrr.c +++ b/arch/x86/kernel/cpu/mtrr/mtrr.c @@ -609,7 +609,7 @@ void mtrr_save_state(void) { int first_cpu; - if (!mtrr_enabled()) + if (!mtrr_enabled() || !mtrr_state.have_fixed) return; first_cpu = cpumask_first(cpu_online_mask); diff --git a/arch/x86/kernel/paravirt.c b/arch/x86/kernel/paravirt.c index 5358d43886ad..fec381533555 100644 --- a/arch/x86/kernel/paravirt.c +++ b/arch/x86/kernel/paravirt.c @@ -51,13 +51,12 @@ DEFINE_ASM_FUNC(pv_native_irq_enable, "sti", .noinstr.text); DEFINE_ASM_FUNC(pv_native_read_cr2, "mov %cr2, %rax", .noinstr.text); #endif -DEFINE_STATIC_KEY_TRUE(virt_spin_lock_key); +DEFINE_STATIC_KEY_FALSE(virt_spin_lock_key); void __init native_pv_lock_init(void) { - if (IS_ENABLED(CONFIG_PARAVIRT_SPINLOCKS) && - !boot_cpu_has(X86_FEATURE_HYPERVISOR)) - static_branch_disable(&virt_spin_lock_key); + if (boot_cpu_has(X86_FEATURE_HYPERVISOR)) + static_branch_enable(&virt_spin_lock_key); } static void native_tlb_remove_table(struct mmu_gather *tlb, void *table) diff --git a/arch/x86/mm/pti.c b/arch/x86/mm/pti.c index bfdf5f45b137..851ec8f1363a 100644 --- a/arch/x86/mm/pti.c +++ b/arch/x86/mm/pti.c @@ -241,7 +241,7 @@ static pmd_t *pti_user_pagetable_walk_pmd(unsigned long address) * * Returns a pointer to a PTE on success, or NULL on failure. */ -static pte_t *pti_user_pagetable_walk_pte(unsigned long address) +static pte_t *pti_user_pagetable_walk_pte(unsigned long address, bool late_text) { gfp_t gfp = (GFP_KERNEL | __GFP_NOTRACK | __GFP_ZERO); pmd_t *pmd; @@ -251,10 +251,15 @@ static pte_t *pti_user_pagetable_walk_pte(unsigned long address) if (!pmd) return NULL; - /* We can't do anything sensible if we hit a large mapping. */ + /* Large PMD mapping found */ if (pmd_leaf(*pmd)) { - WARN_ON(1); - return NULL; + /* Clear the PMD if we hit a large mapping from the first round */ + if (late_text) { + set_pmd(pmd, __pmd(0)); + } else { + WARN_ON_ONCE(1); + return NULL; + } } if (pmd_none(*pmd)) { @@ -283,7 +288,7 @@ static void __init pti_setup_vsyscall(void) if (!pte || WARN_ON(level != PG_LEVEL_4K) || pte_none(*pte)) return; - target_pte = pti_user_pagetable_walk_pte(VSYSCALL_ADDR); + target_pte = pti_user_pagetable_walk_pte(VSYSCALL_ADDR, false); if (WARN_ON(!target_pte)) return; @@ -301,7 +306,7 @@ enum pti_clone_level { static void pti_clone_pgtable(unsigned long start, unsigned long end, - enum pti_clone_level level) + enum pti_clone_level level, bool late_text) { unsigned long addr; @@ -390,7 +395,7 @@ pti_clone_pgtable(unsigned long start, unsigned long end, return; /* Allocate PTE in the user page-table */ - target_pte = pti_user_pagetable_walk_pte(addr); + target_pte = pti_user_pagetable_walk_pte(addr, late_text); if (WARN_ON(!target_pte)) return; @@ -452,7 +457,7 @@ static void __init pti_clone_user_shared(void) phys_addr_t pa = per_cpu_ptr_to_phys((void *)va); pte_t *target_pte; - target_pte = pti_user_pagetable_walk_pte(va); + target_pte = pti_user_pagetable_walk_pte(va, false); if (WARN_ON(!target_pte)) return; @@ -475,7 +480,7 @@ static void __init pti_clone_user_shared(void) start = CPU_ENTRY_AREA_BASE; end = start + (PAGE_SIZE * CPU_ENTRY_AREA_PAGES); - pti_clone_pgtable(start, end, PTI_CLONE_PMD); + pti_clone_pgtable(start, end, PTI_CLONE_PMD, false); } #endif /* CONFIG_X86_64 */ @@ -492,11 +497,11 @@ static void __init pti_setup_espfix64(void) /* * Clone the populated PMDs of the entry text and force it RO. */ -static void pti_clone_entry_text(void) +static void pti_clone_entry_text(bool late) { pti_clone_pgtable((unsigned long) __entry_text_start, (unsigned long) __entry_text_end, - PTI_LEVEL_KERNEL_IMAGE); + PTI_LEVEL_KERNEL_IMAGE, late); } /* @@ -571,7 +576,7 @@ static void pti_clone_kernel_text(void) * pti_set_kernel_image_nonglobal() did to clear the * global bit. */ - pti_clone_pgtable(start, end_clone, PTI_LEVEL_KERNEL_IMAGE); + pti_clone_pgtable(start, end_clone, PTI_LEVEL_KERNEL_IMAGE, false); /* * pti_clone_pgtable() will set the global bit in any PMDs @@ -638,8 +643,15 @@ void __init pti_init(void) /* Undo all global bits from the init pagetables in head_64.S: */ pti_set_kernel_image_nonglobal(); + /* Replace some of the global bits just for shared entry text: */ - pti_clone_entry_text(); + /* + * This is very early in boot. Device and Late initcalls can do + * modprobe before free_initmem() and mark_readonly(). This + * pti_clone_entry_text() allows those user-mode-helpers to function, + * but notably the text is still RW. + */ + pti_clone_entry_text(false); pti_setup_espfix64(); pti_setup_vsyscall(); } @@ -656,10 +668,11 @@ void pti_finalize(void) if (!boot_cpu_has(X86_FEATURE_PTI)) return; /* - * We need to clone everything (again) that maps parts of the - * kernel image. + * This is after free_initmem() (all initcalls are done) and we've done + * mark_readonly(). Text is now NX which might've split some PMDs + * relative to the early clone. */ - pti_clone_entry_text(); + pti_clone_entry_text(true); pti_clone_kernel_text(); debug_checkwx_user(); |