ASR_BASE
Change-Id: Icf3719cc0afe3eeb3edc7fa80a2eb5199ca9dda1
diff --git a/marvell/linux/arch/x86/include/asm/mmu_context.h b/marvell/linux/arch/x86/include/asm/mmu_context.h
new file mode 100644
index 0000000..bcad681
--- /dev/null
+++ b/marvell/linux/arch/x86/include/asm/mmu_context.h
@@ -0,0 +1,424 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _ASM_X86_MMU_CONTEXT_H
+#define _ASM_X86_MMU_CONTEXT_H
+
+#include <asm/desc.h>
+#include <linux/atomic.h>
+#include <linux/mm_types.h>
+#include <linux/pkeys.h>
+
+#include <trace/events/tlb.h>
+
+#include <asm/pgalloc.h>
+#include <asm/tlbflush.h>
+#include <asm/paravirt.h>
+#include <asm/mpx.h>
+#include <asm/debugreg.h>
+
+extern atomic64_t last_mm_ctx_id;
+
+#ifndef CONFIG_PARAVIRT_XXL
+static inline void paravirt_activate_mm(struct mm_struct *prev,
+ struct mm_struct *next)
+{
+}
+#endif /* !CONFIG_PARAVIRT_XXL */
+
+#ifdef CONFIG_PERF_EVENTS
+
+DECLARE_STATIC_KEY_FALSE(rdpmc_always_available_key);
+
+static inline void load_mm_cr4_irqsoff(struct mm_struct *mm)
+{
+ if (static_branch_unlikely(&rdpmc_always_available_key) ||
+ atomic_read(&mm->context.perf_rdpmc_allowed))
+ cr4_set_bits_irqsoff(X86_CR4_PCE);
+ else
+ cr4_clear_bits_irqsoff(X86_CR4_PCE);
+}
+#else
+static inline void load_mm_cr4_irqsoff(struct mm_struct *mm) {}
+#endif
+
+#ifdef CONFIG_MODIFY_LDT_SYSCALL
+/*
+ * ldt_structs can be allocated, used, and freed, but they are never
+ * modified while live.
+ */
+struct ldt_struct {
+ /*
+ * Xen requires page-aligned LDTs with special permissions. This is
+ * needed to prevent us from installing evil descriptors such as
+ * call gates. On native, we could merge the ldt_struct and LDT
+ * allocations, but it's not worth trying to optimize.
+ */
+ struct desc_struct *entries;
+ unsigned int nr_entries;
+
+ /*
+ * If PTI is in use, then the entries array is not mapped while we're
+ * in user mode. The whole array will be aliased at the addressed
+ * given by ldt_slot_va(slot). We use two slots so that we can allocate
+ * and map, and enable a new LDT without invalidating the mapping
+ * of an older, still-in-use LDT.
+ *
+ * slot will be -1 if this LDT doesn't have an alias mapping.
+ */
+ int slot;
+};
+
+/* This is a multiple of PAGE_SIZE. */
+#define LDT_SLOT_STRIDE (LDT_ENTRIES * LDT_ENTRY_SIZE)
+
+static inline void *ldt_slot_va(int slot)
+{
+ return (void *)(LDT_BASE_ADDR + LDT_SLOT_STRIDE * slot);
+}
+
+/*
+ * Used for LDT copy/destruction.
+ */
+static inline void init_new_context_ldt(struct mm_struct *mm)
+{
+ mm->context.ldt = NULL;
+ init_rwsem(&mm->context.ldt_usr_sem);
+}
+int ldt_dup_context(struct mm_struct *oldmm, struct mm_struct *mm);
+void destroy_context_ldt(struct mm_struct *mm);
+void ldt_arch_exit_mmap(struct mm_struct *mm);
+#else /* CONFIG_MODIFY_LDT_SYSCALL */
+static inline void init_new_context_ldt(struct mm_struct *mm) { }
+static inline int ldt_dup_context(struct mm_struct *oldmm,
+ struct mm_struct *mm)
+{
+ return 0;
+}
+static inline void destroy_context_ldt(struct mm_struct *mm) { }
+static inline void ldt_arch_exit_mmap(struct mm_struct *mm) { }
+#endif
+
+static inline void load_mm_ldt(struct mm_struct *mm)
+{
+#ifdef CONFIG_MODIFY_LDT_SYSCALL
+ struct ldt_struct *ldt;
+
+ /* READ_ONCE synchronizes with smp_store_release */
+ ldt = READ_ONCE(mm->context.ldt);
+
+ /*
+ * Any change to mm->context.ldt is followed by an IPI to all
+ * CPUs with the mm active. The LDT will not be freed until
+ * after the IPI is handled by all such CPUs. This means that,
+ * if the ldt_struct changes before we return, the values we see
+ * will be safe, and the new values will be loaded before we run
+ * any user code.
+ *
+ * NB: don't try to convert this to use RCU without extreme care.
+ * We would still need IRQs off, because we don't want to change
+ * the local LDT after an IPI loaded a newer value than the one
+ * that we can see.
+ */
+
+ if (unlikely(ldt)) {
+ if (static_cpu_has(X86_FEATURE_PTI)) {
+ if (WARN_ON_ONCE((unsigned long)ldt->slot > 1)) {
+ /*
+ * Whoops -- either the new LDT isn't mapped
+ * (if slot == -1) or is mapped into a bogus
+ * slot (if slot > 1).
+ */
+ clear_LDT();
+ return;
+ }
+
+ /*
+ * If page table isolation is enabled, ldt->entries
+ * will not be mapped in the userspace pagetables.
+ * Tell the CPU to access the LDT through the alias
+ * at ldt_slot_va(ldt->slot).
+ */
+ set_ldt(ldt_slot_va(ldt->slot), ldt->nr_entries);
+ } else {
+ set_ldt(ldt->entries, ldt->nr_entries);
+ }
+ } else {
+ clear_LDT();
+ }
+#else
+ clear_LDT();
+#endif
+}
+
+static inline void switch_ldt(struct mm_struct *prev, struct mm_struct *next)
+{
+#ifdef CONFIG_MODIFY_LDT_SYSCALL
+ /*
+ * Load the LDT if either the old or new mm had an LDT.
+ *
+ * An mm will never go from having an LDT to not having an LDT. Two
+ * mms never share an LDT, so we don't gain anything by checking to
+ * see whether the LDT changed. There's also no guarantee that
+ * prev->context.ldt actually matches LDTR, but, if LDTR is non-NULL,
+ * then prev->context.ldt will also be non-NULL.
+ *
+ * If we really cared, we could optimize the case where prev == next
+ * and we're exiting lazy mode. Most of the time, if this happens,
+ * we don't actually need to reload LDTR, but modify_ldt() is mostly
+ * used by legacy code and emulators where we don't need this level of
+ * performance.
+ *
+ * This uses | instead of || because it generates better code.
+ */
+ if (unlikely((unsigned long)prev->context.ldt |
+ (unsigned long)next->context.ldt))
+ load_mm_ldt(next);
+#endif
+
+ DEBUG_LOCKS_WARN_ON(preemptible());
+}
+
+void enter_lazy_tlb(struct mm_struct *mm, struct task_struct *tsk);
+
+/*
+ * Init a new mm. Used on mm copies, like at fork()
+ * and on mm's that are brand-new, like at execve().
+ */
+static inline int init_new_context(struct task_struct *tsk,
+ struct mm_struct *mm)
+{
+ mutex_init(&mm->context.lock);
+
+ mm->context.ctx_id = atomic64_inc_return(&last_mm_ctx_id);
+ atomic64_set(&mm->context.tlb_gen, 0);
+
+#ifdef CONFIG_X86_INTEL_MEMORY_PROTECTION_KEYS
+ if (cpu_feature_enabled(X86_FEATURE_OSPKE)) {
+ /* pkey 0 is the default and allocated implicitly */
+ mm->context.pkey_allocation_map = 0x1;
+ /* -1 means unallocated or invalid */
+ mm->context.execute_only_pkey = -1;
+ }
+#endif
+ init_new_context_ldt(mm);
+ return 0;
+}
+static inline void destroy_context(struct mm_struct *mm)
+{
+ destroy_context_ldt(mm);
+}
+
+extern void switch_mm(struct mm_struct *prev, struct mm_struct *next,
+ struct task_struct *tsk);
+
+extern void switch_mm_irqs_off(struct mm_struct *prev, struct mm_struct *next,
+ struct task_struct *tsk);
+#define switch_mm_irqs_off switch_mm_irqs_off
+
+#define activate_mm(prev, next) \
+do { \
+ paravirt_activate_mm((prev), (next)); \
+ switch_mm((prev), (next), NULL); \
+} while (0);
+
+#ifdef CONFIG_X86_32
+#define deactivate_mm(tsk, mm) \
+do { \
+ lazy_load_gs(0); \
+} while (0)
+#else
+#define deactivate_mm(tsk, mm) \
+do { \
+ load_gs_index(0); \
+ loadsegment(fs, 0); \
+} while (0)
+#endif
+
+static inline void arch_dup_pkeys(struct mm_struct *oldmm,
+ struct mm_struct *mm)
+{
+#ifdef CONFIG_X86_INTEL_MEMORY_PROTECTION_KEYS
+ if (!cpu_feature_enabled(X86_FEATURE_OSPKE))
+ return;
+
+ /* Duplicate the oldmm pkey state in mm: */
+ mm->context.pkey_allocation_map = oldmm->context.pkey_allocation_map;
+ mm->context.execute_only_pkey = oldmm->context.execute_only_pkey;
+#endif
+}
+
+static inline int arch_dup_mmap(struct mm_struct *oldmm, struct mm_struct *mm)
+{
+ arch_dup_pkeys(oldmm, mm);
+ paravirt_arch_dup_mmap(oldmm, mm);
+ return ldt_dup_context(oldmm, mm);
+}
+
+static inline void arch_exit_mmap(struct mm_struct *mm)
+{
+ paravirt_arch_exit_mmap(mm);
+ ldt_arch_exit_mmap(mm);
+}
+
+#ifdef CONFIG_X86_64
+static inline bool is_64bit_mm(struct mm_struct *mm)
+{
+ return !IS_ENABLED(CONFIG_IA32_EMULATION) ||
+ !(mm->context.ia32_compat == TIF_IA32);
+}
+#else
+static inline bool is_64bit_mm(struct mm_struct *mm)
+{
+ return false;
+}
+#endif
+
+static inline void arch_bprm_mm_init(struct mm_struct *mm,
+ struct vm_area_struct *vma)
+{
+ mpx_mm_init(mm);
+}
+
+static inline void arch_unmap(struct mm_struct *mm, unsigned long start,
+ unsigned long end)
+{
+ /*
+ * mpx_notify_unmap() goes and reads a rarely-hot
+ * cacheline in the mm_struct. That can be expensive
+ * enough to be seen in profiles.
+ *
+ * The mpx_notify_unmap() call and its contents have been
+ * observed to affect munmap() performance on hardware
+ * where MPX is not present.
+ *
+ * The unlikely() optimizes for the fast case: no MPX
+ * in the CPU, or no MPX use in the process. Even if
+ * we get this wrong (in the unlikely event that MPX
+ * is widely enabled on some system) the overhead of
+ * MPX itself (reading bounds tables) is expected to
+ * overwhelm the overhead of getting this unlikely()
+ * consistently wrong.
+ */
+ if (unlikely(cpu_feature_enabled(X86_FEATURE_MPX)))
+ mpx_notify_unmap(mm, start, end);
+}
+
+/*
+ * We only want to enforce protection keys on the current process
+ * because we effectively have no access to PKRU for other
+ * processes or any way to tell *which * PKRU in a threaded
+ * process we could use.
+ *
+ * So do not enforce things if the VMA is not from the current
+ * mm, or if we are in a kernel thread.
+ */
+static inline bool vma_is_foreign(struct vm_area_struct *vma)
+{
+ if (!current->mm)
+ return true;
+ /*
+ * Should PKRU be enforced on the access to this VMA? If
+ * the VMA is from another process, then PKRU has no
+ * relevance and should not be enforced.
+ */
+ if (current->mm != vma->vm_mm)
+ return true;
+
+ return false;
+}
+
+static inline bool arch_vma_access_permitted(struct vm_area_struct *vma,
+ bool write, bool execute, bool foreign)
+{
+ /* pkeys never affect instruction fetches */
+ if (execute)
+ return true;
+ /* allow access if the VMA is not one from this process */
+ if (foreign || vma_is_foreign(vma))
+ return true;
+ return __pkru_allows_pkey(vma_pkey(vma), write);
+}
+
+/*
+ * This can be used from process context to figure out what the value of
+ * CR3 is without needing to do a (slow) __read_cr3().
+ *
+ * It's intended to be used for code like KVM that sneakily changes CR3
+ * and needs to restore it. It needs to be used very carefully.
+ */
+static inline unsigned long __get_current_cr3_fast(void)
+{
+ unsigned long cr3 = build_cr3(this_cpu_read(cpu_tlbstate.loaded_mm)->pgd,
+ this_cpu_read(cpu_tlbstate.loaded_mm_asid));
+
+ /* For now, be very restrictive about when this can be called. */
+ VM_WARN_ON(in_nmi() || preemptible());
+
+ VM_BUG_ON(cr3 != __read_cr3());
+ return cr3;
+}
+
+typedef struct {
+ struct mm_struct *mm;
+} temp_mm_state_t;
+
+/*
+ * Using a temporary mm allows to set temporary mappings that are not accessible
+ * by other CPUs. Such mappings are needed to perform sensitive memory writes
+ * that override the kernel memory protections (e.g., W^X), without exposing the
+ * temporary page-table mappings that are required for these write operations to
+ * other CPUs. Using a temporary mm also allows to avoid TLB shootdowns when the
+ * mapping is torn down.
+ *
+ * Context: The temporary mm needs to be used exclusively by a single core. To
+ * harden security IRQs must be disabled while the temporary mm is
+ * loaded, thereby preventing interrupt handler bugs from overriding
+ * the kernel memory protection.
+ */
+static inline temp_mm_state_t use_temporary_mm(struct mm_struct *mm)
+{
+ temp_mm_state_t temp_state;
+
+ lockdep_assert_irqs_disabled();
+
+ /*
+ * Make sure not to be in TLB lazy mode, as otherwise we'll end up
+ * with a stale address space WITHOUT being in lazy mode after
+ * restoring the previous mm.
+ */
+ if (this_cpu_read(cpu_tlbstate.is_lazy))
+ leave_mm(smp_processor_id());
+
+ temp_state.mm = this_cpu_read(cpu_tlbstate.loaded_mm);
+ switch_mm_irqs_off(NULL, mm, current);
+
+ /*
+ * If breakpoints are enabled, disable them while the temporary mm is
+ * used. Userspace might set up watchpoints on addresses that are used
+ * in the temporary mm, which would lead to wrong signals being sent or
+ * crashes.
+ *
+ * Note that breakpoints are not disabled selectively, which also causes
+ * kernel breakpoints (e.g., perf's) to be disabled. This might be
+ * undesirable, but still seems reasonable as the code that runs in the
+ * temporary mm should be short.
+ */
+ if (hw_breakpoint_active())
+ hw_breakpoint_disable();
+
+ return temp_state;
+}
+
+static inline void unuse_temporary_mm(temp_mm_state_t prev_state)
+{
+ lockdep_assert_irqs_disabled();
+ switch_mm_irqs_off(NULL, prev_state.mm, current);
+
+ /*
+ * Restore the breakpoints if they were disabled before the temporary mm
+ * was loaded.
+ */
+ if (hw_breakpoint_active())
+ hw_breakpoint_restore();
+}
+
+#endif /* _ASM_X86_MMU_CONTEXT_H */