/* 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/tlbflush.h>
|
#include <asm/paravirt.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_never_available_key);
|
DECLARE_STATIC_KEY_FALSE(rdpmc_always_available_key);
|
void cr4_update_pce(void *ignored);
|
#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;
|
};
|
|
/*
|
* 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
|
|
#ifdef CONFIG_MODIFY_LDT_SYSCALL
|
extern void load_mm_ldt(struct mm_struct *mm);
|
extern void switch_ldt(struct mm_struct *prev, struct mm_struct *next);
|
#else
|
static inline void load_mm_ldt(struct mm_struct *mm)
|
{
|
clear_LDT();
|
}
|
static inline void switch_ldt(struct mm_struct *prev, struct mm_struct *next)
|
{
|
DEBUG_LOCKS_WARN_ON(preemptible());
|
}
|
#endif
|
|
extern 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_unmap(struct mm_struct *mm, unsigned long start,
|
unsigned long 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 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);
|
}
|
|
unsigned long __get_current_cr3_fast(void);
|
|
#endif /* _ASM_X86_MMU_CONTEXT_H */
|
