1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef _ASM_X86_MMU_CONTEXT_H
3 #define _ASM_X86_MMU_CONTEXT_H
6 #include <linux/atomic.h>
7 #include <linux/mm_types.h>
8 #include <linux/pkeys.h>
10 #include <trace/events/tlb.h>
12 #include <asm/pgalloc.h>
13 #include <asm/tlbflush.h>
14 #include <asm/paravirt.h>
15 #include <asm/debugreg.h>
17 extern atomic64_t last_mm_ctx_id;
19 #ifndef CONFIG_PARAVIRT_XXL
20 static inline void paravirt_activate_mm(struct mm_struct *prev,
21 struct mm_struct *next)
24 #endif /* !CONFIG_PARAVIRT_XXL */
26 #ifdef CONFIG_PERF_EVENTS
27 DECLARE_STATIC_KEY_FALSE(rdpmc_never_available_key);
28 DECLARE_STATIC_KEY_FALSE(rdpmc_always_available_key);
29 void cr4_update_pce(void *ignored);
32 #ifdef CONFIG_MODIFY_LDT_SYSCALL
34 * ldt_structs can be allocated, used, and freed, but they are never
35 * modified while live.
39 * Xen requires page-aligned LDTs with special permissions. This is
40 * needed to prevent us from installing evil descriptors such as
41 * call gates. On native, we could merge the ldt_struct and LDT
42 * allocations, but it's not worth trying to optimize.
44 struct desc_struct *entries;
45 unsigned int nr_entries;
48 * If PTI is in use, then the entries array is not mapped while we're
49 * in user mode. The whole array will be aliased at the addressed
50 * given by ldt_slot_va(slot). We use two slots so that we can allocate
51 * and map, and enable a new LDT without invalidating the mapping
52 * of an older, still-in-use LDT.
54 * slot will be -1 if this LDT doesn't have an alias mapping.
60 * Used for LDT copy/destruction.
62 static inline void init_new_context_ldt(struct mm_struct *mm)
64 mm->context.ldt = NULL;
65 init_rwsem(&mm->context.ldt_usr_sem);
67 int ldt_dup_context(struct mm_struct *oldmm, struct mm_struct *mm);
68 void destroy_context_ldt(struct mm_struct *mm);
69 void ldt_arch_exit_mmap(struct mm_struct *mm);
70 #else /* CONFIG_MODIFY_LDT_SYSCALL */
71 static inline void init_new_context_ldt(struct mm_struct *mm) { }
72 static inline int ldt_dup_context(struct mm_struct *oldmm,
77 static inline void destroy_context_ldt(struct mm_struct *mm) { }
78 static inline void ldt_arch_exit_mmap(struct mm_struct *mm) { }
81 #ifdef CONFIG_MODIFY_LDT_SYSCALL
82 extern void load_mm_ldt(struct mm_struct *mm);
83 extern void switch_ldt(struct mm_struct *prev, struct mm_struct *next);
85 static inline void load_mm_ldt(struct mm_struct *mm)
89 static inline void switch_ldt(struct mm_struct *prev, struct mm_struct *next)
91 DEBUG_LOCKS_WARN_ON(preemptible());
95 extern void enter_lazy_tlb(struct mm_struct *mm, struct task_struct *tsk);
98 * Init a new mm. Used on mm copies, like at fork()
99 * and on mm's that are brand-new, like at execve().
101 static inline int init_new_context(struct task_struct *tsk,
102 struct mm_struct *mm)
104 mutex_init(&mm->context.lock);
106 mm->context.ctx_id = atomic64_inc_return(&last_mm_ctx_id);
107 atomic64_set(&mm->context.tlb_gen, 0);
109 #ifdef CONFIG_X86_INTEL_MEMORY_PROTECTION_KEYS
110 if (cpu_feature_enabled(X86_FEATURE_OSPKE)) {
111 /* pkey 0 is the default and allocated implicitly */
112 mm->context.pkey_allocation_map = 0x1;
113 /* -1 means unallocated or invalid */
114 mm->context.execute_only_pkey = -1;
117 init_new_context_ldt(mm);
120 static inline void destroy_context(struct mm_struct *mm)
122 destroy_context_ldt(mm);
125 extern void switch_mm(struct mm_struct *prev, struct mm_struct *next,
126 struct task_struct *tsk);
128 extern void switch_mm_irqs_off(struct mm_struct *prev, struct mm_struct *next,
129 struct task_struct *tsk);
130 #define switch_mm_irqs_off switch_mm_irqs_off
132 #define activate_mm(prev, next) \
134 paravirt_activate_mm((prev), (next)); \
135 switch_mm((prev), (next), NULL); \
139 #define deactivate_mm(tsk, mm) \
144 #define deactivate_mm(tsk, mm) \
147 loadsegment(fs, 0); \
151 static inline void arch_dup_pkeys(struct mm_struct *oldmm,
152 struct mm_struct *mm)
154 #ifdef CONFIG_X86_INTEL_MEMORY_PROTECTION_KEYS
155 if (!cpu_feature_enabled(X86_FEATURE_OSPKE))
158 /* Duplicate the oldmm pkey state in mm: */
159 mm->context.pkey_allocation_map = oldmm->context.pkey_allocation_map;
160 mm->context.execute_only_pkey = oldmm->context.execute_only_pkey;
164 static inline int arch_dup_mmap(struct mm_struct *oldmm, struct mm_struct *mm)
166 arch_dup_pkeys(oldmm, mm);
167 paravirt_arch_dup_mmap(oldmm, mm);
168 return ldt_dup_context(oldmm, mm);
171 static inline void arch_exit_mmap(struct mm_struct *mm)
173 paravirt_arch_exit_mmap(mm);
174 ldt_arch_exit_mmap(mm);
178 static inline bool is_64bit_mm(struct mm_struct *mm)
180 return !IS_ENABLED(CONFIG_IA32_EMULATION) ||
181 !(mm->context.ia32_compat == TIF_IA32);
184 static inline bool is_64bit_mm(struct mm_struct *mm)
190 static inline void arch_unmap(struct mm_struct *mm, unsigned long start,
196 * We only want to enforce protection keys on the current process
197 * because we effectively have no access to PKRU for other
198 * processes or any way to tell *which * PKRU in a threaded
199 * process we could use.
201 * So do not enforce things if the VMA is not from the current
202 * mm, or if we are in a kernel thread.
204 static inline bool arch_vma_access_permitted(struct vm_area_struct *vma,
205 bool write, bool execute, bool foreign)
207 /* pkeys never affect instruction fetches */
210 /* allow access if the VMA is not one from this process */
211 if (foreign || vma_is_foreign(vma))
213 return __pkru_allows_pkey(vma_pkey(vma), write);
216 unsigned long __get_current_cr3_fast(void);
218 #endif /* _ASM_X86_MMU_CONTEXT_H */