LXR linux/arch/x86/include/asm/pkeys.h

   1#ifndef _ASM_X86_PKEYS_H
   2#define _ASM_X86_PKEYS_H
   3
   4#define arch_max_pkey() (boot_cpu_has(X86_FEATURE_OSPKE) ? 16 : 1)
   5
   6extern int arch_set_user_pkey_access(struct task_struct *tsk, int pkey,
   7                unsigned long init_val);
   8
   9/*
  10 * Try to dedicate one of the protection keys to be used as an
  11 * execute-only protection key.
  12 */
  13extern int __execute_only_pkey(struct mm_struct *mm);
  14static inline int execute_only_pkey(struct mm_struct *mm)
  15{
  16        if (!boot_cpu_has(X86_FEATURE_OSPKE))
  17                return 0;
  18
  19        return __execute_only_pkey(mm);
  20}
  21
  22extern int __arch_override_mprotect_pkey(struct vm_area_struct *vma,
  23                int prot, int pkey);
  24static inline int arch_override_mprotect_pkey(struct vm_area_struct *vma,
  25                int prot, int pkey)
  26{
  27        if (!boot_cpu_has(X86_FEATURE_OSPKE))
  28                return 0;
  29
  30        return __arch_override_mprotect_pkey(vma, prot, pkey);
  31}
  32
  33extern int __arch_set_user_pkey_access(struct task_struct *tsk, int pkey,
  34                unsigned long init_val);
  35
  36#define ARCH_VM_PKEY_FLAGS (VM_PKEY_BIT0 | VM_PKEY_BIT1 | VM_PKEY_BIT2 | VM_PKEY_BIT3)
  37
  38#define mm_pkey_allocation_map(mm)      (mm->pkey_allocation_map)
  39#define mm_set_pkey_allocated(mm, pkey) do {            \
  40        mm_pkey_allocation_map(mm) |= (1U << pkey);     \
  41} while (0)
  42#define mm_set_pkey_free(mm, pkey) do {                 \
  43        mm_pkey_allocation_map(mm) &= ~(1U << pkey);    \
  44} while (0)
  45
  46static inline
  47bool mm_pkey_is_allocated(struct mm_struct *mm, int pkey)
  48{
  49        return mm_pkey_allocation_map(mm) & (1U << pkey);
  50}
  51
  52/*
  53 * Returns a positive, 4-bit key on success, or -1 on failure.
  54 */
  55static inline
  56int mm_pkey_alloc(struct mm_struct *mm)
  57{
  58        /*
  59         * Note: this is the one and only place we make sure
  60         * that the pkey is valid as far as the hardware is
  61         * concerned.  The rest of the kernel trusts that
  62         * only good, valid pkeys come out of here.
  63         */
  64        u16 all_pkeys_mask = ((1U << arch_max_pkey()) - 1);
  65        int ret;
  66
  67        /*
  68         * Are we out of pkeys?  We must handle this specially
  69         * because ffz() behavior is undefined if there are no
  70         * zeros.
  71         */
  72        if (mm_pkey_allocation_map(mm) == all_pkeys_mask)
  73                return -1;
  74
  75        ret = ffz(mm_pkey_allocation_map(mm));
  76
  77        mm_set_pkey_allocated(mm, ret);
  78
  79        return ret;
  80}
  81
  82static inline
  83int mm_pkey_free(struct mm_struct *mm, int pkey)
  84{
  85        /*
  86         * pkey 0 is special, always allocated and can never
  87         * be freed.
  88         */
  89        if (!pkey)
  90                return -EINVAL;
  91        if (!mm_pkey_is_allocated(mm, pkey))
  92                return -EINVAL;
  93
  94        mm_set_pkey_free(mm, pkey);
  95
  96        return 0;
  97}
  98
  99extern int arch_set_user_pkey_access(struct task_struct *tsk, int pkey,
 100                unsigned long init_val);
 101extern int __arch_set_user_pkey_access(struct task_struct *tsk, int pkey,
 102                unsigned long init_val);
 103extern void copy_init_pkru_to_fpregs(void);
 104
 105#endif /*_ASM_X86_PKEYS_H */
 106