arch/x86/include/asm/mpx.h

   1 /* SPDX-License-Identifier: GPL-2.0 */
   2 #ifndef _ASM_X86_MPX_H
   3 #define _ASM_X86_MPX_H
   4
   5 #include <linux/types.h>
   6 #include <linux/mm_types.h>
   7
   8 #include <asm/ptrace.h>
   9 #include <asm/insn.h>
  10
  11 /*
  12  * NULL is theoretically a valid place to put the bounds
  13  * directory, so point this at an invalid address.
  14  */
  15 #define MPX_INVALID_BOUNDS_DIR  ((void __user *)-1)
  16 #define MPX_BNDCFG_ENABLE_FLAG  0x1
  17 #define MPX_BD_ENTRY_VALID_FLAG 0x1
  18
  19 /*
  20  * The upper 28 bits [47:20] of the virtual address in 64-bit
  21  * are used to index into bounds directory (BD).
  22  *
  23  * The directory is 2G (2^31) in size, and with 8-byte entries
  24  * it has 2^28 entries.
  25  */
  26 #define MPX_BD_SIZE_BYTES_64    (1UL<<31)
  27 #define MPX_BD_ENTRY_BYTES_64   8
  28 #define MPX_BD_NR_ENTRIES_64    (MPX_BD_SIZE_BYTES_64/MPX_BD_ENTRY_BYTES_64)
  29
  30 /*
  31  * The 32-bit directory is 4MB (2^22) in size, and with 4-byte
  32  * entries it has 2^20 entries.
  33  */
  34 #define MPX_BD_SIZE_BYTES_32    (1UL<<22)
  35 #define MPX_BD_ENTRY_BYTES_32   4
  36 #define MPX_BD_NR_ENTRIES_32    (MPX_BD_SIZE_BYTES_32/MPX_BD_ENTRY_BYTES_32)
  37
  38 /*
  39  * A 64-bit table is 4MB total in size, and an entry is
  40  * 4 64-bit pointers in size.
  41  */
  42 #define MPX_BT_SIZE_BYTES_64    (1UL<<22)
  43 #define MPX_BT_ENTRY_BYTES_64   32
  44 #define MPX_BT_NR_ENTRIES_64    (MPX_BT_SIZE_BYTES_64/MPX_BT_ENTRY_BYTES_64)
  45
  46 /*
  47  * A 32-bit table is 16kB total in size, and an entry is
  48  * 4 32-bit pointers in size.
  49  */
  50 #define MPX_BT_SIZE_BYTES_32    (1UL<<14)
  51 #define MPX_BT_ENTRY_BYTES_32   16
  52 #define MPX_BT_NR_ENTRIES_32    (MPX_BT_SIZE_BYTES_32/MPX_BT_ENTRY_BYTES_32)
  53
  54 #define MPX_BNDSTA_TAIL         2
  55 #define MPX_BNDCFG_TAIL         12
  56 #define MPX_BNDSTA_ADDR_MASK    (~((1UL<<MPX_BNDSTA_TAIL)-1))
  57 #define MPX_BNDCFG_ADDR_MASK    (~((1UL<<MPX_BNDCFG_TAIL)-1))
  58 #define MPX_BNDSTA_ERROR_CODE   0x3
  59
  60 struct mpx_fault_info {
  61         void __user *addr;
  62         void __user *lower;
  63         void __user *upper;
  64 };
  65
  66 #ifdef CONFIG_X86_INTEL_MPX
  67
  68 extern int mpx_fault_info(struct mpx_fault_info *info, struct pt_regs *regs);
  69 extern int mpx_handle_bd_fault(void);
  70
  71 static inline int kernel_managing_mpx_tables(struct mm_struct *mm)
  72 {
  73         return (mm->context.bd_addr != MPX_INVALID_BOUNDS_DIR);
  74 }
  75
  76 static inline void mpx_mm_init(struct mm_struct *mm)
  77 {
  78         /*
  79          * NULL is theoretically a valid place to put the bounds
  80          * directory, so point this at an invalid address.
  81          */
  82         mm->context.bd_addr = MPX_INVALID_BOUNDS_DIR;
  83 }
  84
  85 extern void mpx_notify_unmap(struct mm_struct *mm, unsigned long start, unsigned long end);
  86 extern unsigned long mpx_unmapped_area_check(unsigned long addr, unsigned long len, unsigned long flags);
  87
  88 #else
  89 static inline int mpx_fault_info(struct mpx_fault_info *info, struct pt_regs *regs)
  90 {
  91         return -EINVAL;
  92 }
  93 static inline int mpx_handle_bd_fault(void)
  94 {
  95         return -EINVAL;
  96 }
  97 static inline int kernel_managing_mpx_tables(struct mm_struct *mm)
  98 {
  99         return 0;
 100 }
 101 static inline void mpx_mm_init(struct mm_struct *mm)
 102 {
 103 }
 104 static inline void mpx_notify_unmap(struct mm_struct *mm,
 105                                     unsigned long start, unsigned long end)
 106 {
 107 }
 108
 109 static inline unsigned long mpx_unmapped_area_check(unsigned long addr,
 110                 unsigned long len, unsigned long flags)
 111 {
 112         return addr;
 113 }
 114 #endif /* CONFIG_X86_INTEL_MPX */
 115
 116 #endif /* _ASM_X86_MPX_H */