LXR linux/arch/powerpc/include/asm/kup.h

   1/* SPDX-License-Identifier: GPL-2.0 */
   2#ifndef _ASM_POWERPC_KUP_H_
   3#define _ASM_POWERPC_KUP_H_
   4
   5#define KUAP_READ       1
   6#define KUAP_WRITE      2
   7#define KUAP_READ_WRITE (KUAP_READ | KUAP_WRITE)
   8
   9#ifdef CONFIG_PPC_BOOK3S_64
  10#include <asm/book3s/64/kup.h>
  11#endif
  12
  13#ifdef CONFIG_PPC_8xx
  14#include <asm/nohash/32/kup-8xx.h>
  15#endif
  16
  17#ifdef CONFIG_PPC_BOOK3S_32
  18#include <asm/book3s/32/kup.h>
  19#endif
  20
  21#ifdef __ASSEMBLY__
  22#ifndef CONFIG_PPC_KUAP
  23.macro kuap_check_amr   gpr1, gpr2
  24.endm
  25
  26#endif
  27
  28#else /* !__ASSEMBLY__ */
  29
  30extern bool disable_kuep;
  31extern bool disable_kuap;
  32
  33#include <linux/pgtable.h>
  34
  35#ifdef CONFIG_PPC_KUEP
  36void setup_kuep(bool disabled);
  37#else
  38static inline void setup_kuep(bool disabled) { }
  39#endif /* CONFIG_PPC_KUEP */
  40
  41#ifndef CONFIG_PPC_BOOK3S_32
  42static inline void kuep_lock(void) { }
  43static inline void kuep_unlock(void) { }
  44#endif
  45
  46#ifdef CONFIG_PPC_KUAP
  47void setup_kuap(bool disabled);
  48#else
  49static inline void setup_kuap(bool disabled) { }
  50
  51static inline bool
  52bad_kuap_fault(struct pt_regs *regs, unsigned long address, bool is_write)
  53{
  54        return false;
  55}
  56
  57static inline void kuap_assert_locked(void) { }
  58static inline void kuap_save_and_lock(struct pt_regs *regs) { }
  59static inline void kuap_user_restore(struct pt_regs *regs) { }
  60static inline void kuap_kernel_restore(struct pt_regs *regs, unsigned long amr) { }
  61
  62static inline unsigned long kuap_get_and_assert_locked(void)
  63{
  64        return 0;
  65}
  66
  67/*
  68 * book3s/64/kup-radix.h defines these functions for the !KUAP case to flush
  69 * the L1D cache after user accesses. Only include the empty stubs for other
  70 * platforms.
  71 */
  72#ifndef CONFIG_PPC_BOOK3S_64
  73static inline void allow_user_access(void __user *to, const void __user *from,
  74                                     unsigned long size, unsigned long dir) { }
  75static inline void prevent_user_access(unsigned long dir) { }
  76static inline unsigned long prevent_user_access_return(void) { return 0UL; }
  77static inline void restore_user_access(unsigned long flags) { }
  78#endif /* CONFIG_PPC_BOOK3S_64 */
  79#endif /* CONFIG_PPC_KUAP */
  80
  81static __always_inline void setup_kup(void)
  82{
  83        setup_kuep(disable_kuep);
  84        setup_kuap(disable_kuap);
  85}
  86
  87static __always_inline void allow_read_from_user(const void __user *from, unsigned long size)
  88{
  89        barrier_nospec();
  90        allow_user_access(NULL, from, size, KUAP_READ);
  91}
  92
  93static __always_inline void allow_write_to_user(void __user *to, unsigned long size)
  94{
  95        allow_user_access(to, NULL, size, KUAP_WRITE);
  96}
  97
  98static __always_inline void allow_read_write_user(void __user *to, const void __user *from,
  99                                                  unsigned long size)
 100{
 101        barrier_nospec();
 102        allow_user_access(to, from, size, KUAP_READ_WRITE);
 103}
 104
 105static __always_inline void prevent_read_from_user(const void __user *from, unsigned long size)
 106{
 107        prevent_user_access(KUAP_READ);
 108}
 109
 110static __always_inline void prevent_write_to_user(void __user *to, unsigned long size)
 111{
 112        prevent_user_access(KUAP_WRITE);
 113}
 114
 115static __always_inline void prevent_read_write_user(void __user *to, const void __user *from,
 116                                                    unsigned long size)
 117{
 118        prevent_user_access(KUAP_READ_WRITE);
 119}
 120
 121static __always_inline void prevent_current_access_user(void)
 122{
 123        prevent_user_access(KUAP_READ_WRITE);
 124}
 125
 126static __always_inline void prevent_current_read_from_user(void)
 127{
 128        prevent_user_access(KUAP_READ);
 129}
 130
 131static __always_inline void prevent_current_write_to_user(void)
 132{
 133        prevent_user_access(KUAP_WRITE);
 134}
 135
 136#endif /* !__ASSEMBLY__ */
 137
 138#endif /* _ASM_POWERPC_KUAP_H_ */
 139