include/linux/thread_info.h

   1 /* SPDX-License-Identifier: GPL-2.0 */
   2 /* thread_info.h: common low-level thread information accessors
   3  *
   4  * Copyright (C) 2002  David Howells (dhowells@redhat.com)
   5  * - Incorporating suggestions made by Linus Torvalds
   6  */
   7
   8 #ifndef _LINUX_THREAD_INFO_H
   9 #define _LINUX_THREAD_INFO_H
  10
  11 #include <linux/types.h>
  12 #include <linux/bug.h>
  13 #include <linux/restart_block.h>
  14
  15 #ifdef CONFIG_THREAD_INFO_IN_TASK
  16 /*
  17  * For CONFIG_THREAD_INFO_IN_TASK kernels we need <asm/current.h> for the
  18  * definition of current, but for !CONFIG_THREAD_INFO_IN_TASK kernels,
  19  * including <asm/current.h> can cause a circular dependency on some platforms.
  20  */
  21 #include <asm/current.h>
  22 #define current_thread_info() ((struct thread_info *)current)
  23 #endif
  24
  25 #include <linux/bitops.h>
  26
  27 /*
  28  * For per-arch arch_within_stack_frames() implementations, defined in
  29  * asm/thread_info.h.
  30  */
  31 enum {
  32         BAD_STACK = -1,
  33         NOT_STACK = 0,
  34         GOOD_FRAME,
  35         GOOD_STACK,
  36 };
  37
  38 #include <asm/thread_info.h>
  39
  40 #ifdef __KERNEL__
  41
  42 #ifndef THREAD_ALIGN
  43 #define THREAD_ALIGN    THREAD_SIZE
  44 #endif
  45
  46 #define THREADINFO_GFP          (GFP_KERNEL_ACCOUNT | __GFP_ZERO)
  47
  48 /*
  49  * flag set/clear/test wrappers
  50  * - pass TIF_xxxx constants to these functions
  51  */
  52
  53 static inline void set_ti_thread_flag(struct thread_info *ti, int flag)
  54 {
  55         set_bit(flag, (unsigned long *)&ti->flags);
  56 }
  57
  58 static inline void clear_ti_thread_flag(struct thread_info *ti, int flag)
  59 {
  60         clear_bit(flag, (unsigned long *)&ti->flags);
  61 }
  62
  63 static inline void update_ti_thread_flag(struct thread_info *ti, int flag,
  64                                          bool value)
  65 {
  66         if (value)
  67                 set_ti_thread_flag(ti, flag);
  68         else
  69                 clear_ti_thread_flag(ti, flag);
  70 }
  71
  72 static inline int test_and_set_ti_thread_flag(struct thread_info *ti, int flag)
  73 {
  74         return test_and_set_bit(flag, (unsigned long *)&ti->flags);
  75 }
  76
  77 static inline int test_and_clear_ti_thread_flag(struct thread_info *ti, int flag)
  78 {
  79         return test_and_clear_bit(flag, (unsigned long *)&ti->flags);
  80 }
  81
  82 static inline int test_ti_thread_flag(struct thread_info *ti, int flag)
  83 {
  84         return test_bit(flag, (unsigned long *)&ti->flags);
  85 }
  86
  87 #define set_thread_flag(flag) \
  88         set_ti_thread_flag(current_thread_info(), flag)
  89 #define clear_thread_flag(flag) \
  90         clear_ti_thread_flag(current_thread_info(), flag)
  91 #define update_thread_flag(flag, value) \
  92         update_ti_thread_flag(current_thread_info(), flag, value)
  93 #define test_and_set_thread_flag(flag) \
  94         test_and_set_ti_thread_flag(current_thread_info(), flag)
  95 #define test_and_clear_thread_flag(flag) \
  96         test_and_clear_ti_thread_flag(current_thread_info(), flag)
  97 #define test_thread_flag(flag) \
  98         test_ti_thread_flag(current_thread_info(), flag)
  99
 100 #define tif_need_resched() test_thread_flag(TIF_NEED_RESCHED)
 101
 102 #ifndef CONFIG_HAVE_ARCH_WITHIN_STACK_FRAMES
 103 static inline int arch_within_stack_frames(const void * const stack,
 104                                            const void * const stackend,
 105                                            const void *obj, unsigned long len)
 106 {
 107         return 0;
 108 }
 109 #endif
 110
 111 #ifdef CONFIG_HARDENED_USERCOPY
 112 extern void __check_object_size(const void *ptr, unsigned long n,
 113                                         bool to_user);
 114
 115 static __always_inline void check_object_size(const void *ptr, unsigned long n,
 116                                               bool to_user)
 117 {
 118         if (!__builtin_constant_p(n))
 119                 __check_object_size(ptr, n, to_user);
 120 }
 121 #else
 122 static inline void check_object_size(const void *ptr, unsigned long n,
 123                                      bool to_user)
 124 { }
 125 #endif /* CONFIG_HARDENED_USERCOPY */
 126
 127 extern void __compiletime_error("copy source size is too small")
 128 __bad_copy_from(void);
 129 extern void __compiletime_error("copy destination size is too small")
 130 __bad_copy_to(void);
 131
 132 static inline void copy_overflow(int size, unsigned long count)
 133 {
 134         WARN(1, "Buffer overflow detected (%d < %lu)!\n", size, count);
 135 }
 136
 137 static __always_inline __must_check bool
 138 check_copy_size(const void *addr, size_t bytes, bool is_source)
 139 {
 140         int sz = __compiletime_object_size(addr);
 141         if (unlikely(sz >= 0 && sz < bytes)) {
 142                 if (!__builtin_constant_p(bytes))
 143                         copy_overflow(sz, bytes);
 144                 else if (is_source)
 145                         __bad_copy_from();
 146                 else
 147                         __bad_copy_to();
 148                 return false;
 149         }
 150         if (WARN_ON_ONCE(bytes > INT_MAX))
 151                 return false;
 152         check_object_size(addr, bytes, is_source);
 153         return true;
 154 }
 155
 156 #ifndef arch_setup_new_exec
 157 static inline void arch_setup_new_exec(void) { }
 158 #endif
 159
 160 #endif  /* __KERNEL__ */
 161
 162 #endif /* _LINUX_THREAD_INFO_H */