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 #if IS_ENABLED(CONFIG_DEBUG_STACK_USAGE) || IS_ENABLED(CONFIG_DEBUG_KMEMLEAK)
  47 # define THREADINFO_GFP         (GFP_KERNEL_ACCOUNT | __GFP_ZERO)
  48 #else
  49 # define THREADINFO_GFP         (GFP_KERNEL_ACCOUNT)
  50 #endif
  51
  52 /*
  53  * flag set/clear/test wrappers
  54  * - pass TIF_xxxx constants to these functions
  55  */
  56
  57 static inline void set_ti_thread_flag(struct thread_info *ti, int flag)
  58 {
  59         set_bit(flag, (unsigned long *)&ti->flags);
  60 }
  61
  62 static inline void clear_ti_thread_flag(struct thread_info *ti, int flag)
  63 {
  64         clear_bit(flag, (unsigned long *)&ti->flags);
  65 }
  66
  67 static inline int test_and_set_ti_thread_flag(struct thread_info *ti, int flag)
  68 {
  69         return test_and_set_bit(flag, (unsigned long *)&ti->flags);
  70 }
  71
  72 static inline int test_and_clear_ti_thread_flag(struct thread_info *ti, int flag)
  73 {
  74         return test_and_clear_bit(flag, (unsigned long *)&ti->flags);
  75 }
  76
  77 static inline int test_ti_thread_flag(struct thread_info *ti, int flag)
  78 {
  79         return test_bit(flag, (unsigned long *)&ti->flags);
  80 }
  81
  82 #define set_thread_flag(flag) \
  83         set_ti_thread_flag(current_thread_info(), flag)
  84 #define clear_thread_flag(flag) \
  85         clear_ti_thread_flag(current_thread_info(), flag)
  86 #define test_and_set_thread_flag(flag) \
  87         test_and_set_ti_thread_flag(current_thread_info(), flag)
  88 #define test_and_clear_thread_flag(flag) \
  89         test_and_clear_ti_thread_flag(current_thread_info(), flag)
  90 #define test_thread_flag(flag) \
  91         test_ti_thread_flag(current_thread_info(), flag)
  92
  93 #define tif_need_resched() test_thread_flag(TIF_NEED_RESCHED)
  94
  95 #ifndef CONFIG_HAVE_ARCH_WITHIN_STACK_FRAMES
  96 static inline int arch_within_stack_frames(const void * const stack,
  97                                            const void * const stackend,
  98                                            const void *obj, unsigned long len)
  99 {
 100         return 0;
 101 }
 102 #endif
 103
 104 #ifdef CONFIG_HARDENED_USERCOPY
 105 extern void __check_object_size(const void *ptr, unsigned long n,
 106                                         bool to_user);
 107
 108 static __always_inline void check_object_size(const void *ptr, unsigned long n,
 109                                               bool to_user)
 110 {
 111         if (!__builtin_constant_p(n))
 112                 __check_object_size(ptr, n, to_user);
 113 }
 114 #else
 115 static inline void check_object_size(const void *ptr, unsigned long n,
 116                                      bool to_user)
 117 { }
 118 #endif /* CONFIG_HARDENED_USERCOPY */
 119
 120 extern void __compiletime_error("copy source size is too small")
 121 __bad_copy_from(void);
 122 extern void __compiletime_error("copy destination size is too small")
 123 __bad_copy_to(void);
 124
 125 static inline void copy_overflow(int size, unsigned long count)
 126 {
 127         WARN(1, "Buffer overflow detected (%d < %lu)!\n", size, count);
 128 }
 129
 130 static __always_inline bool
 131 check_copy_size(const void *addr, size_t bytes, bool is_source)
 132 {
 133         int sz = __compiletime_object_size(addr);
 134         if (unlikely(sz >= 0 && sz < bytes)) {
 135                 if (!__builtin_constant_p(bytes))
 136                         copy_overflow(sz, bytes);
 137                 else if (is_source)
 138                         __bad_copy_from();
 139                 else
 140                         __bad_copy_to();
 141                 return false;
 142         }
 143         check_object_size(addr, bytes, is_source);
 144         return true;
 145 }
 146
 147 #ifndef arch_setup_new_exec
 148 static inline void arch_setup_new_exec(void) { }
 149 #endif
 150
 151 #endif  /* __KERNEL__ */
 152
 153 #endif /* _LINUX_THREAD_INFO_H */