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 #ifdef CONFIG_GENERIC_ENTRY
  39 enum syscall_work_bit {
  40         SYSCALL_WORK_BIT_SECCOMP,
  41         SYSCALL_WORK_BIT_SYSCALL_TRACEPOINT,
  42         SYSCALL_WORK_BIT_SYSCALL_TRACE,
  43         SYSCALL_WORK_BIT_SYSCALL_EMU,
  44         SYSCALL_WORK_BIT_SYSCALL_AUDIT,
  45         SYSCALL_WORK_BIT_SYSCALL_USER_DISPATCH,
  46 };
  47
  48 #define SYSCALL_WORK_SECCOMP            BIT(SYSCALL_WORK_BIT_SECCOMP)
  49 #define SYSCALL_WORK_SYSCALL_TRACEPOINT BIT(SYSCALL_WORK_BIT_SYSCALL_TRACEPOINT)
  50 #define SYSCALL_WORK_SYSCALL_TRACE      BIT(SYSCALL_WORK_BIT_SYSCALL_TRACE)
  51 #define SYSCALL_WORK_SYSCALL_EMU        BIT(SYSCALL_WORK_BIT_SYSCALL_EMU)
  52 #define SYSCALL_WORK_SYSCALL_AUDIT      BIT(SYSCALL_WORK_BIT_SYSCALL_AUDIT)
  53 #define SYSCALL_WORK_SYSCALL_USER_DISPATCH BIT(SYSCALL_WORK_BIT_SYSCALL_USER_DISPATCH)
  54 #endif
  55
  56 #include <asm/thread_info.h>
  57
  58 #ifdef __KERNEL__
  59
  60 #ifndef THREAD_ALIGN
  61 #define THREAD_ALIGN    THREAD_SIZE
  62 #endif
  63
  64 #define THREADINFO_GFP          (GFP_KERNEL_ACCOUNT | __GFP_ZERO)
  65
  66 /*
  67  * flag set/clear/test wrappers
  68  * - pass TIF_xxxx constants to these functions
  69  */
  70
  71 static inline void set_ti_thread_flag(struct thread_info *ti, int flag)
  72 {
  73         set_bit(flag, (unsigned long *)&ti->flags);
  74 }
  75
  76 static inline void clear_ti_thread_flag(struct thread_info *ti, int flag)
  77 {
  78         clear_bit(flag, (unsigned long *)&ti->flags);
  79 }
  80
  81 static inline void update_ti_thread_flag(struct thread_info *ti, int flag,
  82                                          bool value)
  83 {
  84         if (value)
  85                 set_ti_thread_flag(ti, flag);
  86         else
  87                 clear_ti_thread_flag(ti, flag);
  88 }
  89
  90 static inline int test_and_set_ti_thread_flag(struct thread_info *ti, int flag)
  91 {
  92         return test_and_set_bit(flag, (unsigned long *)&ti->flags);
  93 }
  94
  95 static inline int test_and_clear_ti_thread_flag(struct thread_info *ti, int flag)
  96 {
  97         return test_and_clear_bit(flag, (unsigned long *)&ti->flags);
  98 }
  99
 100 static inline int test_ti_thread_flag(struct thread_info *ti, int flag)
 101 {
 102         return test_bit(flag, (unsigned long *)&ti->flags);
 103 }
 104
 105 #define set_thread_flag(flag) \
 106         set_ti_thread_flag(current_thread_info(), flag)
 107 #define clear_thread_flag(flag) \
 108         clear_ti_thread_flag(current_thread_info(), flag)
 109 #define update_thread_flag(flag, value) \
 110         update_ti_thread_flag(current_thread_info(), flag, value)
 111 #define test_and_set_thread_flag(flag) \
 112         test_and_set_ti_thread_flag(current_thread_info(), flag)
 113 #define test_and_clear_thread_flag(flag) \
 114         test_and_clear_ti_thread_flag(current_thread_info(), flag)
 115 #define test_thread_flag(flag) \
 116         test_ti_thread_flag(current_thread_info(), flag)
 117
 118 #ifdef CONFIG_GENERIC_ENTRY
 119 #define set_syscall_work(fl) \
 120         set_bit(SYSCALL_WORK_BIT_##fl, &current_thread_info()->syscall_work)
 121 #define test_syscall_work(fl) \
 122         test_bit(SYSCALL_WORK_BIT_##fl, &current_thread_info()->syscall_work)
 123 #define clear_syscall_work(fl) \
 124         clear_bit(SYSCALL_WORK_BIT_##fl, &current_thread_info()->syscall_work)
 125
 126 #define set_task_syscall_work(t, fl) \
 127         set_bit(SYSCALL_WORK_BIT_##fl, &task_thread_info(t)->syscall_work)
 128 #define test_task_syscall_work(t, fl) \
 129         test_bit(SYSCALL_WORK_BIT_##fl, &task_thread_info(t)->syscall_work)
 130 #define clear_task_syscall_work(t, fl) \
 131         clear_bit(SYSCALL_WORK_BIT_##fl, &task_thread_info(t)->syscall_work)
 132
 133 #else /* CONFIG_GENERIC_ENTRY */
 134
 135 #define set_syscall_work(fl)                                            \
 136         set_ti_thread_flag(current_thread_info(), TIF_##fl)
 137 #define test_syscall_work(fl) \
 138         test_ti_thread_flag(current_thread_info(), TIF_##fl)
 139 #define clear_syscall_work(fl) \
 140         clear_ti_thread_flag(current_thread_info(), TIF_##fl)
 141
 142 #define set_task_syscall_work(t, fl) \
 143         set_ti_thread_flag(task_thread_info(t), TIF_##fl)
 144 #define test_task_syscall_work(t, fl) \
 145         test_ti_thread_flag(task_thread_info(t), TIF_##fl)
 146 #define clear_task_syscall_work(t, fl) \
 147         clear_ti_thread_flag(task_thread_info(t), TIF_##fl)
 148 #endif /* !CONFIG_GENERIC_ENTRY */
 149
 150 #define tif_need_resched() test_thread_flag(TIF_NEED_RESCHED)
 151
 152 #ifndef CONFIG_HAVE_ARCH_WITHIN_STACK_FRAMES
 153 static inline int arch_within_stack_frames(const void * const stack,
 154                                            const void * const stackend,
 155                                            const void *obj, unsigned long len)
 156 {
 157         return 0;
 158 }
 159 #endif
 160
 161 #ifdef CONFIG_HARDENED_USERCOPY
 162 extern void __check_object_size(const void *ptr, unsigned long n,
 163                                         bool to_user);
 164
 165 static __always_inline void check_object_size(const void *ptr, unsigned long n,
 166                                               bool to_user)
 167 {
 168         if (!__builtin_constant_p(n))
 169                 __check_object_size(ptr, n, to_user);
 170 }
 171 #else
 172 static inline void check_object_size(const void *ptr, unsigned long n,
 173                                      bool to_user)
 174 { }
 175 #endif /* CONFIG_HARDENED_USERCOPY */
 176
 177 extern void __compiletime_error("copy source size is too small")
 178 __bad_copy_from(void);
 179 extern void __compiletime_error("copy destination size is too small")
 180 __bad_copy_to(void);
 181
 182 static inline void copy_overflow(int size, unsigned long count)
 183 {
 184         WARN(1, "Buffer overflow detected (%d < %lu)!\n", size, count);
 185 }
 186
 187 static __always_inline __must_check bool
 188 check_copy_size(const void *addr, size_t bytes, bool is_source)
 189 {
 190         int sz = __compiletime_object_size(addr);
 191         if (unlikely(sz >= 0 && sz < bytes)) {
 192                 if (!__builtin_constant_p(bytes))
 193                         copy_overflow(sz, bytes);
 194                 else if (is_source)
 195                         __bad_copy_from();
 196                 else
 197                         __bad_copy_to();
 198                 return false;
 199         }
 200         if (WARN_ON_ONCE(bytes > INT_MAX))
 201                 return false;
 202         check_object_size(addr, bytes, is_source);
 203         return true;
 204 }
 205
 206 #ifndef arch_setup_new_exec
 207 static inline void arch_setup_new_exec(void) { }
 208 #endif
 209
 210 #endif  /* __KERNEL__ */
 211
 212 #endif /* _LINUX_THREAD_INFO_H */