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 #include <linux/errno.h>
  15
  16 #ifdef CONFIG_THREAD_INFO_IN_TASK
  17 /*
  18  * For CONFIG_THREAD_INFO_IN_TASK kernels we need <asm/current.h> for the
  19  * definition of current, but for !CONFIG_THREAD_INFO_IN_TASK kernels,
  20  * including <asm/current.h> can cause a circular dependency on some platforms.
  21  */
  22 #include <asm/current.h>
  23 #define current_thread_info() ((struct thread_info *)current)
  24 #endif
  25
  26 #include <linux/bitops.h>
  27
  28 /*
  29  * For per-arch arch_within_stack_frames() implementations, defined in
  30  * asm/thread_info.h.
  31  */
  32 enum {
  33         BAD_STACK = -1,
  34         NOT_STACK = 0,
  35         GOOD_FRAME,
  36         GOOD_STACK,
  37 };
  38
  39 #ifdef CONFIG_GENERIC_ENTRY
  40 enum syscall_work_bit {
  41         SYSCALL_WORK_BIT_SECCOMP,
  42         SYSCALL_WORK_BIT_SYSCALL_TRACEPOINT,
  43         SYSCALL_WORK_BIT_SYSCALL_TRACE,
  44         SYSCALL_WORK_BIT_SYSCALL_EMU,
  45         SYSCALL_WORK_BIT_SYSCALL_AUDIT,
  46         SYSCALL_WORK_BIT_SYSCALL_USER_DISPATCH,
  47         SYSCALL_WORK_BIT_SYSCALL_EXIT_TRAP,
  48 };
  49
  50 #define SYSCALL_WORK_SECCOMP            BIT(SYSCALL_WORK_BIT_SECCOMP)
  51 #define SYSCALL_WORK_SYSCALL_TRACEPOINT BIT(SYSCALL_WORK_BIT_SYSCALL_TRACEPOINT)
  52 #define SYSCALL_WORK_SYSCALL_TRACE      BIT(SYSCALL_WORK_BIT_SYSCALL_TRACE)
  53 #define SYSCALL_WORK_SYSCALL_EMU        BIT(SYSCALL_WORK_BIT_SYSCALL_EMU)
  54 #define SYSCALL_WORK_SYSCALL_AUDIT      BIT(SYSCALL_WORK_BIT_SYSCALL_AUDIT)
  55 #define SYSCALL_WORK_SYSCALL_USER_DISPATCH BIT(SYSCALL_WORK_BIT_SYSCALL_USER_DISPATCH)
  56 #define SYSCALL_WORK_SYSCALL_EXIT_TRAP  BIT(SYSCALL_WORK_BIT_SYSCALL_EXIT_TRAP)
  57 #endif
  58
  59 #include <asm/thread_info.h>
  60
  61 #ifdef __KERNEL__
  62
  63 #ifndef arch_set_restart_data
  64 #define arch_set_restart_data(restart) do { } while (0)
  65 #endif
  66
  67 static inline long set_restart_fn(struct restart_block *restart,
  68                                         long (*fn)(struct restart_block *))
  69 {
  70         restart->fn = fn;
  71         arch_set_restart_data(restart);
  72         return -ERESTART_RESTARTBLOCK;
  73 }
  74
  75 #ifndef THREAD_ALIGN
  76 #define THREAD_ALIGN    THREAD_SIZE
  77 #endif
  78
  79 #define THREADINFO_GFP          (GFP_KERNEL_ACCOUNT | __GFP_ZERO)
  80
  81 /*
  82  * flag set/clear/test wrappers
  83  * - pass TIF_xxxx constants to these functions
  84  */
  85
  86 static inline void set_ti_thread_flag(struct thread_info *ti, int flag)
  87 {
  88         set_bit(flag, (unsigned long *)&ti->flags);
  89 }
  90
  91 static inline void clear_ti_thread_flag(struct thread_info *ti, int flag)
  92 {
  93         clear_bit(flag, (unsigned long *)&ti->flags);
  94 }
  95
  96 static inline void update_ti_thread_flag(struct thread_info *ti, int flag,
  97                                          bool value)
  98 {
  99         if (value)
 100                 set_ti_thread_flag(ti, flag);
 101         else
 102                 clear_ti_thread_flag(ti, flag);
 103 }
 104
 105 static inline int test_and_set_ti_thread_flag(struct thread_info *ti, int flag)
 106 {
 107         return test_and_set_bit(flag, (unsigned long *)&ti->flags);
 108 }
 109
 110 static inline int test_and_clear_ti_thread_flag(struct thread_info *ti, int flag)
 111 {
 112         return test_and_clear_bit(flag, (unsigned long *)&ti->flags);
 113 }
 114
 115 static inline int test_ti_thread_flag(struct thread_info *ti, int flag)
 116 {
 117         return test_bit(flag, (unsigned long *)&ti->flags);
 118 }
 119
 120 #define set_thread_flag(flag) \
 121         set_ti_thread_flag(current_thread_info(), flag)
 122 #define clear_thread_flag(flag) \
 123         clear_ti_thread_flag(current_thread_info(), flag)
 124 #define update_thread_flag(flag, value) \
 125         update_ti_thread_flag(current_thread_info(), flag, value)
 126 #define test_and_set_thread_flag(flag) \
 127         test_and_set_ti_thread_flag(current_thread_info(), flag)
 128 #define test_and_clear_thread_flag(flag) \
 129         test_and_clear_ti_thread_flag(current_thread_info(), flag)
 130 #define test_thread_flag(flag) \
 131         test_ti_thread_flag(current_thread_info(), flag)
 132
 133 #ifdef CONFIG_GENERIC_ENTRY
 134 #define set_syscall_work(fl) \
 135         set_bit(SYSCALL_WORK_BIT_##fl, &current_thread_info()->syscall_work)
 136 #define test_syscall_work(fl) \
 137         test_bit(SYSCALL_WORK_BIT_##fl, &current_thread_info()->syscall_work)
 138 #define clear_syscall_work(fl) \
 139         clear_bit(SYSCALL_WORK_BIT_##fl, &current_thread_info()->syscall_work)
 140
 141 #define set_task_syscall_work(t, fl) \
 142         set_bit(SYSCALL_WORK_BIT_##fl, &task_thread_info(t)->syscall_work)
 143 #define test_task_syscall_work(t, fl) \
 144         test_bit(SYSCALL_WORK_BIT_##fl, &task_thread_info(t)->syscall_work)
 145 #define clear_task_syscall_work(t, fl) \
 146         clear_bit(SYSCALL_WORK_BIT_##fl, &task_thread_info(t)->syscall_work)
 147
 148 #else /* CONFIG_GENERIC_ENTRY */
 149
 150 #define set_syscall_work(fl)                                            \
 151         set_ti_thread_flag(current_thread_info(), TIF_##fl)
 152 #define test_syscall_work(fl) \
 153         test_ti_thread_flag(current_thread_info(), TIF_##fl)
 154 #define clear_syscall_work(fl) \
 155         clear_ti_thread_flag(current_thread_info(), TIF_##fl)
 156
 157 #define set_task_syscall_work(t, fl) \
 158         set_ti_thread_flag(task_thread_info(t), TIF_##fl)
 159 #define test_task_syscall_work(t, fl) \
 160         test_ti_thread_flag(task_thread_info(t), TIF_##fl)
 161 #define clear_task_syscall_work(t, fl) \
 162         clear_ti_thread_flag(task_thread_info(t), TIF_##fl)
 163 #endif /* !CONFIG_GENERIC_ENTRY */
 164
 165 #define tif_need_resched() test_thread_flag(TIF_NEED_RESCHED)
 166
 167 #ifndef CONFIG_HAVE_ARCH_WITHIN_STACK_FRAMES
 168 static inline int arch_within_stack_frames(const void * const stack,
 169                                            const void * const stackend,
 170                                            const void *obj, unsigned long len)
 171 {
 172         return 0;
 173 }
 174 #endif
 175
 176 #ifdef CONFIG_HARDENED_USERCOPY
 177 extern void __check_object_size(const void *ptr, unsigned long n,
 178                                         bool to_user);
 179
 180 static __always_inline void check_object_size(const void *ptr, unsigned long n,
 181                                               bool to_user)
 182 {
 183         if (!__builtin_constant_p(n))
 184                 __check_object_size(ptr, n, to_user);
 185 }
 186 #else
 187 static inline void check_object_size(const void *ptr, unsigned long n,
 188                                      bool to_user)
 189 { }
 190 #endif /* CONFIG_HARDENED_USERCOPY */
 191
 192 extern void __compiletime_error("copy source size is too small")
 193 __bad_copy_from(void);
 194 extern void __compiletime_error("copy destination size is too small")
 195 __bad_copy_to(void);
 196
 197 static inline void copy_overflow(int size, unsigned long count)
 198 {
 199         WARN(1, "Buffer overflow detected (%d < %lu)!\n", size, count);
 200 }
 201
 202 static __always_inline __must_check bool
 203 check_copy_size(const void *addr, size_t bytes, bool is_source)
 204 {
 205         int sz = __compiletime_object_size(addr);
 206         if (unlikely(sz >= 0 && sz < bytes)) {
 207                 if (!__builtin_constant_p(bytes))
 208                         copy_overflow(sz, bytes);
 209                 else if (is_source)
 210                         __bad_copy_from();
 211                 else
 212                         __bad_copy_to();
 213                 return false;
 214         }
 215         if (WARN_ON_ONCE(bytes > INT_MAX))
 216                 return false;
 217         check_object_size(addr, bytes, is_source);
 218         return true;
 219 }
 220
 221 #ifndef arch_setup_new_exec
 222 static inline void arch_setup_new_exec(void) { }
 223 #endif
 224
 225 #endif  /* __KERNEL__ */
 226
 227 #endif /* _LINUX_THREAD_INFO_H */