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         SYSCALL_WORK_BIT_SYSCALL_EXIT_TRAP,
  47 };
  48
  49 #define SYSCALL_WORK_SECCOMP            BIT(SYSCALL_WORK_BIT_SECCOMP)
  50 #define SYSCALL_WORK_SYSCALL_TRACEPOINT BIT(SYSCALL_WORK_BIT_SYSCALL_TRACEPOINT)
  51 #define SYSCALL_WORK_SYSCALL_TRACE      BIT(SYSCALL_WORK_BIT_SYSCALL_TRACE)
  52 #define SYSCALL_WORK_SYSCALL_EMU        BIT(SYSCALL_WORK_BIT_SYSCALL_EMU)
  53 #define SYSCALL_WORK_SYSCALL_AUDIT      BIT(SYSCALL_WORK_BIT_SYSCALL_AUDIT)
  54 #define SYSCALL_WORK_SYSCALL_USER_DISPATCH BIT(SYSCALL_WORK_BIT_SYSCALL_USER_DISPATCH)
  55 #define SYSCALL_WORK_SYSCALL_EXIT_TRAP  BIT(SYSCALL_WORK_BIT_SYSCALL_EXIT_TRAP)
  56 #endif
  57
  58 #include <asm/thread_info.h>
  59
  60 #ifdef __KERNEL__
  61
  62 #ifndef THREAD_ALIGN
  63 #define THREAD_ALIGN    THREAD_SIZE
  64 #endif
  65
  66 #define THREADINFO_GFP          (GFP_KERNEL_ACCOUNT | __GFP_ZERO)
  67
  68 /*
  69  * flag set/clear/test wrappers
  70  * - pass TIF_xxxx constants to these functions
  71  */
  72
  73 static inline void set_ti_thread_flag(struct thread_info *ti, int flag)
  74 {
  75         set_bit(flag, (unsigned long *)&ti->flags);
  76 }
  77
  78 static inline void clear_ti_thread_flag(struct thread_info *ti, int flag)
  79 {
  80         clear_bit(flag, (unsigned long *)&ti->flags);
  81 }
  82
  83 static inline void update_ti_thread_flag(struct thread_info *ti, int flag,
  84                                          bool value)
  85 {
  86         if (value)
  87                 set_ti_thread_flag(ti, flag);
  88         else
  89                 clear_ti_thread_flag(ti, flag);
  90 }
  91
  92 static inline int test_and_set_ti_thread_flag(struct thread_info *ti, int flag)
  93 {
  94         return test_and_set_bit(flag, (unsigned long *)&ti->flags);
  95 }
  96
  97 static inline int test_and_clear_ti_thread_flag(struct thread_info *ti, int flag)
  98 {
  99         return test_and_clear_bit(flag, (unsigned long *)&ti->flags);
 100 }
 101
 102 static inline int test_ti_thread_flag(struct thread_info *ti, int flag)
 103 {
 104         return test_bit(flag, (unsigned long *)&ti->flags);
 105 }
 106
 107 #define set_thread_flag(flag) \
 108         set_ti_thread_flag(current_thread_info(), flag)
 109 #define clear_thread_flag(flag) \
 110         clear_ti_thread_flag(current_thread_info(), flag)
 111 #define update_thread_flag(flag, value) \
 112         update_ti_thread_flag(current_thread_info(), flag, value)
 113 #define test_and_set_thread_flag(flag) \
 114         test_and_set_ti_thread_flag(current_thread_info(), flag)
 115 #define test_and_clear_thread_flag(flag) \
 116         test_and_clear_ti_thread_flag(current_thread_info(), flag)
 117 #define test_thread_flag(flag) \
 118         test_ti_thread_flag(current_thread_info(), flag)
 119
 120 #ifdef CONFIG_GENERIC_ENTRY
 121 #define set_syscall_work(fl) \
 122         set_bit(SYSCALL_WORK_BIT_##fl, &current_thread_info()->syscall_work)
 123 #define test_syscall_work(fl) \
 124         test_bit(SYSCALL_WORK_BIT_##fl, &current_thread_info()->syscall_work)
 125 #define clear_syscall_work(fl) \
 126         clear_bit(SYSCALL_WORK_BIT_##fl, &current_thread_info()->syscall_work)
 127
 128 #define set_task_syscall_work(t, fl) \
 129         set_bit(SYSCALL_WORK_BIT_##fl, &task_thread_info(t)->syscall_work)
 130 #define test_task_syscall_work(t, fl) \
 131         test_bit(SYSCALL_WORK_BIT_##fl, &task_thread_info(t)->syscall_work)
 132 #define clear_task_syscall_work(t, fl) \
 133         clear_bit(SYSCALL_WORK_BIT_##fl, &task_thread_info(t)->syscall_work)
 134
 135 #else /* CONFIG_GENERIC_ENTRY */
 136
 137 #define set_syscall_work(fl)                                            \
 138         set_ti_thread_flag(current_thread_info(), TIF_##fl)
 139 #define test_syscall_work(fl) \
 140         test_ti_thread_flag(current_thread_info(), TIF_##fl)
 141 #define clear_syscall_work(fl) \
 142         clear_ti_thread_flag(current_thread_info(), TIF_##fl)
 143
 144 #define set_task_syscall_work(t, fl) \
 145         set_ti_thread_flag(task_thread_info(t), TIF_##fl)
 146 #define test_task_syscall_work(t, fl) \
 147         test_ti_thread_flag(task_thread_info(t), TIF_##fl)
 148 #define clear_task_syscall_work(t, fl) \
 149         clear_ti_thread_flag(task_thread_info(t), TIF_##fl)
 150 #endif /* !CONFIG_GENERIC_ENTRY */
 151
 152 #define tif_need_resched() test_thread_flag(TIF_NEED_RESCHED)
 153
 154 #ifndef CONFIG_HAVE_ARCH_WITHIN_STACK_FRAMES
 155 static inline int arch_within_stack_frames(const void * const stack,
 156                                            const void * const stackend,
 157                                            const void *obj, unsigned long len)
 158 {
 159         return 0;
 160 }
 161 #endif
 162
 163 #ifdef CONFIG_HARDENED_USERCOPY
 164 extern void __check_object_size(const void *ptr, unsigned long n,
 165                                         bool to_user);
 166
 167 static __always_inline void check_object_size(const void *ptr, unsigned long n,
 168                                               bool to_user)
 169 {
 170         if (!__builtin_constant_p(n))
 171                 __check_object_size(ptr, n, to_user);
 172 }
 173 #else
 174 static inline void check_object_size(const void *ptr, unsigned long n,
 175                                      bool to_user)
 176 { }
 177 #endif /* CONFIG_HARDENED_USERCOPY */
 178
 179 extern void __compiletime_error("copy source size is too small")
 180 __bad_copy_from(void);
 181 extern void __compiletime_error("copy destination size is too small")
 182 __bad_copy_to(void);
 183
 184 static inline void copy_overflow(int size, unsigned long count)
 185 {
 186         WARN(1, "Buffer overflow detected (%d < %lu)!\n", size, count);
 187 }
 188
 189 static __always_inline __must_check bool
 190 check_copy_size(const void *addr, size_t bytes, bool is_source)
 191 {
 192         int sz = __compiletime_object_size(addr);
 193         if (unlikely(sz >= 0 && sz < bytes)) {
 194                 if (!__builtin_constant_p(bytes))
 195                         copy_overflow(sz, bytes);
 196                 else if (is_source)
 197                         __bad_copy_from();
 198                 else
 199                         __bad_copy_to();
 200                 return false;
 201         }
 202         if (WARN_ON_ONCE(bytes > INT_MAX))
 203                 return false;
 204         check_object_size(addr, bytes, is_source);
 205         return true;
 206 }
 207
 208 #ifndef arch_setup_new_exec
 209 static inline void arch_setup_new_exec(void) { }
 210 #endif
 211
 212 #endif  /* __KERNEL__ */
 213
 214 #endif /* _LINUX_THREAD_INFO_H */