LXR linux/include/linux/thread

   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 */
  32enum {
  33        BAD_STACK = -1,
  34        NOT_STACK = 0,
  35        GOOD_FRAME,
  36        GOOD_STACK,
  37};
  38
  39#ifdef CONFIG_GENERIC_ENTRY
  40enum 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
  67static 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
  86static inline void set_ti_thread_flag(struct thread_info *ti, int flag)
  87{
  88        set_bit(flag, (unsigned long *)&ti->flags);
  89}
  90
  91static inline void clear_ti_thread_flag(struct thread_info *ti, int flag)
  92{
  93        clear_bit(flag, (unsigned long *)&ti->flags);
  94}
  95
  96static 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
 105static 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
 110static 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
 115static 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
 168static 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
 177extern void __check_object_size(const void *ptr, unsigned long n,
 178                                        bool to_user);
 179
 180static __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
 187static inline void check_object_size(const void *ptr, unsigned long n,
 188                                     bool to_user)
 189{ }
 190#endif /* CONFIG_HARDENED_USERCOPY */
 191
 192extern void __compiletime_error("copy source size is too small")
 193__bad_copy_from(void);
 194extern void __compiletime_error("copy destination size is too small")
 195__bad_copy_to(void);
 196
 197static inline void copy_overflow(int size, unsigned long count)
 198{
 199        WARN(1, "Buffer overflow detected (%d < %lu)!\n", size, count);
 200}
 201
 202static __always_inline __must_check bool
 203check_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
 222static inline void arch_setup_new_exec(void) { }
 223#endif
 224
 225#endif  /* __KERNEL__ */
 226
 227#endif /* _LINUX_THREAD_INFO_H */
 228