thread_info.h (7105B)
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/limits.h> 13#include <linux/bug.h> 14#include <linux/restart_block.h> 15#include <linux/errno.h> 16 17#ifdef CONFIG_THREAD_INFO_IN_TASK 18/* 19 * For CONFIG_THREAD_INFO_IN_TASK kernels we need <asm/current.h> for the 20 * definition of current, but for !CONFIG_THREAD_INFO_IN_TASK kernels, 21 * including <asm/current.h> can cause a circular dependency on some platforms. 22 */ 23#include <asm/current.h> 24#define current_thread_info() ((struct thread_info *)current) 25#endif 26 27#include <linux/bitops.h> 28 29/* 30 * For per-arch arch_within_stack_frames() implementations, defined in 31 * asm/thread_info.h. 32 */ 33enum { 34 BAD_STACK = -1, 35 NOT_STACK = 0, 36 GOOD_FRAME, 37 GOOD_STACK, 38}; 39 40#ifdef CONFIG_GENERIC_ENTRY 41enum syscall_work_bit { 42 SYSCALL_WORK_BIT_SECCOMP, 43 SYSCALL_WORK_BIT_SYSCALL_TRACEPOINT, 44 SYSCALL_WORK_BIT_SYSCALL_TRACE, 45 SYSCALL_WORK_BIT_SYSCALL_EMU, 46 SYSCALL_WORK_BIT_SYSCALL_AUDIT, 47 SYSCALL_WORK_BIT_SYSCALL_USER_DISPATCH, 48 SYSCALL_WORK_BIT_SYSCALL_EXIT_TRAP, 49}; 50 51#define SYSCALL_WORK_SECCOMP BIT(SYSCALL_WORK_BIT_SECCOMP) 52#define SYSCALL_WORK_SYSCALL_TRACEPOINT BIT(SYSCALL_WORK_BIT_SYSCALL_TRACEPOINT) 53#define SYSCALL_WORK_SYSCALL_TRACE BIT(SYSCALL_WORK_BIT_SYSCALL_TRACE) 54#define SYSCALL_WORK_SYSCALL_EMU BIT(SYSCALL_WORK_BIT_SYSCALL_EMU) 55#define SYSCALL_WORK_SYSCALL_AUDIT BIT(SYSCALL_WORK_BIT_SYSCALL_AUDIT) 56#define SYSCALL_WORK_SYSCALL_USER_DISPATCH BIT(SYSCALL_WORK_BIT_SYSCALL_USER_DISPATCH) 57#define SYSCALL_WORK_SYSCALL_EXIT_TRAP BIT(SYSCALL_WORK_BIT_SYSCALL_EXIT_TRAP) 58#endif 59 60#include <asm/thread_info.h> 61 62#ifdef __KERNEL__ 63 64#ifndef arch_set_restart_data 65#define arch_set_restart_data(restart) do { } while (0) 66#endif 67 68static inline long set_restart_fn(struct restart_block *restart, 69 long (*fn)(struct restart_block *)) 70{ 71 restart->fn = fn; 72 arch_set_restart_data(restart); 73 return -ERESTART_RESTARTBLOCK; 74} 75 76#ifndef THREAD_ALIGN 77#define THREAD_ALIGN THREAD_SIZE 78#endif 79 80#define THREADINFO_GFP (GFP_KERNEL_ACCOUNT | __GFP_ZERO) 81 82/* 83 * flag set/clear/test wrappers 84 * - pass TIF_xxxx constants to these functions 85 */ 86 87static inline void set_ti_thread_flag(struct thread_info *ti, int flag) 88{ 89 set_bit(flag, (unsigned long *)&ti->flags); 90} 91 92static inline void clear_ti_thread_flag(struct thread_info *ti, int flag) 93{ 94 clear_bit(flag, (unsigned long *)&ti->flags); 95} 96 97static inline void update_ti_thread_flag(struct thread_info *ti, int flag, 98 bool value) 99{ 100 if (value) 101 set_ti_thread_flag(ti, flag); 102 else 103 clear_ti_thread_flag(ti, flag); 104} 105 106static inline int test_and_set_ti_thread_flag(struct thread_info *ti, int flag) 107{ 108 return test_and_set_bit(flag, (unsigned long *)&ti->flags); 109} 110 111static inline int test_and_clear_ti_thread_flag(struct thread_info *ti, int flag) 112{ 113 return test_and_clear_bit(flag, (unsigned long *)&ti->flags); 114} 115 116static inline int test_ti_thread_flag(struct thread_info *ti, int flag) 117{ 118 return test_bit(flag, (unsigned long *)&ti->flags); 119} 120 121/* 122 * This may be used in noinstr code, and needs to be __always_inline to prevent 123 * inadvertent instrumentation. 124 */ 125static __always_inline unsigned long read_ti_thread_flags(struct thread_info *ti) 126{ 127 return READ_ONCE(ti->flags); 128} 129 130#define set_thread_flag(flag) \ 131 set_ti_thread_flag(current_thread_info(), flag) 132#define clear_thread_flag(flag) \ 133 clear_ti_thread_flag(current_thread_info(), flag) 134#define update_thread_flag(flag, value) \ 135 update_ti_thread_flag(current_thread_info(), flag, value) 136#define test_and_set_thread_flag(flag) \ 137 test_and_set_ti_thread_flag(current_thread_info(), flag) 138#define test_and_clear_thread_flag(flag) \ 139 test_and_clear_ti_thread_flag(current_thread_info(), flag) 140#define test_thread_flag(flag) \ 141 test_ti_thread_flag(current_thread_info(), flag) 142#define read_thread_flags() \ 143 read_ti_thread_flags(current_thread_info()) 144 145#define read_task_thread_flags(t) \ 146 read_ti_thread_flags(task_thread_info(t)) 147 148#ifdef CONFIG_GENERIC_ENTRY 149#define set_syscall_work(fl) \ 150 set_bit(SYSCALL_WORK_BIT_##fl, ¤t_thread_info()->syscall_work) 151#define test_syscall_work(fl) \ 152 test_bit(SYSCALL_WORK_BIT_##fl, ¤t_thread_info()->syscall_work) 153#define clear_syscall_work(fl) \ 154 clear_bit(SYSCALL_WORK_BIT_##fl, ¤t_thread_info()->syscall_work) 155 156#define set_task_syscall_work(t, fl) \ 157 set_bit(SYSCALL_WORK_BIT_##fl, &task_thread_info(t)->syscall_work) 158#define test_task_syscall_work(t, fl) \ 159 test_bit(SYSCALL_WORK_BIT_##fl, &task_thread_info(t)->syscall_work) 160#define clear_task_syscall_work(t, fl) \ 161 clear_bit(SYSCALL_WORK_BIT_##fl, &task_thread_info(t)->syscall_work) 162 163#else /* CONFIG_GENERIC_ENTRY */ 164 165#define set_syscall_work(fl) \ 166 set_ti_thread_flag(current_thread_info(), TIF_##fl) 167#define test_syscall_work(fl) \ 168 test_ti_thread_flag(current_thread_info(), TIF_##fl) 169#define clear_syscall_work(fl) \ 170 clear_ti_thread_flag(current_thread_info(), TIF_##fl) 171 172#define set_task_syscall_work(t, fl) \ 173 set_ti_thread_flag(task_thread_info(t), TIF_##fl) 174#define test_task_syscall_work(t, fl) \ 175 test_ti_thread_flag(task_thread_info(t), TIF_##fl) 176#define clear_task_syscall_work(t, fl) \ 177 clear_ti_thread_flag(task_thread_info(t), TIF_##fl) 178#endif /* !CONFIG_GENERIC_ENTRY */ 179 180#define tif_need_resched() test_thread_flag(TIF_NEED_RESCHED) 181 182#ifndef CONFIG_HAVE_ARCH_WITHIN_STACK_FRAMES 183static inline int arch_within_stack_frames(const void * const stack, 184 const void * const stackend, 185 const void *obj, unsigned long len) 186{ 187 return 0; 188} 189#endif 190 191#ifdef CONFIG_HARDENED_USERCOPY 192extern void __check_object_size(const void *ptr, unsigned long n, 193 bool to_user); 194 195static __always_inline void check_object_size(const void *ptr, unsigned long n, 196 bool to_user) 197{ 198 if (!__builtin_constant_p(n)) 199 __check_object_size(ptr, n, to_user); 200} 201#else 202static inline void check_object_size(const void *ptr, unsigned long n, 203 bool to_user) 204{ } 205#endif /* CONFIG_HARDENED_USERCOPY */ 206 207extern void __compiletime_error("copy source size is too small") 208__bad_copy_from(void); 209extern void __compiletime_error("copy destination size is too small") 210__bad_copy_to(void); 211 212void __copy_overflow(int size, unsigned long count); 213 214static inline void copy_overflow(int size, unsigned long count) 215{ 216 if (IS_ENABLED(CONFIG_BUG)) 217 __copy_overflow(size, count); 218} 219 220static __always_inline __must_check bool 221check_copy_size(const void *addr, size_t bytes, bool is_source) 222{ 223 int sz = __builtin_object_size(addr, 0); 224 if (unlikely(sz >= 0 && sz < bytes)) { 225 if (!__builtin_constant_p(bytes)) 226 copy_overflow(sz, bytes); 227 else if (is_source) 228 __bad_copy_from(); 229 else 230 __bad_copy_to(); 231 return false; 232 } 233 if (WARN_ON_ONCE(bytes > INT_MAX)) 234 return false; 235 check_object_size(addr, bytes, is_source); 236 return true; 237} 238 239#ifndef arch_setup_new_exec 240static inline void arch_setup_new_exec(void) { } 241#endif 242 243#endif /* __KERNEL__ */ 244 245#endif /* _LINUX_THREAD_INFO_H */