1 /* thread_info.h: low-level thread information 2 * 3 * Copyright (C) 2002 David Howells (dhowells@redhat.com) 4 * - Incorporating suggestions made by Linus Torvalds and Dave Miller 5 */ 6 7 #ifndef _ASM_X86_THREAD_INFO_H 8 #define _ASM_X86_THREAD_INFO_H 9 10 #include <linux/compiler.h> 11 #include <asm/page.h> 12 #include <asm/types.h> 13 14 /* 15 * low level task data that entry.S needs immediate access to 16 * - this struct should fit entirely inside of one cache line 17 * - this struct shares the supervisor stack pages 18 */ 19 #ifndef __ASSEMBLY__ 20 struct task_struct; 21 struct exec_domain; 22 #include <asm/processor.h> 23 #include <linux/atomic.h> 24 25 struct thread_info { 26 struct task_struct *task; /* main task structure */ 27 struct exec_domain *exec_domain; /* execution domain */ 28 __u32 flags; /* low level flags */ 29 __u32 status; /* thread synchronous flags */ 30 __u32 cpu; /* current CPU */ 31 int preempt_count; /* 0 => preemptable, 32 <0 => BUG */ 33 mm_segment_t addr_limit; 34 struct restart_block restart_block; 35 void __user *sysenter_return; 36 #ifdef CONFIG_X86_32 37 unsigned long previous_esp; /* ESP of the previous stack in 38 case of nested (IRQ) stacks 39 */ 40 __u8 supervisor_stack[0]; 41 #endif 42 unsigned int sig_on_uaccess_error:1; 43 unsigned int uaccess_err:1; /* uaccess failed */ 44 }; 45 46 #define INIT_THREAD_INFO(tsk) \ 47 { \ 48 .task = &tsk, \ 49 .exec_domain = &default_exec_domain, \ 50 .flags = 0, \ 51 .cpu = 0, \ 52 .preempt_count = INIT_PREEMPT_COUNT, \ 53 .addr_limit = KERNEL_DS, \ 54 .restart_block = { \ 55 .fn = do_no_restart_syscall, \ 56 }, \ 57 } 58 59 #define init_thread_info (init_thread_union.thread_info) 60 #define init_stack (init_thread_union.stack) 61 62 #else /* !__ASSEMBLY__ */ 63 64 #include <asm/asm-offsets.h> 65 66 #endif 67 68 /* 69 * thread information flags 70 * - these are process state flags that various assembly files 71 * may need to access 72 * - pending work-to-be-done flags are in LSW 73 * - other flags in MSW 74 * Warning: layout of LSW is hardcoded in entry.S 75 */ 76 #define TIF_SYSCALL_TRACE 0 /* syscall trace active */ 77 #define TIF_NOTIFY_RESUME 1 /* callback before returning to user */ 78 #define TIF_SIGPENDING 2 /* signal pending */ 79 #define TIF_NEED_RESCHED 3 /* rescheduling necessary */ 80 #define TIF_SINGLESTEP 4 /* reenable singlestep on user return*/ 81 #define TIF_SYSCALL_EMU 6 /* syscall emulation active */ 82 #define TIF_SYSCALL_AUDIT 7 /* syscall auditing active */ 83 #define TIF_SECCOMP 8 /* secure computing */ 84 #define TIF_MCE_NOTIFY 10 /* notify userspace of an MCE */ 85 #define TIF_USER_RETURN_NOTIFY 11 /* notify kernel of userspace return */ 86 #define TIF_UPROBE 12 /* breakpointed or singlestepping */ 87 #define TIF_NOTSC 16 /* TSC is not accessible in userland */ 88 #define TIF_IA32 17 /* IA32 compatibility process */ 89 #define TIF_FORK 18 /* ret_from_fork */ 90 #define TIF_NOHZ 19 /* in adaptive nohz mode */ 91 #define TIF_MEMDIE 20 /* is terminating due to OOM killer */ 92 #define TIF_DEBUG 21 /* uses debug registers */ 93 #define TIF_IO_BITMAP 22 /* uses I/O bitmap */ 94 #define TIF_FORCED_TF 24 /* true if TF in eflags artificially */ 95 #define TIF_BLOCKSTEP 25 /* set when we want DEBUGCTLMSR_BTF */ 96 #define TIF_LAZY_MMU_UPDATES 27 /* task is updating the mmu lazily */ 97 #define TIF_SYSCALL_TRACEPOINT 28 /* syscall tracepoint instrumentation */ 98 #define TIF_ADDR32 29 /* 32-bit address space on 64 bits */ 99 #define TIF_X32 30 /* 32-bit native x86-64 binary */ 100 101 #define _TIF_SYSCALL_TRACE (1 << TIF_SYSCALL_TRACE) 102 #define _TIF_NOTIFY_RESUME (1 << TIF_NOTIFY_RESUME) 103 #define _TIF_SIGPENDING (1 << TIF_SIGPENDING) 104 #define _TIF_SINGLESTEP (1 << TIF_SINGLESTEP) 105 #define _TIF_NEED_RESCHED (1 << TIF_NEED_RESCHED) 106 #define _TIF_SYSCALL_EMU (1 << TIF_SYSCALL_EMU) 107 #define _TIF_SYSCALL_AUDIT (1 << TIF_SYSCALL_AUDIT) 108 #define _TIF_SECCOMP (1 << TIF_SECCOMP) 109 #define _TIF_MCE_NOTIFY (1 << TIF_MCE_NOTIFY) 110 #define _TIF_USER_RETURN_NOTIFY (1 << TIF_USER_RETURN_NOTIFY) 111 #define _TIF_UPROBE (1 << TIF_UPROBE) 112 #define _TIF_NOTSC (1 << TIF_NOTSC) 113 #define _TIF_IA32 (1 << TIF_IA32) 114 #define _TIF_FORK (1 << TIF_FORK) 115 #define _TIF_NOHZ (1 << TIF_NOHZ) 116 #define _TIF_DEBUG (1 << TIF_DEBUG) 117 #define _TIF_IO_BITMAP (1 << TIF_IO_BITMAP) 118 #define _TIF_FORCED_TF (1 << TIF_FORCED_TF) 119 #define _TIF_BLOCKSTEP (1 << TIF_BLOCKSTEP) 120 #define _TIF_LAZY_MMU_UPDATES (1 << TIF_LAZY_MMU_UPDATES) 121 #define _TIF_SYSCALL_TRACEPOINT (1 << TIF_SYSCALL_TRACEPOINT) 122 #define _TIF_ADDR32 (1 << TIF_ADDR32) 123 #define _TIF_X32 (1 << TIF_X32) 124 125 /* work to do in syscall_trace_enter() */ 126 #define _TIF_WORK_SYSCALL_ENTRY \ 127 (_TIF_SYSCALL_TRACE | _TIF_SYSCALL_EMU | _TIF_SYSCALL_AUDIT | \ 128 _TIF_SECCOMP | _TIF_SINGLESTEP | _TIF_SYSCALL_TRACEPOINT | \ 129 _TIF_NOHZ) 130 131 /* work to do in syscall_trace_leave() */ 132 #define _TIF_WORK_SYSCALL_EXIT \ 133 (_TIF_SYSCALL_TRACE | _TIF_SYSCALL_AUDIT | _TIF_SINGLESTEP | \ 134 _TIF_SYSCALL_TRACEPOINT | _TIF_NOHZ) 135 136 /* work to do on interrupt/exception return */ 137 #define _TIF_WORK_MASK \ 138 (0x0000FFFF & \ 139 ~(_TIF_SYSCALL_TRACE|_TIF_SYSCALL_AUDIT| \ 140 _TIF_SINGLESTEP|_TIF_SECCOMP|_TIF_SYSCALL_EMU)) 141 142 /* work to do on any return to user space */ 143 #define _TIF_ALLWORK_MASK \ 144 ((0x0000FFFF & ~_TIF_SECCOMP) | _TIF_SYSCALL_TRACEPOINT | \ 145 _TIF_NOHZ) 146 147 /* Only used for 64 bit */ 148 #define _TIF_DO_NOTIFY_MASK \ 149 (_TIF_SIGPENDING | _TIF_MCE_NOTIFY | _TIF_NOTIFY_RESUME | \ 150 _TIF_USER_RETURN_NOTIFY) 151 152 /* flags to check in __switch_to() */ 153 #define _TIF_WORK_CTXSW \ 154 (_TIF_IO_BITMAP|_TIF_NOTSC|_TIF_BLOCKSTEP) 155 156 #define _TIF_WORK_CTXSW_PREV (_TIF_WORK_CTXSW|_TIF_USER_RETURN_NOTIFY) 157 #define _TIF_WORK_CTXSW_NEXT (_TIF_WORK_CTXSW|_TIF_DEBUG) 158 159 #define PREEMPT_ACTIVE 0x10000000 160 161 #ifdef CONFIG_X86_32 162 163 #define STACK_WARN (THREAD_SIZE/8) 164 /* 165 * macros/functions for gaining access to the thread information structure 166 * 167 * preempt_count needs to be 1 initially, until the scheduler is functional. 168 */ 169 #ifndef __ASSEMBLY__ 170 171 172 /* how to get the current stack pointer from C */ 173 register unsigned long current_stack_pointer asm("esp") __used; 174 175 /* how to get the thread information struct from C */ 176 static inline struct thread_info *current_thread_info(void) 177 { 178 return (struct thread_info *) 179 (current_stack_pointer & ~(THREAD_SIZE - 1)); 180 } 181 182 #else /* !__ASSEMBLY__ */ 183 184 /* how to get the thread information struct from ASM */ 185 #define GET_THREAD_INFO(reg) \ 186 movl $-THREAD_SIZE, reg; \ 187 andl %esp, reg 188 189 /* use this one if reg already contains %esp */ 190 #define GET_THREAD_INFO_WITH_ESP(reg) \ 191 andl $-THREAD_SIZE, reg 192 193 #endif 194 195 #else /* X86_32 */ 196 197 #include <asm/percpu.h> 198 #define KERNEL_STACK_OFFSET (5*8) 199 200 /* 201 * macros/functions for gaining access to the thread information structure 202 * preempt_count needs to be 1 initially, until the scheduler is functional. 203 */ 204 #ifndef __ASSEMBLY__ 205 DECLARE_PER_CPU(unsigned long, kernel_stack); 206 207 static inline struct thread_info *current_thread_info(void) 208 { 209 struct thread_info *ti; 210 ti = (void *)(this_cpu_read_stable(kernel_stack) + 211 KERNEL_STACK_OFFSET - THREAD_SIZE); 212 return ti; 213 } 214 215 #else /* !__ASSEMBLY__ */ 216 217 /* how to get the thread information struct from ASM */ 218 #define GET_THREAD_INFO(reg) \ 219 movq PER_CPU_VAR(kernel_stack),reg ; \ 220 subq $(THREAD_SIZE-KERNEL_STACK_OFFSET),reg 221 222 /* 223 * Same if PER_CPU_VAR(kernel_stack) is, perhaps with some offset, already in 224 * a certain register (to be used in assembler memory operands). 225 */ 226 #define THREAD_INFO(reg, off) KERNEL_STACK_OFFSET+(off)-THREAD_SIZE(reg) 227 228 #endif 229 230 #endif /* !X86_32 */ 231 232 /* 233 * Thread-synchronous status. 234 * 235 * This is different from the flags in that nobody else 236 * ever touches our thread-synchronous status, so we don't 237 * have to worry about atomic accesses. 238 */ 239 #define TS_COMPAT 0x0002 /* 32bit syscall active (64BIT)*/ 240 #define TS_POLLING 0x0004 /* idle task polling need_resched, 241 skip sending interrupt */ 242 #define TS_RESTORE_SIGMASK 0x0008 /* restore signal mask in do_signal() */ 243 244 #define tsk_is_polling(t) (task_thread_info(t)->status & TS_POLLING) 245 246 #ifndef __ASSEMBLY__ 247 #define HAVE_SET_RESTORE_SIGMASK 1 248 static inline void set_restore_sigmask(void) 249 { 250 struct thread_info *ti = current_thread_info(); 251 ti->status |= TS_RESTORE_SIGMASK; 252 WARN_ON(!test_bit(TIF_SIGPENDING, (unsigned long *)&ti->flags)); 253 } 254 static inline void clear_restore_sigmask(void) 255 { 256 current_thread_info()->status &= ~TS_RESTORE_SIGMASK; 257 } 258 static inline bool test_restore_sigmask(void) 259 { 260 return current_thread_info()->status & TS_RESTORE_SIGMASK; 261 } 262 static inline bool test_and_clear_restore_sigmask(void) 263 { 264 struct thread_info *ti = current_thread_info(); 265 if (!(ti->status & TS_RESTORE_SIGMASK)) 266 return false; 267 ti->status &= ~TS_RESTORE_SIGMASK; 268 return true; 269 } 270 271 static inline bool is_ia32_task(void) 272 { 273 #ifdef CONFIG_X86_32 274 return true; 275 #endif 276 #ifdef CONFIG_IA32_EMULATION 277 if (current_thread_info()->status & TS_COMPAT) 278 return true; 279 #endif 280 return false; 281 } 282 #endif /* !__ASSEMBLY__ */ 283 284 #ifndef __ASSEMBLY__ 285 extern void arch_task_cache_init(void); 286 extern int arch_dup_task_struct(struct task_struct *dst, struct task_struct *src); 287 extern void arch_release_task_struct(struct task_struct *tsk); 288 #endif 289 #endif /* _ASM_X86_THREAD_INFO_H */ 290