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