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_NOTSC 16 /* TSC is not accessible in userland */ 89 #define TIF_IA32 17 /* IA32 compatibility process */ 90 #define TIF_FORK 18 /* ret_from_fork */ 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_IRET (1 << TIF_IRET) 107 #define _TIF_SYSCALL_EMU (1 << TIF_SYSCALL_EMU) 108 #define _TIF_SYSCALL_AUDIT (1 << TIF_SYSCALL_AUDIT) 109 #define _TIF_SECCOMP (1 << TIF_SECCOMP) 110 #define _TIF_MCE_NOTIFY (1 << TIF_MCE_NOTIFY) 111 #define _TIF_USER_RETURN_NOTIFY (1 << TIF_USER_RETURN_NOTIFY) 112 #define _TIF_NOTSC (1 << TIF_NOTSC) 113 #define _TIF_IA32 (1 << TIF_IA32) 114 #define _TIF_FORK (1 << TIF_FORK) 115 #define _TIF_DEBUG (1 << TIF_DEBUG) 116 #define _TIF_IO_BITMAP (1 << TIF_IO_BITMAP) 117 #define _TIF_FORCED_TF (1 << TIF_FORCED_TF) 118 #define _TIF_BLOCKSTEP (1 << TIF_BLOCKSTEP) 119 #define _TIF_LAZY_MMU_UPDATES (1 << TIF_LAZY_MMU_UPDATES) 120 #define _TIF_SYSCALL_TRACEPOINT (1 << TIF_SYSCALL_TRACEPOINT) 121 #define _TIF_ADDR32 (1 << TIF_ADDR32) 122 #define _TIF_X32 (1 << TIF_X32) 123 124 /* work to do in syscall_trace_enter() */ 125 #define _TIF_WORK_SYSCALL_ENTRY \ 126 (_TIF_SYSCALL_TRACE | _TIF_SYSCALL_EMU | _TIF_SYSCALL_AUDIT | \ 127 _TIF_SECCOMP | _TIF_SINGLESTEP | _TIF_SYSCALL_TRACEPOINT) 128 129 /* work to do in syscall_trace_leave() */ 130 #define _TIF_WORK_SYSCALL_EXIT \ 131 (_TIF_SYSCALL_TRACE | _TIF_SYSCALL_AUDIT | _TIF_SINGLESTEP | \ 132 _TIF_SYSCALL_TRACEPOINT) 133 134 /* work to do on interrupt/exception return */ 135 #define _TIF_WORK_MASK \ 136 (0x0000FFFF & \ 137 ~(_TIF_SYSCALL_TRACE|_TIF_SYSCALL_AUDIT| \ 138 _TIF_SINGLESTEP|_TIF_SECCOMP|_TIF_SYSCALL_EMU)) 139 140 /* work to do on any return to user space */ 141 #define _TIF_ALLWORK_MASK \ 142 ((0x0000FFFF & ~_TIF_SECCOMP) | _TIF_SYSCALL_TRACEPOINT) 143 144 /* Only used for 64 bit */ 145 #define _TIF_DO_NOTIFY_MASK \ 146 (_TIF_SIGPENDING | _TIF_MCE_NOTIFY | _TIF_NOTIFY_RESUME | \ 147 _TIF_USER_RETURN_NOTIFY) 148 149 /* flags to check in __switch_to() */ 150 #define _TIF_WORK_CTXSW \ 151 (_TIF_IO_BITMAP|_TIF_NOTSC|_TIF_BLOCKSTEP) 152 153 #define _TIF_WORK_CTXSW_PREV (_TIF_WORK_CTXSW|_TIF_USER_RETURN_NOTIFY) 154 #define _TIF_WORK_CTXSW_NEXT (_TIF_WORK_CTXSW|_TIF_DEBUG) 155 156 #define PREEMPT_ACTIVE 0x10000000 157 158 #ifdef CONFIG_X86_32 159 160 #define STACK_WARN (THREAD_SIZE/8) 161 /* 162 * macros/functions for gaining access to the thread information structure 163 * 164 * preempt_count needs to be 1 initially, until the scheduler is functional. 165 */ 166 #ifndef __ASSEMBLY__ 167 168 169 /* how to get the current stack pointer from C */ 170 register unsigned long current_stack_pointer asm("esp") __used; 171 172 /* how to get the thread information struct from C */ 173 static inline struct thread_info *current_thread_info(void) 174 { 175 return (struct thread_info *) 176 (current_stack_pointer & ~(THREAD_SIZE - 1)); 177 } 178 179 #else /* !__ASSEMBLY__ */ 180 181 /* how to get the thread information struct from ASM */ 182 #define GET_THREAD_INFO(reg) \ 183 movl $-THREAD_SIZE, reg; \ 184 andl %esp, reg 185 186 /* use this one if reg already contains %esp */ 187 #define GET_THREAD_INFO_WITH_ESP(reg) \ 188 andl $-THREAD_SIZE, reg 189 190 #endif 191 192 #else /* X86_32 */ 193 194 #include <asm/percpu.h> 195 #define KERNEL_STACK_OFFSET (5*8) 196 197 /* 198 * macros/functions for gaining access to the thread information structure 199 * preempt_count needs to be 1 initially, until the scheduler is functional. 200 */ 201 #ifndef __ASSEMBLY__ 202 DECLARE_PER_CPU(unsigned long, kernel_stack); 203 204 static inline struct thread_info *current_thread_info(void) 205 { 206 struct thread_info *ti; 207 ti = (void *)(this_cpu_read_stable(kernel_stack) + 208 KERNEL_STACK_OFFSET - THREAD_SIZE); 209 return ti; 210 } 211 212 #else /* !__ASSEMBLY__ */ 213 214 /* how to get the thread information struct from ASM */ 215 #define GET_THREAD_INFO(reg) \ 216 movq PER_CPU_VAR(kernel_stack),reg ; \ 217 subq $(THREAD_SIZE-KERNEL_STACK_OFFSET),reg 218 219 /* 220 * Same if PER_CPU_VAR(kernel_stack) is, perhaps with some offset, already in 221 * a certain register (to be used in assembler memory operands). 222 */ 223 #define THREAD_INFO(reg, off) KERNEL_STACK_OFFSET+(off)-THREAD_SIZE(reg) 224 225 #endif 226 227 #endif /* !X86_32 */ 228 229 /* 230 * Thread-synchronous status. 231 * 232 * This is different from the flags in that nobody else 233 * ever touches our thread-synchronous status, so we don't 234 * have to worry about atomic accesses. 235 */ 236 #define TS_COMPAT 0x0002 /* 32bit syscall active (64BIT)*/ 237 #define TS_POLLING 0x0004 /* idle task polling need_resched, 238 skip sending interrupt */ 239 #define TS_RESTORE_SIGMASK 0x0008 /* restore signal mask in do_signal() */ 240 241 #define tsk_is_polling(t) (task_thread_info(t)->status & TS_POLLING) 242 243 #ifndef __ASSEMBLY__ 244 #define HAVE_SET_RESTORE_SIGMASK 1 245 static inline void set_restore_sigmask(void) 246 { 247 struct thread_info *ti = current_thread_info(); 248 ti->status |= TS_RESTORE_SIGMASK; 249 set_bit(TIF_SIGPENDING, (unsigned long *)&ti->flags); 250 } 251 252 static inline bool is_ia32_task(void) 253 { 254 #ifdef CONFIG_X86_32 255 return true; 256 #endif 257 #ifdef CONFIG_IA32_EMULATION 258 if (current_thread_info()->status & TS_COMPAT) 259 return true; 260 #endif 261 return false; 262 } 263 #endif /* !__ASSEMBLY__ */ 264 265 #ifndef __ASSEMBLY__ 266 extern void arch_task_cache_init(void); 267 extern int arch_dup_task_struct(struct task_struct *dst, struct task_struct *src); 268 extern void arch_release_task_struct(struct task_struct *tsk); 269 #endif 270 #endif /* _ASM_X86_THREAD_INFO_H */ 271