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_IO_BITMAP 22 /* uses I/O bitmap */ 93 #define TIF_FORCED_TF 24 /* true if TF in eflags artificially */ 94 #define TIF_BLOCKSTEP 25 /* set when we want DEBUGCTLMSR_BTF */ 95 #define TIF_LAZY_MMU_UPDATES 27 /* task is updating the mmu lazily */ 96 #define TIF_SYSCALL_TRACEPOINT 28 /* syscall tracepoint instrumentation */ 97 #define TIF_ADDR32 29 /* 32-bit address space on 64 bits */ 98 #define TIF_X32 30 /* 32-bit native x86-64 binary */ 99 100 #define _TIF_SYSCALL_TRACE (1 << TIF_SYSCALL_TRACE) 101 #define _TIF_NOTIFY_RESUME (1 << TIF_NOTIFY_RESUME) 102 #define _TIF_SIGPENDING (1 << TIF_SIGPENDING) 103 #define _TIF_SINGLESTEP (1 << TIF_SINGLESTEP) 104 #define _TIF_NEED_RESCHED (1 << TIF_NEED_RESCHED) 105 #define _TIF_SYSCALL_EMU (1 << TIF_SYSCALL_EMU) 106 #define _TIF_SYSCALL_AUDIT (1 << TIF_SYSCALL_AUDIT) 107 #define _TIF_SECCOMP (1 << TIF_SECCOMP) 108 #define _TIF_MCE_NOTIFY (1 << TIF_MCE_NOTIFY) 109 #define _TIF_USER_RETURN_NOTIFY (1 << TIF_USER_RETURN_NOTIFY) 110 #define _TIF_UPROBE (1 << TIF_UPROBE) 111 #define _TIF_NOTSC (1 << TIF_NOTSC) 112 #define _TIF_IA32 (1 << TIF_IA32) 113 #define _TIF_FORK (1 << TIF_FORK) 114 #define _TIF_NOHZ (1 << TIF_NOHZ) 115 #define _TIF_IO_BITMAP (1 << TIF_IO_BITMAP) 116 #define _TIF_FORCED_TF (1 << TIF_FORCED_TF) 117 #define _TIF_BLOCKSTEP (1 << TIF_BLOCKSTEP) 118 #define _TIF_LAZY_MMU_UPDATES (1 << TIF_LAZY_MMU_UPDATES) 119 #define _TIF_SYSCALL_TRACEPOINT (1 << TIF_SYSCALL_TRACEPOINT) 120 #define _TIF_ADDR32 (1 << TIF_ADDR32) 121 #define _TIF_X32 (1 << TIF_X32) 122 123 /* work to do in syscall_trace_enter() */ 124 #define _TIF_WORK_SYSCALL_ENTRY \ 125 (_TIF_SYSCALL_TRACE | _TIF_SYSCALL_EMU | _TIF_SYSCALL_AUDIT | \ 126 _TIF_SECCOMP | _TIF_SINGLESTEP | _TIF_SYSCALL_TRACEPOINT | \ 127 _TIF_NOHZ) 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 | _TIF_NOHZ) 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 _TIF_NOHZ) 144 145 /* Only used for 64 bit */ 146 #define _TIF_DO_NOTIFY_MASK \ 147 (_TIF_SIGPENDING | _TIF_MCE_NOTIFY | _TIF_NOTIFY_RESUME | \ 148 _TIF_USER_RETURN_NOTIFY) 149 150 /* flags to check in __switch_to() */ 151 #define _TIF_WORK_CTXSW \ 152 (_TIF_IO_BITMAP|_TIF_NOTSC|_TIF_BLOCKSTEP) 153 154 #define _TIF_WORK_CTXSW_PREV (_TIF_WORK_CTXSW|_TIF_USER_RETURN_NOTIFY) 155 #define _TIF_WORK_CTXSW_NEXT (_TIF_WORK_CTXSW) 156 157 #define PREEMPT_ACTIVE 0x10000000 158 159 #ifdef CONFIG_X86_32 160 161 #define STACK_WARN (THREAD_SIZE/8) 162 /* 163 * macros/functions for gaining access to the thread information structure 164 * 165 * preempt_count needs to be 1 initially, until the scheduler is functional. 166 */ 167 #ifndef __ASSEMBLY__ 168 169 170 /* how to get the current stack pointer from C */ 171 register unsigned long current_stack_pointer asm("esp") __used; 172 173 /* how to get the thread information struct from C */ 174 static inline struct thread_info *current_thread_info(void) 175 { 176 return (struct thread_info *) 177 (current_stack_pointer & ~(THREAD_SIZE - 1)); 178 } 179 180 #else /* !__ASSEMBLY__ */ 181 182 /* how to get the thread information struct from ASM */ 183 #define GET_THREAD_INFO(reg) \ 184 movl $-THREAD_SIZE, reg; \ 185 andl %esp, reg 186 187 /* use this one if reg already contains %esp */ 188 #define GET_THREAD_INFO_WITH_ESP(reg) \ 189 andl $-THREAD_SIZE, reg 190 191 #endif 192 193 #else /* X86_32 */ 194 195 #include <asm/percpu.h> 196 #define KERNEL_STACK_OFFSET (5*8) 197 198 /* 199 * macros/functions for gaining access to the thread information structure 200 * preempt_count needs to be 1 initially, until the scheduler is functional. 201 */ 202 #ifndef __ASSEMBLY__ 203 DECLARE_PER_CPU(unsigned long, kernel_stack); 204 205 static inline struct thread_info *current_thread_info(void) 206 { 207 struct thread_info *ti; 208 ti = (void *)(this_cpu_read_stable(kernel_stack) + 209 KERNEL_STACK_OFFSET - THREAD_SIZE); 210 return ti; 211 } 212 213 #else /* !__ASSEMBLY__ */ 214 215 /* how to get the thread information struct from ASM */ 216 #define GET_THREAD_INFO(reg) \ 217 movq PER_CPU_VAR(kernel_stack),reg ; \ 218 subq $(THREAD_SIZE-KERNEL_STACK_OFFSET),reg 219 220 /* 221 * Same if PER_CPU_VAR(kernel_stack) is, perhaps with some offset, already in 222 * a certain register (to be used in assembler memory operands). 223 */ 224 #define THREAD_INFO(reg, off) KERNEL_STACK_OFFSET+(off)-THREAD_SIZE(reg) 225 226 #endif 227 228 #endif /* !X86_32 */ 229 230 /* 231 * Thread-synchronous status. 232 * 233 * This is different from the flags in that nobody else 234 * ever touches our thread-synchronous status, so we don't 235 * have to worry about atomic accesses. 236 */ 237 #define TS_COMPAT 0x0002 /* 32bit syscall active (64BIT)*/ 238 #define TS_POLLING 0x0004 /* idle task polling need_resched, 239 skip sending interrupt */ 240 #define TS_RESTORE_SIGMASK 0x0008 /* restore signal mask in do_signal() */ 241 242 #ifndef __ASSEMBLY__ 243 #define HAVE_SET_RESTORE_SIGMASK 1 244 static inline void set_restore_sigmask(void) 245 { 246 struct thread_info *ti = current_thread_info(); 247 ti->status |= TS_RESTORE_SIGMASK; 248 WARN_ON(!test_bit(TIF_SIGPENDING, (unsigned long *)&ti->flags)); 249 } 250 static inline void clear_restore_sigmask(void) 251 { 252 current_thread_info()->status &= ~TS_RESTORE_SIGMASK; 253 } 254 static inline bool test_restore_sigmask(void) 255 { 256 return current_thread_info()->status & TS_RESTORE_SIGMASK; 257 } 258 static inline bool test_and_clear_restore_sigmask(void) 259 { 260 struct thread_info *ti = current_thread_info(); 261 if (!(ti->status & TS_RESTORE_SIGMASK)) 262 return false; 263 ti->status &= ~TS_RESTORE_SIGMASK; 264 return true; 265 } 266 267 static inline bool is_ia32_task(void) 268 { 269 #ifdef CONFIG_X86_32 270 return true; 271 #endif 272 #ifdef CONFIG_IA32_EMULATION 273 if (current_thread_info()->status & TS_COMPAT) 274 return true; 275 #endif 276 return false; 277 } 278 #endif /* !__ASSEMBLY__ */ 279 280 #ifndef __ASSEMBLY__ 281 extern void arch_task_cache_init(void); 282 extern int arch_dup_task_struct(struct task_struct *dst, struct task_struct *src); 283 extern void arch_release_task_struct(struct task_struct *tsk); 284 #endif 285 #endif /* _ASM_X86_THREAD_INFO_H */ 286