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 /* 32bit 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 99 #define _TIF_SYSCALL_TRACE (1 << TIF_SYSCALL_TRACE) 100 #define _TIF_NOTIFY_RESUME (1 << TIF_NOTIFY_RESUME) 101 #define _TIF_SIGPENDING (1 << TIF_SIGPENDING) 102 #define _TIF_SINGLESTEP (1 << TIF_SINGLESTEP) 103 #define _TIF_NEED_RESCHED (1 << TIF_NEED_RESCHED) 104 #define _TIF_IRET (1 << TIF_IRET) 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_NOTSC (1 << TIF_NOTSC) 111 #define _TIF_IA32 (1 << TIF_IA32) 112 #define _TIF_FORK (1 << TIF_FORK) 113 #define _TIF_DEBUG (1 << TIF_DEBUG) 114 #define _TIF_IO_BITMAP (1 << TIF_IO_BITMAP) 115 #define _TIF_FORCED_TF (1 << TIF_FORCED_TF) 116 #define _TIF_BLOCKSTEP (1 << TIF_BLOCKSTEP) 117 #define _TIF_LAZY_MMU_UPDATES (1 << TIF_LAZY_MMU_UPDATES) 118 #define _TIF_SYSCALL_TRACEPOINT (1 << TIF_SYSCALL_TRACEPOINT) 119 120 /* work to do in syscall_trace_enter() */ 121 #define _TIF_WORK_SYSCALL_ENTRY \ 122 (_TIF_SYSCALL_TRACE | _TIF_SYSCALL_EMU | _TIF_SYSCALL_AUDIT | \ 123 _TIF_SECCOMP | _TIF_SINGLESTEP | _TIF_SYSCALL_TRACEPOINT) 124 125 /* work to do in syscall_trace_leave() */ 126 #define _TIF_WORK_SYSCALL_EXIT \ 127 (_TIF_SYSCALL_TRACE | _TIF_SYSCALL_AUDIT | _TIF_SINGLESTEP | \ 128 _TIF_SYSCALL_TRACEPOINT) 129 130 /* work to do on interrupt/exception return */ 131 #define _TIF_WORK_MASK \ 132 (0x0000FFFF & \ 133 ~(_TIF_SYSCALL_TRACE|_TIF_SYSCALL_AUDIT| \ 134 _TIF_SINGLESTEP|_TIF_SECCOMP|_TIF_SYSCALL_EMU)) 135 136 /* work to do on any return to user space */ 137 #define _TIF_ALLWORK_MASK \ 138 ((0x0000FFFF & ~_TIF_SECCOMP) | _TIF_SYSCALL_TRACEPOINT) 139 140 /* Only used for 64 bit */ 141 #define _TIF_DO_NOTIFY_MASK \ 142 (_TIF_SIGPENDING | _TIF_MCE_NOTIFY | _TIF_NOTIFY_RESUME | \ 143 _TIF_USER_RETURN_NOTIFY) 144 145 /* flags to check in __switch_to() */ 146 #define _TIF_WORK_CTXSW \ 147 (_TIF_IO_BITMAP|_TIF_NOTSC|_TIF_BLOCKSTEP) 148 149 #define _TIF_WORK_CTXSW_PREV (_TIF_WORK_CTXSW|_TIF_USER_RETURN_NOTIFY) 150 #define _TIF_WORK_CTXSW_NEXT (_TIF_WORK_CTXSW|_TIF_DEBUG) 151 152 #define PREEMPT_ACTIVE 0x10000000 153 154 /* thread information allocation */ 155 #ifdef CONFIG_DEBUG_STACK_USAGE 156 #define THREAD_FLAGS (GFP_KERNEL | __GFP_NOTRACK | __GFP_ZERO) 157 #else 158 #define THREAD_FLAGS (GFP_KERNEL | __GFP_NOTRACK) 159 #endif 160 161 #define __HAVE_ARCH_THREAD_INFO_ALLOCATOR 162 163 #define alloc_thread_info_node(tsk, node) \ 164 ({ \ 165 struct page *page = alloc_pages_node(node, THREAD_FLAGS, \ 166 THREAD_ORDER); \ 167 struct thread_info *ret = page ? page_address(page) : NULL; \ 168 \ 169 ret; \ 170 }) 171 172 #ifdef CONFIG_X86_32 173 174 #define STACK_WARN (THREAD_SIZE/8) 175 /* 176 * macros/functions for gaining access to the thread information structure 177 * 178 * preempt_count needs to be 1 initially, until the scheduler is functional. 179 */ 180 #ifndef __ASSEMBLY__ 181 182 183 /* how to get the current stack pointer from C */ 184 register unsigned long current_stack_pointer asm("esp") __used; 185 186 /* how to get the thread information struct from C */ 187 static inline struct thread_info *current_thread_info(void) 188 { 189 return (struct thread_info *) 190 (current_stack_pointer & ~(THREAD_SIZE - 1)); 191 } 192 193 #else /* !__ASSEMBLY__ */ 194 195 /* how to get the thread information struct from ASM */ 196 #define GET_THREAD_INFO(reg) \ 197 movl $-THREAD_SIZE, reg; \ 198 andl %esp, reg 199 200 /* use this one if reg already contains %esp */ 201 #define GET_THREAD_INFO_WITH_ESP(reg) \ 202 andl $-THREAD_SIZE, reg 203 204 #endif 205 206 #else /* X86_32 */ 207 208 #include <asm/percpu.h> 209 #define KERNEL_STACK_OFFSET (5*8) 210 211 /* 212 * macros/functions for gaining access to the thread information structure 213 * preempt_count needs to be 1 initially, until the scheduler is functional. 214 */ 215 #ifndef __ASSEMBLY__ 216 DECLARE_PER_CPU(unsigned long, kernel_stack); 217 218 static inline struct thread_info *current_thread_info(void) 219 { 220 struct thread_info *ti; 221 ti = (void *)(percpu_read_stable(kernel_stack) + 222 KERNEL_STACK_OFFSET - THREAD_SIZE); 223 return ti; 224 } 225 226 #else /* !__ASSEMBLY__ */ 227 228 /* how to get the thread information struct from ASM */ 229 #define GET_THREAD_INFO(reg) \ 230 movq PER_CPU_VAR(kernel_stack),reg ; \ 231 subq $(THREAD_SIZE-KERNEL_STACK_OFFSET),reg 232 233 /* 234 * Same if PER_CPU_VAR(kernel_stack) is, perhaps with some offset, already in 235 * a certain register (to be used in assembler memory operands). 236 */ 237 #define THREAD_INFO(reg, off) KERNEL_STACK_OFFSET+(off)-THREAD_SIZE(reg) 238 239 #endif 240 241 #endif /* !X86_32 */ 242 243 /* 244 * Thread-synchronous status. 245 * 246 * This is different from the flags in that nobody else 247 * ever touches our thread-synchronous status, so we don't 248 * have to worry about atomic accesses. 249 */ 250 #define TS_USEDFPU 0x0001 /* FPU was used by this task 251 this quantum (SMP) */ 252 #define TS_COMPAT 0x0002 /* 32bit syscall active (64BIT)*/ 253 #define TS_POLLING 0x0004 /* idle task polling need_resched, 254 skip sending interrupt */ 255 #define TS_RESTORE_SIGMASK 0x0008 /* restore signal mask in do_signal() */ 256 257 #define tsk_is_polling(t) (task_thread_info(t)->status & TS_POLLING) 258 259 #ifndef __ASSEMBLY__ 260 #define HAVE_SET_RESTORE_SIGMASK 1 261 static inline void set_restore_sigmask(void) 262 { 263 struct thread_info *ti = current_thread_info(); 264 ti->status |= TS_RESTORE_SIGMASK; 265 set_bit(TIF_SIGPENDING, (unsigned long *)&ti->flags); 266 } 267 #endif /* !__ASSEMBLY__ */ 268 269 #ifndef __ASSEMBLY__ 270 extern void arch_task_cache_init(void); 271 extern void free_thread_info(struct thread_info *ti); 272 extern int arch_dup_task_struct(struct task_struct *dst, struct task_struct *src); 273 #define arch_task_cache_init arch_task_cache_init 274 #endif 275 #endif /* _ASM_X86_THREAD_INFO_H */ 276