1 /* thread_info.h: low-level thread information
3 * Copyright (C) 2002 David Howells (dhowells@redhat.com)
4 * - Incorporating suggestions made by Linus Torvalds and Dave Miller
7 #ifndef _ASM_X86_THREAD_INFO_H
8 #define _ASM_X86_THREAD_INFO_H
10 #include <linux/compiler.h>
12 #include <asm/types.h>
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
22 #include <asm/processor.h>
25 struct task_struct *task; /* main task structure */
26 struct exec_domain *exec_domain; /* execution domain */
27 unsigned long flags; /* low level flags */
28 __u32 status; /* thread synchronous flags */
29 __u32 cpu; /* current CPU */
30 int preempt_count; /* 0 => preemptable,
32 mm_segment_t addr_limit;
33 struct restart_block restart_block;
34 void __user *sysenter_return;
36 unsigned long previous_esp; /* ESP of the previous stack in
37 case of nested (IRQ) stacks
39 __u8 supervisor_stack[0];
43 #define INIT_THREAD_INFO(tsk) \
46 .exec_domain = &default_exec_domain, \
50 .addr_limit = KERNEL_DS, \
52 .fn = do_no_restart_syscall, \
56 #define init_thread_info (init_thread_union.thread_info)
57 #define init_stack (init_thread_union.stack)
59 #else /* !__ASSEMBLY__ */
61 #include <asm/asm-offsets.h>
66 * thread information flags
67 * - these are process state flags that various assembly files
69 * - pending work-to-be-done flags are in LSW
70 * - other flags in MSW
71 * Warning: layout of LSW is hardcoded in entry.S
73 #define TIF_SYSCALL_TRACE 0 /* syscall trace active */
74 #define TIF_SIGPENDING 2 /* signal pending */
75 #define TIF_NEED_RESCHED 3 /* rescheduling necessary */
76 #define TIF_SINGLESTEP 4 /* reenable singlestep on user return*/
77 #define TIF_IRET 5 /* force IRET */
78 #define TIF_SYSCALL_EMU 6 /* syscall emulation active */
79 #define TIF_SYSCALL_AUDIT 7 /* syscall auditing active */
80 #define TIF_SECCOMP 8 /* secure computing */
81 #define TIF_MCE_NOTIFY 10 /* notify userspace of an MCE */
82 #define TIF_NOTSC 16 /* TSC is not accessible in userland */
83 #define TIF_IA32 17 /* 32bit process */
84 #define TIF_FORK 18 /* ret_from_fork */
85 #define TIF_ABI_PENDING 19
87 #define TIF_DEBUG 21 /* uses debug registers */
88 #define TIF_IO_BITMAP 22 /* uses I/O bitmap */
89 #define TIF_FREEZE 23 /* is freezing for suspend */
90 #define TIF_FORCED_TF 24 /* true if TF in eflags artificially */
91 #define TIF_DEBUGCTLMSR 25 /* uses thread_struct.debugctlmsr */
92 #define TIF_DS_AREA_MSR 26 /* uses thread_struct.ds_area_msr */
93 #define TIF_BTS_TRACE_TS 27 /* record scheduling event timestamps */
95 #define _TIF_SYSCALL_TRACE (1 << TIF_SYSCALL_TRACE)
96 #define _TIF_SIGPENDING (1 << TIF_SIGPENDING)
97 #define _TIF_SINGLESTEP (1 << TIF_SINGLESTEP)
98 #define _TIF_NEED_RESCHED (1 << TIF_NEED_RESCHED)
99 #define _TIF_IRET (1 << TIF_IRET)
100 #define _TIF_SYSCALL_EMU (1 << TIF_SYSCALL_EMU)
101 #define _TIF_SYSCALL_AUDIT (1 << TIF_SYSCALL_AUDIT)
102 #define _TIF_SECCOMP (1 << TIF_SECCOMP)
103 #define _TIF_MCE_NOTIFY (1 << TIF_MCE_NOTIFY)
104 #define _TIF_NOTSC (1 << TIF_NOTSC)
105 #define _TIF_IA32 (1 << TIF_IA32)
106 #define _TIF_FORK (1 << TIF_FORK)
107 #define _TIF_ABI_PENDING (1 << TIF_ABI_PENDING)
108 #define _TIF_DEBUG (1 << TIF_DEBUG)
109 #define _TIF_IO_BITMAP (1 << TIF_IO_BITMAP)
110 #define _TIF_FREEZE (1 << TIF_FREEZE)
111 #define _TIF_FORCED_TF (1 << TIF_FORCED_TF)
112 #define _TIF_DEBUGCTLMSR (1 << TIF_DEBUGCTLMSR)
113 #define _TIF_DS_AREA_MSR (1 << TIF_DS_AREA_MSR)
114 #define _TIF_BTS_TRACE_TS (1 << TIF_BTS_TRACE_TS)
116 /* work to do in syscall_trace_enter() */
117 #define _TIF_WORK_SYSCALL_ENTRY \
118 (_TIF_SYSCALL_TRACE | _TIF_SYSCALL_EMU | \
119 _TIF_SYSCALL_AUDIT | _TIF_SECCOMP | _TIF_SINGLESTEP)
121 /* work to do in syscall_trace_leave() */
122 #define _TIF_WORK_SYSCALL_EXIT \
123 (_TIF_SYSCALL_TRACE | _TIF_SYSCALL_AUDIT | _TIF_SINGLESTEP)
125 /* work to do on interrupt/exception return */
126 #define _TIF_WORK_MASK \
128 ~(_TIF_SYSCALL_TRACE|_TIF_SYSCALL_AUDIT| \
129 _TIF_SINGLESTEP|_TIF_SECCOMP|_TIF_SYSCALL_EMU))
131 /* work to do on any return to user space */
132 #define _TIF_ALLWORK_MASK (0x0000FFFF & ~_TIF_SECCOMP)
134 /* Only used for 64 bit */
135 #define _TIF_DO_NOTIFY_MASK \
136 (_TIF_SIGPENDING|_TIF_MCE_NOTIFY)
138 /* flags to check in __switch_to() */
139 #define _TIF_WORK_CTXSW \
140 (_TIF_IO_BITMAP|_TIF_DEBUGCTLMSR|_TIF_DS_AREA_MSR|_TIF_BTS_TRACE_TS| \
143 #define _TIF_WORK_CTXSW_PREV _TIF_WORK_CTXSW
144 #define _TIF_WORK_CTXSW_NEXT (_TIF_WORK_CTXSW|_TIF_DEBUG)
146 #define PREEMPT_ACTIVE 0x10000000
148 /* thread information allocation */
149 #ifdef CONFIG_DEBUG_STACK_USAGE
150 #define THREAD_FLAGS (GFP_KERNEL | __GFP_ZERO)
152 #define THREAD_FLAGS GFP_KERNEL
155 #define __HAVE_ARCH_THREAD_INFO_ALLOCATOR
157 #define alloc_thread_info(tsk) \
158 ((struct thread_info *)__get_free_pages(THREAD_FLAGS, THREAD_ORDER))
162 #define STACK_WARN (THREAD_SIZE/8)
164 * macros/functions for gaining access to the thread information structure
166 * preempt_count needs to be 1 initially, until the scheduler is functional.
171 /* how to get the current stack pointer from C */
172 register unsigned long current_stack_pointer asm("esp") __used;
174 /* how to get the thread information struct from C */
175 static inline struct thread_info *current_thread_info(void)
177 return (struct thread_info *)
178 (current_stack_pointer & ~(THREAD_SIZE - 1));
181 #else /* !__ASSEMBLY__ */
183 /* how to get the thread information struct from ASM */
184 #define GET_THREAD_INFO(reg) \
185 movl $-THREAD_SIZE, reg; \
188 /* use this one if reg already contains %esp */
189 #define GET_THREAD_INFO_WITH_ESP(reg) \
190 andl $-THREAD_SIZE, reg
199 * macros/functions for gaining access to the thread information structure
200 * preempt_count needs to be 1 initially, until the scheduler is functional.
203 static inline struct thread_info *current_thread_info(void)
205 struct thread_info *ti;
206 ti = (void *)(read_pda(kernelstack) + PDA_STACKOFFSET - THREAD_SIZE);
210 /* do not use in interrupt context */
211 static inline struct thread_info *stack_thread_info(void)
213 struct thread_info *ti;
214 asm("andq %%rsp,%0; " : "=r" (ti) : "0" (~(THREAD_SIZE - 1)));
218 #else /* !__ASSEMBLY__ */
220 /* how to get the thread information struct from ASM */
221 #define GET_THREAD_INFO(reg) \
222 movq %gs:pda_kernelstack,reg ; \
223 subq $(THREAD_SIZE-PDA_STACKOFFSET),reg
230 * Thread-synchronous status.
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.
236 #define TS_USEDFPU 0x0001 /* FPU was used by this task
237 this quantum (SMP) */
238 #define TS_COMPAT 0x0002 /* 32bit syscall active (64BIT)*/
239 #define TS_POLLING 0x0004 /* true if in idle loop
241 #define TS_RESTORE_SIGMASK 0x0008 /* restore signal mask in do_signal() */
243 #define tsk_is_polling(t) (task_thread_info(t)->status & TS_POLLING)
246 #define HAVE_SET_RESTORE_SIGMASK 1
247 static inline void set_restore_sigmask(void)
249 struct thread_info *ti = current_thread_info();
250 ti->status |= TS_RESTORE_SIGMASK;
251 set_bit(TIF_SIGPENDING, (unsigned long *)&ti->flags);
253 #endif /* !__ASSEMBLY__ */
256 extern void arch_task_cache_init(void);
257 extern void free_thread_info(struct thread_info *ti);
258 extern int arch_dup_task_struct(struct task_struct *dst, struct task_struct *src);
259 #define arch_task_cache_init arch_task_cache_init
261 #endif /* _ASM_X86_THREAD_INFO_H */