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>
23 #include <asm/ftrace.h>
24 #include <asm/atomic.h>
27 struct task_struct *task; /* main task structure */
28 struct exec_domain *exec_domain; /* execution domain */
29 unsigned long flags; /* low level flags */
30 __u32 status; /* thread synchronous flags */
31 __u32 cpu; /* current CPU */
32 int preempt_count; /* 0 => preemptable,
34 mm_segment_t addr_limit;
35 struct restart_block restart_block;
36 void __user *sysenter_return;
38 unsigned long previous_esp; /* ESP of the previous stack in
39 case of nested (IRQ) stacks
41 __u8 supervisor_stack[0];
44 #ifdef CONFIG_FUNCTION_RET_TRACER
45 /* Index of current stored adress in ret_stack */
47 /* Stack of return addresses for return function tracing */
48 struct ftrace_ret_stack ret_stack[FTRACE_RET_STACK_SIZE];
50 * Number of functions that haven't been traced
51 * because of depth overrun.
53 atomic_t trace_overrun;
57 #ifdef CONFIG_FUNCTION_RET_TRACER
58 #define INIT_THREAD_INFO(tsk) \
61 .exec_domain = &default_exec_domain, \
65 .addr_limit = KERNEL_DS, \
67 .fn = do_no_restart_syscall, \
69 .curr_ret_stack = -1,\
70 .trace_overrun = ATOMIC_INIT(0) \
73 #define INIT_THREAD_INFO(tsk) \
76 .exec_domain = &default_exec_domain, \
80 .addr_limit = KERNEL_DS, \
82 .fn = do_no_restart_syscall, \
87 #define init_thread_info (init_thread_union.thread_info)
88 #define init_stack (init_thread_union.stack)
90 #else /* !__ASSEMBLY__ */
92 #include <asm/asm-offsets.h>
97 * thread information flags
98 * - these are process state flags that various assembly files
100 * - pending work-to-be-done flags are in LSW
101 * - other flags in MSW
102 * Warning: layout of LSW is hardcoded in entry.S
104 #define TIF_SYSCALL_TRACE 0 /* syscall trace active */
105 #define TIF_NOTIFY_RESUME 1 /* callback before returning to user */
106 #define TIF_SIGPENDING 2 /* signal pending */
107 #define TIF_NEED_RESCHED 3 /* rescheduling necessary */
108 #define TIF_SINGLESTEP 4 /* reenable singlestep on user return*/
109 #define TIF_IRET 5 /* force IRET */
110 #define TIF_SYSCALL_EMU 6 /* syscall emulation active */
111 #define TIF_SYSCALL_AUDIT 7 /* syscall auditing active */
112 #define TIF_SECCOMP 8 /* secure computing */
113 #define TIF_MCE_NOTIFY 10 /* notify userspace of an MCE */
114 #define TIF_NOTSC 16 /* TSC is not accessible in userland */
115 #define TIF_IA32 17 /* 32bit process */
116 #define TIF_FORK 18 /* ret_from_fork */
117 #define TIF_ABI_PENDING 19
118 #define TIF_MEMDIE 20
119 #define TIF_DEBUG 21 /* uses debug registers */
120 #define TIF_IO_BITMAP 22 /* uses I/O bitmap */
121 #define TIF_FREEZE 23 /* is freezing for suspend */
122 #define TIF_FORCED_TF 24 /* true if TF in eflags artificially */
123 #define TIF_DEBUGCTLMSR 25 /* uses thread_struct.debugctlmsr */
124 #define TIF_DS_AREA_MSR 26 /* uses thread_struct.ds_area_msr */
125 #define TIF_BTS_TRACE_TS 27 /* record scheduling event timestamps */
127 #define _TIF_SYSCALL_TRACE (1 << TIF_SYSCALL_TRACE)
128 #define _TIF_NOTIFY_RESUME (1 << TIF_NOTIFY_RESUME)
129 #define _TIF_SIGPENDING (1 << TIF_SIGPENDING)
130 #define _TIF_SINGLESTEP (1 << TIF_SINGLESTEP)
131 #define _TIF_NEED_RESCHED (1 << TIF_NEED_RESCHED)
132 #define _TIF_IRET (1 << TIF_IRET)
133 #define _TIF_SYSCALL_EMU (1 << TIF_SYSCALL_EMU)
134 #define _TIF_SYSCALL_AUDIT (1 << TIF_SYSCALL_AUDIT)
135 #define _TIF_SECCOMP (1 << TIF_SECCOMP)
136 #define _TIF_MCE_NOTIFY (1 << TIF_MCE_NOTIFY)
137 #define _TIF_NOTSC (1 << TIF_NOTSC)
138 #define _TIF_IA32 (1 << TIF_IA32)
139 #define _TIF_FORK (1 << TIF_FORK)
140 #define _TIF_ABI_PENDING (1 << TIF_ABI_PENDING)
141 #define _TIF_DEBUG (1 << TIF_DEBUG)
142 #define _TIF_IO_BITMAP (1 << TIF_IO_BITMAP)
143 #define _TIF_FREEZE (1 << TIF_FREEZE)
144 #define _TIF_FORCED_TF (1 << TIF_FORCED_TF)
145 #define _TIF_DEBUGCTLMSR (1 << TIF_DEBUGCTLMSR)
146 #define _TIF_DS_AREA_MSR (1 << TIF_DS_AREA_MSR)
147 #define _TIF_BTS_TRACE_TS (1 << TIF_BTS_TRACE_TS)
149 /* work to do in syscall_trace_enter() */
150 #define _TIF_WORK_SYSCALL_ENTRY \
151 (_TIF_SYSCALL_TRACE | _TIF_SYSCALL_EMU | \
152 _TIF_SYSCALL_AUDIT | _TIF_SECCOMP | _TIF_SINGLESTEP)
154 /* work to do in syscall_trace_leave() */
155 #define _TIF_WORK_SYSCALL_EXIT \
156 (_TIF_SYSCALL_TRACE | _TIF_SYSCALL_AUDIT | _TIF_SINGLESTEP)
158 /* work to do on interrupt/exception return */
159 #define _TIF_WORK_MASK \
161 ~(_TIF_SYSCALL_TRACE|_TIF_SYSCALL_AUDIT| \
162 _TIF_SINGLESTEP|_TIF_SECCOMP|_TIF_SYSCALL_EMU))
164 /* work to do on any return to user space */
165 #define _TIF_ALLWORK_MASK (0x0000FFFF & ~_TIF_SECCOMP)
167 /* Only used for 64 bit */
168 #define _TIF_DO_NOTIFY_MASK \
169 (_TIF_SIGPENDING|_TIF_MCE_NOTIFY|_TIF_NOTIFY_RESUME)
171 /* flags to check in __switch_to() */
172 #define _TIF_WORK_CTXSW \
173 (_TIF_IO_BITMAP|_TIF_DEBUGCTLMSR|_TIF_DS_AREA_MSR|_TIF_BTS_TRACE_TS| \
176 #define _TIF_WORK_CTXSW_PREV _TIF_WORK_CTXSW
177 #define _TIF_WORK_CTXSW_NEXT (_TIF_WORK_CTXSW|_TIF_DEBUG)
179 #define PREEMPT_ACTIVE 0x10000000
181 /* thread information allocation */
182 #ifdef CONFIG_DEBUG_STACK_USAGE
183 #define THREAD_FLAGS (GFP_KERNEL | __GFP_ZERO)
185 #define THREAD_FLAGS GFP_KERNEL
188 #define __HAVE_ARCH_THREAD_INFO_ALLOCATOR
190 #define alloc_thread_info(tsk) \
191 ((struct thread_info *)__get_free_pages(THREAD_FLAGS, THREAD_ORDER))
195 #define STACK_WARN (THREAD_SIZE/8)
197 * macros/functions for gaining access to the thread information structure
199 * preempt_count needs to be 1 initially, until the scheduler is functional.
204 /* how to get the current stack pointer from C */
205 register unsigned long current_stack_pointer asm("esp") __used;
207 /* how to get the thread information struct from C */
208 static inline struct thread_info *current_thread_info(void)
210 return (struct thread_info *)
211 (current_stack_pointer & ~(THREAD_SIZE - 1));
214 #else /* !__ASSEMBLY__ */
216 /* how to get the thread information struct from ASM */
217 #define GET_THREAD_INFO(reg) \
218 movl $-THREAD_SIZE, reg; \
221 /* use this one if reg already contains %esp */
222 #define GET_THREAD_INFO_WITH_ESP(reg) \
223 andl $-THREAD_SIZE, reg
232 * macros/functions for gaining access to the thread information structure
233 * preempt_count needs to be 1 initially, until the scheduler is functional.
236 static inline struct thread_info *current_thread_info(void)
238 struct thread_info *ti;
239 ti = (void *)(read_pda(kernelstack) + PDA_STACKOFFSET - THREAD_SIZE);
243 /* do not use in interrupt context */
244 static inline struct thread_info *stack_thread_info(void)
246 struct thread_info *ti;
247 asm("andq %%rsp,%0; " : "=r" (ti) : "0" (~(THREAD_SIZE - 1)));
251 #else /* !__ASSEMBLY__ */
253 /* how to get the thread information struct from ASM */
254 #define GET_THREAD_INFO(reg) \
255 movq %gs:pda_kernelstack,reg ; \
256 subq $(THREAD_SIZE-PDA_STACKOFFSET),reg
263 * Thread-synchronous status.
265 * This is different from the flags in that nobody else
266 * ever touches our thread-synchronous status, so we don't
267 * have to worry about atomic accesses.
269 #define TS_USEDFPU 0x0001 /* FPU was used by this task
270 this quantum (SMP) */
271 #define TS_COMPAT 0x0002 /* 32bit syscall active (64BIT)*/
272 #define TS_POLLING 0x0004 /* true if in idle loop
274 #define TS_RESTORE_SIGMASK 0x0008 /* restore signal mask in do_signal() */
275 #define TS_XSAVE 0x0010 /* Use xsave/xrstor */
277 #define tsk_is_polling(t) (task_thread_info(t)->status & TS_POLLING)
280 #define HAVE_SET_RESTORE_SIGMASK 1
281 static inline void set_restore_sigmask(void)
283 struct thread_info *ti = current_thread_info();
284 ti->status |= TS_RESTORE_SIGMASK;
285 set_bit(TIF_SIGPENDING, (unsigned long *)&ti->flags);
287 #endif /* !__ASSEMBLY__ */
290 extern void arch_task_cache_init(void);
291 extern void free_thread_info(struct thread_info *ti);
292 extern int arch_dup_task_struct(struct task_struct *dst, struct task_struct *src);
293 #define arch_task_cache_init arch_task_cache_init
295 #endif /* _ASM_X86_THREAD_INFO_H */