Line data Source code
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 <asm/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 : int uaccess_err;
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_IRET 5 /* force IRET */
82 : #define TIF_SYSCALL_EMU 6 /* syscall emulation active */
83 : #define TIF_SYSCALL_AUDIT 7 /* syscall auditing active */
84 : #define TIF_SECCOMP 8 /* secure computing */
85 : #define TIF_MCE_NOTIFY 10 /* notify userspace of an MCE */
86 : #define TIF_USER_RETURN_NOTIFY 11 /* notify kernel of userspace return */
87 : #define TIF_NOTSC 16 /* TSC is not accessible in userland */
88 : #define TIF_IA32 17 /* 32bit process */
89 : #define TIF_FORK 18 /* ret_from_fork */
90 : #define TIF_MEMDIE 20
91 : #define TIF_DEBUG 21 /* uses debug registers */
92 : #define TIF_IO_BITMAP 22 /* uses I/O bitmap */
93 : #define TIF_FREEZE 23 /* is freezing for suspend */
94 : #define TIF_FORCED_TF 24 /* true if TF in eflags artificially */
95 : #define TIF_DEBUGCTLMSR 25 /* uses thread_struct.debugctlmsr */
96 : #define TIF_DS_AREA_MSR 26 /* uses thread_struct.ds_area_msr */
97 : #define TIF_LAZY_MMU_UPDATES 27 /* task is updating the mmu lazily */
98 : #define TIF_SYSCALL_TRACEPOINT 28 /* syscall tracepoint instrumentation */
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_IRET (1 << TIF_IRET)
106 : #define _TIF_SYSCALL_EMU (1 << TIF_SYSCALL_EMU)
107 : #define _TIF_SYSCALL_AUDIT (1 << TIF_SYSCALL_AUDIT)
108 : #define _TIF_SECCOMP (1 << TIF_SECCOMP)
109 : #define _TIF_MCE_NOTIFY (1 << TIF_MCE_NOTIFY)
110 : #define _TIF_USER_RETURN_NOTIFY (1 << TIF_USER_RETURN_NOTIFY)
111 : #define _TIF_NOTSC (1 << TIF_NOTSC)
112 : #define _TIF_IA32 (1 << TIF_IA32)
113 : #define _TIF_FORK (1 << TIF_FORK)
114 : #define _TIF_DEBUG (1 << TIF_DEBUG)
115 : #define _TIF_IO_BITMAP (1 << TIF_IO_BITMAP)
116 : #define _TIF_FREEZE (1 << TIF_FREEZE)
117 : #define _TIF_FORCED_TF (1 << TIF_FORCED_TF)
118 : #define _TIF_DEBUGCTLMSR (1 << TIF_DEBUGCTLMSR)
119 : #define _TIF_DS_AREA_MSR (1 << TIF_DS_AREA_MSR)
120 : #define _TIF_LAZY_MMU_UPDATES (1 << TIF_LAZY_MMU_UPDATES)
121 : #define _TIF_SYSCALL_TRACEPOINT (1 << TIF_SYSCALL_TRACEPOINT)
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 :
128 : /* work to do in syscall_trace_leave() */
129 : #define _TIF_WORK_SYSCALL_EXIT \
130 : (_TIF_SYSCALL_TRACE | _TIF_SYSCALL_AUDIT | _TIF_SINGLESTEP | \
131 : _TIF_SYSCALL_TRACEPOINT)
132 :
133 : /* work to do on interrupt/exception return */
134 : #define _TIF_WORK_MASK \
135 : (0x0000FFFF & \
136 : ~(_TIF_SYSCALL_TRACE|_TIF_SYSCALL_AUDIT| \
137 : _TIF_SINGLESTEP|_TIF_SECCOMP|_TIF_SYSCALL_EMU))
138 :
139 : /* work to do on any return to user space */
140 : #define _TIF_ALLWORK_MASK \
141 : ((0x0000FFFF & ~_TIF_SECCOMP) | _TIF_SYSCALL_TRACEPOINT)
142 :
143 : /* Only used for 64 bit */
144 : #define _TIF_DO_NOTIFY_MASK \
145 : (_TIF_SIGPENDING | _TIF_MCE_NOTIFY | _TIF_NOTIFY_RESUME | \
146 : _TIF_USER_RETURN_NOTIFY)
147 :
148 : /* flags to check in __switch_to() */
149 : #define _TIF_WORK_CTXSW \
150 : (_TIF_IO_BITMAP|_TIF_DEBUGCTLMSR|_TIF_DS_AREA_MSR|_TIF_NOTSC)
151 :
152 : #define _TIF_WORK_CTXSW_PREV (_TIF_WORK_CTXSW|_TIF_USER_RETURN_NOTIFY)
153 : #define _TIF_WORK_CTXSW_NEXT (_TIF_WORK_CTXSW|_TIF_DEBUG)
154 :
155 : #define PREEMPT_ACTIVE 0x10000000
156 :
157 : /* thread information allocation */
158 : #ifdef CONFIG_DEBUG_STACK_USAGE
159 : #define THREAD_FLAGS (GFP_KERNEL | __GFP_NOTRACK | __GFP_ZERO)
160 : #else
161 : #define THREAD_FLAGS (GFP_KERNEL | __GFP_NOTRACK)
162 : #endif
163 :
164 : #define __HAVE_ARCH_THREAD_INFO_ALLOCATOR
165 :
166 : #define alloc_thread_info(tsk) \
167 : ((struct thread_info *)__get_free_pages(THREAD_FLAGS, THREAD_ORDER))
168 :
169 : #ifdef CONFIG_X86_32
170 :
171 : #define STACK_WARN (THREAD_SIZE/8)
172 : /*
173 : * macros/functions for gaining access to the thread information structure
174 : *
175 : * preempt_count needs to be 1 initially, until the scheduler is functional.
176 : */
177 : #ifndef __ASSEMBLY__
178 :
179 :
180 : /* how to get the current stack pointer from C */
181 : register unsigned long current_stack_pointer asm("esp") __used;
182 :
183 : /* how to get the thread information struct from C */
184 : static inline struct thread_info *current_thread_info(void)
185 : {
186 : return (struct thread_info *)
187 : (current_stack_pointer & ~(THREAD_SIZE - 1));
188 : }
189 :
190 : #else /* !__ASSEMBLY__ */
191 :
192 : /* how to get the thread information struct from ASM */
193 : #define GET_THREAD_INFO(reg) \
194 : movl $-THREAD_SIZE, reg; \
195 : andl %esp, reg
196 :
197 : /* use this one if reg already contains %esp */
198 : #define GET_THREAD_INFO_WITH_ESP(reg) \
199 : andl $-THREAD_SIZE, reg
200 :
201 : #endif
202 :
203 : #else /* X86_32 */
204 :
205 : #include <asm/percpu.h>
206 : #define KERNEL_STACK_OFFSET (5*8)
207 :
208 : /*
209 : * macros/functions for gaining access to the thread information structure
210 : * preempt_count needs to be 1 initially, until the scheduler is functional.
211 : */
212 : #ifndef __ASSEMBLY__
213 1 : DECLARE_PER_CPU(unsigned long, kernel_stack);
214 :
215 : static inline struct thread_info *current_thread_info(void)
216 : {
217 39 : struct thread_info *ti;
218 351 : ti = (void *)(percpu_read_stable(kernel_stack) +
219 39 : KERNEL_STACK_OFFSET - THREAD_SIZE);
220 39 : return ti;
221 : }
222 :
223 : #else /* !__ASSEMBLY__ */
224 :
225 : /* how to get the thread information struct from ASM */
226 : #define GET_THREAD_INFO(reg) \
227 : movq PER_CPU_VAR(kernel_stack),reg ; \
228 : subq $(THREAD_SIZE-KERNEL_STACK_OFFSET),reg
229 :
230 : #endif
231 :
232 : #endif /* !X86_32 */
233 :
234 : /*
235 : * Thread-synchronous status.
236 : *
237 : * This is different from the flags in that nobody else
238 : * ever touches our thread-synchronous status, so we don't
239 : * have to worry about atomic accesses.
240 : */
241 : #define TS_USEDFPU 0x0001 /* FPU was used by this task
242 : this quantum (SMP) */
243 : #define TS_COMPAT 0x0002 /* 32bit syscall active (64BIT)*/
244 : #define TS_POLLING 0x0004 /* true if in idle loop
245 : and not sleeping */
246 : #define TS_RESTORE_SIGMASK 0x0008 /* restore signal mask in do_signal() */
247 : #define TS_XSAVE 0x0010 /* Use xsave/xrstor */
248 :
249 : #define tsk_is_polling(t) (task_thread_info(t)->status & TS_POLLING)
250 :
251 : #ifndef __ASSEMBLY__
252 : #define HAVE_SET_RESTORE_SIGMASK 1
253 : static inline void set_restore_sigmask(void)
254 : {
255 : struct thread_info *ti = current_thread_info();
256 : ti->status |= TS_RESTORE_SIGMASK;
257 : set_bit(TIF_SIGPENDING, (unsigned long *)&ti->flags);
258 : }
259 : #endif /* !__ASSEMBLY__ */
260 :
261 : #ifndef __ASSEMBLY__
262 : extern void arch_task_cache_init(void);
263 : extern void free_thread_info(struct thread_info *ti);
264 : extern int arch_dup_task_struct(struct task_struct *dst, struct task_struct *src);
265 : #define arch_task_cache_init arch_task_cache_init
266 : #endif
267 : #endif /* _ASM_X86_THREAD_INFO_H */
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