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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__
20struct task_struct;
21struct exec_domain;
22#include <asm/processor.h>
23#include <asm/ftrace.h>
24#include <asm/atomic.h>
25
26struct 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 /* is terminating due to OOM killer */
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_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_FREEZE (1 << TIF_FREEZE)
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
121/* work to do in syscall_trace_enter() */
122#define _TIF_WORK_SYSCALL_ENTRY \
123 (_TIF_SYSCALL_TRACE | _TIF_SYSCALL_EMU | _TIF_SYSCALL_AUDIT | \
124 _TIF_SECCOMP | _TIF_SINGLESTEP | _TIF_SYSCALL_TRACEPOINT)
125
126/* work to do in syscall_trace_leave() */
127#define _TIF_WORK_SYSCALL_EXIT \
128 (_TIF_SYSCALL_TRACE | _TIF_SYSCALL_AUDIT | _TIF_SINGLESTEP | \
129 _TIF_SYSCALL_TRACEPOINT)
130
131/* work to do on interrupt/exception return */
132#define _TIF_WORK_MASK \
133 (0x0000FFFF & \
134 ~(_TIF_SYSCALL_TRACE|_TIF_SYSCALL_AUDIT| \
135 _TIF_SINGLESTEP|_TIF_SECCOMP|_TIF_SYSCALL_EMU))
136
137/* work to do on any return to user space */
138#define _TIF_ALLWORK_MASK \
139 ((0x0000FFFF & ~_TIF_SECCOMP) | _TIF_SYSCALL_TRACEPOINT)
140
141/* Only used for 64 bit */
142#define _TIF_DO_NOTIFY_MASK \
143 (_TIF_SIGPENDING | _TIF_MCE_NOTIFY | _TIF_NOTIFY_RESUME | \
144 _TIF_USER_RETURN_NOTIFY)
145
146/* flags to check in __switch_to() */
147#define _TIF_WORK_CTXSW \
148 (_TIF_IO_BITMAP|_TIF_NOTSC|_TIF_BLOCKSTEP)
149
150#define _TIF_WORK_CTXSW_PREV (_TIF_WORK_CTXSW|_TIF_USER_RETURN_NOTIFY)
151#define _TIF_WORK_CTXSW_NEXT (_TIF_WORK_CTXSW|_TIF_DEBUG)
152
153#define PREEMPT_ACTIVE 0x10000000
154
155/* thread information allocation */
156#ifdef CONFIG_DEBUG_STACK_USAGE
157#define THREAD_FLAGS (GFP_KERNEL | __GFP_NOTRACK | __GFP_ZERO)
158#else
159#define THREAD_FLAGS (GFP_KERNEL | __GFP_NOTRACK)
160#endif
161
162#define __HAVE_ARCH_THREAD_INFO_ALLOCATOR
163
164#define alloc_thread_info_node(tsk, node) \
165({ \
166 struct page *page = alloc_pages_node(node, THREAD_FLAGS, \
167 THREAD_ORDER); \
168 struct thread_info *ret = page ? page_address(page) : NULL; \
169 \
170 ret; \
171})
172
173#ifdef CONFIG_X86_32
174
175#define STACK_WARN (THREAD_SIZE/8)
176/*
177 * macros/functions for gaining access to the thread information structure
178 *
179 * preempt_count needs to be 1 initially, until the scheduler is functional.
180 */
181#ifndef __ASSEMBLY__
182
183
184/* how to get the current stack pointer from C */
185register unsigned long current_stack_pointer asm("esp") __used;
186
187/* how to get the thread information struct from C */
188static inline struct thread_info *current_thread_info(void)
189{
190 return (struct thread_info *)
191 (current_stack_pointer & ~(THREAD_SIZE - 1));
192}
193
194#else /* !__ASSEMBLY__ */
195
196/* how to get the thread information struct from ASM */
197#define GET_THREAD_INFO(reg) \
198 movl $-THREAD_SIZE, reg; \
199 andl %esp, reg
200
201/* use this one if reg already contains %esp */
202#define GET_THREAD_INFO_WITH_ESP(reg) \
203 andl $-THREAD_SIZE, reg
204
205#endif
206
207#else /* X86_32 */
208
209#include <asm/percpu.h>
210#define KERNEL_STACK_OFFSET (5*8)
211
212/*
213 * macros/functions for gaining access to the thread information structure
214 * preempt_count needs to be 1 initially, until the scheduler is functional.
215 */
216#ifndef __ASSEMBLY__
217DECLARE_PER_CPU(unsigned long, kernel_stack);
218
219static inline struct thread_info *current_thread_info(void)
220{
221 struct thread_info *ti;
222 ti = (void *)(percpu_read_stable(kernel_stack) +
223 KERNEL_STACK_OFFSET - THREAD_SIZE);
224 return ti;
225}
226
227#else /* !__ASSEMBLY__ */
228
229/* how to get the thread information struct from ASM */
230#define GET_THREAD_INFO(reg) \
231 movq PER_CPU_VAR(kernel_stack),reg ; \
232 subq $(THREAD_SIZE-KERNEL_STACK_OFFSET),reg
233
234#endif
235
236#endif /* !X86_32 */
237
238/*
239 * Thread-synchronous status.
240 *
241 * This is different from the flags in that nobody else
242 * ever touches our thread-synchronous status, so we don't
243 * have to worry about atomic accesses.
244 */
245#define TS_USEDFPU 0x0001 /* FPU was used by this task
246 this quantum (SMP) */
247#define TS_COMPAT 0x0002 /* 32bit syscall active (64BIT)*/
248#define TS_POLLING 0x0004 /* idle task polling need_resched,
249 skip sending interrupt */
250#define TS_RESTORE_SIGMASK 0x0008 /* restore signal mask in do_signal() */
251
252#define tsk_is_polling(t) (task_thread_info(t)->status & TS_POLLING)
253
254#ifndef __ASSEMBLY__
255#define HAVE_SET_RESTORE_SIGMASK 1
256static inline void set_restore_sigmask(void)
257{
258 struct thread_info *ti = current_thread_info();
259 ti->status |= TS_RESTORE_SIGMASK;
260 set_bit(TIF_SIGPENDING, (unsigned long *)&ti->flags);
261}
262#endif /* !__ASSEMBLY__ */
263
264#ifndef __ASSEMBLY__
265extern void arch_task_cache_init(void);
266extern void free_thread_info(struct thread_info *ti);
267extern int arch_dup_task_struct(struct task_struct *dst, struct task_struct *src);
268#define arch_task_cache_init arch_task_cache_init
269#endif
270#endif /* _ASM_X86_THREAD_INFO_H */