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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 <linux/atomic.h>
24
25struct thread_info {
26 struct task_struct *task; /* main task structure */
27 struct exec_domain *exec_domain; /* execution domain */
28 __u32 flags; /* low level flags */
29 __u32 status; /* thread synchronous flags */
30 __u32 cpu; /* current CPU */
31 int preempt_count; /* 0 => preemptable,
32 <0 => BUG */
33 mm_segment_t addr_limit;
34 struct restart_block restart_block;
35 void __user *sysenter_return;
36#ifdef CONFIG_X86_32
37 unsigned long previous_esp; /* ESP of the previous stack in
38 case of nested (IRQ) stacks
39 */
40 __u8 supervisor_stack[0];
41#endif
42 unsigned int sig_on_uaccess_error:1;
43 unsigned int uaccess_err:1; /* uaccess failed */
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_SYSCALL_EMU 6 /* syscall emulation active */
82#define TIF_SYSCALL_AUDIT 7 /* syscall auditing active */
83#define TIF_SECCOMP 8 /* secure computing */
84#define TIF_MCE_NOTIFY 10 /* notify userspace of an MCE */
85#define TIF_USER_RETURN_NOTIFY 11 /* notify kernel of userspace return */
86#define TIF_UPROBE 12 /* breakpointed or singlestepping */
87#define TIF_NOTSC 16 /* TSC is not accessible in userland */
88#define TIF_IA32 17 /* IA32 compatibility process */
89#define TIF_FORK 18 /* ret_from_fork */
90#define TIF_NOHZ 19 /* in adaptive nohz mode */
91#define TIF_MEMDIE 20 /* is terminating due to OOM killer */
92#define TIF_IO_BITMAP 22 /* uses I/O bitmap */
93#define TIF_FORCED_TF 24 /* true if TF in eflags artificially */
94#define TIF_BLOCKSTEP 25 /* set when we want DEBUGCTLMSR_BTF */
95#define TIF_LAZY_MMU_UPDATES 27 /* task is updating the mmu lazily */
96#define TIF_SYSCALL_TRACEPOINT 28 /* syscall tracepoint instrumentation */
97#define TIF_ADDR32 29 /* 32-bit address space on 64 bits */
98#define TIF_X32 30 /* 32-bit native x86-64 binary */
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_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_UPROBE (1 << TIF_UPROBE)
111#define _TIF_NOTSC (1 << TIF_NOTSC)
112#define _TIF_IA32 (1 << TIF_IA32)
113#define _TIF_FORK (1 << TIF_FORK)
114#define _TIF_NOHZ (1 << TIF_NOHZ)
115#define _TIF_IO_BITMAP (1 << TIF_IO_BITMAP)
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#define _TIF_ADDR32 (1 << TIF_ADDR32)
121#define _TIF_X32 (1 << TIF_X32)
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 _TIF_NOHZ)
128
129/* work to do in syscall_trace_leave() */
130#define _TIF_WORK_SYSCALL_EXIT \
131 (_TIF_SYSCALL_TRACE | _TIF_SYSCALL_AUDIT | _TIF_SINGLESTEP | \
132 _TIF_SYSCALL_TRACEPOINT | _TIF_NOHZ)
133
134/* work to do on interrupt/exception return */
135#define _TIF_WORK_MASK \
136 (0x0000FFFF & \
137 ~(_TIF_SYSCALL_TRACE|_TIF_SYSCALL_AUDIT| \
138 _TIF_SINGLESTEP|_TIF_SECCOMP|_TIF_SYSCALL_EMU))
139
140/* work to do on any return to user space */
141#define _TIF_ALLWORK_MASK \
142 ((0x0000FFFF & ~_TIF_SECCOMP) | _TIF_SYSCALL_TRACEPOINT | \
143 _TIF_NOHZ)
144
145/* Only used for 64 bit */
146#define _TIF_DO_NOTIFY_MASK \
147 (_TIF_SIGPENDING | _TIF_MCE_NOTIFY | _TIF_NOTIFY_RESUME | \
148 _TIF_USER_RETURN_NOTIFY)
149
150/* flags to check in __switch_to() */
151#define _TIF_WORK_CTXSW \
152 (_TIF_IO_BITMAP|_TIF_NOTSC|_TIF_BLOCKSTEP)
153
154#define _TIF_WORK_CTXSW_PREV (_TIF_WORK_CTXSW|_TIF_USER_RETURN_NOTIFY)
155#define _TIF_WORK_CTXSW_NEXT (_TIF_WORK_CTXSW)
156
157#define PREEMPT_ACTIVE 0x10000000
158
159#ifdef CONFIG_X86_32
160
161#define STACK_WARN (THREAD_SIZE/8)
162/*
163 * macros/functions for gaining access to the thread information structure
164 *
165 * preempt_count needs to be 1 initially, until the scheduler is functional.
166 */
167#ifndef __ASSEMBLY__
168
169
170/* how to get the current stack pointer from C */
171register unsigned long current_stack_pointer asm("esp") __used;
172
173/* how to get the thread information struct from C */
174static inline struct thread_info *current_thread_info(void)
175{
176 return (struct thread_info *)
177 (current_stack_pointer & ~(THREAD_SIZE - 1));
178}
179
180#else /* !__ASSEMBLY__ */
181
182/* how to get the thread information struct from ASM */
183#define GET_THREAD_INFO(reg) \
184 movl $-THREAD_SIZE, reg; \
185 andl %esp, reg
186
187/* use this one if reg already contains %esp */
188#define GET_THREAD_INFO_WITH_ESP(reg) \
189 andl $-THREAD_SIZE, reg
190
191#endif
192
193#else /* X86_32 */
194
195#include <asm/percpu.h>
196#define KERNEL_STACK_OFFSET (5*8)
197
198/*
199 * macros/functions for gaining access to the thread information structure
200 * preempt_count needs to be 1 initially, until the scheduler is functional.
201 */
202#ifndef __ASSEMBLY__
203DECLARE_PER_CPU(unsigned long, kernel_stack);
204
205static inline struct thread_info *current_thread_info(void)
206{
207 struct thread_info *ti;
208 ti = (void *)(this_cpu_read_stable(kernel_stack) +
209 KERNEL_STACK_OFFSET - THREAD_SIZE);
210 return ti;
211}
212
213#else /* !__ASSEMBLY__ */
214
215/* how to get the thread information struct from ASM */
216#define GET_THREAD_INFO(reg) \
217 movq PER_CPU_VAR(kernel_stack),reg ; \
218 subq $(THREAD_SIZE-KERNEL_STACK_OFFSET),reg
219
220/*
221 * Same if PER_CPU_VAR(kernel_stack) is, perhaps with some offset, already in
222 * a certain register (to be used in assembler memory operands).
223 */
224#define THREAD_INFO(reg, off) KERNEL_STACK_OFFSET+(off)-THREAD_SIZE(reg)
225
226#endif
227
228#endif /* !X86_32 */
229
230/*
231 * Thread-synchronous status.
232 *
233 * This is different from the flags in that nobody else
234 * ever touches our thread-synchronous status, so we don't
235 * have to worry about atomic accesses.
236 */
237#define TS_COMPAT 0x0002 /* 32bit syscall active (64BIT)*/
238#define TS_POLLING 0x0004 /* idle task polling need_resched,
239 skip sending interrupt */
240#define TS_RESTORE_SIGMASK 0x0008 /* restore signal mask in do_signal() */
241
242#ifndef __ASSEMBLY__
243#define HAVE_SET_RESTORE_SIGMASK 1
244static inline void set_restore_sigmask(void)
245{
246 struct thread_info *ti = current_thread_info();
247 ti->status |= TS_RESTORE_SIGMASK;
248 WARN_ON(!test_bit(TIF_SIGPENDING, (unsigned long *)&ti->flags));
249}
250static inline void clear_restore_sigmask(void)
251{
252 current_thread_info()->status &= ~TS_RESTORE_SIGMASK;
253}
254static inline bool test_restore_sigmask(void)
255{
256 return current_thread_info()->status & TS_RESTORE_SIGMASK;
257}
258static inline bool test_and_clear_restore_sigmask(void)
259{
260 struct thread_info *ti = current_thread_info();
261 if (!(ti->status & TS_RESTORE_SIGMASK))
262 return false;
263 ti->status &= ~TS_RESTORE_SIGMASK;
264 return true;
265}
266
267static inline bool is_ia32_task(void)
268{
269#ifdef CONFIG_X86_32
270 return true;
271#endif
272#ifdef CONFIG_IA32_EMULATION
273 if (current_thread_info()->status & TS_COMPAT)
274 return true;
275#endif
276 return false;
277}
278#endif /* !__ASSEMBLY__ */
279
280#ifndef __ASSEMBLY__
281extern void arch_task_cache_init(void);
282extern int arch_dup_task_struct(struct task_struct *dst, struct task_struct *src);
283extern void arch_release_task_struct(struct task_struct *tsk);
284#endif
285#endif /* _ASM_X86_THREAD_INFO_H */