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/percpu.h>
13 : #include <asm/types.h>
14 :
15 : /*
16 : * low level task data that entry.S needs immediate access to
17 : * - this struct should fit entirely inside of one cache line
18 : * - this struct shares the supervisor stack pages
19 : */
20 : #ifndef __ASSEMBLY__
21 : struct task_struct;
22 : struct exec_domain;
23 : #include <asm/processor.h>
24 : #include <linux/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 saved_preempt_count;
33 : mm_segment_t addr_limit;
34 : struct restart_block restart_block;
35 : void __user *sysenter_return;
36 : unsigned int sig_on_uaccess_error:1;
37 : unsigned int uaccess_err:1; /* uaccess failed */
38 : };
39 :
40 : #define INIT_THREAD_INFO(tsk) \
41 : { \
42 : .task = &tsk, \
43 : .exec_domain = &default_exec_domain, \
44 : .flags = 0, \
45 : .cpu = 0, \
46 : .saved_preempt_count = INIT_PREEMPT_COUNT, \
47 : .addr_limit = KERNEL_DS, \
48 : .restart_block = { \
49 : .fn = do_no_restart_syscall, \
50 : }, \
51 : }
52 :
53 : #define init_thread_info (init_thread_union.thread_info)
54 : #define init_stack (init_thread_union.stack)
55 :
56 : #else /* !__ASSEMBLY__ */
57 :
58 : #include <asm/asm-offsets.h>
59 :
60 : #endif
61 :
62 : /*
63 : * thread information flags
64 : * - these are process state flags that various assembly files
65 : * may need to access
66 : * - pending work-to-be-done flags are in LSW
67 : * - other flags in MSW
68 : * Warning: layout of LSW is hardcoded in entry.S
69 : */
70 : #define TIF_SYSCALL_TRACE 0 /* syscall trace active */
71 : #define TIF_NOTIFY_RESUME 1 /* callback before returning to user */
72 : #define TIF_SIGPENDING 2 /* signal pending */
73 : #define TIF_NEED_RESCHED 3 /* rescheduling necessary */
74 : #define TIF_SINGLESTEP 4 /* reenable singlestep on user return*/
75 : #define TIF_SYSCALL_EMU 6 /* syscall emulation active */
76 : #define TIF_SYSCALL_AUDIT 7 /* syscall auditing active */
77 : #define TIF_SECCOMP 8 /* secure computing */
78 : #define TIF_MCE_NOTIFY 10 /* notify userspace of an MCE */
79 : #define TIF_USER_RETURN_NOTIFY 11 /* notify kernel of userspace return */
80 : #define TIF_UPROBE 12 /* breakpointed or singlestepping */
81 : #define TIF_NOTSC 16 /* TSC is not accessible in userland */
82 : #define TIF_IA32 17 /* IA32 compatibility process */
83 : #define TIF_FORK 18 /* ret_from_fork */
84 : #define TIF_NOHZ 19 /* in adaptive nohz mode */
85 : #define TIF_MEMDIE 20 /* is terminating due to OOM killer */
86 : #define TIF_POLLING_NRFLAG 21 /* idle is polling for TIF_NEED_RESCHED */
87 : #define TIF_IO_BITMAP 22 /* uses I/O bitmap */
88 : #define TIF_FORCED_TF 24 /* true if TF in eflags artificially */
89 : #define TIF_BLOCKSTEP 25 /* set when we want DEBUGCTLMSR_BTF */
90 : #define TIF_LAZY_MMU_UPDATES 27 /* task is updating the mmu lazily */
91 : #define TIF_SYSCALL_TRACEPOINT 28 /* syscall tracepoint instrumentation */
92 : #define TIF_ADDR32 29 /* 32-bit address space on 64 bits */
93 : #define TIF_X32 30 /* 32-bit native x86-64 binary */
94 :
95 : #define _TIF_SYSCALL_TRACE (1 << TIF_SYSCALL_TRACE)
96 : #define _TIF_NOTIFY_RESUME (1 << TIF_NOTIFY_RESUME)
97 : #define _TIF_SIGPENDING (1 << TIF_SIGPENDING)
98 : #define _TIF_SINGLESTEP (1 << TIF_SINGLESTEP)
99 : #define _TIF_NEED_RESCHED (1 << TIF_NEED_RESCHED)
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_USER_RETURN_NOTIFY (1 << TIF_USER_RETURN_NOTIFY)
105 : #define _TIF_UPROBE (1 << TIF_UPROBE)
106 : #define _TIF_NOTSC (1 << TIF_NOTSC)
107 : #define _TIF_IA32 (1 << TIF_IA32)
108 : #define _TIF_FORK (1 << TIF_FORK)
109 : #define _TIF_NOHZ (1 << TIF_NOHZ)
110 : #define _TIF_POLLING_NRFLAG (1 << TIF_POLLING_NRFLAG)
111 : #define _TIF_IO_BITMAP (1 << TIF_IO_BITMAP)
112 : #define _TIF_FORCED_TF (1 << TIF_FORCED_TF)
113 : #define _TIF_BLOCKSTEP (1 << TIF_BLOCKSTEP)
114 : #define _TIF_LAZY_MMU_UPDATES (1 << TIF_LAZY_MMU_UPDATES)
115 : #define _TIF_SYSCALL_TRACEPOINT (1 << TIF_SYSCALL_TRACEPOINT)
116 : #define _TIF_ADDR32 (1 << TIF_ADDR32)
117 : #define _TIF_X32 (1 << TIF_X32)
118 :
119 : /* work to do in syscall_trace_enter() */
120 : #define _TIF_WORK_SYSCALL_ENTRY \
121 : (_TIF_SYSCALL_TRACE | _TIF_SYSCALL_EMU | _TIF_SYSCALL_AUDIT | \
122 : _TIF_SECCOMP | _TIF_SINGLESTEP | _TIF_SYSCALL_TRACEPOINT | \
123 : _TIF_NOHZ)
124 :
125 : /* work to do in syscall_trace_leave() */
126 : #define _TIF_WORK_SYSCALL_EXIT \
127 : (_TIF_SYSCALL_TRACE | _TIF_SYSCALL_AUDIT | _TIF_SINGLESTEP | \
128 : _TIF_SYSCALL_TRACEPOINT | _TIF_NOHZ)
129 :
130 : /* work to do on interrupt/exception return */
131 : #define _TIF_WORK_MASK \
132 : (0x0000FFFF & \
133 : ~(_TIF_SYSCALL_TRACE|_TIF_SYSCALL_AUDIT| \
134 : _TIF_SINGLESTEP|_TIF_SECCOMP|_TIF_SYSCALL_EMU))
135 :
136 : /* work to do on any return to user space */
137 : #define _TIF_ALLWORK_MASK \
138 : ((0x0000FFFF & ~_TIF_SECCOMP) | _TIF_SYSCALL_TRACEPOINT | \
139 : _TIF_NOHZ)
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)
152 :
153 : #define STACK_WARN (THREAD_SIZE/8)
154 : #define KERNEL_STACK_OFFSET (5*(BITS_PER_LONG/8))
155 :
156 : /*
157 : * macros/functions for gaining access to the thread information structure
158 : *
159 : * preempt_count needs to be 1 initially, until the scheduler is functional.
160 : */
161 : #ifndef __ASSEMBLY__
162 :
163 : DECLARE_PER_CPU(unsigned long, kernel_stack);
164 :
165 248946 : static inline struct thread_info *current_thread_info(void)
166 : {
167 : struct thread_info *ti;
168 641586 : ti = (void *)(this_cpu_read_stable(kernel_stack) +
169 320793 : KERNEL_STACK_OFFSET - THREAD_SIZE);
170 248946 : return ti;
171 : }
172 :
173 : #else /* !__ASSEMBLY__ */
174 :
175 : /* how to get the thread information struct from ASM */
176 : #define GET_THREAD_INFO(reg) \
177 : _ASM_MOV PER_CPU_VAR(kernel_stack),reg ; \
178 : _ASM_SUB $(THREAD_SIZE-KERNEL_STACK_OFFSET),reg ;
179 :
180 : /*
181 : * Same if PER_CPU_VAR(kernel_stack) is, perhaps with some offset, already in
182 : * a certain register (to be used in assembler memory operands).
183 : */
184 : #define THREAD_INFO(reg, off) KERNEL_STACK_OFFSET+(off)-THREAD_SIZE(reg)
185 :
186 : #endif
187 :
188 : /*
189 : * Thread-synchronous status.
190 : *
191 : * This is different from the flags in that nobody else
192 : * ever touches our thread-synchronous status, so we don't
193 : * have to worry about atomic accesses.
194 : */
195 : #define TS_COMPAT 0x0002 /* 32bit syscall active (64BIT)*/
196 : #define TS_RESTORE_SIGMASK 0x0008 /* restore signal mask in do_signal() */
197 :
198 : #ifndef __ASSEMBLY__
199 : #define HAVE_SET_RESTORE_SIGMASK 1
200 : static inline void set_restore_sigmask(void)
201 : {
202 : struct thread_info *ti = current_thread_info();
203 : ti->status |= TS_RESTORE_SIGMASK;
204 : WARN_ON(!test_bit(TIF_SIGPENDING, (unsigned long *)&ti->flags));
205 : }
206 : static inline void clear_restore_sigmask(void)
207 : {
208 : current_thread_info()->status &= ~TS_RESTORE_SIGMASK;
209 : }
210 : static inline bool test_restore_sigmask(void)
211 : {
212 : return current_thread_info()->status & TS_RESTORE_SIGMASK;
213 : }
214 : static inline bool test_and_clear_restore_sigmask(void)
215 : {
216 : struct thread_info *ti = current_thread_info();
217 : if (!(ti->status & TS_RESTORE_SIGMASK))
218 : return false;
219 : ti->status &= ~TS_RESTORE_SIGMASK;
220 : return true;
221 : }
222 :
223 : static inline bool is_ia32_task(void)
224 : {
225 : #ifdef CONFIG_X86_32
226 : return true;
227 : #endif
228 : #ifdef CONFIG_IA32_EMULATION
229 : if (current_thread_info()->status & TS_COMPAT)
230 : return true;
231 : #endif
232 : return false;
233 : }
234 : #endif /* !__ASSEMBLY__ */
235 :
236 : #ifndef __ASSEMBLY__
237 : extern void arch_task_cache_init(void);
238 : extern int arch_dup_task_struct(struct task_struct *dst, struct task_struct *src);
239 : extern void arch_release_task_struct(struct task_struct *tsk);
240 : #endif
241 : #endif /* _ASM_X86_THREAD_INFO_H */
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