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 <linux/atomic.h>
24
25 struct 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_DEBUG 21 /* uses debug registers */
93 #define TIF_IO_BITMAP 22 /* uses I/O bitmap */
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 #define TIF_ADDR32 29 /* 32-bit address space on 64 bits */
99 #define TIF_X32 30 /* 32-bit native x86-64 binary */
100
101 #define _TIF_SYSCALL_TRACE (1 << TIF_SYSCALL_TRACE)
102 #define _TIF_NOTIFY_RESUME (1 << TIF_NOTIFY_RESUME)
103 #define _TIF_SIGPENDING (1 << TIF_SIGPENDING)
104 #define _TIF_SINGLESTEP (1 << TIF_SINGLESTEP)
105 #define _TIF_NEED_RESCHED (1 << TIF_NEED_RESCHED)
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_UPROBE (1 << TIF_UPROBE)
112 #define _TIF_NOTSC (1 << TIF_NOTSC)
113 #define _TIF_IA32 (1 << TIF_IA32)
114 #define _TIF_FORK (1 << TIF_FORK)
115 #define _TIF_NOHZ (1 << TIF_NOHZ)
116 #define _TIF_DEBUG (1 << TIF_DEBUG)
117 #define _TIF_IO_BITMAP (1 << TIF_IO_BITMAP)
118 #define _TIF_FORCED_TF (1 << TIF_FORCED_TF)
119 #define _TIF_BLOCKSTEP (1 << TIF_BLOCKSTEP)
120 #define _TIF_LAZY_MMU_UPDATES (1 << TIF_LAZY_MMU_UPDATES)
121 #define _TIF_SYSCALL_TRACEPOINT (1 << TIF_SYSCALL_TRACEPOINT)
122 #define _TIF_ADDR32 (1 << TIF_ADDR32)
123 #define _TIF_X32 (1 << TIF_X32)
124
125 /* work to do in syscall_trace_enter() */
126 #define _TIF_WORK_SYSCALL_ENTRY \
127 (_TIF_SYSCALL_TRACE | _TIF_SYSCALL_EMU | _TIF_SYSCALL_AUDIT | \
128 _TIF_SECCOMP | _TIF_SINGLESTEP | _TIF_SYSCALL_TRACEPOINT | \
129 _TIF_NOHZ)
130
131 /* work to do in syscall_trace_leave() */
132 #define _TIF_WORK_SYSCALL_EXIT \
133 (_TIF_SYSCALL_TRACE | _TIF_SYSCALL_AUDIT | _TIF_SINGLESTEP | \
134 _TIF_SYSCALL_TRACEPOINT | _TIF_NOHZ)
135
136 /* work to do on interrupt/exception return */
137 #define _TIF_WORK_MASK \
138 (0x0000FFFF & \
139 ~(_TIF_SYSCALL_TRACE|_TIF_SYSCALL_AUDIT| \
140 _TIF_SINGLESTEP|_TIF_SECCOMP|_TIF_SYSCALL_EMU))
141
142 /* work to do on any return to user space */
143 #define _TIF_ALLWORK_MASK \
144 ((0x0000FFFF & ~_TIF_SECCOMP) | _TIF_SYSCALL_TRACEPOINT | \
145 _TIF_NOHZ)
146
147 /* Only used for 64 bit */
148 #define _TIF_DO_NOTIFY_MASK \
149 (_TIF_SIGPENDING | _TIF_MCE_NOTIFY | _TIF_NOTIFY_RESUME | \
150 _TIF_USER_RETURN_NOTIFY)
151
152 /* flags to check in __switch_to() */
153 #define _TIF_WORK_CTXSW \
154 (_TIF_IO_BITMAP|_TIF_NOTSC|_TIF_BLOCKSTEP)
155
156 #define _TIF_WORK_CTXSW_PREV (_TIF_WORK_CTXSW|_TIF_USER_RETURN_NOTIFY)
157 #define _TIF_WORK_CTXSW_NEXT (_TIF_WORK_CTXSW|_TIF_DEBUG)
158
159 #define PREEMPT_ACTIVE 0x10000000
160
161 #ifdef CONFIG_X86_32
162
163 #define STACK_WARN (THREAD_SIZE/8)
164 /*
165 * macros/functions for gaining access to the thread information structure
166 *
167 * preempt_count needs to be 1 initially, until the scheduler is functional.
168 */
169 #ifndef __ASSEMBLY__
170
171
172 /* how to get the current stack pointer from C */
173 register unsigned long current_stack_pointer asm("esp") __used;
174
175 /* how to get the thread information struct from C */
current_thread_info(void)176 static inline struct thread_info *current_thread_info(void)
177 {
178 return (struct thread_info *)
179 (current_stack_pointer & ~(THREAD_SIZE - 1));
180 }
181
182 #else /* !__ASSEMBLY__ */
183
184 /* how to get the thread information struct from ASM */
185 #define GET_THREAD_INFO(reg) \
186 movl $-THREAD_SIZE, reg; \
187 andl %esp, reg
188
189 /* use this one if reg already contains %esp */
190 #define GET_THREAD_INFO_WITH_ESP(reg) \
191 andl $-THREAD_SIZE, reg
192
193 #endif
194
195 #else /* X86_32 */
196
197 #include <asm/percpu.h>
198 #define KERNEL_STACK_OFFSET (5*8)
199
200 /*
201 * macros/functions for gaining access to the thread information structure
202 * preempt_count needs to be 1 initially, until the scheduler is functional.
203 */
204 #ifndef __ASSEMBLY__
205 DECLARE_PER_CPU(unsigned long, kernel_stack);
206
current_thread_info(void)207 static inline struct thread_info *current_thread_info(void)
208 {
209 struct thread_info *ti;
210 ti = (void *)(this_cpu_read_stable(kernel_stack) +
211 KERNEL_STACK_OFFSET - THREAD_SIZE);
212 return ti;
213 }
214
215 #else /* !__ASSEMBLY__ */
216
217 /* how to get the thread information struct from ASM */
218 #define GET_THREAD_INFO(reg) \
219 movq PER_CPU_VAR(kernel_stack),reg ; \
220 subq $(THREAD_SIZE-KERNEL_STACK_OFFSET),reg
221
222 /*
223 * Same if PER_CPU_VAR(kernel_stack) is, perhaps with some offset, already in
224 * a certain register (to be used in assembler memory operands).
225 */
226 #define THREAD_INFO(reg, off) KERNEL_STACK_OFFSET+(off)-THREAD_SIZE(reg)
227
228 #endif
229
230 #endif /* !X86_32 */
231
232 /*
233 * Thread-synchronous status.
234 *
235 * This is different from the flags in that nobody else
236 * ever touches our thread-synchronous status, so we don't
237 * have to worry about atomic accesses.
238 */
239 #define TS_COMPAT 0x0002 /* 32bit syscall active (64BIT)*/
240 #define TS_POLLING 0x0004 /* idle task polling need_resched,
241 skip sending interrupt */
242 #define TS_RESTORE_SIGMASK 0x0008 /* restore signal mask in do_signal() */
243
244 #ifndef __ASSEMBLY__
245 #define HAVE_SET_RESTORE_SIGMASK 1
set_restore_sigmask(void)246 static inline void set_restore_sigmask(void)
247 {
248 struct thread_info *ti = current_thread_info();
249 ti->status |= TS_RESTORE_SIGMASK;
250 WARN_ON(!test_bit(TIF_SIGPENDING, (unsigned long *)&ti->flags));
251 }
clear_restore_sigmask(void)252 static inline void clear_restore_sigmask(void)
253 {
254 current_thread_info()->status &= ~TS_RESTORE_SIGMASK;
255 }
test_restore_sigmask(void)256 static inline bool test_restore_sigmask(void)
257 {
258 return current_thread_info()->status & TS_RESTORE_SIGMASK;
259 }
test_and_clear_restore_sigmask(void)260 static inline bool test_and_clear_restore_sigmask(void)
261 {
262 struct thread_info *ti = current_thread_info();
263 if (!(ti->status & TS_RESTORE_SIGMASK))
264 return false;
265 ti->status &= ~TS_RESTORE_SIGMASK;
266 return true;
267 }
268
is_ia32_task(void)269 static inline bool is_ia32_task(void)
270 {
271 #ifdef CONFIG_X86_32
272 return true;
273 #endif
274 #ifdef CONFIG_IA32_EMULATION
275 if (current_thread_info()->status & TS_COMPAT)
276 return true;
277 #endif
278 return false;
279 }
280 #endif /* !__ASSEMBLY__ */
281
282 #ifndef __ASSEMBLY__
283 extern void arch_task_cache_init(void);
284 extern int arch_dup_task_struct(struct task_struct *dst, struct task_struct *src);
285 extern void arch_release_task_struct(struct task_struct *tsk);
286 #endif
287 #endif /* _ASM_X86_THREAD_INFO_H */
288