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 <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 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 unsigned int sig_on_uaccess_error:1;
44 unsigned int uaccess_err:1; /* uaccess failed */
45 };
46
47 #define INIT_THREAD_INFO(tsk) \
48 { \
49 .task = &tsk, \
50 .exec_domain = &default_exec_domain, \
51 .flags = 0, \
52 .cpu = 0, \
53 .preempt_count = INIT_PREEMPT_COUNT, \
54 .addr_limit = KERNEL_DS, \
55 .restart_block = { \
56 .fn = do_no_restart_syscall, \
57 }, \
58 }
59
60 #define init_thread_info (init_thread_union.thread_info)
61 #define init_stack (init_thread_union.stack)
62
63 #else /* !__ASSEMBLY__ */
64
65 #include <asm/asm-offsets.h>
66
67 #endif
68
69 /*
70 * thread information flags
71 * - these are process state flags that various assembly files
72 * may need to access
73 * - pending work-to-be-done flags are in LSW
74 * - other flags in MSW
75 * Warning: layout of LSW is hardcoded in entry.S
76 */
77 #define TIF_SYSCALL_TRACE 0 /* syscall trace active */
78 #define TIF_NOTIFY_RESUME 1 /* callback before returning to user */
79 #define TIF_SIGPENDING 2 /* signal pending */
80 #define TIF_NEED_RESCHED 3 /* rescheduling necessary */
81 #define TIF_SINGLESTEP 4 /* reenable singlestep on user return*/
82 #define TIF_IRET 5 /* force IRET */
83 #define TIF_SYSCALL_EMU 6 /* syscall emulation active */
84 #define TIF_SYSCALL_AUDIT 7 /* syscall auditing active */
85 #define TIF_SECCOMP 8 /* secure computing */
86 #define TIF_MCE_NOTIFY 10 /* notify userspace of an MCE */
87 #define TIF_USER_RETURN_NOTIFY 11 /* notify kernel of userspace return */
88 #define TIF_NOTSC 16 /* TSC is not accessible in userland */
89 #define TIF_IA32 17 /* IA32 compatibility process */
90 #define TIF_FORK 18 /* ret_from_fork */
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_IRET (1 << TIF_IRET)
107 #define _TIF_SYSCALL_EMU (1 << TIF_SYSCALL_EMU)
108 #define _TIF_SYSCALL_AUDIT (1 << TIF_SYSCALL_AUDIT)
109 #define _TIF_SECCOMP (1 << TIF_SECCOMP)
110 #define _TIF_MCE_NOTIFY (1 << TIF_MCE_NOTIFY)
111 #define _TIF_USER_RETURN_NOTIFY (1 << TIF_USER_RETURN_NOTIFY)
112 #define _TIF_NOTSC (1 << TIF_NOTSC)
113 #define _TIF_IA32 (1 << TIF_IA32)
114 #define _TIF_FORK (1 << TIF_FORK)
115 #define _TIF_DEBUG (1 << TIF_DEBUG)
116 #define _TIF_IO_BITMAP (1 << TIF_IO_BITMAP)
117 #define _TIF_FORCED_TF (1 << TIF_FORCED_TF)
118 #define _TIF_BLOCKSTEP (1 << TIF_BLOCKSTEP)
119 #define _TIF_LAZY_MMU_UPDATES (1 << TIF_LAZY_MMU_UPDATES)
120 #define _TIF_SYSCALL_TRACEPOINT (1 << TIF_SYSCALL_TRACEPOINT)
121 #define _TIF_ADDR32 (1 << TIF_ADDR32)
122 #define _TIF_X32 (1 << TIF_X32)
123
124 /* work to do in syscall_trace_enter() */
125 #define _TIF_WORK_SYSCALL_ENTRY \
126 (_TIF_SYSCALL_TRACE | _TIF_SYSCALL_EMU | _TIF_SYSCALL_AUDIT | \
127 _TIF_SECCOMP | _TIF_SINGLESTEP | _TIF_SYSCALL_TRACEPOINT)
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)
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
144 /* Only used for 64 bit */
145 #define _TIF_DO_NOTIFY_MASK \
146 (_TIF_SIGPENDING | _TIF_MCE_NOTIFY | _TIF_NOTIFY_RESUME | \
147 _TIF_USER_RETURN_NOTIFY)
148
149 /* flags to check in __switch_to() */
150 #define _TIF_WORK_CTXSW \
151 (_TIF_IO_BITMAP|_TIF_NOTSC|_TIF_BLOCKSTEP)
152
153 #define _TIF_WORK_CTXSW_PREV (_TIF_WORK_CTXSW|_TIF_USER_RETURN_NOTIFY)
154 #define _TIF_WORK_CTXSW_NEXT (_TIF_WORK_CTXSW|_TIF_DEBUG)
155
156 #define PREEMPT_ACTIVE 0x10000000
157
158 /* thread information allocation */
159 #ifdef CONFIG_DEBUG_STACK_USAGE
160 #define THREAD_FLAGS (GFP_KERNEL | __GFP_NOTRACK | __GFP_ZERO)
161 #else
162 #define THREAD_FLAGS (GFP_KERNEL | __GFP_NOTRACK)
163 #endif
164
165 #define __HAVE_ARCH_THREAD_INFO_ALLOCATOR
166
167 #define alloc_thread_info_node(tsk, node) \
168 ({ \
169 struct page *page = alloc_pages_node(node, THREAD_FLAGS, \
170 THREAD_ORDER); \
171 struct thread_info *ret = page ? page_address(page) : NULL; \
172 \
173 ret; \
174 })
175
176 #ifdef CONFIG_X86_32
177
178 #define STACK_WARN (THREAD_SIZE/8)
179 /*
180 * macros/functions for gaining access to the thread information structure
181 *
182 * preempt_count needs to be 1 initially, until the scheduler is functional.
183 */
184 #ifndef __ASSEMBLY__
185
186
187 /* how to get the current stack pointer from C */
188 register unsigned long current_stack_pointer asm("esp") __used;
189
190 /* how to get the thread information struct from C */
current_thread_info(void)191 static inline struct thread_info *current_thread_info(void)
192 {
193 return (struct thread_info *)
194 (current_stack_pointer & ~(THREAD_SIZE - 1));
195 }
196
197 #else /* !__ASSEMBLY__ */
198
199 /* how to get the thread information struct from ASM */
200 #define GET_THREAD_INFO(reg) \
201 movl $-THREAD_SIZE, reg; \
202 andl %esp, reg
203
204 /* use this one if reg already contains %esp */
205 #define GET_THREAD_INFO_WITH_ESP(reg) \
206 andl $-THREAD_SIZE, reg
207
208 #endif
209
210 #else /* X86_32 */
211
212 #include <asm/percpu.h>
213 #define KERNEL_STACK_OFFSET (5*8)
214
215 /*
216 * macros/functions for gaining access to the thread information structure
217 * preempt_count needs to be 1 initially, until the scheduler is functional.
218 */
219 #ifndef __ASSEMBLY__
220 DECLARE_PER_CPU(unsigned long, kernel_stack);
221
current_thread_info(void)222 static inline struct thread_info *current_thread_info(void)
223 {
224 struct thread_info *ti;
225 ti = (void *)(percpu_read_stable(kernel_stack) +
226 KERNEL_STACK_OFFSET - THREAD_SIZE);
227 return ti;
228 }
229
230 #else /* !__ASSEMBLY__ */
231
232 /* how to get the thread information struct from ASM */
233 #define GET_THREAD_INFO(reg) \
234 movq PER_CPU_VAR(kernel_stack),reg ; \
235 subq $(THREAD_SIZE-KERNEL_STACK_OFFSET),reg
236
237 /*
238 * Same if PER_CPU_VAR(kernel_stack) is, perhaps with some offset, already in
239 * a certain register (to be used in assembler memory operands).
240 */
241 #define THREAD_INFO(reg, off) KERNEL_STACK_OFFSET+(off)-THREAD_SIZE(reg)
242
243 #endif
244
245 #endif /* !X86_32 */
246
247 /*
248 * Thread-synchronous status.
249 *
250 * This is different from the flags in that nobody else
251 * ever touches our thread-synchronous status, so we don't
252 * have to worry about atomic accesses.
253 */
254 #define TS_COMPAT 0x0002 /* 32bit syscall active (64BIT)*/
255 #define TS_POLLING 0x0004 /* idle task polling need_resched,
256 skip sending interrupt */
257 #define TS_RESTORE_SIGMASK 0x0008 /* restore signal mask in do_signal() */
258
259 #define tsk_is_polling(t) (task_thread_info(t)->status & TS_POLLING)
260
261 #ifndef __ASSEMBLY__
262 #define HAVE_SET_RESTORE_SIGMASK 1
set_restore_sigmask(void)263 static inline void set_restore_sigmask(void)
264 {
265 struct thread_info *ti = current_thread_info();
266 ti->status |= TS_RESTORE_SIGMASK;
267 set_bit(TIF_SIGPENDING, (unsigned long *)&ti->flags);
268 }
269
is_ia32_task(void)270 static inline bool is_ia32_task(void)
271 {
272 #ifdef CONFIG_X86_32
273 return true;
274 #endif
275 #ifdef CONFIG_IA32_EMULATION
276 if (current_thread_info()->status & TS_COMPAT)
277 return true;
278 #endif
279 return false;
280 }
281 #endif /* !__ASSEMBLY__ */
282
283 #ifndef __ASSEMBLY__
284 extern void arch_task_cache_init(void);
285 extern void free_thread_info(struct thread_info *ti);
286 extern int arch_dup_task_struct(struct task_struct *dst, struct task_struct *src);
287 #define arch_task_cache_init arch_task_cache_init
288 #endif
289 #endif /* _ASM_X86_THREAD_INFO_H */
290