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2052e8d4 CL |
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 | ||
1965aae3 PA |
7 | #ifndef _ASM_X86_THREAD_INFO_H |
8 | #define _ASM_X86_THREAD_INFO_H | |
2052e8d4 | 9 | |
2052e8d4 CL |
10 | #include <linux/compiler.h> |
11 | #include <asm/page.h> | |
198d208d | 12 | #include <asm/percpu.h> |
12a638e1 CL |
13 | #include <asm/types.h> |
14 | ||
3ee4298f AL |
15 | /* |
16 | * TOP_OF_KERNEL_STACK_PADDING is a number of unused bytes that we | |
17 | * reserve at the top of the kernel stack. We do it because of a nasty | |
18 | * 32-bit corner case. On x86_32, the hardware stack frame is | |
19 | * variable-length. Except for vm86 mode, struct pt_regs assumes a | |
20 | * maximum-length frame. If we enter from CPL 0, the top 8 bytes of | |
21 | * pt_regs don't actually exist. Ordinarily this doesn't matter, but it | |
22 | * does in at least one case: | |
23 | * | |
24 | * If we take an NMI early enough in SYSENTER, then we can end up with | |
25 | * pt_regs that extends above sp0. On the way out, in the espfix code, | |
26 | * we can read the saved SS value, but that value will be above sp0. | |
27 | * Without this offset, that can result in a page fault. (We are | |
28 | * careful that, in this case, the value we read doesn't matter.) | |
29 | * | |
30 | * In vm86 mode, the hardware frame is much longer still, but we neither | |
31 | * access the extra members from NMI context, nor do we write such a | |
32 | * frame at sp0 at all. | |
33 | * | |
34 | * x86_64 has a fixed-length stack frame. | |
35 | */ | |
36 | #ifdef CONFIG_X86_32 | |
37 | # define TOP_OF_KERNEL_STACK_PADDING 8 | |
38 | #else | |
39 | # define TOP_OF_KERNEL_STACK_PADDING 0 | |
40 | #endif | |
41 | ||
2052e8d4 CL |
42 | /* |
43 | * low level task data that entry.S needs immediate access to | |
44 | * - this struct should fit entirely inside of one cache line | |
45 | * - this struct shares the supervisor stack pages | |
2052e8d4 CL |
46 | */ |
47 | #ifndef __ASSEMBLY__ | |
006c484b CL |
48 | struct task_struct; |
49 | struct exec_domain; | |
50 | #include <asm/processor.h> | |
60063497 | 51 | #include <linux/atomic.h> |
2052e8d4 CL |
52 | |
53 | struct thread_info { | |
54 | struct task_struct *task; /* main task structure */ | |
55 | struct exec_domain *exec_domain; /* execution domain */ | |
affa219b | 56 | __u32 flags; /* low level flags */ |
006c484b | 57 | __u32 status; /* thread synchronous flags */ |
2052e8d4 | 58 | __u32 cpu; /* current CPU */ |
c2daa3be | 59 | int saved_preempt_count; |
006c484b | 60 | mm_segment_t addr_limit; |
006c484b | 61 | void __user *sysenter_return; |
0788aa6a SR |
62 | unsigned int sig_on_uaccess_error:1; |
63 | unsigned int uaccess_err:1; /* uaccess failed */ | |
2052e8d4 | 64 | }; |
3351cc03 CL |
65 | |
66 | #define INIT_THREAD_INFO(tsk) \ | |
67 | { \ | |
68 | .task = &tsk, \ | |
69 | .exec_domain = &default_exec_domain, \ | |
70 | .flags = 0, \ | |
71 | .cpu = 0, \ | |
c2daa3be | 72 | .saved_preempt_count = INIT_PREEMPT_COUNT, \ |
3351cc03 | 73 | .addr_limit = KERNEL_DS, \ |
3351cc03 CL |
74 | } |
75 | ||
76 | #define init_thread_info (init_thread_union.thread_info) | |
77 | #define init_stack (init_thread_union.stack) | |
78 | ||
2052e8d4 CL |
79 | #else /* !__ASSEMBLY__ */ |
80 | ||
81 | #include <asm/asm-offsets.h> | |
82 | ||
83 | #endif | |
84 | ||
e57549b0 CL |
85 | /* |
86 | * thread information flags | |
87 | * - these are process state flags that various assembly files | |
88 | * may need to access | |
89 | * - pending work-to-be-done flags are in LSW | |
90 | * - other flags in MSW | |
91 | * Warning: layout of LSW is hardcoded in entry.S | |
92 | */ | |
93 | #define TIF_SYSCALL_TRACE 0 /* syscall trace active */ | |
59e52130 | 94 | #define TIF_NOTIFY_RESUME 1 /* callback before returning to user */ |
e57549b0 CL |
95 | #define TIF_SIGPENDING 2 /* signal pending */ |
96 | #define TIF_NEED_RESCHED 3 /* rescheduling necessary */ | |
97 | #define TIF_SINGLESTEP 4 /* reenable singlestep on user return*/ | |
e57549b0 | 98 | #define TIF_SYSCALL_EMU 6 /* syscall emulation active */ |
e57549b0 CL |
99 | #define TIF_SYSCALL_AUDIT 7 /* syscall auditing active */ |
100 | #define TIF_SECCOMP 8 /* secure computing */ | |
7c68af6e | 101 | #define TIF_USER_RETURN_NOTIFY 11 /* notify kernel of userspace return */ |
0326f5a9 | 102 | #define TIF_UPROBE 12 /* breakpointed or singlestepping */ |
e57549b0 | 103 | #define TIF_NOTSC 16 /* TSC is not accessible in userland */ |
6bd33008 | 104 | #define TIF_IA32 17 /* IA32 compatibility process */ |
e57549b0 | 105 | #define TIF_FORK 18 /* ret_from_fork */ |
bf5a3c13 | 106 | #define TIF_NOHZ 19 /* in adaptive nohz mode */ |
0ddc9324 | 107 | #define TIF_MEMDIE 20 /* is terminating due to OOM killer */ |
f80c5b39 | 108 | #define TIF_POLLING_NRFLAG 21 /* idle is polling for TIF_NEED_RESCHED */ |
e57549b0 | 109 | #define TIF_IO_BITMAP 22 /* uses I/O bitmap */ |
e57549b0 | 110 | #define TIF_FORCED_TF 24 /* true if TF in eflags artificially */ |
ea8e61b7 | 111 | #define TIF_BLOCKSTEP 25 /* set when we want DEBUGCTLMSR_BTF */ |
b407fc57 | 112 | #define TIF_LAZY_MMU_UPDATES 27 /* task is updating the mmu lazily */ |
66700001 | 113 | #define TIF_SYSCALL_TRACEPOINT 28 /* syscall tracepoint instrumentation */ |
6bd33008 | 114 | #define TIF_ADDR32 29 /* 32-bit address space on 64 bits */ |
bb212724 | 115 | #define TIF_X32 30 /* 32-bit native x86-64 binary */ |
e57549b0 CL |
116 | |
117 | #define _TIF_SYSCALL_TRACE (1 << TIF_SYSCALL_TRACE) | |
59e52130 | 118 | #define _TIF_NOTIFY_RESUME (1 << TIF_NOTIFY_RESUME) |
e57549b0 CL |
119 | #define _TIF_SIGPENDING (1 << TIF_SIGPENDING) |
120 | #define _TIF_SINGLESTEP (1 << TIF_SINGLESTEP) | |
121 | #define _TIF_NEED_RESCHED (1 << TIF_NEED_RESCHED) | |
e57549b0 | 122 | #define _TIF_SYSCALL_EMU (1 << TIF_SYSCALL_EMU) |
e57549b0 CL |
123 | #define _TIF_SYSCALL_AUDIT (1 << TIF_SYSCALL_AUDIT) |
124 | #define _TIF_SECCOMP (1 << TIF_SECCOMP) | |
7c68af6e | 125 | #define _TIF_USER_RETURN_NOTIFY (1 << TIF_USER_RETURN_NOTIFY) |
0326f5a9 | 126 | #define _TIF_UPROBE (1 << TIF_UPROBE) |
e57549b0 CL |
127 | #define _TIF_NOTSC (1 << TIF_NOTSC) |
128 | #define _TIF_IA32 (1 << TIF_IA32) | |
129 | #define _TIF_FORK (1 << TIF_FORK) | |
bf5a3c13 | 130 | #define _TIF_NOHZ (1 << TIF_NOHZ) |
f80c5b39 | 131 | #define _TIF_POLLING_NRFLAG (1 << TIF_POLLING_NRFLAG) |
e57549b0 | 132 | #define _TIF_IO_BITMAP (1 << TIF_IO_BITMAP) |
e57549b0 | 133 | #define _TIF_FORCED_TF (1 << TIF_FORCED_TF) |
ea8e61b7 | 134 | #define _TIF_BLOCKSTEP (1 << TIF_BLOCKSTEP) |
b407fc57 | 135 | #define _TIF_LAZY_MMU_UPDATES (1 << TIF_LAZY_MMU_UPDATES) |
66700001 | 136 | #define _TIF_SYSCALL_TRACEPOINT (1 << TIF_SYSCALL_TRACEPOINT) |
6bd33008 | 137 | #define _TIF_ADDR32 (1 << TIF_ADDR32) |
bb212724 | 138 | #define _TIF_X32 (1 << TIF_X32) |
e57549b0 | 139 | |
d4d67150 RM |
140 | /* work to do in syscall_trace_enter() */ |
141 | #define _TIF_WORK_SYSCALL_ENTRY \ | |
66700001 | 142 | (_TIF_SYSCALL_TRACE | _TIF_SYSCALL_EMU | _TIF_SYSCALL_AUDIT | \ |
bf5a3c13 FW |
143 | _TIF_SECCOMP | _TIF_SINGLESTEP | _TIF_SYSCALL_TRACEPOINT | \ |
144 | _TIF_NOHZ) | |
d4d67150 RM |
145 | |
146 | /* work to do in syscall_trace_leave() */ | |
147 | #define _TIF_WORK_SYSCALL_EXIT \ | |
1b3fa2ce | 148 | (_TIF_SYSCALL_TRACE | _TIF_SYSCALL_AUDIT | _TIF_SINGLESTEP | \ |
bf5a3c13 | 149 | _TIF_SYSCALL_TRACEPOINT | _TIF_NOHZ) |
d4d67150 | 150 | |
00c1bb13 CL |
151 | /* work to do on interrupt/exception return */ |
152 | #define _TIF_WORK_MASK \ | |
153 | (0x0000FFFF & \ | |
64f09733 | 154 | ~(_TIF_SYSCALL_TRACE|_TIF_SYSCALL_AUDIT| \ |
d4d67150 | 155 | _TIF_SINGLESTEP|_TIF_SECCOMP|_TIF_SYSCALL_EMU)) |
00c1bb13 CL |
156 | |
157 | /* work to do on any return to user space */ | |
66700001 | 158 | #define _TIF_ALLWORK_MASK \ |
bf5a3c13 FW |
159 | ((0x0000FFFF & ~_TIF_SECCOMP) | _TIF_SYSCALL_TRACEPOINT | \ |
160 | _TIF_NOHZ) | |
00c1bb13 | 161 | |
b84200b3 | 162 | /* Only used for 64 bit */ |
00c1bb13 | 163 | #define _TIF_DO_NOTIFY_MASK \ |
d4812e16 | 164 | (_TIF_SIGPENDING | _TIF_NOTIFY_RESUME | \ |
82975bc6 | 165 | _TIF_USER_RETURN_NOTIFY | _TIF_UPROBE) |
00c1bb13 CL |
166 | |
167 | /* flags to check in __switch_to() */ | |
168 | #define _TIF_WORK_CTXSW \ | |
ea8e61b7 | 169 | (_TIF_IO_BITMAP|_TIF_NOTSC|_TIF_BLOCKSTEP) |
00c1bb13 | 170 | |
7c68af6e | 171 | #define _TIF_WORK_CTXSW_PREV (_TIF_WORK_CTXSW|_TIF_USER_RETURN_NOTIFY) |
37f07655 | 172 | #define _TIF_WORK_CTXSW_NEXT (_TIF_WORK_CTXSW) |
00c1bb13 | 173 | |
198d208d | 174 | #define STACK_WARN (THREAD_SIZE/8) |
b84200b3 | 175 | |
2052e8d4 CL |
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 | ||
9af45651 | 183 | DECLARE_PER_CPU(unsigned long, kernel_stack); |
2052e8d4 | 184 | |
9af45651 | 185 | static inline struct thread_info *current_thread_info(void) |
2052e8d4 | 186 | { |
a7fcf28d | 187 | return (struct thread_info *)(current_top_of_stack() - THREAD_SIZE); |
2052e8d4 CL |
188 | } |
189 | ||
83653c16 AL |
190 | static inline unsigned long current_stack_pointer(void) |
191 | { | |
192 | unsigned long sp; | |
193 | #ifdef CONFIG_X86_64 | |
194 | asm("mov %%rsp,%0" : "=g" (sp)); | |
195 | #else | |
196 | asm("mov %%esp,%0" : "=g" (sp)); | |
197 | #endif | |
198 | return sp; | |
199 | } | |
200 | ||
2052e8d4 CL |
201 | #else /* !__ASSEMBLY__ */ |
202 | ||
ef593260 | 203 | /* Load thread_info address into "reg" */ |
2052e8d4 | 204 | #define GET_THREAD_INFO(reg) \ |
198d208d | 205 | _ASM_MOV PER_CPU_VAR(kernel_stack),reg ; \ |
ef593260 | 206 | _ASM_SUB $(THREAD_SIZE),reg ; |
2052e8d4 | 207 | |
46db09d3 | 208 | /* |
b3fe8ba3 DV |
209 | * ASM operand which evaluates to thread_info address |
210 | * if it is known that "reg" is exactly "off" bytes below stack top. | |
211 | * Example (fetch thread_info->fieldname): | |
212 | * mov TI_fieldname+THREAD_INFO(reg, off),%eax | |
46db09d3 | 213 | */ |
b3fe8ba3 | 214 | #define THREAD_INFO(reg, off) ((off)-THREAD_SIZE)(reg) |
46db09d3 | 215 | |
2052e8d4 CL |
216 | #endif |
217 | ||
2052e8d4 CL |
218 | /* |
219 | * Thread-synchronous status. | |
220 | * | |
221 | * This is different from the flags in that nobody else | |
222 | * ever touches our thread-synchronous status, so we don't | |
223 | * have to worry about atomic accesses. | |
224 | */ | |
f2ea3b1d | 225 | #define TS_COMPAT 0x0002 /* 32bit syscall active (64BIT)*/ |
8a6c160a | 226 | #define TS_RESTORE_SIGMASK 0x0008 /* restore signal mask in do_signal() */ |
2052e8d4 | 227 | |
8a6c160a IM |
228 | #ifndef __ASSEMBLY__ |
229 | #define HAVE_SET_RESTORE_SIGMASK 1 | |
230 | static inline void set_restore_sigmask(void) | |
231 | { | |
232 | struct thread_info *ti = current_thread_info(); | |
233 | ti->status |= TS_RESTORE_SIGMASK; | |
edd63a27 | 234 | WARN_ON(!test_bit(TIF_SIGPENDING, (unsigned long *)&ti->flags)); |
8a6c160a | 235 | } |
4ebefe3e AV |
236 | static inline void clear_restore_sigmask(void) |
237 | { | |
238 | current_thread_info()->status &= ~TS_RESTORE_SIGMASK; | |
239 | } | |
240 | static inline bool test_restore_sigmask(void) | |
241 | { | |
242 | return current_thread_info()->status & TS_RESTORE_SIGMASK; | |
243 | } | |
244 | static inline bool test_and_clear_restore_sigmask(void) | |
245 | { | |
246 | struct thread_info *ti = current_thread_info(); | |
247 | if (!(ti->status & TS_RESTORE_SIGMASK)) | |
248 | return false; | |
249 | ti->status &= ~TS_RESTORE_SIGMASK; | |
250 | return true; | |
251 | } | |
ef334a20 SD |
252 | |
253 | static inline bool is_ia32_task(void) | |
254 | { | |
255 | #ifdef CONFIG_X86_32 | |
256 | return true; | |
257 | #endif | |
258 | #ifdef CONFIG_IA32_EMULATION | |
259 | if (current_thread_info()->status & TS_COMPAT) | |
260 | return true; | |
261 | #endif | |
262 | return false; | |
263 | } | |
1daeaa31 BG |
264 | |
265 | /* | |
266 | * Force syscall return via IRET by making it look as if there was | |
267 | * some work pending. IRET is our most capable (but slowest) syscall | |
268 | * return path, which is able to restore modified SS, CS and certain | |
269 | * EFLAGS values that other (fast) syscall return instructions | |
270 | * are not able to restore properly. | |
271 | */ | |
272 | #define force_iret() set_thread_flag(TIF_NOTIFY_RESUME) | |
273 | ||
8a6c160a IM |
274 | #endif /* !__ASSEMBLY__ */ |
275 | ||
61c4628b SS |
276 | #ifndef __ASSEMBLY__ |
277 | extern void arch_task_cache_init(void); | |
61c4628b | 278 | extern int arch_dup_task_struct(struct task_struct *dst, struct task_struct *src); |
38e7c572 | 279 | extern void arch_release_task_struct(struct task_struct *tsk); |
61c4628b | 280 | #endif |
1965aae3 | 281 | #endif /* _ASM_X86_THREAD_INFO_H */ |