1 /* thread_info.h: low-level thread information
3 * Copyright (C) 2002 David Howells (dhowells@redhat.com)
4 * - Incorporating suggestions made by Linus Torvalds and Dave Miller
7 #ifndef _ASM_X86_THREAD_INFO_H
8 #define _ASM_X86_THREAD_INFO_H
10 #include <linux/compiler.h>
12 #include <asm/types.h>
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
22 #include <asm/processor.h>
23 #include <asm/ftrace.h>
24 #include <linux/atomic.h>
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,
34 mm_segment_t addr_limit
;
35 struct restart_block restart_block
;
36 void __user
*sysenter_return
;
38 unsigned long previous_esp
; /* ESP of the previous stack in
39 case of nested (IRQ) stacks
41 __u8 supervisor_stack
[0];
43 unsigned int sig_on_uaccess_error
:1;
44 unsigned int uaccess_err
:1; /* uaccess failed */
47 #define INIT_THREAD_INFO(tsk) \
50 .exec_domain = &default_exec_domain, \
53 .preempt_count = INIT_PREEMPT_COUNT, \
54 .addr_limit = KERNEL_DS, \
56 .fn = do_no_restart_syscall, \
60 #define init_thread_info (init_thread_union.thread_info)
61 #define init_stack (init_thread_union.stack)
63 #else /* !__ASSEMBLY__ */
65 #include <asm/asm-offsets.h>
70 * thread information flags
71 * - these are process state flags that various assembly files
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
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 /* 32bit 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 */
99 #define _TIF_SYSCALL_TRACE (1 << TIF_SYSCALL_TRACE)
100 #define _TIF_NOTIFY_RESUME (1 << TIF_NOTIFY_RESUME)
101 #define _TIF_SIGPENDING (1 << TIF_SIGPENDING)
102 #define _TIF_SINGLESTEP (1 << TIF_SINGLESTEP)
103 #define _TIF_NEED_RESCHED (1 << TIF_NEED_RESCHED)
104 #define _TIF_IRET (1 << TIF_IRET)
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_NOTSC (1 << TIF_NOTSC)
111 #define _TIF_IA32 (1 << TIF_IA32)
112 #define _TIF_FORK (1 << TIF_FORK)
113 #define _TIF_DEBUG (1 << TIF_DEBUG)
114 #define _TIF_IO_BITMAP (1 << TIF_IO_BITMAP)
115 #define _TIF_FORCED_TF (1 << TIF_FORCED_TF)
116 #define _TIF_BLOCKSTEP (1 << TIF_BLOCKSTEP)
117 #define _TIF_LAZY_MMU_UPDATES (1 << TIF_LAZY_MMU_UPDATES)
118 #define _TIF_SYSCALL_TRACEPOINT (1 << TIF_SYSCALL_TRACEPOINT)
120 /* work to do in syscall_trace_enter() */
121 #define _TIF_WORK_SYSCALL_ENTRY \
122 (_TIF_SYSCALL_TRACE | _TIF_SYSCALL_EMU | _TIF_SYSCALL_AUDIT | \
123 _TIF_SECCOMP | _TIF_SINGLESTEP | _TIF_SYSCALL_TRACEPOINT)
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)
130 /* work to do on interrupt/exception return */
131 #define _TIF_WORK_MASK \
133 ~(_TIF_SYSCALL_TRACE|_TIF_SYSCALL_AUDIT| \
134 _TIF_SINGLESTEP|_TIF_SECCOMP|_TIF_SYSCALL_EMU))
136 /* work to do on any return to user space */
137 #define _TIF_ALLWORK_MASK \
138 ((0x0000FFFF & ~_TIF_SECCOMP) | _TIF_SYSCALL_TRACEPOINT)
140 /* Only used for 64 bit */
141 #define _TIF_DO_NOTIFY_MASK \
142 (_TIF_SIGPENDING | _TIF_MCE_NOTIFY | _TIF_NOTIFY_RESUME | \
143 _TIF_USER_RETURN_NOTIFY)
145 /* flags to check in __switch_to() */
146 #define _TIF_WORK_CTXSW \
147 (_TIF_IO_BITMAP|_TIF_NOTSC|_TIF_BLOCKSTEP)
149 #define _TIF_WORK_CTXSW_PREV (_TIF_WORK_CTXSW|_TIF_USER_RETURN_NOTIFY)
150 #define _TIF_WORK_CTXSW_NEXT (_TIF_WORK_CTXSW|_TIF_DEBUG)
152 #define PREEMPT_ACTIVE 0x10000000
154 /* thread information allocation */
155 #ifdef CONFIG_DEBUG_STACK_USAGE
156 #define THREAD_FLAGS (GFP_KERNEL | __GFP_NOTRACK | __GFP_ZERO)
158 #define THREAD_FLAGS (GFP_KERNEL | __GFP_NOTRACK)
161 #define __HAVE_ARCH_THREAD_INFO_ALLOCATOR
163 #define alloc_thread_info_node(tsk, node) \
165 struct page *page = alloc_pages_node(node, THREAD_FLAGS, \
167 struct thread_info *ret = page ? page_address(page) : NULL; \
174 #define STACK_WARN (THREAD_SIZE/8)
176 * macros/functions for gaining access to the thread information structure
178 * preempt_count needs to be 1 initially, until the scheduler is functional.
183 /* how to get the current stack pointer from C */
184 register unsigned long current_stack_pointer
asm("esp") __used
;
186 /* how to get the thread information struct from C */
187 static inline struct thread_info
*current_thread_info(void)
189 return (struct thread_info
*)
190 (current_stack_pointer
& ~(THREAD_SIZE
- 1));
193 #else /* !__ASSEMBLY__ */
195 /* how to get the thread information struct from ASM */
196 #define GET_THREAD_INFO(reg) \
197 movl $-THREAD_SIZE, reg; \
200 /* use this one if reg already contains %esp */
201 #define GET_THREAD_INFO_WITH_ESP(reg) \
202 andl $-THREAD_SIZE, reg
208 #include <asm/percpu.h>
209 #define KERNEL_STACK_OFFSET (5*8)
212 * macros/functions for gaining access to the thread information structure
213 * preempt_count needs to be 1 initially, until the scheduler is functional.
216 DECLARE_PER_CPU(unsigned long, kernel_stack
);
218 static inline struct thread_info
*current_thread_info(void)
220 struct thread_info
*ti
;
221 ti
= (void *)(percpu_read_stable(kernel_stack
) +
222 KERNEL_STACK_OFFSET
- THREAD_SIZE
);
226 #else /* !__ASSEMBLY__ */
228 /* how to get the thread information struct from ASM */
229 #define GET_THREAD_INFO(reg) \
230 movq PER_CPU_VAR(kernel_stack),reg ; \
231 subq $(THREAD_SIZE-KERNEL_STACK_OFFSET),reg
234 * Same if PER_CPU_VAR(kernel_stack) is, perhaps with some offset, already in
235 * a certain register (to be used in assembler memory operands).
237 #define THREAD_INFO(reg, off) KERNEL_STACK_OFFSET+(off)-THREAD_SIZE(reg)
244 * Thread-synchronous status.
246 * This is different from the flags in that nobody else
247 * ever touches our thread-synchronous status, so we don't
248 * have to worry about atomic accesses.
250 #define TS_USEDFPU 0x0001 /* FPU was used by this task
251 this quantum (SMP) */
252 #define TS_COMPAT 0x0002 /* 32bit syscall active (64BIT)*/
253 #define TS_POLLING 0x0004 /* idle task polling need_resched,
254 skip sending interrupt */
255 #define TS_RESTORE_SIGMASK 0x0008 /* restore signal mask in do_signal() */
257 #define tsk_is_polling(t) (task_thread_info(t)->status & TS_POLLING)
260 #define HAVE_SET_RESTORE_SIGMASK 1
261 static inline void set_restore_sigmask(void)
263 struct thread_info
*ti
= current_thread_info();
264 ti
->status
|= TS_RESTORE_SIGMASK
;
265 set_bit(TIF_SIGPENDING
, (unsigned long *)&ti
->flags
);
267 #endif /* !__ASSEMBLY__ */
270 extern void arch_task_cache_init(void);
271 extern void free_thread_info(struct thread_info
*ti
);
272 extern int arch_dup_task_struct(struct task_struct
*dst
, struct task_struct
*src
);
273 #define arch_task_cache_init arch_task_cache_init
275 #endif /* _ASM_X86_THREAD_INFO_H */