thread_info.h 8.8 KB

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  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. #ifndef _ASM_X86_THREAD_INFO_H
  7. #define _ASM_X86_THREAD_INFO_H
  8. #include <linux/compiler.h>
  9. #include <asm/page.h>
  10. #include <asm/types.h>
  11. /*
  12. * low level task data that entry.S needs immediate access to
  13. * - this struct should fit entirely inside of one cache line
  14. * - this struct shares the supervisor stack pages
  15. */
  16. #ifndef __ASSEMBLY__
  17. struct task_struct;
  18. struct exec_domain;
  19. #include <asm/processor.h>
  20. #include <asm/ftrace.h>
  21. #include <linux/atomic.h>
  22. struct thread_info {
  23. struct task_struct *task; /* main task structure */
  24. struct exec_domain *exec_domain; /* execution domain */
  25. __u32 flags; /* low level flags */
  26. __u32 status; /* thread synchronous flags */
  27. __u32 cpu; /* current CPU */
  28. int preempt_count; /* 0 => preemptable,
  29. <0 => BUG */
  30. mm_segment_t addr_limit;
  31. struct restart_block restart_block;
  32. void __user *sysenter_return;
  33. #ifdef CONFIG_X86_32
  34. unsigned long previous_esp; /* ESP of the previous stack in
  35. case of nested (IRQ) stacks
  36. */
  37. __u8 supervisor_stack[0];
  38. #endif
  39. unsigned int sig_on_uaccess_error:1;
  40. unsigned int uaccess_err:1; /* uaccess failed */
  41. };
  42. #define INIT_THREAD_INFO(tsk) \
  43. { \
  44. .task = &tsk, \
  45. .exec_domain = &default_exec_domain, \
  46. .flags = 0, \
  47. .cpu = 0, \
  48. .preempt_count = INIT_PREEMPT_COUNT, \
  49. .addr_limit = KERNEL_DS, \
  50. .restart_block = { \
  51. .fn = do_no_restart_syscall, \
  52. }, \
  53. }
  54. #define init_thread_info (init_thread_union.thread_info)
  55. #define init_stack (init_thread_union.stack)
  56. #else /* !__ASSEMBLY__ */
  57. #include <asm/asm-offsets.h>
  58. #endif
  59. /*
  60. * thread information flags
  61. * - these are process state flags that various assembly files
  62. * may need to access
  63. * - pending work-to-be-done flags are in LSW
  64. * - other flags in MSW
  65. * Warning: layout of LSW is hardcoded in entry.S
  66. */
  67. #define TIF_SYSCALL_TRACE 0 /* syscall trace active */
  68. #define TIF_NOTIFY_RESUME 1 /* callback before returning to user */
  69. #define TIF_SIGPENDING 2 /* signal pending */
  70. #define TIF_NEED_RESCHED 3 /* rescheduling necessary */
  71. #define TIF_SINGLESTEP 4 /* reenable singlestep on user return*/
  72. #define TIF_IRET 5 /* force IRET */
  73. #define TIF_SYSCALL_EMU 6 /* syscall emulation active */
  74. #define TIF_SYSCALL_AUDIT 7 /* syscall auditing active */
  75. #define TIF_SECCOMP 8 /* secure computing */
  76. #define TIF_MCE_NOTIFY 10 /* notify userspace of an MCE */
  77. #define TIF_USER_RETURN_NOTIFY 11 /* notify kernel of userspace return */
  78. #define TIF_NOTSC 16 /* TSC is not accessible in userland */
  79. #define TIF_IA32 17 /* IA32 compatibility process */
  80. #define TIF_FORK 18 /* ret_from_fork */
  81. #define TIF_MEMDIE 20 /* is terminating due to OOM killer */
  82. #define TIF_DEBUG 21 /* uses debug registers */
  83. #define TIF_IO_BITMAP 22 /* uses I/O bitmap */
  84. #define TIF_FORCED_TF 24 /* true if TF in eflags artificially */
  85. #define TIF_BLOCKSTEP 25 /* set when we want DEBUGCTLMSR_BTF */
  86. #define TIF_LAZY_MMU_UPDATES 27 /* task is updating the mmu lazily */
  87. #define TIF_SYSCALL_TRACEPOINT 28 /* syscall tracepoint instrumentation */
  88. #define TIF_ADDR32 29 /* 32-bit address space on 64 bits */
  89. #define TIF_X32 30 /* 32-bit native x86-64 binary */
  90. #define _TIF_SYSCALL_TRACE (1 << TIF_SYSCALL_TRACE)
  91. #define _TIF_NOTIFY_RESUME (1 << TIF_NOTIFY_RESUME)
  92. #define _TIF_SIGPENDING (1 << TIF_SIGPENDING)
  93. #define _TIF_SINGLESTEP (1 << TIF_SINGLESTEP)
  94. #define _TIF_NEED_RESCHED (1 << TIF_NEED_RESCHED)
  95. #define _TIF_IRET (1 << TIF_IRET)
  96. #define _TIF_SYSCALL_EMU (1 << TIF_SYSCALL_EMU)
  97. #define _TIF_SYSCALL_AUDIT (1 << TIF_SYSCALL_AUDIT)
  98. #define _TIF_SECCOMP (1 << TIF_SECCOMP)
  99. #define _TIF_MCE_NOTIFY (1 << TIF_MCE_NOTIFY)
  100. #define _TIF_USER_RETURN_NOTIFY (1 << TIF_USER_RETURN_NOTIFY)
  101. #define _TIF_NOTSC (1 << TIF_NOTSC)
  102. #define _TIF_IA32 (1 << TIF_IA32)
  103. #define _TIF_FORK (1 << TIF_FORK)
  104. #define _TIF_DEBUG (1 << TIF_DEBUG)
  105. #define _TIF_IO_BITMAP (1 << TIF_IO_BITMAP)
  106. #define _TIF_FORCED_TF (1 << TIF_FORCED_TF)
  107. #define _TIF_BLOCKSTEP (1 << TIF_BLOCKSTEP)
  108. #define _TIF_LAZY_MMU_UPDATES (1 << TIF_LAZY_MMU_UPDATES)
  109. #define _TIF_SYSCALL_TRACEPOINT (1 << TIF_SYSCALL_TRACEPOINT)
  110. #define _TIF_ADDR32 (1 << TIF_ADDR32)
  111. #define _TIF_X32 (1 << TIF_X32)
  112. /* work to do in syscall_trace_enter() */
  113. #define _TIF_WORK_SYSCALL_ENTRY \
  114. (_TIF_SYSCALL_TRACE | _TIF_SYSCALL_EMU | _TIF_SYSCALL_AUDIT | \
  115. _TIF_SECCOMP | _TIF_SINGLESTEP | _TIF_SYSCALL_TRACEPOINT)
  116. /* work to do in syscall_trace_leave() */
  117. #define _TIF_WORK_SYSCALL_EXIT \
  118. (_TIF_SYSCALL_TRACE | _TIF_SYSCALL_AUDIT | _TIF_SINGLESTEP | \
  119. _TIF_SYSCALL_TRACEPOINT)
  120. /* work to do on interrupt/exception return */
  121. #define _TIF_WORK_MASK \
  122. (0x0000FFFF & \
  123. ~(_TIF_SYSCALL_TRACE|_TIF_SYSCALL_AUDIT| \
  124. _TIF_SINGLESTEP|_TIF_SECCOMP|_TIF_SYSCALL_EMU))
  125. /* work to do on any return to user space */
  126. #define _TIF_ALLWORK_MASK \
  127. ((0x0000FFFF & ~_TIF_SECCOMP) | _TIF_SYSCALL_TRACEPOINT)
  128. /* Only used for 64 bit */
  129. #define _TIF_DO_NOTIFY_MASK \
  130. (_TIF_SIGPENDING | _TIF_MCE_NOTIFY | _TIF_NOTIFY_RESUME | \
  131. _TIF_USER_RETURN_NOTIFY)
  132. /* flags to check in __switch_to() */
  133. #define _TIF_WORK_CTXSW \
  134. (_TIF_IO_BITMAP|_TIF_NOTSC|_TIF_BLOCKSTEP)
  135. #define _TIF_WORK_CTXSW_PREV (_TIF_WORK_CTXSW|_TIF_USER_RETURN_NOTIFY)
  136. #define _TIF_WORK_CTXSW_NEXT (_TIF_WORK_CTXSW|_TIF_DEBUG)
  137. #define PREEMPT_ACTIVE 0x10000000
  138. /* thread information allocation */
  139. #ifdef CONFIG_DEBUG_STACK_USAGE
  140. #define THREAD_FLAGS (GFP_KERNEL | __GFP_NOTRACK | __GFP_ZERO)
  141. #else
  142. #define THREAD_FLAGS (GFP_KERNEL | __GFP_NOTRACK)
  143. #endif
  144. #define __HAVE_ARCH_THREAD_INFO_ALLOCATOR
  145. #define alloc_thread_info_node(tsk, node) \
  146. ({ \
  147. struct page *page = alloc_pages_node(node, THREAD_FLAGS, \
  148. THREAD_ORDER); \
  149. struct thread_info *ret = page ? page_address(page) : NULL; \
  150. \
  151. ret; \
  152. })
  153. #ifdef CONFIG_X86_32
  154. #define STACK_WARN (THREAD_SIZE/8)
  155. /*
  156. * macros/functions for gaining access to the thread information structure
  157. *
  158. * preempt_count needs to be 1 initially, until the scheduler is functional.
  159. */
  160. #ifndef __ASSEMBLY__
  161. /* how to get the current stack pointer from C */
  162. register unsigned long current_stack_pointer asm("esp") __used;
  163. /* how to get the thread information struct from C */
  164. static inline struct thread_info *current_thread_info(void)
  165. {
  166. return (struct thread_info *)
  167. (current_stack_pointer & ~(THREAD_SIZE - 1));
  168. }
  169. #else /* !__ASSEMBLY__ */
  170. /* how to get the thread information struct from ASM */
  171. #define GET_THREAD_INFO(reg) \
  172. movl $-THREAD_SIZE, reg; \
  173. andl %esp, reg
  174. /* use this one if reg already contains %esp */
  175. #define GET_THREAD_INFO_WITH_ESP(reg) \
  176. andl $-THREAD_SIZE, reg
  177. #endif
  178. #else /* X86_32 */
  179. #include <asm/percpu.h>
  180. #define KERNEL_STACK_OFFSET (5*8)
  181. /*
  182. * macros/functions for gaining access to the thread information structure
  183. * preempt_count needs to be 1 initially, until the scheduler is functional.
  184. */
  185. #ifndef __ASSEMBLY__
  186. DECLARE_PER_CPU(unsigned long, kernel_stack);
  187. static inline struct thread_info *current_thread_info(void)
  188. {
  189. struct thread_info *ti;
  190. ti = (void *)(percpu_read_stable(kernel_stack) +
  191. KERNEL_STACK_OFFSET - THREAD_SIZE);
  192. return ti;
  193. }
  194. #else /* !__ASSEMBLY__ */
  195. /* how to get the thread information struct from ASM */
  196. #define GET_THREAD_INFO(reg) \
  197. movq PER_CPU_VAR(kernel_stack),reg ; \
  198. subq $(THREAD_SIZE-KERNEL_STACK_OFFSET),reg
  199. /*
  200. * Same if PER_CPU_VAR(kernel_stack) is, perhaps with some offset, already in
  201. * a certain register (to be used in assembler memory operands).
  202. */
  203. #define THREAD_INFO(reg, off) KERNEL_STACK_OFFSET+(off)-THREAD_SIZE(reg)
  204. #endif
  205. #endif /* !X86_32 */
  206. /*
  207. * Thread-synchronous status.
  208. *
  209. * This is different from the flags in that nobody else
  210. * ever touches our thread-synchronous status, so we don't
  211. * have to worry about atomic accesses.
  212. */
  213. #define TS_COMPAT 0x0002 /* 32bit syscall active (64BIT)*/
  214. #define TS_POLLING 0x0004 /* idle task polling need_resched,
  215. skip sending interrupt */
  216. #define TS_RESTORE_SIGMASK 0x0008 /* restore signal mask in do_signal() */
  217. #define tsk_is_polling(t) (task_thread_info(t)->status & TS_POLLING)
  218. #ifndef __ASSEMBLY__
  219. #define HAVE_SET_RESTORE_SIGMASK 1
  220. static inline void set_restore_sigmask(void)
  221. {
  222. struct thread_info *ti = current_thread_info();
  223. ti->status |= TS_RESTORE_SIGMASK;
  224. set_bit(TIF_SIGPENDING, (unsigned long *)&ti->flags);
  225. }
  226. static inline bool is_ia32_task(void)
  227. {
  228. #ifdef CONFIG_X86_32
  229. return true;
  230. #endif
  231. #ifdef CONFIG_IA32_EMULATION
  232. if (current_thread_info()->status & TS_COMPAT)
  233. return true;
  234. #endif
  235. return false;
  236. }
  237. #endif /* !__ASSEMBLY__ */
  238. #ifndef __ASSEMBLY__
  239. extern void arch_task_cache_init(void);
  240. extern void free_thread_info(struct thread_info *ti);
  241. extern int arch_dup_task_struct(struct task_struct *dst, struct task_struct *src);
  242. #define arch_task_cache_init arch_task_cache_init
  243. #endif
  244. #endif /* _ASM_X86_THREAD_INFO_H */