File: /Users/paulross/dev/linux/linux-3.13/arch/x86/include/asm/thread_info.h

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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: 
       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            saved_preempt_count;
      32:     mm_segment_t        addr_limit;
      33:     struct restart_block    restart_block;
      34:     void __user        *sysenter_return;
      35: #ifdef CONFIG_X86_32
      36:     unsigned long           previous_esp;   /* ESP of the previous stack in
      37:                            case of nested (IRQ) stacks
      38:                         */
      39:     __u8            supervisor_stack[0];
      40: #endif
      41:     unsigned int        sig_on_uaccess_error:1;
      42:     unsigned int        uaccess_err:1;    /* uaccess failed */
      43: };
      44: 
      45: #define INIT_THREAD_INFO(tsk)            \
      46: {                        \
      47:     .task        = &tsk,            \
      48:     .exec_domain    = &default_exec_domain,    \
      49:     .flags        = 0,            \
      50:     .cpu        = 0,            \
      51:     .saved_preempt_count = INIT_PREEMPT_COUNT,    \
      52:     .addr_limit    = KERNEL_DS,        \
      53:     .restart_block = {            \
      54:         .fn = do_no_restart_syscall,    \
      55:     },                    \
      56: }
      57: 
      58: #define init_thread_info    (init_thread_union.thread_info)
      59: #define init_stack        (init_thread_union.stack)
      60: 
      61: #else /* !__ASSEMBLY__ */
      62: 
      63: #include <asm/asm-offsets.h>
      64: 
      65: #endif
      66: 
      67: /*
      68:  * thread information flags
      69:  * - these are process state flags that various assembly files
      70:  *   may need to access
      71:  * - pending work-to-be-done flags are in LSW
      72:  * - other flags in MSW
      73:  * Warning: layout of LSW is hardcoded in entry.S
      74:  */
      75: #define TIF_SYSCALL_TRACE    0    /* syscall trace active */
      76: #define TIF_NOTIFY_RESUME    1    /* callback before returning to user */
      77: #define TIF_SIGPENDING        2    /* signal pending */
      78: #define TIF_NEED_RESCHED    3    /* rescheduling necessary */
      79: #define TIF_SINGLESTEP        4    /* reenable singlestep on user return*/
      80: #define TIF_SYSCALL_EMU        6    /* syscall emulation active */
      81: #define TIF_SYSCALL_AUDIT    7    /* syscall auditing active */
      82: #define TIF_SECCOMP        8    /* secure computing */
      83: #define TIF_MCE_NOTIFY        10    /* notify userspace of an MCE */
      84: #define TIF_USER_RETURN_NOTIFY    11    /* notify kernel of userspace return */
      85: #define TIF_UPROBE        12    /* breakpointed or singlestepping */
      86: #define TIF_NOTSC        16    /* TSC is not accessible in userland */
      87: #define TIF_IA32        17    /* IA32 compatibility process */
      88: #define TIF_FORK        18    /* ret_from_fork */
      89: #define TIF_NOHZ        19    /* in adaptive nohz mode */
      90: #define TIF_MEMDIE        20    /* is terminating due to OOM killer */
      91: #define TIF_IO_BITMAP        22    /* uses I/O bitmap */
      92: #define TIF_FORCED_TF        24    /* true if TF in eflags artificially */
      93: #define TIF_BLOCKSTEP        25    /* set when we want DEBUGCTLMSR_BTF */
      94: #define TIF_LAZY_MMU_UPDATES    27    /* task is updating the mmu lazily */
      95: #define TIF_SYSCALL_TRACEPOINT    28    /* syscall tracepoint instrumentation */
      96: #define TIF_ADDR32        29    /* 32-bit address space on 64 bits */
      97: #define TIF_X32            30    /* 32-bit native x86-64 binary */
      98: 
      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_SYSCALL_EMU    (1 << TIF_SYSCALL_EMU)
     105: #define _TIF_SYSCALL_AUDIT    (1 << TIF_SYSCALL_AUDIT)
     106: #define _TIF_SECCOMP        (1 << TIF_SECCOMP)
     107: #define _TIF_MCE_NOTIFY        (1 << TIF_MCE_NOTIFY)
     108: #define _TIF_USER_RETURN_NOTIFY    (1 << TIF_USER_RETURN_NOTIFY)
     109: #define _TIF_UPROBE        (1 << TIF_UPROBE)
     110: #define _TIF_NOTSC        (1 << TIF_NOTSC)
     111: #define _TIF_IA32        (1 << TIF_IA32)
     112: #define _TIF_FORK        (1 << TIF_FORK)
     113: #define _TIF_NOHZ        (1 << TIF_NOHZ)
     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)
     119: #define _TIF_ADDR32        (1 << TIF_ADDR32)
     120: #define _TIF_X32        (1 << TIF_X32)
     121: 
     122: /* work to do in syscall_trace_enter() */
     123: #define _TIF_WORK_SYSCALL_ENTRY    \
     124:     (_TIF_SYSCALL_TRACE | _TIF_SYSCALL_EMU | _TIF_SYSCALL_AUDIT |    \
     125:      _TIF_SECCOMP | _TIF_SINGLESTEP | _TIF_SYSCALL_TRACEPOINT |    \
     126:      _TIF_NOHZ)
     127: 
     128: /* work to do in syscall_trace_leave() */
     129: #define _TIF_WORK_SYSCALL_EXIT    \
     130:     (_TIF_SYSCALL_TRACE | _TIF_SYSCALL_AUDIT | _TIF_SINGLESTEP |    \
     131:      _TIF_SYSCALL_TRACEPOINT | _TIF_NOHZ)
     132: 
     133: /* work to do on interrupt/exception return */
     134: #define _TIF_WORK_MASK                            \
     135:     (0x0000FFFF &                            \
     136:      ~(_TIF_SYSCALL_TRACE|_TIF_SYSCALL_AUDIT|            \
     137:        _TIF_SINGLESTEP|_TIF_SECCOMP|_TIF_SYSCALL_EMU))
     138: 
     139: /* work to do on any return to user space */
     140: #define _TIF_ALLWORK_MASK                        \
     141:     ((0x0000FFFF & ~_TIF_SECCOMP) | _TIF_SYSCALL_TRACEPOINT |    \
     142:     _TIF_NOHZ)
     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)
     155: 
     156: #ifdef CONFIG_X86_32
     157: 
     158: #define STACK_WARN    (THREAD_SIZE/8)
     159: /*
     160:  * macros/functions for gaining access to the thread information structure
     161:  *
     162:  * preempt_count needs to be 1 initially, until the scheduler is functional.
     163:  */
     164: #ifndef __ASSEMBLY__
     165: 
     166: 
     167: /* how to get the current stack pointer from C */
     168: register unsigned long current_stack_pointer asm("esp") __used;
     169: 
     170: /* how to get the thread information struct from C */
     171: static inline struct thread_info *current_thread_info(void)
     172: {
     173:     return (struct thread_info *)
     174:         (current_stack_pointer & ~(THREAD_SIZE - 1));
     175: }
     176: 
     177: #else /* !__ASSEMBLY__ */
     178: 
     179: /* how to get the thread information struct from ASM */
     180: #define GET_THREAD_INFO(reg)     \
     181:     movl $-THREAD_SIZE, reg; \
     182:     andl %esp, reg
     183: 
     184: /* use this one if reg already contains %esp */
     185: #define GET_THREAD_INFO_WITH_ESP(reg) \
     186:     andl $-THREAD_SIZE, reg
     187: 
     188: #endif
     189: 
     190: #else /* X86_32 */
     191: 
     192: #include <asm/percpu.h>
     193: #define KERNEL_STACK_OFFSET (5*8)
     194: 
     195: /*
     196:  * macros/functions for gaining access to the thread information structure
     197:  * preempt_count needs to be 1 initially, until the scheduler is functional.
     198:  */
     199: #ifndef __ASSEMBLY__
     200: DECLARE_PER_CPU(unsigned long, kernel_stack);
     201: 
     202: static inline struct thread_info *current_thread_info(void)
     203: {
     204:     struct thread_info *ti;
     205:     ti = (void *)(this_cpu_read_stable(kernel_stack) +
     206:               KERNEL_STACK_OFFSET - THREAD_SIZE);
     207:     return ti;
     208: }
     209: 
     210: #else /* !__ASSEMBLY__ */
     211: 
     212: /* how to get the thread information struct from ASM */
     213: #define GET_THREAD_INFO(reg) \
     214:     movq PER_CPU_VAR(kernel_stack),reg ; \
     215:     subq $(THREAD_SIZE-KERNEL_STACK_OFFSET),reg
     216: 
     217: /*
     218:  * Same if PER_CPU_VAR(kernel_stack) is, perhaps with some offset, already in
     219:  * a certain register (to be used in assembler memory operands).
     220:  */
     221: #define THREAD_INFO(reg, off) KERNEL_STACK_OFFSET+(off)-THREAD_SIZE(reg)
     222: 
     223: #endif
     224: 
     225: #endif /* !X86_32 */
     226: 
     227: /*
     228:  * Thread-synchronous status.
     229:  *
     230:  * This is different from the flags in that nobody else
     231:  * ever touches our thread-synchronous status, so we don't
     232:  * have to worry about atomic accesses.
     233:  */
     234: #define TS_COMPAT        0x0002    /* 32bit syscall active (64BIT)*/
     235: #define TS_POLLING        0x0004    /* idle task polling need_resched,
     236:                        skip sending interrupt */
     237: #define TS_RESTORE_SIGMASK    0x0008    /* restore signal mask in do_signal() */
     238: 
     239: #ifndef __ASSEMBLY__
     240: #define HAVE_SET_RESTORE_SIGMASK    1
     241: static inline void set_restore_sigmask(void)
     242: {
     243:     struct thread_info *ti = current_thread_info();
     244:     ti->status |= TS_RESTORE_SIGMASK;
     245:     WARN_ON(!test_bit(TIF_SIGPENDING, (unsigned long *)&ti->flags));
     246: }
     247: static inline void clear_restore_sigmask(void)
     248: {
     249:     current_thread_info()->status &= ~TS_RESTORE_SIGMASK;
     250: }
     251: static inline bool test_restore_sigmask(void)
     252: {
     253:     return current_thread_info()->status & TS_RESTORE_SIGMASK;
     254: }
     255: static inline bool test_and_clear_restore_sigmask(void)
     256: {
     257:     struct thread_info *ti = current_thread_info();
     258:     if (!(ti->status & TS_RESTORE_SIGMASK))
     259:         return false;
     260:     ti->status &= ~TS_RESTORE_SIGMASK;
     261:     return true;
     262: }
     263: 
     264: static inline bool is_ia32_task(void)
     265: {
     266: #ifdef CONFIG_X86_32
     267:     return true;
     268: #endif
     269: #ifdef CONFIG_IA32_EMULATION
     270:     if (current_thread_info()->status & TS_COMPAT)
     271:         return true;
     272: #endif
     273:     return false;
     274: }
     275: #endif    /* !__ASSEMBLY__ */
     276: 
     277: #ifndef __ASSEMBLY__
     278: extern void arch_task_cache_init(void);
     279: extern int arch_dup_task_struct(struct task_struct *dst, struct task_struct *src);
     280: extern void arch_release_task_struct(struct task_struct *tsk);
     281: #endif
     282: #endif /* _ASM_X86_THREAD_INFO_H */
     283: