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root/include/asm-x86/thread_info.h

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INCLUDED FROM


DEFINITIONS

This source file includes following definitions.
  1. current_thread_info
  2. current_thread_info
  3. stack_thread_info
  4. set_restore_sigmask

/* thread_info.h: low-level thread information
 *
 * Copyright (C) 2002  David Howells (dhowells@redhat.com)
 * - Incorporating suggestions made by Linus Torvalds and Dave Miller
 */

#ifndef ASM_X86__THREAD_INFO_H
#define ASM_X86__THREAD_INFO_H

#include <linux/compiler.h>
#include <asm/page.h>
#include <asm/types.h>

/*
 * low level task data that entry.S needs immediate access to
 * - this struct should fit entirely inside of one cache line
 * - this struct shares the supervisor stack pages
 */
#ifndef __ASSEMBLY__
struct task_struct;
struct exec_domain;
#include <asm/processor.h>

struct thread_info {
        struct task_struct      *task;          /* main task structure */
        struct exec_domain      *exec_domain;   /* execution domain */
        unsigned long           flags;          /* low level flags */
        __u32                   status;         /* thread synchronous flags */
        __u32                   cpu;            /* current CPU */
        int                     preempt_count;  /* 0 => preemptable,
                                                   <0 => BUG */
        mm_segment_t            addr_limit;
        struct restart_block    restart_block;
        void __user             *sysenter_return;
#ifdef CONFIG_X86_32
        unsigned long           previous_esp;   /* ESP of the previous stack in
                                                   case of nested (IRQ) stacks
                                                */
        __u8                    supervisor_stack[0];
#endif
};

#define INIT_THREAD_INFO(tsk)                   \
{                                               \
        .task           = &tsk,                 \
        .exec_domain    = &default_exec_domain, \
        .flags          = 0,                    \
        .cpu            = 0,                    \
        .preempt_count  = 1,                    \
        .addr_limit     = KERNEL_DS,            \
        .restart_block = {                      \
                .fn = do_no_restart_syscall,    \
        },                                      \
}

#define init_thread_info        (init_thread_union.thread_info)
#define init_stack              (init_thread_union.stack)

#else /* !__ASSEMBLY__ */

#include <asm/asm-offsets.h>

#endif

/*
 * thread information flags
 * - these are process state flags that various assembly files
 *   may need to access
 * - pending work-to-be-done flags are in LSW
 * - other flags in MSW
 * Warning: layout of LSW is hardcoded in entry.S
 */
#define TIF_SYSCALL_TRACE       0       /* syscall trace active */
#define TIF_NOTIFY_RESUME       1       /* callback before returning to user */
#define TIF_SIGPENDING          2       /* signal pending */
#define TIF_NEED_RESCHED        3       /* rescheduling necessary */
#define TIF_SINGLESTEP          4       /* reenable singlestep on user return*/
#define TIF_IRET                5       /* force IRET */
#define TIF_SYSCALL_EMU         6       /* syscall emulation active */
#define TIF_SYSCALL_AUDIT       7       /* syscall auditing active */
#define TIF_SECCOMP             8       /* secure computing */
#define TIF_MCE_NOTIFY          10      /* notify userspace of an MCE */
#define TIF_NOTSC               16      /* TSC is not accessible in userland */
#define TIF_IA32                17      /* 32bit process */
#define TIF_FORK                18      /* ret_from_fork */
#define TIF_ABI_PENDING         19
#define TIF_MEMDIE              20
#define TIF_DEBUG               21      /* uses debug registers */
#define TIF_IO_BITMAP           22      /* uses I/O bitmap */
#define TIF_FREEZE              23      /* is freezing for suspend */
#define TIF_FORCED_TF           24      /* true if TF in eflags artificially */
#define TIF_DEBUGCTLMSR         25      /* uses thread_struct.debugctlmsr */
#define TIF_DS_AREA_MSR         26      /* uses thread_struct.ds_area_msr */
#define TIF_BTS_TRACE_TS        27      /* record scheduling event timestamps */

#define _TIF_SYSCALL_TRACE      (1 << TIF_SYSCALL_TRACE)
#define _TIF_NOTIFY_RESUME      (1 << TIF_NOTIFY_RESUME)
#define _TIF_SIGPENDING         (1 << TIF_SIGPENDING)
#define _TIF_SINGLESTEP         (1 << TIF_SINGLESTEP)
#define _TIF_NEED_RESCHED       (1 << TIF_NEED_RESCHED)
#define _TIF_IRET               (1 << TIF_IRET)
#define _TIF_SYSCALL_EMU        (1 << TIF_SYSCALL_EMU)
#define _TIF_SYSCALL_AUDIT      (1 << TIF_SYSCALL_AUDIT)
#define _TIF_SECCOMP            (1 << TIF_SECCOMP)
#define _TIF_MCE_NOTIFY         (1 << TIF_MCE_NOTIFY)
#define _TIF_NOTSC              (1 << TIF_NOTSC)
#define _TIF_IA32               (1 << TIF_IA32)
#define _TIF_FORK               (1 << TIF_FORK)
#define _TIF_ABI_PENDING        (1 << TIF_ABI_PENDING)
#define _TIF_DEBUG              (1 << TIF_DEBUG)
#define _TIF_IO_BITMAP          (1 << TIF_IO_BITMAP)
#define _TIF_FREEZE             (1 << TIF_FREEZE)
#define _TIF_FORCED_TF          (1 << TIF_FORCED_TF)
#define _TIF_DEBUGCTLMSR        (1 << TIF_DEBUGCTLMSR)
#define _TIF_DS_AREA_MSR        (1 << TIF_DS_AREA_MSR)
#define _TIF_BTS_TRACE_TS       (1 << TIF_BTS_TRACE_TS)

/* work to do in syscall_trace_enter() */
#define _TIF_WORK_SYSCALL_ENTRY \
        (_TIF_SYSCALL_TRACE | _TIF_SYSCALL_EMU | \
         _TIF_SYSCALL_AUDIT | _TIF_SECCOMP | _TIF_SINGLESTEP)

/* work to do in syscall_trace_leave() */
#define _TIF_WORK_SYSCALL_EXIT  \
        (_TIF_SYSCALL_TRACE | _TIF_SYSCALL_AUDIT | _TIF_SINGLESTEP)

/* work to do on interrupt/exception return */
#define _TIF_WORK_MASK                                                  \
        (0x0000FFFF &                                                   \
         ~(_TIF_SYSCALL_TRACE|_TIF_SYSCALL_AUDIT|                       \
           _TIF_SINGLESTEP|_TIF_SECCOMP|_TIF_SYSCALL_EMU))

/* work to do on any return to user space */
#define _TIF_ALLWORK_MASK (0x0000FFFF & ~_TIF_SECCOMP)

/* Only used for 64 bit */
#define _TIF_DO_NOTIFY_MASK                                             \
        (_TIF_SIGPENDING|_TIF_MCE_NOTIFY|_TIF_NOTIFY_RESUME)

/* flags to check in __switch_to() */
#define _TIF_WORK_CTXSW                                                 \
        (_TIF_IO_BITMAP|_TIF_DEBUGCTLMSR|_TIF_DS_AREA_MSR|_TIF_BTS_TRACE_TS| \
                                                                _TIF_NOTSC)

#define _TIF_WORK_CTXSW_PREV _TIF_WORK_CTXSW
#define _TIF_WORK_CTXSW_NEXT (_TIF_WORK_CTXSW|_TIF_DEBUG)

#define PREEMPT_ACTIVE          0x10000000

/* thread information allocation */
#ifdef CONFIG_DEBUG_STACK_USAGE
#define THREAD_FLAGS (GFP_KERNEL | __GFP_ZERO)
#else
#define THREAD_FLAGS GFP_KERNEL
#endif

#define __HAVE_ARCH_THREAD_INFO_ALLOCATOR

#define alloc_thread_info(tsk)                                          \
        ((struct thread_info *)__get_free_pages(THREAD_FLAGS, THREAD_ORDER))

#ifdef CONFIG_X86_32

#define STACK_WARN      (THREAD_SIZE/8)
/*
 * macros/functions for gaining access to the thread information structure
 *
 * preempt_count needs to be 1 initially, until the scheduler is functional.
 */
#ifndef __ASSEMBLY__


/* how to get the current stack pointer from C */
register unsigned long current_stack_pointer asm("esp") __used;

/* how to get the thread information struct from C */
static inline struct thread_info *current_thread_info(void)
{
        return (struct thread_info *)
                (current_stack_pointer & ~(THREAD_SIZE - 1));
}

#else /* !__ASSEMBLY__ */

/* how to get the thread information struct from ASM */
#define GET_THREAD_INFO(reg)     \
        movl $-THREAD_SIZE, reg; \
        andl %esp, reg

/* use this one if reg already contains %esp */
#define GET_THREAD_INFO_WITH_ESP(reg) \
        andl $-THREAD_SIZE, reg

#endif

#else /* X86_32 */

#include <asm/pda.h>

/*
 * macros/functions for gaining access to the thread information structure
 * preempt_count needs to be 1 initially, until the scheduler is functional.
 */
#ifndef __ASSEMBLY__
static inline struct thread_info *current_thread_info(void)
{
        struct thread_info *ti;
        ti = (void *)(read_pda(kernelstack) + PDA_STACKOFFSET - THREAD_SIZE);
        return ti;
}

/* do not use in interrupt context */
static inline struct thread_info *stack_thread_info(void)
{
        struct thread_info *ti;
        asm("andq %%rsp,%0; " : "=r" (ti) : "0" (~(THREAD_SIZE - 1)));
        return ti;
}

#else /* !__ASSEMBLY__ */

/* how to get the thread information struct from ASM */
#define GET_THREAD_INFO(reg) \
        movq %gs:pda_kernelstack,reg ; \
        subq $(THREAD_SIZE-PDA_STACKOFFSET),reg

#endif

#endif /* !X86_32 */

/*
 * Thread-synchronous status.
 *
 * This is different from the flags in that nobody else
 * ever touches our thread-synchronous status, so we don't
 * have to worry about atomic accesses.
 */
#define TS_USEDFPU              0x0001  /* FPU was used by this task
                                           this quantum (SMP) */
#define TS_COMPAT               0x0002  /* 32bit syscall active (64BIT)*/
#define TS_POLLING              0x0004  /* true if in idle loop
                                           and not sleeping */
#define TS_RESTORE_SIGMASK      0x0008  /* restore signal mask in do_signal() */
#define TS_XSAVE                0x0010  /* Use xsave/xrstor */

#define tsk_is_polling(t) (task_thread_info(t)->status & TS_POLLING)

#ifndef __ASSEMBLY__
#define HAVE_SET_RESTORE_SIGMASK        1
static inline void set_restore_sigmask(void)
{
        struct thread_info *ti = current_thread_info();
        ti->status |= TS_RESTORE_SIGMASK;
        set_bit(TIF_SIGPENDING, (unsigned long *)&ti->flags);
}
#endif  /* !__ASSEMBLY__ */

#ifndef __ASSEMBLY__
extern void arch_task_cache_init(void);
extern void free_thread_info(struct thread_info *ti);
extern int arch_dup_task_struct(struct task_struct *dst, struct task_struct *src);
#define arch_task_cache_init arch_task_cache_init
#endif
#endif /* ASM_X86__THREAD_INFO_H */

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