LXR linux/arch/x86/include/asm/thread

   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__
  20struct task_struct;
  21struct exec_domain;
  22#include <asm/processor.h>
  23#include <asm/ftrace.h>
  24#include <asm/atomic.h>
  25
  26struct thread_info {
  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,
  33                                                   <0 => BUG */
  34        mm_segment_t            addr_limit;
  35        struct restart_block    restart_block;
  36        void __user             *sysenter_return;
  37#ifdef CONFIG_X86_32
  38        unsigned long           previous_esp;   /* ESP of the previous stack in
  39                                                   case of nested (IRQ) stacks
  40                                                */
  41        __u8                    supervisor_stack[0];
  42#endif
  43        int                     uaccess_err;
  44};
  45
  46#define INIT_THREAD_INFO(tsk)                   \
  47{                                               \
  48        .task           = &tsk,                 \
  49        .exec_domain    = &default_exec_domain, \
  50        .flags          = 0,                    \
  51        .cpu            = 0,                    \
  52        .preempt_count  = INIT_PREEMPT_COUNT,   \
  53        .addr_limit     = KERNEL_DS,            \
  54        .restart_block = {                      \
  55                .fn = do_no_restart_syscall,    \
  56        },                                      \
  57}
  58
  59#define init_thread_info        (init_thread_union.thread_info)
  60#define init_stack              (init_thread_union.stack)
  61
  62#else /* !__ASSEMBLY__ */
  63
  64#include <asm/asm-offsets.h>
  65
  66#endif
  67
  68/*
  69 * thread information flags
  70 * - these are process state flags that various assembly files
  71 *   may need to access
  72 * - pending work-to-be-done flags are in LSW
  73 * - other flags in MSW
  74 * Warning: layout of LSW is hardcoded in entry.S
  75 */
  76#define TIF_SYSCALL_TRACE       0       /* syscall trace active */
  77#define TIF_NOTIFY_RESUME       1       /* callback before returning to user */
  78#define TIF_SIGPENDING          2       /* signal pending */
  79#define TIF_NEED_RESCHED        3       /* rescheduling necessary */
  80#define TIF_SINGLESTEP          4       /* reenable singlestep on user return*/
  81#define TIF_IRET                5       /* force IRET */
  82#define TIF_SYSCALL_EMU         6       /* syscall emulation active */
  83#define TIF_SYSCALL_AUDIT       7       /* syscall auditing active */
  84#define TIF_SECCOMP             8       /* secure computing */
  85#define TIF_MCE_NOTIFY          10      /* notify userspace of an MCE */
  86#define TIF_NOTSC               16      /* TSC is not accessible in userland */
  87#define TIF_IA32                17      /* 32bit process */
  88#define TIF_FORK                18      /* ret_from_fork */
  89#define TIF_ABI_PENDING         19
  90#define TIF_MEMDIE              20
  91#define TIF_DEBUG               21      /* uses debug registers */
  92#define TIF_IO_BITMAP           22      /* uses I/O bitmap */
  93#define TIF_FREEZE              23      /* is freezing for suspend */
  94#define TIF_FORCED_TF           24      /* true if TF in eflags artificially */
  95#define TIF_DEBUGCTLMSR         25      /* uses thread_struct.debugctlmsr */
  96#define TIF_DS_AREA_MSR         26      /* uses thread_struct.ds_area_msr */
  97#define TIF_LAZY_MMU_UPDATES    27      /* task is updating the mmu lazily */
  98#define TIF_SYSCALL_TRACEPOINT  28      /* syscall tracepoint instrumentation */
  99
 100#define _TIF_SYSCALL_TRACE      (1 << TIF_SYSCALL_TRACE)
 101#define _TIF_NOTIFY_RESUME      (1 << TIF_NOTIFY_RESUME)
 102#define _TIF_SIGPENDING         (1 << TIF_SIGPENDING)
 103#define _TIF_SINGLESTEP         (1 << TIF_SINGLESTEP)
 104#define _TIF_NEED_RESCHED       (1 << TIF_NEED_RESCHED)
 105#define _TIF_IRET               (1 << TIF_IRET)
 106#define _TIF_SYSCALL_EMU        (1 << TIF_SYSCALL_EMU)
 107#define _TIF_SYSCALL_AUDIT      (1 << TIF_SYSCALL_AUDIT)
 108#define _TIF_SECCOMP            (1 << TIF_SECCOMP)
 109#define _TIF_MCE_NOTIFY         (1 << TIF_MCE_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_ABI_PENDING        (1 << TIF_ABI_PENDING)
 114#define _TIF_DEBUG              (1 << TIF_DEBUG)
 115#define _TIF_IO_BITMAP          (1 << TIF_IO_BITMAP)
 116#define _TIF_FREEZE             (1 << TIF_FREEZE)
 117#define _TIF_FORCED_TF          (1 << TIF_FORCED_TF)
 118#define _TIF_DEBUGCTLMSR        (1 << TIF_DEBUGCTLMSR)
 119#define _TIF_DS_AREA_MSR        (1 << TIF_DS_AREA_MSR)
 120#define _TIF_LAZY_MMU_UPDATES   (1 << TIF_LAZY_MMU_UPDATES)
 121#define _TIF_SYSCALL_TRACEPOINT (1 << TIF_SYSCALL_TRACEPOINT)
 122
 123/* work to do in syscall_trace_enter() */
 124#define _TIF_WORK_SYSCALL_ENTRY \
 125        (_TIF_SYSCALL_TRACE | _TIF_SYSCALL_EMU | _TIF_SYSCALL_AUDIT |   \
 126         _TIF_SECCOMP | _TIF_SINGLESTEP | _TIF_SYSCALL_TRACEPOINT)
 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)
 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
 143/* Only used for 64 bit */
 144#define _TIF_DO_NOTIFY_MASK                                             \
 145        (_TIF_SIGPENDING|_TIF_MCE_NOTIFY|_TIF_NOTIFY_RESUME)
 146
 147/* flags to check in __switch_to() */
 148#define _TIF_WORK_CTXSW                                                 \
 149        (_TIF_IO_BITMAP|_TIF_DEBUGCTLMSR|_TIF_DS_AREA_MSR|_TIF_NOTSC)
 150
 151#define _TIF_WORK_CTXSW_PREV _TIF_WORK_CTXSW
 152#define _TIF_WORK_CTXSW_NEXT (_TIF_WORK_CTXSW|_TIF_DEBUG)
 153
 154#define PREEMPT_ACTIVE          0x10000000
 155
 156/* thread information allocation */
 157#ifdef CONFIG_DEBUG_STACK_USAGE
 158#define THREAD_FLAGS (GFP_KERNEL | __GFP_NOTRACK | __GFP_ZERO)
 159#else
 160#define THREAD_FLAGS (GFP_KERNEL | __GFP_NOTRACK)
 161#endif
 162
 163#define __HAVE_ARCH_THREAD_INFO_ALLOCATOR
 164
 165#define alloc_thread_info(tsk)                                          \
 166        ((struct thread_info *)__get_free_pages(THREAD_FLAGS, THREAD_ORDER))
 167
 168#ifdef CONFIG_X86_32
 169
 170#define STACK_WARN      (THREAD_SIZE/8)
 171/*
 172 * macros/functions for gaining access to the thread information structure
 173 *
 174 * preempt_count needs to be 1 initially, until the scheduler is functional.
 175 */
 176#ifndef __ASSEMBLY__
 177
 178
 179/* how to get the current stack pointer from C */
 180register unsigned long current_stack_pointer asm("esp") __used;
 181
 182/* how to get the thread information struct from C */
 183static inline struct thread_info *current_thread_info(void)
 184{
 185        return (struct thread_info *)
 186                (current_stack_pointer & ~(THREAD_SIZE - 1));
 187}
 188
 189#else /* !__ASSEMBLY__ */
 190
 191/* how to get the thread information struct from ASM */
 192#define GET_THREAD_INFO(reg)     \
 193        movl $-THREAD_SIZE, reg; \
 194        andl %esp, reg
 195
 196/* use this one if reg already contains %esp */
 197#define GET_THREAD_INFO_WITH_ESP(reg) \
 198        andl $-THREAD_SIZE, reg
 199
 200#endif
 201
 202#else /* X86_32 */
 203
 204#include <asm/percpu.h>
 205#define KERNEL_STACK_OFFSET (5*8)
 206
 207/*
 208 * macros/functions for gaining access to the thread information structure
 209 * preempt_count needs to be 1 initially, until the scheduler is functional.
 210 */
 211#ifndef __ASSEMBLY__
 212DECLARE_PER_CPU(unsigned long, kernel_stack);
 213
 214static inline struct thread_info *current_thread_info(void)
 215{
 216        struct thread_info *ti;
 217        ti = (void *)(percpu_read_stable(kernel_stack) +
 218                      KERNEL_STACK_OFFSET - THREAD_SIZE);
 219        return ti;
 220}
 221
 222#else /* !__ASSEMBLY__ */
 223
 224/* how to get the thread information struct from ASM */
 225#define GET_THREAD_INFO(reg) \
 226        movq PER_CPU_VAR(kernel_stack),reg ; \
 227        subq $(THREAD_SIZE-KERNEL_STACK_OFFSET),reg
 228
 229#endif
 230
 231#endif /* !X86_32 */
 232
 233/*
 234 * Thread-synchronous status.
 235 *
 236 * This is different from the flags in that nobody else
 237 * ever touches our thread-synchronous status, so we don't
 238 * have to worry about atomic accesses.
 239 */
 240#define TS_USEDFPU              0x0001  /* FPU was used by this task
 241                                           this quantum (SMP) */
 242#define TS_COMPAT               0x0002  /* 32bit syscall active (64BIT)*/
 243#define TS_POLLING              0x0004  /* true if in idle loop
 244                                           and not sleeping */
 245#define TS_RESTORE_SIGMASK      0x0008  /* restore signal mask in do_signal() */
 246#define TS_XSAVE                0x0010  /* Use xsave/xrstor */
 247
 248#define tsk_is_polling(t) (task_thread_info(t)->status & TS_POLLING)
 249
 250#ifndef __ASSEMBLY__
 251#define HAVE_SET_RESTORE_SIGMASK        1
 252static inline void set_restore_sigmask(void)
 253{
 254        struct thread_info *ti = current_thread_info();
 255        ti->status |= TS_RESTORE_SIGMASK;
 256        set_bit(TIF_SIGPENDING, (unsigned long *)&ti->flags);
 257}
 258#endif  /* !__ASSEMBLY__ */
 259
 260#ifndef __ASSEMBLY__
 261extern void arch_task_cache_init(void);
 262extern void free_thread_info(struct thread_info *ti);
 263extern int arch_dup_task_struct(struct task_struct *dst, struct task_struct *src);
 264#define arch_task_cache_init arch_task_cache_init
 265#endif
 266#endif /* _ASM_X86_THREAD_INFO_H */
 267