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 <linux/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        unsigned int            sig_on_uaccess_error:1;
  44        unsigned int            uaccess_err:1;  /* uaccess failed */
  45};
  46
  47#define INIT_THREAD_INFO(tsk)                   \
  48{                                               \
  49        .task           = &tsk,                 \
  50        .exec_domain    = &default_exec_domain, \
  51        .flags          = 0,                    \
  52        .cpu            = 0,                    \
  53        .preempt_count  = INIT_PREEMPT_COUNT,   \
  54        .addr_limit     = KERNEL_DS,            \
  55        .restart_block = {                      \
  56                .fn = do_no_restart_syscall,    \
  57        },                                      \
  58}
  59
  60#define init_thread_info        (init_thread_union.thread_info)
  61#define init_stack              (init_thread_union.stack)
  62
  63#else /* !__ASSEMBLY__ */
  64
  65#include <asm/asm-offsets.h>
  66
  67#endif
  68
  69/*
  70 * thread information flags
  71 * - these are process state flags that various assembly files
  72 *   may need to access
  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
  76 */
  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      /* IA32 compatibility 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 */
  98#define TIF_ADDR32              29      /* 32-bit address space on 64 bits */
  99#define TIF_X32                 30      /* 32-bit native x86-64 binary */
 100
 101#define _TIF_SYSCALL_TRACE      (1 << TIF_SYSCALL_TRACE)
 102#define _TIF_NOTIFY_RESUME      (1 << TIF_NOTIFY_RESUME)
 103#define _TIF_SIGPENDING         (1 << TIF_SIGPENDING)
 104#define _TIF_SINGLESTEP         (1 << TIF_SINGLESTEP)
 105#define _TIF_NEED_RESCHED       (1 << TIF_NEED_RESCHED)
 106#define _TIF_IRET               (1 << TIF_IRET)
 107#define _TIF_SYSCALL_EMU        (1 << TIF_SYSCALL_EMU)
 108#define _TIF_SYSCALL_AUDIT      (1 << TIF_SYSCALL_AUDIT)
 109#define _TIF_SECCOMP            (1 << TIF_SECCOMP)
 110#define _TIF_MCE_NOTIFY         (1 << TIF_MCE_NOTIFY)
 111#define _TIF_USER_RETURN_NOTIFY (1 << TIF_USER_RETURN_NOTIFY)
 112#define _TIF_NOTSC              (1 << TIF_NOTSC)
 113#define _TIF_IA32               (1 << TIF_IA32)
 114#define _TIF_FORK               (1 << TIF_FORK)
 115#define _TIF_DEBUG              (1 << TIF_DEBUG)
 116#define _TIF_IO_BITMAP          (1 << TIF_IO_BITMAP)
 117#define _TIF_FORCED_TF          (1 << TIF_FORCED_TF)
 118#define _TIF_BLOCKSTEP          (1 << TIF_BLOCKSTEP)
 119#define _TIF_LAZY_MMU_UPDATES   (1 << TIF_LAZY_MMU_UPDATES)
 120#define _TIF_SYSCALL_TRACEPOINT (1 << TIF_SYSCALL_TRACEPOINT)
 121#define _TIF_ADDR32             (1 << TIF_ADDR32)
 122#define _TIF_X32                (1 << TIF_X32)
 123
 124/* work to do in syscall_trace_enter() */
 125#define _TIF_WORK_SYSCALL_ENTRY \
 126        (_TIF_SYSCALL_TRACE | _TIF_SYSCALL_EMU | _TIF_SYSCALL_AUDIT |   \
 127         _TIF_SECCOMP | _TIF_SINGLESTEP | _TIF_SYSCALL_TRACEPOINT)
 128
 129/* work to do in syscall_trace_leave() */
 130#define _TIF_WORK_SYSCALL_EXIT  \
 131        (_TIF_SYSCALL_TRACE | _TIF_SYSCALL_AUDIT | _TIF_SINGLESTEP |    \
 132         _TIF_SYSCALL_TRACEPOINT)
 133
 134/* work to do on interrupt/exception return */
 135#define _TIF_WORK_MASK                                                  \
 136        (0x0000FFFF &                                                   \
 137         ~(_TIF_SYSCALL_TRACE|_TIF_SYSCALL_AUDIT|                       \
 138           _TIF_SINGLESTEP|_TIF_SECCOMP|_TIF_SYSCALL_EMU))
 139
 140/* work to do on any return to user space */
 141#define _TIF_ALLWORK_MASK                                               \
 142        ((0x0000FFFF & ~_TIF_SECCOMP) | _TIF_SYSCALL_TRACEPOINT)
 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|_TIF_DEBUG)
 155
 156#define PREEMPT_ACTIVE          0x10000000
 157
 158/* thread information allocation */
 159#ifdef CONFIG_DEBUG_STACK_USAGE
 160#define THREAD_FLAGS (GFP_KERNEL | __GFP_NOTRACK | __GFP_ZERO)
 161#else
 162#define THREAD_FLAGS (GFP_KERNEL | __GFP_NOTRACK)
 163#endif
 164
 165#define __HAVE_ARCH_THREAD_INFO_ALLOCATOR
 166
 167#define alloc_thread_info_node(tsk, node)                               \
 168({                                                                      \
 169        struct page *page = alloc_pages_node(node, THREAD_FLAGS,        \
 170                                             THREAD_ORDER);             \
 171        struct thread_info *ret = page ? page_address(page) : NULL;     \
 172                                                                        \
 173        ret;                                                            \
 174})
 175
 176#ifdef CONFIG_X86_32
 177
 178#define STACK_WARN      (THREAD_SIZE/8)
 179/*
 180 * macros/functions for gaining access to the thread information structure
 181 *
 182 * preempt_count needs to be 1 initially, until the scheduler is functional.
 183 */
 184#ifndef __ASSEMBLY__
 185
 186
 187/* how to get the current stack pointer from C */
 188register unsigned long current_stack_pointer asm("esp") __used;
 189
 190/* how to get the thread information struct from C */
 191static inline struct thread_info *current_thread_info(void)
 192{
 193        return (struct thread_info *)
 194                (current_stack_pointer & ~(THREAD_SIZE - 1));
 195}
 196
 197#else /* !__ASSEMBLY__ */
 198
 199/* how to get the thread information struct from ASM */
 200#define GET_THREAD_INFO(reg)     \
 201        movl $-THREAD_SIZE, reg; \
 202        andl %esp, reg
 203
 204/* use this one if reg already contains %esp */
 205#define GET_THREAD_INFO_WITH_ESP(reg) \
 206        andl $-THREAD_SIZE, reg
 207
 208#endif
 209
 210#else /* X86_32 */
 211
 212#include <asm/percpu.h>
 213#define KERNEL_STACK_OFFSET (5*8)
 214
 215/*
 216 * macros/functions for gaining access to the thread information structure
 217 * preempt_count needs to be 1 initially, until the scheduler is functional.
 218 */
 219#ifndef __ASSEMBLY__
 220DECLARE_PER_CPU(unsigned long, kernel_stack);
 221
 222static inline struct thread_info *current_thread_info(void)
 223{
 224        struct thread_info *ti;
 225        ti = (void *)(percpu_read_stable(kernel_stack) +
 226                      KERNEL_STACK_OFFSET - THREAD_SIZE);
 227        return ti;
 228}
 229
 230#else /* !__ASSEMBLY__ */
 231
 232/* how to get the thread information struct from ASM */
 233#define GET_THREAD_INFO(reg) \
 234        movq PER_CPU_VAR(kernel_stack),reg ; \
 235        subq $(THREAD_SIZE-KERNEL_STACK_OFFSET),reg
 236
 237/*
 238 * Same if PER_CPU_VAR(kernel_stack) is, perhaps with some offset, already in
 239 * a certain register (to be used in assembler memory operands).
 240 */
 241#define THREAD_INFO(reg, off) KERNEL_STACK_OFFSET+(off)-THREAD_SIZE(reg)
 242
 243#endif
 244
 245#endif /* !X86_32 */
 246
 247/*
 248 * Thread-synchronous status.
 249 *
 250 * This is different from the flags in that nobody else
 251 * ever touches our thread-synchronous status, so we don't
 252 * have to worry about atomic accesses.
 253 */
 254#define TS_COMPAT               0x0002  /* 32bit syscall active (64BIT)*/
 255#define TS_POLLING              0x0004  /* idle task polling need_resched,
 256                                           skip sending interrupt */
 257#define TS_RESTORE_SIGMASK      0x0008  /* restore signal mask in do_signal() */
 258
 259#define tsk_is_polling(t) (task_thread_info(t)->status & TS_POLLING)
 260
 261#ifndef __ASSEMBLY__
 262#define HAVE_SET_RESTORE_SIGMASK        1
 263static inline void set_restore_sigmask(void)
 264{
 265        struct thread_info *ti = current_thread_info();
 266        ti->status |= TS_RESTORE_SIGMASK;
 267        set_bit(TIF_SIGPENDING, (unsigned long *)&ti->flags);
 268}
 269
 270static inline bool is_ia32_task(void)
 271{
 272#ifdef CONFIG_X86_32
 273        return true;
 274#endif
 275#ifdef CONFIG_IA32_EMULATION
 276        if (current_thread_info()->status & TS_COMPAT)
 277                return true;
 278#endif
 279        return false;
 280}
 281#endif  /* !__ASSEMBLY__ */
 282
 283#ifndef __ASSEMBLY__
 284extern void arch_task_cache_init(void);
 285extern void free_thread_info(struct thread_info *ti);
 286extern int arch_dup_task_struct(struct task_struct *dst, struct task_struct *src);
 287#define arch_task_cache_init arch_task_cache_init
 288#endif
 289#endif /* _ASM_X86_THREAD_INFO_H */
 290