arch/x86/include/asm/thread_info.h

   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 <asm/ftrace.h>
  24 #include <asm/atomic.h>
  25
  26 struct 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 };
  44
  45 #define INIT_THREAD_INFO(tsk)                   \
  46 {                                               \
  47         .task           = &tsk,                 \
  48         .exec_domain    = &default_exec_domain, \
  49         .flags          = 0,                    \
  50         .cpu            = 0,                    \
  51         .preempt_count  = 1,                    \
  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_IRET                5       /* force IRET */
  81 #define TIF_SYSCALL_EMU         6       /* syscall emulation active */
  82 #define TIF_SYSCALL_AUDIT       7       /* syscall auditing active */
  83 #define TIF_SECCOMP             8       /* secure computing */
  84 #define TIF_MCE_NOTIFY          10      /* notify userspace of an MCE */
  85 #define TIF_NOTSC               16      /* TSC is not accessible in userland */
  86 #define TIF_IA32                17      /* 32bit process */
  87 #define TIF_FORK                18      /* ret_from_fork */
  88 #define TIF_ABI_PENDING         19
  89 #define TIF_MEMDIE              20
  90 #define TIF_DEBUG               21      /* uses debug registers */
  91 #define TIF_IO_BITMAP           22      /* uses I/O bitmap */
  92 #define TIF_FREEZE              23      /* is freezing for suspend */
  93 #define TIF_FORCED_TF           24      /* true if TF in eflags artificially */
  94 #define TIF_DEBUGCTLMSR         25      /* uses thread_struct.debugctlmsr */
  95 #define TIF_DS_AREA_MSR         26      /* uses thread_struct.ds_area_msr */
  96
  97 #define _TIF_SYSCALL_TRACE      (1 << TIF_SYSCALL_TRACE)
  98 #define _TIF_NOTIFY_RESUME      (1 << TIF_NOTIFY_RESUME)
  99 #define _TIF_SIGPENDING         (1 << TIF_SIGPENDING)
 100 #define _TIF_SINGLESTEP         (1 << TIF_SINGLESTEP)
 101 #define _TIF_NEED_RESCHED       (1 << TIF_NEED_RESCHED)
 102 #define _TIF_IRET               (1 << TIF_IRET)
 103 #define _TIF_SYSCALL_EMU        (1 << TIF_SYSCALL_EMU)
 104 #define _TIF_SYSCALL_AUDIT      (1 << TIF_SYSCALL_AUDIT)
 105 #define _TIF_SECCOMP            (1 << TIF_SECCOMP)
 106 #define _TIF_MCE_NOTIFY         (1 << TIF_MCE_NOTIFY)
 107 #define _TIF_NOTSC              (1 << TIF_NOTSC)
 108 #define _TIF_IA32               (1 << TIF_IA32)
 109 #define _TIF_FORK               (1 << TIF_FORK)
 110 #define _TIF_ABI_PENDING        (1 << TIF_ABI_PENDING)
 111 #define _TIF_DEBUG              (1 << TIF_DEBUG)
 112 #define _TIF_IO_BITMAP          (1 << TIF_IO_BITMAP)
 113 #define _TIF_FREEZE             (1 << TIF_FREEZE)
 114 #define _TIF_FORCED_TF          (1 << TIF_FORCED_TF)
 115 #define _TIF_DEBUGCTLMSR        (1 << TIF_DEBUGCTLMSR)
 116 #define _TIF_DS_AREA_MSR        (1 << TIF_DS_AREA_MSR)
 117
 118 /* work to do in syscall_trace_enter() */
 119 #define _TIF_WORK_SYSCALL_ENTRY \
 120         (_TIF_SYSCALL_TRACE | _TIF_SYSCALL_EMU | \
 121          _TIF_SYSCALL_AUDIT | _TIF_SECCOMP | _TIF_SINGLESTEP)
 122
 123 /* work to do in syscall_trace_leave() */
 124 #define _TIF_WORK_SYSCALL_EXIT  \
 125         (_TIF_SYSCALL_TRACE | _TIF_SYSCALL_AUDIT | _TIF_SINGLESTEP)
 126
 127 /* work to do on interrupt/exception return */
 128 #define _TIF_WORK_MASK                                                  \
 129         (0x0000FFFF &                                                   \
 130          ~(_TIF_SYSCALL_TRACE|_TIF_SYSCALL_AUDIT|                       \
 131            _TIF_SINGLESTEP|_TIF_SECCOMP|_TIF_SYSCALL_EMU))
 132
 133 /* work to do on any return to user space */
 134 #define _TIF_ALLWORK_MASK (0x0000FFFF & ~_TIF_SECCOMP)
 135
 136 /* Only used for 64 bit */
 137 #define _TIF_DO_NOTIFY_MASK                                             \
 138         (_TIF_SIGPENDING|_TIF_MCE_NOTIFY|_TIF_NOTIFY_RESUME)
 139
 140 /* flags to check in __switch_to() */
 141 #define _TIF_WORK_CTXSW                                                 \
 142         (_TIF_IO_BITMAP|_TIF_DEBUGCTLMSR|_TIF_DS_AREA_MSR|_TIF_NOTSC)
 143
 144 #define _TIF_WORK_CTXSW_PREV _TIF_WORK_CTXSW
 145 #define _TIF_WORK_CTXSW_NEXT (_TIF_WORK_CTXSW|_TIF_DEBUG)
 146
 147 #define PREEMPT_ACTIVE          0x10000000
 148
 149 /* thread information allocation */
 150 #ifdef CONFIG_DEBUG_STACK_USAGE
 151 #define THREAD_FLAGS (GFP_KERNEL | __GFP_ZERO)
 152 #else
 153 #define THREAD_FLAGS GFP_KERNEL
 154 #endif
 155
 156 #define __HAVE_ARCH_THREAD_INFO_ALLOCATOR
 157
 158 #define alloc_thread_info(tsk)                                          \
 159         ((struct thread_info *)__get_free_pages(THREAD_FLAGS, THREAD_ORDER))
 160
 161 #ifdef CONFIG_X86_32
 162
 163 #define STACK_WARN      (THREAD_SIZE/8)
 164 /*
 165  * macros/functions for gaining access to the thread information structure
 166  *
 167  * preempt_count needs to be 1 initially, until the scheduler is functional.
 168  */
 169 #ifndef __ASSEMBLY__
 170
 171
 172 /* how to get the current stack pointer from C */
 173 register unsigned long current_stack_pointer asm("esp") __used;
 174
 175 /* how to get the thread information struct from C */
 176 static inline struct thread_info *current_thread_info(void)
 177 {
 178         return (struct thread_info *)
 179                 (current_stack_pointer & ~(THREAD_SIZE - 1));
 180 }
 181
 182 #else /* !__ASSEMBLY__ */
 183
 184 /* how to get the thread information struct from ASM */
 185 #define GET_THREAD_INFO(reg)     \
 186         movl $-THREAD_SIZE, reg; \
 187         andl %esp, reg
 188
 189 /* use this one if reg already contains %esp */
 190 #define GET_THREAD_INFO_WITH_ESP(reg) \
 191         andl $-THREAD_SIZE, reg
 192
 193 #endif
 194
 195 #else /* X86_32 */
 196
 197 #include <asm/pda.h>
 198
 199 /*
 200  * macros/functions for gaining access to the thread information structure
 201  * preempt_count needs to be 1 initially, until the scheduler is functional.
 202  */
 203 #ifndef __ASSEMBLY__
 204 static inline struct thread_info *current_thread_info(void)
 205 {
 206         struct thread_info *ti;
 207         ti = (void *)(read_pda(kernelstack) + PDA_STACKOFFSET - THREAD_SIZE);
 208         return ti;
 209 }
 210
 211 /* do not use in interrupt context */
 212 static inline struct thread_info *stack_thread_info(void)
 213 {
 214         struct thread_info *ti;
 215         asm("andq %%rsp,%0; " : "=r" (ti) : "0" (~(THREAD_SIZE - 1)));
 216         return ti;
 217 }
 218
 219 #else /* !__ASSEMBLY__ */
 220
 221 /* how to get the thread information struct from ASM */
 222 #define GET_THREAD_INFO(reg) \
 223         movq %gs:pda_kernelstack,reg ; \
 224         subq $(THREAD_SIZE-PDA_STACKOFFSET),reg
 225
 226 #endif
 227
 228 #endif /* !X86_32 */
 229
 230 /*
 231  * Thread-synchronous status.
 232  *
 233  * This is different from the flags in that nobody else
 234  * ever touches our thread-synchronous status, so we don't
 235  * have to worry about atomic accesses.
 236  */
 237 #define TS_USEDFPU              0x0001  /* FPU was used by this task
 238                                            this quantum (SMP) */
 239 #define TS_COMPAT               0x0002  /* 32bit syscall active (64BIT)*/
 240 #define TS_POLLING              0x0004  /* true if in idle loop
 241                                            and not sleeping */
 242 #define TS_RESTORE_SIGMASK      0x0008  /* restore signal mask in do_signal() */
 243 #define TS_XSAVE                0x0010  /* Use xsave/xrstor */
 244
 245 #define tsk_is_polling(t) (task_thread_info(t)->status & TS_POLLING)
 246
 247 #ifndef __ASSEMBLY__
 248 #define HAVE_SET_RESTORE_SIGMASK        1
 249 static inline void set_restore_sigmask(void)
 250 {
 251         struct thread_info *ti = current_thread_info();
 252         ti->status |= TS_RESTORE_SIGMASK;
 253         set_bit(TIF_SIGPENDING, (unsigned long *)&ti->flags);
 254 }
 255 #endif  /* !__ASSEMBLY__ */
 256
 257 #ifndef __ASSEMBLY__
 258 extern void arch_task_cache_init(void);
 259 extern void free_thread_info(struct thread_info *ti);
 260 extern int arch_dup_task_struct(struct task_struct *dst, struct task_struct *src);
 261 #define arch_task_cache_init arch_task_cache_init
 262 #endif
 263 #endif /* _ASM_X86_THREAD_INFO_H */