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/percpu.h>
  13 #include <asm/types.h>
  14
  15 /*
  16  * low level task data that entry.S needs immediate access to
  17  * - this struct should fit entirely inside of one cache line
  18  * - this struct shares the supervisor stack pages
  19  */
  20 #ifndef __ASSEMBLY__
  21 struct task_struct;
  22 struct exec_domain;
  23 #include <asm/processor.h>
  24 #include <linux/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                     saved_preempt_count;
  33         mm_segment_t            addr_limit;
  34         struct restart_block    restart_block;
  35         void __user             *sysenter_return;
  36         unsigned int            sig_on_uaccess_error:1;
  37         unsigned int            uaccess_err:1;  /* uaccess failed */
  38 };
  39
  40 #define INIT_THREAD_INFO(tsk)                   \
  41 {                                               \
  42         .task           = &tsk,                 \
  43         .exec_domain    = &default_exec_domain, \
  44         .flags          = 0,                    \
  45         .cpu            = 0,                    \
  46         .saved_preempt_count = INIT_PREEMPT_COUNT,      \
  47         .addr_limit     = KERNEL_DS,            \
  48         .restart_block = {                      \
  49                 .fn = do_no_restart_syscall,    \
  50         },                                      \
  51 }
  52
  53 #define init_thread_info        (init_thread_union.thread_info)
  54 #define init_stack              (init_thread_union.stack)
  55
  56 #else /* !__ASSEMBLY__ */
  57
  58 #include <asm/asm-offsets.h>
  59
  60 #endif
  61
  62 /*
  63  * thread information flags
  64  * - these are process state flags that various assembly files
  65  *   may need to access
  66  * - pending work-to-be-done flags are in LSW
  67  * - other flags in MSW
  68  * Warning: layout of LSW is hardcoded in entry.S
  69  */
  70 #define TIF_SYSCALL_TRACE       0       /* syscall trace active */
  71 #define TIF_NOTIFY_RESUME       1       /* callback before returning to user */
  72 #define TIF_SIGPENDING          2       /* signal pending */
  73 #define TIF_NEED_RESCHED        3       /* rescheduling necessary */
  74 #define TIF_SINGLESTEP          4       /* reenable singlestep on user return*/
  75 #define TIF_SYSCALL_EMU         6       /* syscall emulation active */
  76 #define TIF_SYSCALL_AUDIT       7       /* syscall auditing active */
  77 #define TIF_SECCOMP             8       /* secure computing */
  78 #define TIF_MCE_NOTIFY          10      /* notify userspace of an MCE */
  79 #define TIF_USER_RETURN_NOTIFY  11      /* notify kernel of userspace return */
  80 #define TIF_UPROBE              12      /* breakpointed or singlestepping */
  81 #define TIF_NOTSC               16      /* TSC is not accessible in userland */
  82 #define TIF_IA32                17      /* IA32 compatibility process */
  83 #define TIF_FORK                18      /* ret_from_fork */
  84 #define TIF_NOHZ                19      /* in adaptive nohz mode */
  85 #define TIF_MEMDIE              20      /* is terminating due to OOM killer */
  86 #define TIF_IO_BITMAP           22      /* uses I/O bitmap */
  87 #define TIF_FORCED_TF           24      /* true if TF in eflags artificially */
  88 #define TIF_BLOCKSTEP           25      /* set when we want DEBUGCTLMSR_BTF */
  89 #define TIF_LAZY_MMU_UPDATES    27      /* task is updating the mmu lazily */
  90 #define TIF_SYSCALL_TRACEPOINT  28      /* syscall tracepoint instrumentation */
  91 #define TIF_ADDR32              29      /* 32-bit address space on 64 bits */
  92 #define TIF_X32                 30      /* 32-bit native x86-64 binary */
  93
  94 #define _TIF_SYSCALL_TRACE      (1 << TIF_SYSCALL_TRACE)
  95 #define _TIF_NOTIFY_RESUME      (1 << TIF_NOTIFY_RESUME)
  96 #define _TIF_SIGPENDING         (1 << TIF_SIGPENDING)
  97 #define _TIF_SINGLESTEP         (1 << TIF_SINGLESTEP)
  98 #define _TIF_NEED_RESCHED       (1 << TIF_NEED_RESCHED)
  99 #define _TIF_SYSCALL_EMU        (1 << TIF_SYSCALL_EMU)
 100 #define _TIF_SYSCALL_AUDIT      (1 << TIF_SYSCALL_AUDIT)
 101 #define _TIF_SECCOMP            (1 << TIF_SECCOMP)
 102 #define _TIF_MCE_NOTIFY         (1 << TIF_MCE_NOTIFY)
 103 #define _TIF_USER_RETURN_NOTIFY (1 << TIF_USER_RETURN_NOTIFY)
 104 #define _TIF_UPROBE             (1 << TIF_UPROBE)
 105 #define _TIF_NOTSC              (1 << TIF_NOTSC)
 106 #define _TIF_IA32               (1 << TIF_IA32)
 107 #define _TIF_FORK               (1 << TIF_FORK)
 108 #define _TIF_NOHZ               (1 << TIF_NOHZ)
 109 #define _TIF_IO_BITMAP          (1 << TIF_IO_BITMAP)
 110 #define _TIF_FORCED_TF          (1 << TIF_FORCED_TF)
 111 #define _TIF_BLOCKSTEP          (1 << TIF_BLOCKSTEP)
 112 #define _TIF_LAZY_MMU_UPDATES   (1 << TIF_LAZY_MMU_UPDATES)
 113 #define _TIF_SYSCALL_TRACEPOINT (1 << TIF_SYSCALL_TRACEPOINT)
 114 #define _TIF_ADDR32             (1 << TIF_ADDR32)
 115 #define _TIF_X32                (1 << TIF_X32)
 116
 117 /* work to do in syscall_trace_enter() */
 118 #define _TIF_WORK_SYSCALL_ENTRY \
 119         (_TIF_SYSCALL_TRACE | _TIF_SYSCALL_EMU | _TIF_SYSCALL_AUDIT |   \
 120          _TIF_SECCOMP | _TIF_SINGLESTEP | _TIF_SYSCALL_TRACEPOINT |     \
 121          _TIF_NOHZ)
 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          _TIF_SYSCALL_TRACEPOINT | _TIF_NOHZ)
 127
 128 /* work to do on interrupt/exception return */
 129 #define _TIF_WORK_MASK                                                  \
 130         (0x0000FFFF &                                                   \
 131          ~(_TIF_SYSCALL_TRACE|_TIF_SYSCALL_AUDIT|                       \
 132            _TIF_SINGLESTEP|_TIF_SECCOMP|_TIF_SYSCALL_EMU))
 133
 134 /* work to do on any return to user space */
 135 #define _TIF_ALLWORK_MASK                                               \
 136         ((0x0000FFFF & ~_TIF_SECCOMP) | _TIF_SYSCALL_TRACEPOINT |       \
 137         _TIF_NOHZ)
 138
 139 /* Only used for 64 bit */
 140 #define _TIF_DO_NOTIFY_MASK                                             \
 141         (_TIF_SIGPENDING | _TIF_MCE_NOTIFY | _TIF_NOTIFY_RESUME |       \
 142          _TIF_USER_RETURN_NOTIFY)
 143
 144 /* flags to check in __switch_to() */
 145 #define _TIF_WORK_CTXSW                                                 \
 146         (_TIF_IO_BITMAP|_TIF_NOTSC|_TIF_BLOCKSTEP)
 147
 148 #define _TIF_WORK_CTXSW_PREV (_TIF_WORK_CTXSW|_TIF_USER_RETURN_NOTIFY)
 149 #define _TIF_WORK_CTXSW_NEXT (_TIF_WORK_CTXSW)
 150
 151 #define STACK_WARN              (THREAD_SIZE/8)
 152 #define KERNEL_STACK_OFFSET     (5*(BITS_PER_LONG/8))
 153
 154 /*
 155  * macros/functions for gaining access to the thread information structure
 156  *
 157  * preempt_count needs to be 1 initially, until the scheduler is functional.
 158  */
 159 #ifndef __ASSEMBLY__
 160
 161 DECLARE_PER_CPU(unsigned long, kernel_stack);
 162
 163 static inline struct thread_info *current_thread_info(void)
 164 {
 165         struct thread_info *ti;
 166         ti = (void *)(this_cpu_read_stable(kernel_stack) +
 167                       KERNEL_STACK_OFFSET - THREAD_SIZE);
 168         return ti;
 169 }
 170
 171 #else /* !__ASSEMBLY__ */
 172
 173 /* how to get the thread information struct from ASM */
 174 #define GET_THREAD_INFO(reg) \
 175         _ASM_MOV PER_CPU_VAR(kernel_stack),reg ; \
 176         _ASM_SUB $(THREAD_SIZE-KERNEL_STACK_OFFSET),reg ;
 177
 178 /*
 179  * Same if PER_CPU_VAR(kernel_stack) is, perhaps with some offset, already in
 180  * a certain register (to be used in assembler memory operands).
 181  */
 182 #define THREAD_INFO(reg, off) KERNEL_STACK_OFFSET+(off)-THREAD_SIZE(reg)
 183
 184 #endif
 185
 186 /*
 187  * Thread-synchronous status.
 188  *
 189  * This is different from the flags in that nobody else
 190  * ever touches our thread-synchronous status, so we don't
 191  * have to worry about atomic accesses.
 192  */
 193 #define TS_COMPAT               0x0002  /* 32bit syscall active (64BIT)*/
 194 #define TS_POLLING              0x0004  /* idle task polling need_resched,
 195                                            skip sending interrupt */
 196 #define TS_RESTORE_SIGMASK      0x0008  /* restore signal mask in do_signal() */
 197
 198 #ifndef __ASSEMBLY__
 199 #define HAVE_SET_RESTORE_SIGMASK        1
 200 static inline void set_restore_sigmask(void)
 201 {
 202         struct thread_info *ti = current_thread_info();
 203         ti->status |= TS_RESTORE_SIGMASK;
 204         WARN_ON(!test_bit(TIF_SIGPENDING, (unsigned long *)&ti->flags));
 205 }
 206 static inline void clear_restore_sigmask(void)
 207 {
 208         current_thread_info()->status &= ~TS_RESTORE_SIGMASK;
 209 }
 210 static inline bool test_restore_sigmask(void)
 211 {
 212         return current_thread_info()->status & TS_RESTORE_SIGMASK;
 213 }
 214 static inline bool test_and_clear_restore_sigmask(void)
 215 {
 216         struct thread_info *ti = current_thread_info();
 217         if (!(ti->status & TS_RESTORE_SIGMASK))
 218                 return false;
 219         ti->status &= ~TS_RESTORE_SIGMASK;
 220         return true;
 221 }
 222
 223 static inline bool is_ia32_task(void)
 224 {
 225 #ifdef CONFIG_X86_32
 226         return true;
 227 #endif
 228 #ifdef CONFIG_IA32_EMULATION
 229         if (current_thread_info()->status & TS_COMPAT)
 230                 return true;
 231 #endif
 232         return false;
 233 }
 234 #endif  /* !__ASSEMBLY__ */
 235
 236 #ifndef __ASSEMBLY__
 237 extern void arch_task_cache_init(void);
 238 extern int arch_dup_task_struct(struct task_struct *dst, struct task_struct *src);
 239 extern void arch_release_task_struct(struct task_struct *tsk);
 240 #endif
 241 #endif /* _ASM_X86_THREAD_INFO_H */