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 <linux/atomic.h>
  24
  25 struct thread_info {
  26         struct task_struct      *task;          /* main task structure */
  27         struct exec_domain      *exec_domain;   /* execution domain */
  28         __u32                   flags;          /* low level flags */
  29         __u32                   status;         /* thread synchronous flags */
  30         __u32                   cpu;            /* current CPU */
  31         int                     preempt_count;  /* 0 => preemptable,
  32                                                    <0 => BUG */
  33         mm_segment_t            addr_limit;
  34         struct restart_block    restart_block;
  35         void __user             *sysenter_return;
  36 #ifdef CONFIG_X86_32
  37         unsigned long           previous_esp;   /* ESP of the previous stack in
  38                                                    case of nested (IRQ) stacks
  39                                                 */
  40         __u8                    supervisor_stack[0];
  41 #endif
  42         unsigned int            sig_on_uaccess_error:1;
  43         unsigned int            uaccess_err:1;  /* uaccess failed */
  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_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_USER_RETURN_NOTIFY  11      /* notify kernel of userspace return */
  86 #define TIF_UPROBE              12      /* breakpointed or singlestepping */
  87 #define TIF_NOTSC               16      /* TSC is not accessible in userland */
  88 #define TIF_IA32                17      /* IA32 compatibility process */
  89 #define TIF_FORK                18      /* ret_from_fork */
  90 #define TIF_NOHZ                19      /* in adaptive nohz mode */
  91 #define TIF_MEMDIE              20      /* is terminating due to OOM killer */
  92 #define TIF_IO_BITMAP           22      /* uses I/O bitmap */
  93 #define TIF_FORCED_TF           24      /* true if TF in eflags artificially */
  94 #define TIF_BLOCKSTEP           25      /* set when we want DEBUGCTLMSR_BTF */
  95 #define TIF_LAZY_MMU_UPDATES    27      /* task is updating the mmu lazily */
  96 #define TIF_SYSCALL_TRACEPOINT  28      /* syscall tracepoint instrumentation */
  97 #define TIF_ADDR32              29      /* 32-bit address space on 64 bits */
  98 #define TIF_X32                 30      /* 32-bit native x86-64 binary */
  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_SYSCALL_EMU        (1 << TIF_SYSCALL_EMU)
 106 #define _TIF_SYSCALL_AUDIT      (1 << TIF_SYSCALL_AUDIT)
 107 #define _TIF_SECCOMP            (1 << TIF_SECCOMP)
 108 #define _TIF_MCE_NOTIFY         (1 << TIF_MCE_NOTIFY)
 109 #define _TIF_USER_RETURN_NOTIFY (1 << TIF_USER_RETURN_NOTIFY)
 110 #define _TIF_UPROBE             (1 << TIF_UPROBE)
 111 #define _TIF_NOTSC              (1 << TIF_NOTSC)
 112 #define _TIF_IA32               (1 << TIF_IA32)
 113 #define _TIF_FORK               (1 << TIF_FORK)
 114 #define _TIF_NOHZ               (1 << TIF_NOHZ)
 115 #define _TIF_IO_BITMAP          (1 << TIF_IO_BITMAP)
 116 #define _TIF_FORCED_TF          (1 << TIF_FORCED_TF)
 117 #define _TIF_BLOCKSTEP          (1 << TIF_BLOCKSTEP)
 118 #define _TIF_LAZY_MMU_UPDATES   (1 << TIF_LAZY_MMU_UPDATES)
 119 #define _TIF_SYSCALL_TRACEPOINT (1 << TIF_SYSCALL_TRACEPOINT)
 120 #define _TIF_ADDR32             (1 << TIF_ADDR32)
 121 #define _TIF_X32                (1 << TIF_X32)
 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          _TIF_NOHZ)
 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 | _TIF_NOHZ)
 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         _TIF_NOHZ)
 144
 145 /* Only used for 64 bit */
 146 #define _TIF_DO_NOTIFY_MASK                                             \
 147         (_TIF_SIGPENDING | _TIF_MCE_NOTIFY | _TIF_NOTIFY_RESUME |       \
 148          _TIF_USER_RETURN_NOTIFY)
 149
 150 /* flags to check in __switch_to() */
 151 #define _TIF_WORK_CTXSW                                                 \
 152         (_TIF_IO_BITMAP|_TIF_NOTSC|_TIF_BLOCKSTEP)
 153
 154 #define _TIF_WORK_CTXSW_PREV (_TIF_WORK_CTXSW|_TIF_USER_RETURN_NOTIFY)
 155 #define _TIF_WORK_CTXSW_NEXT (_TIF_WORK_CTXSW)
 156
 157 #define PREEMPT_ACTIVE          0x10000000
 158
 159 #ifdef CONFIG_X86_32
 160
 161 #define STACK_WARN      (THREAD_SIZE/8)
 162 /*
 163  * macros/functions for gaining access to the thread information structure
 164  *
 165  * preempt_count needs to be 1 initially, until the scheduler is functional.
 166  */
 167 #ifndef __ASSEMBLY__
 168
 169
 170 /* how to get the current stack pointer from C */
 171 register unsigned long current_stack_pointer asm("esp") __used;
 172
 173 /* how to get the thread information struct from C */
 174 static inline struct thread_info *current_thread_info(void)
 175 {
 176         return (struct thread_info *)
 177                 (current_stack_pointer & ~(THREAD_SIZE - 1));
 178 }
 179
 180 #else /* !__ASSEMBLY__ */
 181
 182 /* how to get the thread information struct from ASM */
 183 #define GET_THREAD_INFO(reg)     \
 184         movl $-THREAD_SIZE, reg; \
 185         andl %esp, reg
 186
 187 /* use this one if reg already contains %esp */
 188 #define GET_THREAD_INFO_WITH_ESP(reg) \
 189         andl $-THREAD_SIZE, reg
 190
 191 #endif
 192
 193 #else /* X86_32 */
 194
 195 #include <asm/percpu.h>
 196 #define KERNEL_STACK_OFFSET (5*8)
 197
 198 /*
 199  * macros/functions for gaining access to the thread information structure
 200  * preempt_count needs to be 1 initially, until the scheduler is functional.
 201  */
 202 #ifndef __ASSEMBLY__
 203 DECLARE_PER_CPU(unsigned long, kernel_stack);
 204
 205 static inline struct thread_info *current_thread_info(void)
 206 {
 207         struct thread_info *ti;
 208         ti = (void *)(this_cpu_read_stable(kernel_stack) +
 209                       KERNEL_STACK_OFFSET - THREAD_SIZE);
 210         return ti;
 211 }
 212
 213 #else /* !__ASSEMBLY__ */
 214
 215 /* how to get the thread information struct from ASM */
 216 #define GET_THREAD_INFO(reg) \
 217         movq PER_CPU_VAR(kernel_stack),reg ; \
 218         subq $(THREAD_SIZE-KERNEL_STACK_OFFSET),reg
 219
 220 /*
 221  * Same if PER_CPU_VAR(kernel_stack) is, perhaps with some offset, already in
 222  * a certain register (to be used in assembler memory operands).
 223  */
 224 #define THREAD_INFO(reg, off) KERNEL_STACK_OFFSET+(off)-THREAD_SIZE(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_COMPAT               0x0002  /* 32bit syscall active (64BIT)*/
 238 #define TS_POLLING              0x0004  /* idle task polling need_resched,
 239                                            skip sending interrupt */
 240 #define TS_RESTORE_SIGMASK      0x0008  /* restore signal mask in do_signal() */
 241
 242 #ifndef __ASSEMBLY__
 243 #define HAVE_SET_RESTORE_SIGMASK        1
 244 static inline void set_restore_sigmask(void)
 245 {
 246         struct thread_info *ti = current_thread_info();
 247         ti->status |= TS_RESTORE_SIGMASK;
 248         WARN_ON(!test_bit(TIF_SIGPENDING, (unsigned long *)&ti->flags));
 249 }
 250 static inline void clear_restore_sigmask(void)
 251 {
 252         current_thread_info()->status &= ~TS_RESTORE_SIGMASK;
 253 }
 254 static inline bool test_restore_sigmask(void)
 255 {
 256         return current_thread_info()->status & TS_RESTORE_SIGMASK;
 257 }
 258 static inline bool test_and_clear_restore_sigmask(void)
 259 {
 260         struct thread_info *ti = current_thread_info();
 261         if (!(ti->status & TS_RESTORE_SIGMASK))
 262                 return false;
 263         ti->status &= ~TS_RESTORE_SIGMASK;
 264         return true;
 265 }
 266
 267 static inline bool is_ia32_task(void)
 268 {
 269 #ifdef CONFIG_X86_32
 270         return true;
 271 #endif
 272 #ifdef CONFIG_IA32_EMULATION
 273         if (current_thread_info()->status & TS_COMPAT)
 274                 return true;
 275 #endif
 276         return false;
 277 }
 278 #endif  /* !__ASSEMBLY__ */
 279
 280 #ifndef __ASSEMBLY__
 281 extern void arch_task_cache_init(void);
 282 extern int arch_dup_task_struct(struct task_struct *dst, struct task_struct *src);
 283 extern void arch_release_task_struct(struct task_struct *tsk);
 284 #endif
 285 #endif /* _ASM_X86_THREAD_INFO_H */