git.oblomov.eu Git - linux-2.6/blob - arch/um/kernel/process_kern.c

   1 /*
   2  * Copyright (C) 2000, 2001, 2002 Jeff Dike (jdike@karaya.com)
   3  * Copyright 2003 PathScale, Inc.
   4  * Licensed under the GPL
   5  */
   6
   7 #include "linux/config.h"
   8 #include "linux/kernel.h"
   9 #include "linux/sched.h"
  10 #include "linux/interrupt.h"
  11 #include "linux/mm.h"
  12 #include "linux/slab.h"
  13 #include "linux/utsname.h"
  14 #include "linux/fs.h"
  15 #include "linux/utime.h"
  16 #include "linux/smp_lock.h"
  17 #include "linux/module.h"
  18 #include "linux/init.h"
  19 #include "linux/capability.h"
  20 #include "linux/vmalloc.h"
  21 #include "linux/spinlock.h"
  22 #include "linux/proc_fs.h"
  23 #include "linux/ptrace.h"
  24 #include "linux/random.h"
  25 #include "asm/unistd.h"
  26 #include "asm/mman.h"
  27 #include "asm/segment.h"
  28 #include "asm/stat.h"
  29 #include "asm/pgtable.h"
  30 #include "asm/processor.h"
  31 #include "asm/tlbflush.h"
  32 #include "asm/uaccess.h"
  33 #include "asm/user.h"
  34 #include "user_util.h"
  35 #include "kern_util.h"
  36 #include "kern.h"
  37 #include "signal_kern.h"
  38 #include "signal_user.h"
  39 #include "init.h"
  40 #include "irq_user.h"
  41 #include "mem_user.h"
  42 #include "time_user.h"
  43 #include "tlb.h"
  44 #include "frame_kern.h"
  45 #include "sigcontext.h"
  46 #include "os.h"
  47 #include "mode.h"
  48 #include "mode_kern.h"
  49 #include "choose-mode.h"
  50
  51 /* This is a per-cpu array.  A processor only modifies its entry and it only
  52  * cares about its entry, so it's OK if another processor is modifying its
  53  * entry.
  54  */
  55 struct cpu_task cpu_tasks[NR_CPUS] = { [0 ... NR_CPUS - 1] = { -1, NULL } };
  56
  57 int external_pid(void *t)
  58 {
  59         struct task_struct *task = t ? t : current;
  60
  61         return(CHOOSE_MODE_PROC(external_pid_tt, external_pid_skas, task));
  62 }
  63
  64 int pid_to_processor_id(int pid)
  65 {
  66         int i;
  67
  68         for(i = 0; i < ncpus; i++){
  69                 if(cpu_tasks[i].pid == pid) return(i);
  70         }
  71         return(-1);
  72 }
  73
  74 void free_stack(unsigned long stack, int order)
  75 {
  76         free_pages(stack, order);
  77 }
  78
  79 unsigned long alloc_stack(int order, int atomic)
  80 {
  81         unsigned long page;
  82         int flags = GFP_KERNEL;
  83
  84         if(atomic) flags |= GFP_ATOMIC;
  85         page = __get_free_pages(flags, order);
  86         if(page == 0)
  87                 return(0);
  88         stack_protections(page);
  89         return(page);
  90 }
  91
  92 int kernel_thread(int (*fn)(void *), void * arg, unsigned long flags)
  93 {
  94         int pid;
  95
  96         current->thread.request.u.thread.proc = fn;
  97         current->thread.request.u.thread.arg = arg;
  98         pid = do_fork(CLONE_VM | CLONE_UNTRACED | flags, 0, NULL, 0, NULL,
  99                       NULL);
 100         if(pid < 0)
 101                 panic("do_fork failed in kernel_thread, errno = %d", pid);
 102         return(pid);
 103 }
 104
 105 void set_current(void *t)
 106 {
 107         struct task_struct *task = t;
 108
 109         cpu_tasks[task->thread_info->cpu] = ((struct cpu_task)
 110                 { external_pid(task), task });
 111 }
 112
 113 void *_switch_to(void *prev, void *next, void *last)
 114 {
 115         return(CHOOSE_MODE(switch_to_tt(prev, next),
 116                            switch_to_skas(prev, next)));
 117 }
 118
 119 void interrupt_end(void)
 120 {
 121         if(need_resched()) schedule();
 122         if(test_tsk_thread_flag(current, TIF_SIGPENDING)) do_signal();
 123 }
 124
 125 void release_thread(struct task_struct *task)
 126 {
 127         CHOOSE_MODE(release_thread_tt(task), release_thread_skas(task));
 128 }
 129
 130 void exit_thread(void)
 131 {
 132         unprotect_stack((unsigned long) current_thread);
 133 }
 134
 135 void *get_current(void)
 136 {
 137         return(current);
 138 }
 139
 140 int copy_thread(int nr, unsigned long clone_flags, unsigned long sp,
 141                 unsigned long stack_top, struct task_struct * p,
 142                 struct pt_regs *regs)
 143 {
 144         p->thread = (struct thread_struct) INIT_THREAD;
 145         return(CHOOSE_MODE_PROC(copy_thread_tt, copy_thread_skas, nr,
 146                                 clone_flags, sp, stack_top, p, regs));
 147 }
 148
 149 void initial_thread_cb(void (*proc)(void *), void *arg)
 150 {
 151         int save_kmalloc_ok = kmalloc_ok;
 152
 153         kmalloc_ok = 0;
 154         CHOOSE_MODE_PROC(initial_thread_cb_tt, initial_thread_cb_skas, proc,
 155                          arg);
 156         kmalloc_ok = save_kmalloc_ok;
 157 }
 158
 159 unsigned long stack_sp(unsigned long page)
 160 {
 161         return(page + PAGE_SIZE - sizeof(void *));
 162 }
 163
 164 int current_pid(void)
 165 {
 166         return(current->pid);
 167 }
 168
 169 void default_idle(void)
 170 {
 171         uml_idle_timer();
 172
 173         atomic_inc(&init_mm.mm_count);
 174         current->mm = &init_mm;
 175         current->active_mm = &init_mm;
 176
 177         while(1){
 178                 /* endless idle loop with no priority at all */
 179
 180                 /*
 181                  * although we are an idle CPU, we do not want to
 182                  * get into the scheduler unnecessarily.
 183                  */
 184                 if(need_resched())
 185                         schedule();
 186
 187                 idle_sleep(10);
 188         }
 189 }
 190
 191 void cpu_idle(void)
 192 {
 193         CHOOSE_MODE(init_idle_tt(), init_idle_skas());
 194 }
 195
 196 int page_size(void)
 197 {
 198         return(PAGE_SIZE);
 199 }
 200
 201 void *um_virt_to_phys(struct task_struct *task, unsigned long addr,
 202                       pte_t *pte_out)
 203 {
 204         pgd_t *pgd;
 205         pud_t *pud;
 206         pmd_t *pmd;
 207         pte_t *pte;
 208
 209         if(task->mm == NULL)
 210                 return(ERR_PTR(-EINVAL));
 211         pgd = pgd_offset(task->mm, addr);
 212         if(!pgd_present(*pgd))
 213                 return(ERR_PTR(-EINVAL));
 214
 215         pud = pud_offset(pgd, addr);
 216         if(!pud_present(*pud))
 217                 return(ERR_PTR(-EINVAL));
 218
 219         pmd = pmd_offset(pud, addr);
 220         if(!pmd_present(*pmd))
 221                 return(ERR_PTR(-EINVAL));
 222
 223         pte = pte_offset_kernel(pmd, addr);
 224         if(!pte_present(*pte))
 225                 return(ERR_PTR(-EINVAL));
 226
 227         if(pte_out != NULL)
 228                 *pte_out = *pte;
 229         return((void *) (pte_val(*pte) & PAGE_MASK) + (addr & ~PAGE_MASK));
 230 }
 231
 232 char *current_cmd(void)
 233 {
 234 #if defined(CONFIG_SMP) || defined(CONFIG_HIGHMEM)
 235         return("(Unknown)");
 236 #else
 237         void *addr = um_virt_to_phys(current, current->mm->arg_start, NULL);
 238         return IS_ERR(addr) ? "(Unknown)": __va((unsigned long) addr);
 239 #endif
 240 }
 241
 242 void force_sigbus(void)
 243 {
 244         printk(KERN_ERR "Killing pid %d because of a lack of memory\n",
 245                current->pid);
 246         lock_kernel();
 247         sigaddset(&current->pending.signal, SIGBUS);
 248         recalc_sigpending();
 249         current->flags |= PF_SIGNALED;
 250         do_exit(SIGBUS | 0x80);
 251 }
 252
 253 void dump_thread(struct pt_regs *regs, struct user *u)
 254 {
 255 }
 256
 257 void enable_hlt(void)
 258 {
 259         panic("enable_hlt");
 260 }
 261
 262 EXPORT_SYMBOL(enable_hlt);
 263
 264 void disable_hlt(void)
 265 {
 266         panic("disable_hlt");
 267 }
 268
 269 EXPORT_SYMBOL(disable_hlt);
 270
 271 void *um_kmalloc(int size)
 272 {
 273         return(kmalloc(size, GFP_KERNEL));
 274 }
 275
 276 void *um_kmalloc_atomic(int size)
 277 {
 278         return(kmalloc(size, GFP_ATOMIC));
 279 }
 280
 281 void *um_vmalloc(int size)
 282 {
 283         return(vmalloc(size));
 284 }
 285
 286 unsigned long get_fault_addr(void)
 287 {
 288         return((unsigned long) current->thread.fault_addr);
 289 }
 290
 291 EXPORT_SYMBOL(get_fault_addr);
 292
 293 void not_implemented(void)
 294 {
 295         printk(KERN_DEBUG "Something isn't implemented in here\n");
 296 }
 297
 298 EXPORT_SYMBOL(not_implemented);
 299
 300 int user_context(unsigned long sp)
 301 {
 302         unsigned long stack;
 303
 304         stack = sp & (PAGE_MASK << CONFIG_KERNEL_STACK_ORDER);
 305         return(stack != (unsigned long) current_thread);
 306 }
 307
 308 extern void remove_umid_dir(void);
 309
 310 __uml_exitcall(remove_umid_dir);
 311
 312 extern exitcall_t __uml_exitcall_begin, __uml_exitcall_end;
 313
 314 void do_uml_exitcalls(void)
 315 {
 316         exitcall_t *call;
 317
 318         call = &__uml_exitcall_end;
 319         while (--call >= &__uml_exitcall_begin)
 320                 (*call)();
 321 }
 322
 323 char *uml_strdup(char *string)
 324 {
 325         char *new;
 326
 327         new = kmalloc(strlen(string) + 1, GFP_KERNEL);
 328         if(new == NULL) return(NULL);
 329         strcpy(new, string);
 330         return(new);
 331 }
 332
 333 int copy_to_user_proc(void __user *to, void *from, int size)
 334 {
 335         return(copy_to_user(to, from, size));
 336 }
 337
 338 int copy_from_user_proc(void *to, void __user *from, int size)
 339 {
 340         return(copy_from_user(to, from, size));
 341 }
 342
 343 int clear_user_proc(void __user *buf, int size)
 344 {
 345         return(clear_user(buf, size));
 346 }
 347
 348 int strlen_user_proc(char __user *str)
 349 {
 350         return(strlen_user(str));
 351 }
 352
 353 int smp_sigio_handler(void)
 354 {
 355 #ifdef CONFIG_SMP
 356         int cpu = current_thread->cpu;
 357         IPI_handler(cpu);
 358         if(cpu != 0)
 359                 return(1);
 360 #endif
 361         return(0);
 362 }
 363
 364 int um_in_interrupt(void)
 365 {
 366         return(in_interrupt());
 367 }
 368
 369 int cpu(void)
 370 {
 371         return(current_thread->cpu);
 372 }
 373
 374 static atomic_t using_sysemu = ATOMIC_INIT(0);
 375 int sysemu_supported;
 376
 377 void set_using_sysemu(int value)
 378 {
 379         if (value > sysemu_supported)
 380                 return;
 381         atomic_set(&using_sysemu, value);
 382 }
 383
 384 int get_using_sysemu(void)
 385 {
 386         return atomic_read(&using_sysemu);
 387 }
 388
 389 static int proc_read_sysemu(char *buf, char **start, off_t offset, int size,int *eof, void *data)
 390 {
 391         if (snprintf(buf, size, "%d\n", get_using_sysemu()) < size) /*No overflow*/
 392                 *eof = 1;
 393
 394         return strlen(buf);
 395 }
 396
 397 static int proc_write_sysemu(struct file *file,const char *buf, unsigned long count,void *data)
 398 {
 399         char tmp[2];
 400
 401         if (copy_from_user(tmp, buf, 1))
 402                 return -EFAULT;
 403
 404         if (tmp[0] >= '0' && tmp[0] <= '2')
 405                 set_using_sysemu(tmp[0] - '0');
 406         return count; /*We use the first char, but pretend to write everything*/
 407 }
 408
 409 int __init make_proc_sysemu(void)
 410 {
 411         struct proc_dir_entry *ent;
 412         if (!sysemu_supported)
 413                 return 0;
 414
 415         ent = create_proc_entry("sysemu", 0600, &proc_root);
 416
 417         if (ent == NULL)
 418         {
 419                 printk("Failed to register /proc/sysemu\n");
 420                 return(0);
 421         }
 422
 423         ent->read_proc  = proc_read_sysemu;
 424         ent->write_proc = proc_write_sysemu;
 425
 426         return 0;
 427 }
 428
 429 late_initcall(make_proc_sysemu);
 430
 431 int singlestepping(void * t)
 432 {
 433         struct task_struct *task = t ? t : current;
 434
 435         if ( ! (task->ptrace & PT_DTRACE) )
 436                 return(0);
 437
 438         if (task->thread.singlestep_syscall)
 439                 return(1);
 440
 441         return 2;
 442 }
 443
 444 /*
 445  * Only x86 and x86_64 have an arch_align_stack().
 446  * All other arches have "#define arch_align_stack(x) (x)"
 447  * in their asm/system.h
 448  * As this is included in UML from asm-um/system-generic.h,
 449  * we can use it to behave as the subarch does.
 450  */
 451 #ifndef arch_align_stack
 452 unsigned long arch_align_stack(unsigned long sp)
 453 {
 454         if (randomize_va_space)
 455                 sp -= get_random_int() % 8192;
 456         return sp & ~0xf;
 457 }
 458 #endif