SAFE public projects git trees. - safe/jmp/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/string.h"
  12 #include "linux/mm.h"
  13 #include "linux/slab.h"
  14 #include "linux/utsname.h"
  15 #include "linux/fs.h"
  16 #include "linux/utime.h"
  17 #include "linux/smp_lock.h"
  18 #include "linux/module.h"
  19 #include "linux/init.h"
  20 #include "linux/capability.h"
  21 #include "linux/vmalloc.h"
  22 #include "linux/spinlock.h"
  23 #include "linux/proc_fs.h"
  24 #include "linux/ptrace.h"
  25 #include "linux/random.h"
  26 #include "asm/unistd.h"
  27 #include "asm/mman.h"
  28 #include "asm/segment.h"
  29 #include "asm/stat.h"
  30 #include "asm/pgtable.h"
  31 #include "asm/processor.h"
  32 #include "asm/tlbflush.h"
  33 #include "asm/uaccess.h"
  34 #include "asm/user.h"
  35 #include "user_util.h"
  36 #include "kern_util.h"
  37 #include "kern.h"
  38 #include "signal_kern.h"
  39 #include "signal_user.h"
  40 #include "init.h"
  41 #include "irq_user.h"
  42 #include "mem_user.h"
  43 #include "time_user.h"
  44 #include "tlb.h"
  45 #include "frame_kern.h"
  46 #include "sigcontext.h"
  47 #include "os.h"
  48 #include "mode.h"
  49 #include "mode_kern.h"
  50 #include "choose-mode.h"
  51
  52 /* This is a per-cpu array.  A processor only modifies its entry and it only
  53  * cares about its entry, so it's OK if another processor is modifying its
  54  * entry.
  55  */
  56 struct cpu_task cpu_tasks[NR_CPUS] = { [0 ... NR_CPUS - 1] = { -1, NULL } };
  57
  58 int external_pid(void *t)
  59 {
  60         struct task_struct *task = t ? t : current;
  61
  62         return(CHOOSE_MODE_PROC(external_pid_tt, external_pid_skas, task));
  63 }
  64
  65 int pid_to_processor_id(int pid)
  66 {
  67         int i;
  68
  69         for(i = 0; i < ncpus; i++){
  70                 if(cpu_tasks[i].pid == pid) return(i);
  71         }
  72         return(-1);
  73 }
  74
  75 void free_stack(unsigned long stack, int order)
  76 {
  77         free_pages(stack, order);
  78 }
  79
  80 unsigned long alloc_stack(int order, int atomic)
  81 {
  82         unsigned long page;
  83         int flags = GFP_KERNEL;
  84
  85         if(atomic) flags |= GFP_ATOMIC;
  86         page = __get_free_pages(flags, order);
  87         if(page == 0)
  88                 return(0);
  89         stack_protections(page);
  90         return(page);
  91 }
  92
  93 int kernel_thread(int (*fn)(void *), void * arg, unsigned long flags)
  94 {
  95         int pid;
  96
  97         current->thread.request.u.thread.proc = fn;
  98         current->thread.request.u.thread.arg = arg;
  99         pid = do_fork(CLONE_VM | CLONE_UNTRACED | flags, 0,
 100                       &current->thread.regs, 0, NULL, NULL);
 101         if(pid < 0)
 102                 panic("do_fork failed in kernel_thread, errno = %d", pid);
 103         return(pid);
 104 }
 105
 106 void set_current(void *t)
 107 {
 108         struct task_struct *task = t;
 109
 110         cpu_tasks[task->thread_info->cpu] = ((struct cpu_task)
 111                 { external_pid(task), task });
 112 }
 113
 114 void *_switch_to(void *prev, void *next, void *last)
 115 {
 116         struct task_struct *from = prev;
 117         struct task_struct *to= next;
 118
 119         to->thread.prev_sched = from;
 120         set_current(to);
 121
 122         do {
 123                 current->thread.saved_task = NULL ;
 124                 CHOOSE_MODE_PROC(switch_to_tt, switch_to_skas, prev, next);
 125                 if(current->thread.saved_task)
 126                         show_regs(&(current->thread.regs));
 127                 next= current->thread.saved_task;
 128                 prev= current;
 129         } while(current->thread.saved_task);
 130
 131         return(current->thread.prev_sched);
 132
 133 }
 134
 135 void interrupt_end(void)
 136 {
 137         if(need_resched()) schedule();
 138         if(test_tsk_thread_flag(current, TIF_SIGPENDING)) do_signal();
 139 }
 140
 141 void release_thread(struct task_struct *task)
 142 {
 143         CHOOSE_MODE(release_thread_tt(task), release_thread_skas(task));
 144 }
 145
 146 void exit_thread(void)
 147 {
 148         unprotect_stack((unsigned long) current_thread);
 149 }
 150
 151 void *get_current(void)
 152 {
 153         return(current);
 154 }
 155
 156 int copy_thread(int nr, unsigned long clone_flags, unsigned long sp,
 157                 unsigned long stack_top, struct task_struct * p,
 158                 struct pt_regs *regs)
 159 {
 160         p->thread = (struct thread_struct) INIT_THREAD;
 161         return(CHOOSE_MODE_PROC(copy_thread_tt, copy_thread_skas, nr,
 162                                 clone_flags, sp, stack_top, p, regs));
 163 }
 164
 165 void initial_thread_cb(void (*proc)(void *), void *arg)
 166 {
 167         int save_kmalloc_ok = kmalloc_ok;
 168
 169         kmalloc_ok = 0;
 170         CHOOSE_MODE_PROC(initial_thread_cb_tt, initial_thread_cb_skas, proc,
 171                          arg);
 172         kmalloc_ok = save_kmalloc_ok;
 173 }
 174
 175 unsigned long stack_sp(unsigned long page)
 176 {
 177         return(page + PAGE_SIZE - sizeof(void *));
 178 }
 179
 180 int current_pid(void)
 181 {
 182         return(current->pid);
 183 }
 184
 185 void default_idle(void)
 186 {
 187         CHOOSE_MODE(uml_idle_timer(), (void) 0);
 188
 189         atomic_inc(&init_mm.mm_count);
 190         current->mm = &init_mm;
 191         current->active_mm = &init_mm;
 192
 193         while(1){
 194                 /* endless idle loop with no priority at all */
 195
 196                 /*
 197                  * although we are an idle CPU, we do not want to
 198                  * get into the scheduler unnecessarily.
 199                  */
 200                 if(need_resched())
 201                         schedule();
 202
 203                 idle_sleep(10);
 204         }
 205 }
 206
 207 void cpu_idle(void)
 208 {
 209         CHOOSE_MODE(init_idle_tt(), init_idle_skas());
 210 }
 211
 212 int page_size(void)
 213 {
 214         return(PAGE_SIZE);
 215 }
 216
 217 void *um_virt_to_phys(struct task_struct *task, unsigned long addr,
 218                       pte_t *pte_out)
 219 {
 220         pgd_t *pgd;
 221         pud_t *pud;
 222         pmd_t *pmd;
 223         pte_t *pte;
 224
 225         if(task->mm == NULL)
 226                 return(ERR_PTR(-EINVAL));
 227         pgd = pgd_offset(task->mm, addr);
 228         if(!pgd_present(*pgd))
 229                 return(ERR_PTR(-EINVAL));
 230
 231         pud = pud_offset(pgd, addr);
 232         if(!pud_present(*pud))
 233                 return(ERR_PTR(-EINVAL));
 234
 235         pmd = pmd_offset(pud, addr);
 236         if(!pmd_present(*pmd))
 237                 return(ERR_PTR(-EINVAL));
 238
 239         pte = pte_offset_kernel(pmd, addr);
 240         if(!pte_present(*pte))
 241                 return(ERR_PTR(-EINVAL));
 242
 243         if(pte_out != NULL)
 244                 *pte_out = *pte;
 245         return((void *) (pte_val(*pte) & PAGE_MASK) + (addr & ~PAGE_MASK));
 246 }
 247
 248 char *current_cmd(void)
 249 {
 250 #if defined(CONFIG_SMP) || defined(CONFIG_HIGHMEM)
 251         return("(Unknown)");
 252 #else
 253         void *addr = um_virt_to_phys(current, current->mm->arg_start, NULL);
 254         return IS_ERR(addr) ? "(Unknown)": __va((unsigned long) addr);
 255 #endif
 256 }
 257
 258 void force_sigbus(void)
 259 {
 260         printk(KERN_ERR "Killing pid %d because of a lack of memory\n",
 261                current->pid);
 262         lock_kernel();
 263         sigaddset(&current->pending.signal, SIGBUS);
 264         recalc_sigpending();
 265         current->flags |= PF_SIGNALED;
 266         do_exit(SIGBUS | 0x80);
 267 }
 268
 269 void dump_thread(struct pt_regs *regs, struct user *u)
 270 {
 271 }
 272
 273 void enable_hlt(void)
 274 {
 275         panic("enable_hlt");
 276 }
 277
 278 EXPORT_SYMBOL(enable_hlt);
 279
 280 void disable_hlt(void)
 281 {
 282         panic("disable_hlt");
 283 }
 284
 285 EXPORT_SYMBOL(disable_hlt);
 286
 287 void *um_kmalloc(int size)
 288 {
 289         return(kmalloc(size, GFP_KERNEL));
 290 }
 291
 292 void *um_kmalloc_atomic(int size)
 293 {
 294         return(kmalloc(size, GFP_ATOMIC));
 295 }
 296
 297 void *um_vmalloc(int size)
 298 {
 299         return(vmalloc(size));
 300 }
 301
 302 unsigned long get_fault_addr(void)
 303 {
 304         return((unsigned long) current->thread.fault_addr);
 305 }
 306
 307 EXPORT_SYMBOL(get_fault_addr);
 308
 309 void not_implemented(void)
 310 {
 311         printk(KERN_DEBUG "Something isn't implemented in here\n");
 312 }
 313
 314 EXPORT_SYMBOL(not_implemented);
 315
 316 int user_context(unsigned long sp)
 317 {
 318         unsigned long stack;
 319
 320         stack = sp & (PAGE_MASK << CONFIG_KERNEL_STACK_ORDER);
 321         return(stack != (unsigned long) current_thread);
 322 }
 323
 324 extern void remove_umid_dir(void);
 325
 326 __uml_exitcall(remove_umid_dir);
 327
 328 extern exitcall_t __uml_exitcall_begin, __uml_exitcall_end;
 329
 330 void do_uml_exitcalls(void)
 331 {
 332         exitcall_t *call;
 333
 334         call = &__uml_exitcall_end;
 335         while (--call >= &__uml_exitcall_begin)
 336                 (*call)();
 337 }
 338
 339 char *uml_strdup(char *string)
 340 {
 341         return kstrdup(string, GFP_KERNEL);
 342 }
 343
 344 int copy_to_user_proc(void __user *to, void *from, int size)
 345 {
 346         return(copy_to_user(to, from, size));
 347 }
 348
 349 int copy_from_user_proc(void *to, void __user *from, int size)
 350 {
 351         return(copy_from_user(to, from, size));
 352 }
 353
 354 int clear_user_proc(void __user *buf, int size)
 355 {
 356         return(clear_user(buf, size));
 357 }
 358
 359 int strlen_user_proc(char __user *str)
 360 {
 361         return(strlen_user(str));
 362 }
 363
 364 int smp_sigio_handler(void)
 365 {
 366 #ifdef CONFIG_SMP
 367         int cpu = current_thread->cpu;
 368         IPI_handler(cpu);
 369         if(cpu != 0)
 370                 return(1);
 371 #endif
 372         return(0);
 373 }
 374
 375 int um_in_interrupt(void)
 376 {
 377         return(in_interrupt());
 378 }
 379
 380 int cpu(void)
 381 {
 382         return(current_thread->cpu);
 383 }
 384
 385 static atomic_t using_sysemu = ATOMIC_INIT(0);
 386 int sysemu_supported;
 387
 388 void set_using_sysemu(int value)
 389 {
 390         if (value > sysemu_supported)
 391                 return;
 392         atomic_set(&using_sysemu, value);
 393 }
 394
 395 int get_using_sysemu(void)
 396 {
 397         return atomic_read(&using_sysemu);
 398 }
 399
 400 static int proc_read_sysemu(char *buf, char **start, off_t offset, int size,int *eof, void *data)
 401 {
 402         if (snprintf(buf, size, "%d\n", get_using_sysemu()) < size) /*No overflow*/
 403                 *eof = 1;
 404
 405         return strlen(buf);
 406 }
 407
 408 static int proc_write_sysemu(struct file *file,const char *buf, unsigned long count,void *data)
 409 {
 410         char tmp[2];
 411
 412         if (copy_from_user(tmp, buf, 1))
 413                 return -EFAULT;
 414
 415         if (tmp[0] >= '0' && tmp[0] <= '2')
 416                 set_using_sysemu(tmp[0] - '0');
 417         return count; /*We use the first char, but pretend to write everything*/
 418 }
 419
 420 int __init make_proc_sysemu(void)
 421 {
 422         struct proc_dir_entry *ent;
 423         if (!sysemu_supported)
 424                 return 0;
 425
 426         ent = create_proc_entry("sysemu", 0600, &proc_root);
 427
 428         if (ent == NULL)
 429         {
 430                 printk(KERN_WARNING "Failed to register /proc/sysemu\n");
 431                 return(0);
 432         }
 433
 434         ent->read_proc  = proc_read_sysemu;
 435         ent->write_proc = proc_write_sysemu;
 436
 437         return 0;
 438 }
 439
 440 late_initcall(make_proc_sysemu);
 441
 442 int singlestepping(void * t)
 443 {
 444         struct task_struct *task = t ? t : current;
 445
 446         if ( ! (task->ptrace & PT_DTRACE) )
 447                 return(0);
 448
 449         if (task->thread.singlestep_syscall)
 450                 return(1);
 451
 452         return 2;
 453 }
 454
 455 /*
 456  * Only x86 and x86_64 have an arch_align_stack().
 457  * All other arches have "#define arch_align_stack(x) (x)"
 458  * in their asm/system.h
 459  * As this is included in UML from asm-um/system-generic.h,
 460  * we can use it to behave as the subarch does.
 461  */
 462 #ifndef arch_align_stack
 463 unsigned long arch_align_stack(unsigned long sp)
 464 {
 465         if (randomize_va_space)
 466                 sp -= get_random_int() % 8192;
 467         return sp & ~0xf;
 468 }
 469 #endif