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 "2_5compat.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 struct task_struct *get_task(int pid, int require)
  59 {
  60         struct task_struct *ret;
  61
  62         read_lock(&tasklist_lock);
  63         ret = find_task_by_pid(pid);
  64         read_unlock(&tasklist_lock);
  65
  66         if(require && (ret == NULL)) panic("get_task couldn't find a task\n");
  67         return(ret);
  68 }
  69
  70 int external_pid(void *t)
  71 {
  72         struct task_struct *task = t ? t : current;
  73
  74         return(CHOOSE_MODE_PROC(external_pid_tt, external_pid_skas, task));
  75 }
  76
  77 int pid_to_processor_id(int pid)
  78 {
  79         int i;
  80
  81         for(i = 0; i < ncpus; i++){
  82                 if(cpu_tasks[i].pid == pid) return(i);
  83         }
  84         return(-1);
  85 }
  86
  87 void free_stack(unsigned long stack, int order)
  88 {
  89         free_pages(stack, order);
  90 }
  91
  92 unsigned long alloc_stack(int order, int atomic)
  93 {
  94         unsigned long page;
  95         int flags = GFP_KERNEL;
  96
  97         if(atomic) flags |= GFP_ATOMIC;
  98         page = __get_free_pages(flags, order);
  99         if(page == 0)
 100                 return(0);
 101         stack_protections(page);
 102         return(page);
 103 }
 104
 105 int kernel_thread(int (*fn)(void *), void * arg, unsigned long flags)
 106 {
 107         int pid;
 108
 109         current->thread.request.u.thread.proc = fn;
 110         current->thread.request.u.thread.arg = arg;
 111         pid = do_fork(CLONE_VM | CLONE_UNTRACED | flags, 0, NULL, 0, NULL,
 112                       NULL);
 113         if(pid < 0)
 114                 panic("do_fork failed in kernel_thread, errno = %d", pid);
 115         return(pid);
 116 }
 117
 118 void switch_mm(struct mm_struct *prev, struct mm_struct *next,
 119                struct task_struct *tsk)
 120 {
 121         int cpu = smp_processor_id();
 122
 123         if (prev != next)
 124                 cpu_clear(cpu, prev->cpu_vm_mask);
 125         cpu_set(cpu, next->cpu_vm_mask);
 126 }
 127
 128 void set_current(void *t)
 129 {
 130         struct task_struct *task = t;
 131
 132         cpu_tasks[task->thread_info->cpu] = ((struct cpu_task)
 133                 { external_pid(task), task });
 134 }
 135
 136 void *_switch_to(void *prev, void *next, void *last)
 137 {
 138         return(CHOOSE_MODE(switch_to_tt(prev, next),
 139                            switch_to_skas(prev, next)));
 140 }
 141
 142 void interrupt_end(void)
 143 {
 144         if(need_resched()) schedule();
 145         if(test_tsk_thread_flag(current, TIF_SIGPENDING)) do_signal();
 146 }
 147
 148 void release_thread(struct task_struct *task)
 149 {
 150         CHOOSE_MODE(release_thread_tt(task), release_thread_skas(task));
 151 }
 152
 153 void exit_thread(void)
 154 {
 155         CHOOSE_MODE(exit_thread_tt(), exit_thread_skas());
 156         unprotect_stack((unsigned long) current_thread);
 157 }
 158
 159 void *get_current(void)
 160 {
 161         return(current);
 162 }
 163
 164 void prepare_to_copy(struct task_struct *tsk)
 165 {
 166 }
 167
 168 int copy_thread(int nr, unsigned long clone_flags, unsigned long sp,
 169                 unsigned long stack_top, struct task_struct * p,
 170                 struct pt_regs *regs)
 171 {
 172         p->thread = (struct thread_struct) INIT_THREAD;
 173         return(CHOOSE_MODE_PROC(copy_thread_tt, copy_thread_skas, nr,
 174                                 clone_flags, sp, stack_top, p, regs));
 175 }
 176
 177 void initial_thread_cb(void (*proc)(void *), void *arg)
 178 {
 179         int save_kmalloc_ok = kmalloc_ok;
 180
 181         kmalloc_ok = 0;
 182         CHOOSE_MODE_PROC(initial_thread_cb_tt, initial_thread_cb_skas, proc,
 183                          arg);
 184         kmalloc_ok = save_kmalloc_ok;
 185 }
 186
 187 unsigned long stack_sp(unsigned long page)
 188 {
 189         return(page + PAGE_SIZE - sizeof(void *));
 190 }
 191
 192 int current_pid(void)
 193 {
 194         return(current->pid);
 195 }
 196
 197 void default_idle(void)
 198 {
 199         uml_idle_timer();
 200
 201         atomic_inc(&init_mm.mm_count);
 202         current->mm = &init_mm;
 203         current->active_mm = &init_mm;
 204
 205         while(1){
 206                 /* endless idle loop with no priority at all */
 207                 SET_PRI(current);
 208
 209                 /*
 210                  * although we are an idle CPU, we do not want to
 211                  * get into the scheduler unnecessarily.
 212                  */
 213                 if(need_resched())
 214                         schedule();
 215
 216                 idle_sleep(10);
 217         }
 218 }
 219
 220 void cpu_idle(void)
 221 {
 222         CHOOSE_MODE(init_idle_tt(), init_idle_skas());
 223 }
 224
 225 int page_size(void)
 226 {
 227         return(PAGE_SIZE);
 228 }
 229
 230 unsigned long page_mask(void)
 231 {
 232         return(PAGE_MASK);
 233 }
 234
 235 void *um_virt_to_phys(struct task_struct *task, unsigned long addr,
 236                       pte_t *pte_out)
 237 {
 238         pgd_t *pgd;
 239         pud_t *pud;
 240         pmd_t *pmd;
 241         pte_t *pte;
 242
 243         if(task->mm == NULL)
 244                 return(ERR_PTR(-EINVAL));
 245         pgd = pgd_offset(task->mm, addr);
 246         if(!pgd_present(*pgd))
 247                 return(ERR_PTR(-EINVAL));
 248
 249         pud = pud_offset(pgd, addr);
 250         if(!pud_present(*pud))
 251                 return(ERR_PTR(-EINVAL));
 252
 253         pmd = pmd_offset(pud, addr);
 254         if(!pmd_present(*pmd))
 255                 return(ERR_PTR(-EINVAL));
 256
 257         pte = pte_offset_kernel(pmd, addr);
 258         if(!pte_present(*pte))
 259                 return(ERR_PTR(-EINVAL));
 260
 261         if(pte_out != NULL)
 262                 *pte_out = *pte;
 263         return((void *) (pte_val(*pte) & PAGE_MASK) + (addr & ~PAGE_MASK));
 264 }
 265
 266 char *current_cmd(void)
 267 {
 268 #if defined(CONFIG_SMP) || defined(CONFIG_HIGHMEM)
 269         return("(Unknown)");
 270 #else
 271         void *addr = um_virt_to_phys(current, current->mm->arg_start, NULL);
 272         return IS_ERR(addr) ? "(Unknown)": __va((unsigned long) addr);
 273 #endif
 274 }
 275
 276 void force_sigbus(void)
 277 {
 278         printk(KERN_ERR "Killing pid %d because of a lack of memory\n",
 279                current->pid);
 280         lock_kernel();
 281         sigaddset(&current->pending.signal, SIGBUS);
 282         recalc_sigpending();
 283         current->flags |= PF_SIGNALED;
 284         do_exit(SIGBUS | 0x80);
 285 }
 286
 287 void dump_thread(struct pt_regs *regs, struct user *u)
 288 {
 289 }
 290
 291 void enable_hlt(void)
 292 {
 293         panic("enable_hlt");
 294 }
 295
 296 EXPORT_SYMBOL(enable_hlt);
 297
 298 void disable_hlt(void)
 299 {
 300         panic("disable_hlt");
 301 }
 302
 303 EXPORT_SYMBOL(disable_hlt);
 304
 305 void *um_kmalloc(int size)
 306 {
 307         return(kmalloc(size, GFP_KERNEL));
 308 }
 309
 310 void *um_kmalloc_atomic(int size)
 311 {
 312         return(kmalloc(size, GFP_ATOMIC));
 313 }
 314
 315 void *um_vmalloc(int size)
 316 {
 317         return(vmalloc(size));
 318 }
 319
 320 unsigned long get_fault_addr(void)
 321 {
 322         return((unsigned long) current->thread.fault_addr);
 323 }
 324
 325 EXPORT_SYMBOL(get_fault_addr);
 326
 327 void not_implemented(void)
 328 {
 329         printk(KERN_DEBUG "Something isn't implemented in here\n");
 330 }
 331
 332 EXPORT_SYMBOL(not_implemented);
 333
 334 int user_context(unsigned long sp)
 335 {
 336         unsigned long stack;
 337
 338         stack = sp & (PAGE_MASK << CONFIG_KERNEL_STACK_ORDER);
 339         return(stack != (unsigned long) current_thread);
 340 }
 341
 342 extern void remove_umid_dir(void);
 343
 344 __uml_exitcall(remove_umid_dir);
 345
 346 extern exitcall_t __uml_exitcall_begin, __uml_exitcall_end;
 347
 348 void do_uml_exitcalls(void)
 349 {
 350         exitcall_t *call;
 351
 352         call = &__uml_exitcall_end;
 353         while (--call >= &__uml_exitcall_begin)
 354                 (*call)();
 355 }
 356
 357 char *uml_strdup(char *string)
 358 {
 359         char *new;
 360
 361         new = kmalloc(strlen(string) + 1, GFP_KERNEL);
 362         if(new == NULL) return(NULL);
 363         strcpy(new, string);
 364         return(new);
 365 }
 366
 367 void *get_init_task(void)
 368 {
 369         return(&init_thread_union.thread_info.task);
 370 }
 371
 372 int copy_to_user_proc(void __user *to, void *from, int size)
 373 {
 374         return(copy_to_user(to, from, size));
 375 }
 376
 377 int copy_from_user_proc(void *to, void __user *from, int size)
 378 {
 379         return(copy_from_user(to, from, size));
 380 }
 381
 382 int clear_user_proc(void __user *buf, int size)
 383 {
 384         return(clear_user(buf, size));
 385 }
 386
 387 int strlen_user_proc(char __user *str)
 388 {
 389         return(strlen_user(str));
 390 }
 391
 392 int smp_sigio_handler(void)
 393 {
 394 #ifdef CONFIG_SMP
 395         int cpu = current_thread->cpu;
 396         IPI_handler(cpu);
 397         if(cpu != 0)
 398                 return(1);
 399 #endif
 400         return(0);
 401 }
 402
 403 int um_in_interrupt(void)
 404 {
 405         return(in_interrupt());
 406 }
 407
 408 int cpu(void)
 409 {
 410         return(current_thread->cpu);
 411 }
 412
 413 static atomic_t using_sysemu = ATOMIC_INIT(0);
 414 int sysemu_supported;
 415
 416 void set_using_sysemu(int value)
 417 {
 418         if (value > sysemu_supported)
 419                 return;
 420         atomic_set(&using_sysemu, value);
 421 }
 422
 423 int get_using_sysemu(void)
 424 {
 425         return atomic_read(&using_sysemu);
 426 }
 427
 428 static int proc_read_sysemu(char *buf, char **start, off_t offset, int size,int *eof, void *data)
 429 {
 430         if (snprintf(buf, size, "%d\n", get_using_sysemu()) < size) /*No overflow*/
 431                 *eof = 1;
 432
 433         return strlen(buf);
 434 }
 435
 436 static int proc_write_sysemu(struct file *file,const char *buf, unsigned long count,void *data)
 437 {
 438         char tmp[2];
 439
 440         if (copy_from_user(tmp, buf, 1))
 441                 return -EFAULT;
 442
 443         if (tmp[0] >= '0' && tmp[0] <= '2')
 444                 set_using_sysemu(tmp[0] - '0');
 445         return count; /*We use the first char, but pretend to write everything*/
 446 }
 447
 448 int __init make_proc_sysemu(void)
 449 {
 450         struct proc_dir_entry *ent;
 451         if (!sysemu_supported)
 452                 return 0;
 453
 454         ent = create_proc_entry("sysemu", 0600, &proc_root);
 455
 456         if (ent == NULL)
 457         {
 458                 printk("Failed to register /proc/sysemu\n");
 459                 return(0);
 460         }
 461
 462         ent->read_proc  = proc_read_sysemu;
 463         ent->write_proc = proc_write_sysemu;
 464
 465         return 0;
 466 }
 467
 468 late_initcall(make_proc_sysemu);
 469
 470 int singlestepping(void * t)
 471 {
 472         struct task_struct *task = t ? t : current;
 473
 474         if ( ! (task->ptrace & PT_DTRACE) )
 475                 return(0);
 476
 477         if (task->thread.singlestep_syscall)
 478                 return(1);
 479
 480         return 2;
 481 }
 482
 483 unsigned long arch_align_stack(unsigned long sp)
 484 {
 485         if (randomize_va_space)
 486                 sp -= get_random_int() % 8192;
 487         return sp & ~0xf;
 488 }
 489
 490
 491 /*
 492  * Overrides for Emacs so that we follow Linus's tabbing style.
 493  * Emacs will notice this stuff at the end of the file and automatically
 494  * adjust the settings for this buffer only.  This must remain at the end
 495  * of the file.
 496  * ---------------------------------------------------------------------------
 497  * Local variables:
 498  * c-file-style: "linux"
 499  * End:
 500  */