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 set_current(void *t)
 119 {
 120         struct task_struct *task = t;
 121
 122         cpu_tasks[task->thread_info->cpu] = ((struct cpu_task)
 123                 { external_pid(task), task });
 124 }
 125
 126 void *_switch_to(void *prev, void *next, void *last)
 127 {
 128         return(CHOOSE_MODE(switch_to_tt(prev, next),
 129                            switch_to_skas(prev, next)));
 130 }
 131
 132 void interrupt_end(void)
 133 {
 134         if(need_resched()) schedule();
 135         if(test_tsk_thread_flag(current, TIF_SIGPENDING)) do_signal();
 136 }
 137
 138 void release_thread(struct task_struct *task)
 139 {
 140         CHOOSE_MODE(release_thread_tt(task), release_thread_skas(task));
 141 }
 142
 143 void exit_thread(void)
 144 {
 145         unprotect_stack((unsigned long) current_thread);
 146 }
 147
 148 void *get_current(void)
 149 {
 150         return(current);
 151 }
 152
 153 int copy_thread(int nr, unsigned long clone_flags, unsigned long sp,
 154                 unsigned long stack_top, struct task_struct * p,
 155                 struct pt_regs *regs)
 156 {
 157         p->thread = (struct thread_struct) INIT_THREAD;
 158         return(CHOOSE_MODE_PROC(copy_thread_tt, copy_thread_skas, nr,
 159                                 clone_flags, sp, stack_top, p, regs));
 160 }
 161
 162 void initial_thread_cb(void (*proc)(void *), void *arg)
 163 {
 164         int save_kmalloc_ok = kmalloc_ok;
 165
 166         kmalloc_ok = 0;
 167         CHOOSE_MODE_PROC(initial_thread_cb_tt, initial_thread_cb_skas, proc,
 168                          arg);
 169         kmalloc_ok = save_kmalloc_ok;
 170 }
 171
 172 unsigned long stack_sp(unsigned long page)
 173 {
 174         return(page + PAGE_SIZE - sizeof(void *));
 175 }
 176
 177 int current_pid(void)
 178 {
 179         return(current->pid);
 180 }
 181
 182 void default_idle(void)
 183 {
 184         uml_idle_timer();
 185
 186         atomic_inc(&init_mm.mm_count);
 187         current->mm = &init_mm;
 188         current->active_mm = &init_mm;
 189
 190         while(1){
 191                 /* endless idle loop with no priority at all */
 192                 SET_PRI(current);
 193
 194                 /*
 195                  * although we are an idle CPU, we do not want to
 196                  * get into the scheduler unnecessarily.
 197                  */
 198                 if(need_resched())
 199                         schedule();
 200
 201                 idle_sleep(10);
 202         }
 203 }
 204
 205 void cpu_idle(void)
 206 {
 207         CHOOSE_MODE(init_idle_tt(), init_idle_skas());
 208 }
 209
 210 int page_size(void)
 211 {
 212         return(PAGE_SIZE);
 213 }
 214
 215 unsigned long page_mask(void)
 216 {
 217         return(PAGE_MASK);
 218 }
 219
 220 void *um_virt_to_phys(struct task_struct *task, unsigned long addr,
 221                       pte_t *pte_out)
 222 {
 223         pgd_t *pgd;
 224         pud_t *pud;
 225         pmd_t *pmd;
 226         pte_t *pte;
 227
 228         if(task->mm == NULL)
 229                 return(ERR_PTR(-EINVAL));
 230         pgd = pgd_offset(task->mm, addr);
 231         if(!pgd_present(*pgd))
 232                 return(ERR_PTR(-EINVAL));
 233
 234         pud = pud_offset(pgd, addr);
 235         if(!pud_present(*pud))
 236                 return(ERR_PTR(-EINVAL));
 237
 238         pmd = pmd_offset(pud, addr);
 239         if(!pmd_present(*pmd))
 240                 return(ERR_PTR(-EINVAL));
 241
 242         pte = pte_offset_kernel(pmd, addr);
 243         if(!pte_present(*pte))
 244                 return(ERR_PTR(-EINVAL));
 245
 246         if(pte_out != NULL)
 247                 *pte_out = *pte;
 248         return((void *) (pte_val(*pte) & PAGE_MASK) + (addr & ~PAGE_MASK));
 249 }
 250
 251 char *current_cmd(void)
 252 {
 253 #if defined(CONFIG_SMP) || defined(CONFIG_HIGHMEM)
 254         return("(Unknown)");
 255 #else
 256         void *addr = um_virt_to_phys(current, current->mm->arg_start, NULL);
 257         return IS_ERR(addr) ? "(Unknown)": __va((unsigned long) addr);
 258 #endif
 259 }
 260
 261 void force_sigbus(void)
 262 {
 263         printk(KERN_ERR "Killing pid %d because of a lack of memory\n",
 264                current->pid);
 265         lock_kernel();
 266         sigaddset(&current->pending.signal, SIGBUS);
 267         recalc_sigpending();
 268         current->flags |= PF_SIGNALED;
 269         do_exit(SIGBUS | 0x80);
 270 }
 271
 272 void dump_thread(struct pt_regs *regs, struct user *u)
 273 {
 274 }
 275
 276 void enable_hlt(void)
 277 {
 278         panic("enable_hlt");
 279 }
 280
 281 EXPORT_SYMBOL(enable_hlt);
 282
 283 void disable_hlt(void)
 284 {
 285         panic("disable_hlt");
 286 }
 287
 288 EXPORT_SYMBOL(disable_hlt);
 289
 290 void *um_kmalloc(int size)
 291 {
 292         return(kmalloc(size, GFP_KERNEL));
 293 }
 294
 295 void *um_kmalloc_atomic(int size)
 296 {
 297         return(kmalloc(size, GFP_ATOMIC));
 298 }
 299
 300 void *um_vmalloc(int size)
 301 {
 302         return(vmalloc(size));
 303 }
 304
 305 unsigned long get_fault_addr(void)
 306 {
 307         return((unsigned long) current->thread.fault_addr);
 308 }
 309
 310 EXPORT_SYMBOL(get_fault_addr);
 311
 312 void not_implemented(void)
 313 {
 314         printk(KERN_DEBUG "Something isn't implemented in here\n");
 315 }
 316
 317 EXPORT_SYMBOL(not_implemented);
 318
 319 int user_context(unsigned long sp)
 320 {
 321         unsigned long stack;
 322
 323         stack = sp & (PAGE_MASK << CONFIG_KERNEL_STACK_ORDER);
 324         return(stack != (unsigned long) current_thread);
 325 }
 326
 327 extern void remove_umid_dir(void);
 328
 329 __uml_exitcall(remove_umid_dir);
 330
 331 extern exitcall_t __uml_exitcall_begin, __uml_exitcall_end;
 332
 333 void do_uml_exitcalls(void)
 334 {
 335         exitcall_t *call;
 336
 337         call = &__uml_exitcall_end;
 338         while (--call >= &__uml_exitcall_begin)
 339                 (*call)();
 340 }
 341
 342 char *uml_strdup(char *string)
 343 {
 344         char *new;
 345
 346         new = kmalloc(strlen(string) + 1, GFP_KERNEL);
 347         if(new == NULL) return(NULL);
 348         strcpy(new, string);
 349         return(new);
 350 }
 351
 352 void *get_init_task(void)
 353 {
 354         return(&init_thread_union.thread_info.task);
 355 }
 356
 357 int copy_to_user_proc(void __user *to, void *from, int size)
 358 {
 359         return(copy_to_user(to, from, size));
 360 }
 361
 362 int copy_from_user_proc(void *to, void __user *from, int size)
 363 {
 364         return(copy_from_user(to, from, size));
 365 }
 366
 367 int clear_user_proc(void __user *buf, int size)
 368 {
 369         return(clear_user(buf, size));
 370 }
 371
 372 int strlen_user_proc(char __user *str)
 373 {
 374         return(strlen_user(str));
 375 }
 376
 377 int smp_sigio_handler(void)
 378 {
 379 #ifdef CONFIG_SMP
 380         int cpu = current_thread->cpu;
 381         IPI_handler(cpu);
 382         if(cpu != 0)
 383                 return(1);
 384 #endif
 385         return(0);
 386 }
 387
 388 int um_in_interrupt(void)
 389 {
 390         return(in_interrupt());
 391 }
 392
 393 int cpu(void)
 394 {
 395         return(current_thread->cpu);
 396 }
 397
 398 static atomic_t using_sysemu = ATOMIC_INIT(0);
 399 int sysemu_supported;
 400
 401 void set_using_sysemu(int value)
 402 {
 403         if (value > sysemu_supported)
 404                 return;
 405         atomic_set(&using_sysemu, value);
 406 }
 407
 408 int get_using_sysemu(void)
 409 {
 410         return atomic_read(&using_sysemu);
 411 }
 412
 413 static int proc_read_sysemu(char *buf, char **start, off_t offset, int size,int *eof, void *data)
 414 {
 415         if (snprintf(buf, size, "%d\n", get_using_sysemu()) < size) /*No overflow*/
 416                 *eof = 1;
 417
 418         return strlen(buf);
 419 }
 420
 421 static int proc_write_sysemu(struct file *file,const char *buf, unsigned long count,void *data)
 422 {
 423         char tmp[2];
 424
 425         if (copy_from_user(tmp, buf, 1))
 426                 return -EFAULT;
 427
 428         if (tmp[0] >= '0' && tmp[0] <= '2')
 429                 set_using_sysemu(tmp[0] - '0');
 430         return count; /*We use the first char, but pretend to write everything*/
 431 }
 432
 433 int __init make_proc_sysemu(void)
 434 {
 435         struct proc_dir_entry *ent;
 436         if (!sysemu_supported)
 437                 return 0;
 438
 439         ent = create_proc_entry("sysemu", 0600, &proc_root);
 440
 441         if (ent == NULL)
 442         {
 443                 printk("Failed to register /proc/sysemu\n");
 444                 return(0);
 445         }
 446
 447         ent->read_proc  = proc_read_sysemu;
 448         ent->write_proc = proc_write_sysemu;
 449
 450         return 0;
 451 }
 452
 453 late_initcall(make_proc_sysemu);
 454
 455 int singlestepping(void * t)
 456 {
 457         struct task_struct *task = t ? t : current;
 458
 459         if ( ! (task->ptrace & PT_DTRACE) )
 460                 return(0);
 461
 462         if (task->thread.singlestep_syscall)
 463                 return(1);
 464
 465         return 2;
 466 }
 467
 468 /*
 469  * Only x86 and x86_64 have an arch_align_stack().
 470  * All other arches have "#define arch_align_stack(x) (x)"
 471  * in their asm/system.h
 472  * As this is included in UML from asm-um/system-generic.h,
 473  * we can use it to behave as the subarch does.
 474  */
 475 #ifndef arch_align_stack
 476 unsigned long arch_align_stack(unsigned long sp)
 477 {
 478         if (randomize_va_space)
 479                 sp -= get_random_int() % 8192;
 480         return sp & ~0xf;
 481 }
 482 #endif
 483
 484
 485 /*
 486  * Overrides for Emacs so that we follow Linus's tabbing style.
 487  * Emacs will notice this stuff at the end of the file and automatically
 488  * adjust the settings for this buffer only.  This must remain at the end
 489  * of the file.
 490  * ---------------------------------------------------------------------------
 491  * Local variables:
 492  * c-file-style: "linux"
 493  * End:
 494  */