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 "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         gfp_t flags = GFP_KERNEL;
  83
  84         if (atomic)
  85                 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(task)->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         pte_t ptent;
 225
 226         if(task->mm == NULL)
 227                 return(ERR_PTR(-EINVAL));
 228         pgd = pgd_offset(task->mm, addr);
 229         if(!pgd_present(*pgd))
 230                 return(ERR_PTR(-EINVAL));
 231
 232         pud = pud_offset(pgd, addr);
 233         if(!pud_present(*pud))
 234                 return(ERR_PTR(-EINVAL));
 235
 236         pmd = pmd_offset(pud, addr);
 237         if(!pmd_present(*pmd))
 238                 return(ERR_PTR(-EINVAL));
 239
 240         pte = pte_offset_kernel(pmd, addr);
 241         ptent = *pte;
 242         if(!pte_present(ptent))
 243                 return(ERR_PTR(-EINVAL));
 244
 245         if(pte_out != NULL)
 246                 *pte_out = ptent;
 247         return((void *) (pte_val(ptent) & PAGE_MASK) + (addr & ~PAGE_MASK));
 248 }
 249
 250 char *current_cmd(void)
 251 {
 252 #if defined(CONFIG_SMP) || defined(CONFIG_HIGHMEM)
 253         return("(Unknown)");
 254 #else
 255         void *addr = um_virt_to_phys(current, current->mm->arg_start, NULL);
 256         return IS_ERR(addr) ? "(Unknown)": __va((unsigned long) addr);
 257 #endif
 258 }
 259
 260 void force_sigbus(void)
 261 {
 262         printk(KERN_ERR "Killing pid %d because of a lack of memory\n",
 263                current->pid);
 264         lock_kernel();
 265         sigaddset(&current->pending.signal, SIGBUS);
 266         recalc_sigpending();
 267         current->flags |= PF_SIGNALED;
 268         do_exit(SIGBUS | 0x80);
 269 }
 270
 271 void dump_thread(struct pt_regs *regs, struct user *u)
 272 {
 273 }
 274
 275 void enable_hlt(void)
 276 {
 277         panic("enable_hlt");
 278 }
 279
 280 EXPORT_SYMBOL(enable_hlt);
 281
 282 void disable_hlt(void)
 283 {
 284         panic("disable_hlt");
 285 }
 286
 287 EXPORT_SYMBOL(disable_hlt);
 288
 289 void *um_kmalloc(int size)
 290 {
 291         return(kmalloc(size, GFP_KERNEL));
 292 }
 293
 294 void *um_kmalloc_atomic(int size)
 295 {
 296         return(kmalloc(size, GFP_ATOMIC));
 297 }
 298
 299 void *um_vmalloc(int size)
 300 {
 301         return(vmalloc(size));
 302 }
 303
 304 unsigned long get_fault_addr(void)
 305 {
 306         return((unsigned long) current->thread.fault_addr);
 307 }
 308
 309 EXPORT_SYMBOL(get_fault_addr);
 310
 311 void not_implemented(void)
 312 {
 313         printk(KERN_DEBUG "Something isn't implemented in here\n");
 314 }
 315
 316 EXPORT_SYMBOL(not_implemented);
 317
 318 int user_context(unsigned long sp)
 319 {
 320         unsigned long stack;
 321
 322         stack = sp & (PAGE_MASK << CONFIG_KERNEL_STACK_ORDER);
 323         return(stack != (unsigned long) current_thread);
 324 }
 325
 326 extern exitcall_t __uml_exitcall_begin, __uml_exitcall_end;
 327
 328 void do_uml_exitcalls(void)
 329 {
 330         exitcall_t *call;
 331
 332         call = &__uml_exitcall_end;
 333         while (--call >= &__uml_exitcall_begin)
 334                 (*call)();
 335 }
 336
 337 char *uml_strdup(char *string)
 338 {
 339         return kstrdup(string, GFP_KERNEL);
 340 }
 341
 342 int copy_to_user_proc(void __user *to, void *from, int size)
 343 {
 344         return(copy_to_user(to, from, size));
 345 }
 346
 347 int copy_from_user_proc(void *to, void __user *from, int size)
 348 {
 349         return(copy_from_user(to, from, size));
 350 }
 351
 352 int clear_user_proc(void __user *buf, int size)
 353 {
 354         return(clear_user(buf, size));
 355 }
 356
 357 int strlen_user_proc(char __user *str)
 358 {
 359         return(strlen_user(str));
 360 }
 361
 362 int smp_sigio_handler(void)
 363 {
 364 #ifdef CONFIG_SMP
 365         int cpu = current_thread->cpu;
 366         IPI_handler(cpu);
 367         if(cpu != 0)
 368                 return(1);
 369 #endif
 370         return(0);
 371 }
 372
 373 int um_in_interrupt(void)
 374 {
 375         return(in_interrupt());
 376 }
 377
 378 int cpu(void)
 379 {
 380         return(current_thread->cpu);
 381 }
 382
 383 static atomic_t using_sysemu = ATOMIC_INIT(0);
 384 int sysemu_supported;
 385
 386 void set_using_sysemu(int value)
 387 {
 388         if (value > sysemu_supported)
 389                 return;
 390         atomic_set(&using_sysemu, value);
 391 }
 392
 393 int get_using_sysemu(void)
 394 {
 395         return atomic_read(&using_sysemu);
 396 }
 397
 398 static int proc_read_sysemu(char *buf, char **start, off_t offset, int size,int *eof, void *data)
 399 {
 400         if (snprintf(buf, size, "%d\n", get_using_sysemu()) < size) /*No overflow*/
 401                 *eof = 1;
 402
 403         return strlen(buf);
 404 }
 405
 406 static int proc_write_sysemu(struct file *file,const char *buf, unsigned long count,void *data)
 407 {
 408         char tmp[2];
 409
 410         if (copy_from_user(tmp, buf, 1))
 411                 return -EFAULT;
 412
 413         if (tmp[0] >= '0' && tmp[0] <= '2')
 414                 set_using_sysemu(tmp[0] - '0');
 415         return count; /*We use the first char, but pretend to write everything*/
 416 }
 417
 418 int __init make_proc_sysemu(void)
 419 {
 420         struct proc_dir_entry *ent;
 421         if (!sysemu_supported)
 422                 return 0;
 423
 424         ent = create_proc_entry("sysemu", 0600, &proc_root);
 425
 426         if (ent == NULL)
 427         {
 428                 printk(KERN_WARNING "Failed to register /proc/sysemu\n");
 429                 return(0);
 430         }
 431
 432         ent->read_proc  = proc_read_sysemu;
 433         ent->write_proc = proc_write_sysemu;
 434
 435         return 0;
 436 }
 437
 438 late_initcall(make_proc_sysemu);
 439
 440 int singlestepping(void * t)
 441 {
 442         struct task_struct *task = t ? t : current;
 443
 444         if ( ! (task->ptrace & PT_DTRACE) )
 445                 return(0);
 446
 447         if (task->thread.singlestep_syscall)
 448                 return(1);
 449
 450         return 2;
 451 }
 452
 453 /*
 454  * Only x86 and x86_64 have an arch_align_stack().
 455  * All other arches have "#define arch_align_stack(x) (x)"
 456  * in their asm/system.h
 457  * As this is included in UML from asm-um/system-generic.h,
 458  * we can use it to behave as the subarch does.
 459  */
 460 #ifndef arch_align_stack
 461 unsigned long arch_align_stack(unsigned long sp)
 462 {
 463         if (randomize_va_space)
 464                 sp -= get_random_int() % 8192;
 465         return sp & ~0xf;
 466 }
 467 #endif