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