git.oblomov.eu Git - linux-2.6/blob - arch/um/kernel/process.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/kernel.h"
   8 #include "linux/sched.h"
   9 #include "linux/interrupt.h"
  10 #include "linux/string.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/personality.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 "kern_util.h"
  36 #include "as-layout.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 "tlb.h"
  43 #include "frame_kern.h"
  44 #include "sigcontext.h"
  45 #include "os.h"
  46 #include "mode.h"
  47 #include "mode_kern.h"
  48 #include "choose-mode.h"
  49
  50 /* This is a per-cpu array.  A processor only modifies its entry and it only
  51  * cares about its entry, so it's OK if another processor is modifying its
  52  * entry.
  53  */
  54 struct cpu_task cpu_tasks[NR_CPUS] = { [0 ... NR_CPUS - 1] = { -1, NULL } };
  55
  56 static inline int external_pid(struct task_struct *task)
  57 {
  58         return CHOOSE_MODE_PROC(external_pid_tt, external_pid_skas, task);
  59 }
  60
  61 int pid_to_processor_id(int pid)
  62 {
  63         int i;
  64
  65         for(i = 0; i < ncpus; i++){
  66                 if(cpu_tasks[i].pid == pid)
  67                         return i;
  68         }
  69         return -1;
  70 }
  71
  72 void free_stack(unsigned long stack, int order)
  73 {
  74         free_pages(stack, order);
  75 }
  76
  77 unsigned long alloc_stack(int order, int atomic)
  78 {
  79         unsigned long page;
  80         gfp_t flags = GFP_KERNEL;
  81
  82         if (atomic)
  83                 flags = GFP_ATOMIC;
  84         page = __get_free_pages(flags, order);
  85         if(page == 0)
  86                 return 0;
  87         stack_protections(page);
  88         return page;
  89 }
  90
  91 int kernel_thread(int (*fn)(void *), void * arg, unsigned long flags)
  92 {
  93         int pid;
  94
  95         current->thread.request.u.thread.proc = fn;
  96         current->thread.request.u.thread.arg = arg;
  97         pid = do_fork(CLONE_VM | CLONE_UNTRACED | flags, 0,
  98                       &current->thread.regs, 0, NULL, NULL);
  99         return pid;
 100 }
 101
 102 static inline void set_current(struct task_struct *task)
 103 {
 104         cpu_tasks[task_thread_info(task)->cpu] = ((struct cpu_task)
 105                 { external_pid(task), task });
 106 }
 107
 108 void *_switch_to(void *prev, void *next, void *last)
 109 {
 110         struct task_struct *from = prev;
 111         struct task_struct *to= next;
 112
 113         to->thread.prev_sched = from;
 114         set_current(to);
 115
 116         do {
 117                 current->thread.saved_task = NULL ;
 118                 CHOOSE_MODE_PROC(switch_to_tt, switch_to_skas, prev, next);
 119                 if(current->thread.saved_task)
 120                         show_regs(&(current->thread.regs));
 121                 next= current->thread.saved_task;
 122                 prev= current;
 123         } while(current->thread.saved_task);
 124
 125         return current->thread.prev_sched;
 126
 127 }
 128
 129 void interrupt_end(void)
 130 {
 131         if(need_resched())
 132                 schedule();
 133         if(test_tsk_thread_flag(current, TIF_SIGPENDING))
 134                 do_signal();
 135 }
 136
 137 void release_thread(struct task_struct *task)
 138 {
 139         CHOOSE_MODE(release_thread_tt(task), release_thread_skas(task));
 140 }
 141
 142 void exit_thread(void)
 143 {
 144         unprotect_stack((unsigned long) current_thread);
 145 }
 146
 147 void *get_current(void)
 148 {
 149         return current;
 150 }
 151
 152 int copy_thread(int nr, unsigned long clone_flags, unsigned long sp,
 153                 unsigned long stack_top, struct task_struct * p,
 154                 struct pt_regs *regs)
 155 {
 156         int ret;
 157
 158         p->thread = (struct thread_struct) INIT_THREAD;
 159         ret = CHOOSE_MODE_PROC(copy_thread_tt, copy_thread_skas, nr,
 160                                 clone_flags, sp, stack_top, p, regs);
 161
 162         if (ret || !current->thread.forking)
 163                 goto out;
 164
 165         clear_flushed_tls(p);
 166
 167         /*
 168          * Set a new TLS for the child thread?
 169          */
 170         if (clone_flags & CLONE_SETTLS)
 171                 ret = arch_copy_tls(p);
 172
 173 out:
 174         return ret;
 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 #ifdef CONFIG_MODE_TT
 188 unsigned long stack_sp(unsigned long page)
 189 {
 190         return page + PAGE_SIZE - sizeof(void *);
 191 }
 192 #endif
 193
 194 void default_idle(void)
 195 {
 196         CHOOSE_MODE(uml_idle_timer(), (void) 0);
 197
 198         while(1){
 199                 /* endless idle loop with no priority at all */
 200
 201                 /*
 202                  * although we are an idle CPU, we do not want to
 203                  * get into the scheduler unnecessarily.
 204                  */
 205                 if(need_resched())
 206                         schedule();
 207
 208                 idle_sleep(10);
 209         }
 210 }
 211
 212 void cpu_idle(void)
 213 {
 214         CHOOSE_MODE(init_idle_tt(), init_idle_skas());
 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 dump_thread(struct pt_regs *regs, struct user *u)
 261 {
 262 }
 263
 264 int __cant_sleep(void) {
 265         return in_atomic() || irqs_disabled() || in_interrupt();
 266         /* Is in_interrupt() really needed? */
 267 }
 268
 269 int user_context(unsigned long sp)
 270 {
 271         unsigned long stack;
 272
 273         stack = sp & (PAGE_MASK << CONFIG_KERNEL_STACK_ORDER);
 274         return stack != (unsigned long) current_thread;
 275 }
 276
 277 extern exitcall_t __uml_exitcall_begin, __uml_exitcall_end;
 278
 279 void do_uml_exitcalls(void)
 280 {
 281         exitcall_t *call;
 282
 283         call = &__uml_exitcall_end;
 284         while (--call >= &__uml_exitcall_begin)
 285                 (*call)();
 286 }
 287
 288 char *uml_strdup(char *string)
 289 {
 290         return kstrdup(string, GFP_KERNEL);
 291 }
 292
 293 int copy_to_user_proc(void __user *to, void *from, int size)
 294 {
 295         return copy_to_user(to, from, size);
 296 }
 297
 298 int copy_from_user_proc(void *to, void __user *from, int size)
 299 {
 300         return copy_from_user(to, from, size);
 301 }
 302
 303 int clear_user_proc(void __user *buf, int size)
 304 {
 305         return clear_user(buf, size);
 306 }
 307
 308 int strlen_user_proc(char __user *str)
 309 {
 310         return strlen_user(str);
 311 }
 312
 313 int smp_sigio_handler(void)
 314 {
 315 #ifdef CONFIG_SMP
 316         int cpu = current_thread->cpu;
 317         IPI_handler(cpu);
 318         if(cpu != 0)
 319                 return 1;
 320 #endif
 321         return 0;
 322 }
 323
 324 int cpu(void)
 325 {
 326         return current_thread->cpu;
 327 }
 328
 329 static atomic_t using_sysemu = ATOMIC_INIT(0);
 330 int sysemu_supported;
 331
 332 void set_using_sysemu(int value)
 333 {
 334         if (value > sysemu_supported)
 335                 return;
 336         atomic_set(&using_sysemu, value);
 337 }
 338
 339 int get_using_sysemu(void)
 340 {
 341         return atomic_read(&using_sysemu);
 342 }
 343
 344 static int proc_read_sysemu(char *buf, char **start, off_t offset, int size,int *eof, void *data)
 345 {
 346         if (snprintf(buf, size, "%d\n", get_using_sysemu()) < size) /*No overflow*/
 347                 *eof = 1;
 348
 349         return strlen(buf);
 350 }
 351
 352 static int proc_write_sysemu(struct file *file,const char __user *buf, unsigned long count,void *data)
 353 {
 354         char tmp[2];
 355
 356         if (copy_from_user(tmp, buf, 1))
 357                 return -EFAULT;
 358
 359         if (tmp[0] >= '0' && tmp[0] <= '2')
 360                 set_using_sysemu(tmp[0] - '0');
 361         return count; /*We use the first char, but pretend to write everything*/
 362 }
 363
 364 int __init make_proc_sysemu(void)
 365 {
 366         struct proc_dir_entry *ent;
 367         if (!sysemu_supported)
 368                 return 0;
 369
 370         ent = create_proc_entry("sysemu", 0600, &proc_root);
 371
 372         if (ent == NULL)
 373         {
 374                 printk(KERN_WARNING "Failed to register /proc/sysemu\n");
 375                 return 0;
 376         }
 377
 378         ent->read_proc  = proc_read_sysemu;
 379         ent->write_proc = proc_write_sysemu;
 380
 381         return 0;
 382 }
 383
 384 late_initcall(make_proc_sysemu);
 385
 386 int singlestepping(void * t)
 387 {
 388         struct task_struct *task = t ? t : current;
 389
 390         if ( ! (task->ptrace & PT_DTRACE) )
 391                 return(0);
 392
 393         if (task->thread.singlestep_syscall)
 394                 return(1);
 395
 396         return 2;
 397 }
 398
 399 /*
 400  * Only x86 and x86_64 have an arch_align_stack().
 401  * All other arches have "#define arch_align_stack(x) (x)"
 402  * in their asm/system.h
 403  * As this is included in UML from asm-um/system-generic.h,
 404  * we can use it to behave as the subarch does.
 405  */
 406 #ifndef arch_align_stack
 407 unsigned long arch_align_stack(unsigned long sp)
 408 {
 409         if (!(current->personality & ADDR_NO_RANDOMIZE) && randomize_va_space)
 410                 sp -= get_random_int() % 8192;
 411         return sp & ~0xf;
 412 }
 413 #endif