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