SAFE public projects git trees. - safe/jmp/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 #include "um_malloc.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 static inline int external_pid(struct task_struct *task)
  58 {
  59         return CHOOSE_MODE_PROC(external_pid_tt, external_pid_skas, task);
  60 }
  61
  62 int pid_to_processor_id(int pid)
  63 {
  64         int i;
  65
  66         for(i = 0; i < ncpus; i++){
  67                 if(cpu_tasks[i].pid == pid)
  68                         return i;
  69         }
  70         return -1;
  71 }
  72
  73 void free_stack(unsigned long stack, int order)
  74 {
  75         free_pages(stack, order);
  76 }
  77
  78 unsigned long alloc_stack(int order, int atomic)
  79 {
  80         unsigned long page;
  81         gfp_t flags = GFP_KERNEL;
  82
  83         if (atomic)
  84                 flags = GFP_ATOMIC;
  85         page = __get_free_pages(flags, order);
  86         if(page == 0)
  87                 return 0;
  88         stack_protections(page);
  89         return page;
  90 }
  91
  92 int kernel_thread(int (*fn)(void *), void * arg, unsigned long flags)
  93 {
  94         int pid;
  95
  96         current->thread.request.u.thread.proc = fn;
  97         current->thread.request.u.thread.arg = arg;
  98         pid = do_fork(CLONE_VM | CLONE_UNTRACED | flags, 0,
  99                       &current->thread.regs, 0, NULL, NULL);
 100         if(pid < 0)
 101                 panic("do_fork failed in kernel_thread, errno = %d", pid);
 102         return pid;
 103 }
 104
 105 static inline void set_current(struct task_struct *task)
 106 {
 107         cpu_tasks[task_thread_info(task)->cpu] = ((struct cpu_task)
 108                 { external_pid(task), task });
 109 }
 110
 111 void *_switch_to(void *prev, void *next, void *last)
 112 {
 113         struct task_struct *from = prev;
 114         struct task_struct *to= next;
 115
 116         to->thread.prev_sched = from;
 117         set_current(to);
 118
 119         do {
 120                 current->thread.saved_task = NULL ;
 121                 CHOOSE_MODE_PROC(switch_to_tt, switch_to_skas, prev, next);
 122                 if(current->thread.saved_task)
 123                         show_regs(&(current->thread.regs));
 124                 next= current->thread.saved_task;
 125                 prev= current;
 126         } while(current->thread.saved_task);
 127
 128         return current->thread.prev_sched;
 129
 130 }
 131
 132 void interrupt_end(void)
 133 {
 134         if(need_resched())
 135                 schedule();
 136         if(test_tsk_thread_flag(current, TIF_SIGPENDING))
 137                 do_signal();
 138 }
 139
 140 void release_thread(struct task_struct *task)
 141 {
 142         CHOOSE_MODE(release_thread_tt(task), release_thread_skas(task));
 143 }
 144
 145 void exit_thread(void)
 146 {
 147         unprotect_stack((unsigned long) current_thread);
 148 }
 149
 150 void *get_current(void)
 151 {
 152         return current;
 153 }
 154
 155 int copy_thread(int nr, unsigned long clone_flags, unsigned long sp,
 156                 unsigned long stack_top, struct task_struct * p,
 157                 struct pt_regs *regs)
 158 {
 159         int ret;
 160
 161         p->thread = (struct thread_struct) INIT_THREAD;
 162         ret = CHOOSE_MODE_PROC(copy_thread_tt, copy_thread_skas, nr,
 163                                 clone_flags, sp, stack_top, p, regs);
 164
 165         if (ret || !current->thread.forking)
 166                 goto out;
 167
 168         clear_flushed_tls(p);
 169
 170         /*
 171          * Set a new TLS for the child thread?
 172          */
 173         if (clone_flags & CLONE_SETTLS)
 174                 ret = arch_copy_tls(p);
 175
 176 out:
 177         return ret;
 178 }
 179
 180 void initial_thread_cb(void (*proc)(void *), void *arg)
 181 {
 182         int save_kmalloc_ok = kmalloc_ok;
 183
 184         kmalloc_ok = 0;
 185         CHOOSE_MODE_PROC(initial_thread_cb_tt, initial_thread_cb_skas, proc,
 186                          arg);
 187         kmalloc_ok = save_kmalloc_ok;
 188 }
 189
 190 #ifdef CONFIG_MODE_TT
 191 unsigned long stack_sp(unsigned long page)
 192 {
 193         return page + PAGE_SIZE - sizeof(void *);
 194 }
 195 #endif
 196
 197 void default_idle(void)
 198 {
 199         CHOOSE_MODE(uml_idle_timer(), (void) 0);
 200
 201         while(1){
 202                 /* endless idle loop with no priority at all */
 203
 204                 /*
 205                  * although we are an idle CPU, we do not want to
 206                  * get into the scheduler unnecessarily.
 207                  */
 208                 if(need_resched())
 209                         schedule();
 210
 211                 idle_sleep(10);
 212         }
 213 }
 214
 215 void cpu_idle(void)
 216 {
 217         CHOOSE_MODE(init_idle_tt(), init_idle_skas());
 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         pte_t ptent;
 228
 229         if(task->mm == NULL)
 230                 return ERR_PTR(-EINVAL);
 231         pgd = pgd_offset(task->mm, addr);
 232         if(!pgd_present(*pgd))
 233                 return ERR_PTR(-EINVAL);
 234
 235         pud = pud_offset(pgd, addr);
 236         if(!pud_present(*pud))
 237                 return ERR_PTR(-EINVAL);
 238
 239         pmd = pmd_offset(pud, addr);
 240         if(!pmd_present(*pmd))
 241                 return ERR_PTR(-EINVAL);
 242
 243         pte = pte_offset_kernel(pmd, addr);
 244         ptent = *pte;
 245         if(!pte_present(ptent))
 246                 return ERR_PTR(-EINVAL);
 247
 248         if(pte_out != NULL)
 249                 *pte_out = ptent;
 250         return (void *) (pte_val(ptent) & PAGE_MASK) + (addr & ~PAGE_MASK);
 251 }
 252
 253 char *current_cmd(void)
 254 {
 255 #if defined(CONFIG_SMP) || defined(CONFIG_HIGHMEM)
 256         return "(Unknown)";
 257 #else
 258         void *addr = um_virt_to_phys(current, current->mm->arg_start, NULL);
 259         return IS_ERR(addr) ? "(Unknown)": __va((unsigned long) addr);
 260 #endif
 261 }
 262
 263 void dump_thread(struct pt_regs *regs, struct user *u)
 264 {
 265 }
 266
 267 void *um_kmalloc(int size)
 268 {
 269         return kmalloc(size, GFP_KERNEL);
 270 }
 271
 272 void *um_kmalloc_atomic(int size)
 273 {
 274         return kmalloc(size, GFP_ATOMIC);
 275 }
 276
 277 void *um_vmalloc(int size)
 278 {
 279         return vmalloc(size);
 280 }
 281
 282 int __cant_sleep(void) {
 283         return in_atomic() || irqs_disabled() || in_interrupt();
 284         /* Is in_interrupt() really needed? */
 285 }
 286
 287 int user_context(unsigned long sp)
 288 {
 289         unsigned long stack;
 290
 291         stack = sp & (PAGE_MASK << CONFIG_KERNEL_STACK_ORDER);
 292         return stack != (unsigned long) current_thread;
 293 }
 294
 295 extern exitcall_t __uml_exitcall_begin, __uml_exitcall_end;
 296
 297 void do_uml_exitcalls(void)
 298 {
 299         exitcall_t *call;
 300
 301         call = &__uml_exitcall_end;
 302         while (--call >= &__uml_exitcall_begin)
 303                 (*call)();
 304 }
 305
 306 char *uml_strdup(char *string)
 307 {
 308         return kstrdup(string, GFP_KERNEL);
 309 }
 310
 311 int copy_to_user_proc(void __user *to, void *from, int size)
 312 {
 313         return copy_to_user(to, from, size);
 314 }
 315
 316 int copy_from_user_proc(void *to, void __user *from, int size)
 317 {
 318         return copy_from_user(to, from, size);
 319 }
 320
 321 int clear_user_proc(void __user *buf, int size)
 322 {
 323         return clear_user(buf, size);
 324 }
 325
 326 int strlen_user_proc(char __user *str)
 327 {
 328         return strlen_user(str);
 329 }
 330
 331 int smp_sigio_handler(void)
 332 {
 333 #ifdef CONFIG_SMP
 334         int cpu = current_thread->cpu;
 335         IPI_handler(cpu);
 336         if(cpu != 0)
 337                 return 1;
 338 #endif
 339         return 0;
 340 }
 341
 342 int cpu(void)
 343 {
 344         return current_thread->cpu;
 345 }
 346
 347 static atomic_t using_sysemu = ATOMIC_INIT(0);
 348 int sysemu_supported;
 349
 350 void set_using_sysemu(int value)
 351 {
 352         if (value > sysemu_supported)
 353                 return;
 354         atomic_set(&using_sysemu, value);
 355 }
 356
 357 int get_using_sysemu(void)
 358 {
 359         return atomic_read(&using_sysemu);
 360 }
 361
 362 static int proc_read_sysemu(char *buf, char **start, off_t offset, int size,int *eof, void *data)
 363 {
 364         if (snprintf(buf, size, "%d\n", get_using_sysemu()) < size) /*No overflow*/
 365                 *eof = 1;
 366
 367         return strlen(buf);
 368 }
 369
 370 static int proc_write_sysemu(struct file *file,const char __user *buf, unsigned long count,void *data)
 371 {
 372         char tmp[2];
 373
 374         if (copy_from_user(tmp, buf, 1))
 375                 return -EFAULT;
 376
 377         if (tmp[0] >= '0' && tmp[0] <= '2')
 378                 set_using_sysemu(tmp[0] - '0');
 379         return count; /*We use the first char, but pretend to write everything*/
 380 }
 381
 382 int __init make_proc_sysemu(void)
 383 {
 384         struct proc_dir_entry *ent;
 385         if (!sysemu_supported)
 386                 return 0;
 387
 388         ent = create_proc_entry("sysemu", 0600, &proc_root);
 389
 390         if (ent == NULL)
 391         {
 392                 printk(KERN_WARNING "Failed to register /proc/sysemu\n");
 393                 return 0;
 394         }
 395
 396         ent->read_proc  = proc_read_sysemu;
 397         ent->write_proc = proc_write_sysemu;
 398
 399         return 0;
 400 }
 401
 402 late_initcall(make_proc_sysemu);
 403
 404 int singlestepping(void * t)
 405 {
 406         struct task_struct *task = t ? t : current;
 407
 408         if ( ! (task->ptrace & PT_DTRACE) )
 409                 return(0);
 410
 411         if (task->thread.singlestep_syscall)
 412                 return(1);
 413
 414         return 2;
 415 }
 416
 417 /*
 418  * Only x86 and x86_64 have an arch_align_stack().
 419  * All other arches have "#define arch_align_stack(x) (x)"
 420  * in their asm/system.h
 421  * As this is included in UML from asm-um/system-generic.h,
 422  * we can use it to behave as the subarch does.
 423  */
 424 #ifndef arch_align_stack
 425 unsigned long arch_align_stack(unsigned long sp)
 426 {
 427         if (!(current->personality & ADDR_NO_RANDOMIZE) && randomize_va_space)
 428                 sp -= get_random_int() % 8192;
 429         return sp & ~0xf;
 430 }
 431 #endif