git.oblomov.eu Git - linux-2.6/blob - arch/sparc/kernel/process.c

   1 /*  linux/arch/sparc/kernel/process.c
   2  *
   3  *  Copyright (C) 1995 David S. Miller (davem@davemloft.net)
   4  *  Copyright (C) 1996 Eddie C. Dost   (ecd@skynet.be)
   5  */
   6
   7 /*
   8  * This file handles the architecture-dependent parts of process handling..
   9  */
  10
  11 #include <stdarg.h>
  12
  13 #include <linux/errno.h>
  14 #include <linux/module.h>
  15 #include <linux/sched.h>
  16 #include <linux/kernel.h>
  17 #include <linux/kallsyms.h>
  18 #include <linux/mm.h>
  19 #include <linux/stddef.h>
  20 #include <linux/ptrace.h>
  21 #include <linux/slab.h>
  22 #include <linux/user.h>
  23 #include <linux/smp.h>
  24 #include <linux/reboot.h>
  25 #include <linux/delay.h>
  26 #include <linux/pm.h>
  27 #include <linux/init.h>
  28
  29 #include <asm/auxio.h>
  30 #include <asm/oplib.h>
  31 #include <asm/uaccess.h>
  32 #include <asm/system.h>
  33 #include <asm/page.h>
  34 #include <asm/pgalloc.h>
  35 #include <asm/pgtable.h>
  36 #include <asm/delay.h>
  37 #include <asm/processor.h>
  38 #include <asm/psr.h>
  39 #include <asm/elf.h>
  40 #include <asm/prom.h>
  41 #include <asm/unistd.h>
  42
  43 /*
  44  * Power management idle function
  45  * Set in pm platform drivers (apc.c and pmc.c)
  46  */
  47 void (*pm_idle)(void);
  48
  49 /*
  50  * Power-off handler instantiation for pm.h compliance
  51  * This is done via auxio, but could be used as a fallback
  52  * handler when auxio is not present-- unused for now...
  53  */
  54 void (*pm_power_off)(void) = machine_power_off;
  55 EXPORT_SYMBOL(pm_power_off);
  56
  57 /*
  58  * sysctl - toggle power-off restriction for serial console
  59  * systems in machine_power_off()
  60  */
  61 int scons_pwroff = 1;
  62
  63 extern void fpsave(unsigned long *, unsigned long *, void *, unsigned long *);
  64
  65 struct task_struct *last_task_used_math = NULL;
  66 struct thread_info *current_set[NR_CPUS];
  67
  68 #ifndef CONFIG_SMP
  69
  70 #define SUN4C_FAULT_HIGH 100
  71
  72 /*
  73  * the idle loop on a Sparc... ;)
  74  */
  75 void cpu_idle(void)
  76 {
  77         /* endless idle loop with no priority at all */
  78         for (;;) {
  79                 if (ARCH_SUN4C_SUN4) {
  80                         static int count = HZ;
  81                         static unsigned long last_jiffies;
  82                         static unsigned long last_faults;
  83                         static unsigned long fps;
  84                         unsigned long now;
  85                         unsigned long faults;
  86
  87                         extern unsigned long sun4c_kernel_faults;
  88                         extern void sun4c_grow_kernel_ring(void);
  89
  90                         local_irq_disable();
  91                         now = jiffies;
  92                         count -= (now - last_jiffies);
  93                         last_jiffies = now;
  94                         if (count < 0) {
  95                                 count += HZ;
  96                                 faults = sun4c_kernel_faults;
  97                                 fps = (fps + (faults - last_faults)) >> 1;
  98                                 last_faults = faults;
  99 #if 0
 100                                 printk("kernel faults / second = %ld\n", fps);
 101 #endif
 102                                 if (fps >= SUN4C_FAULT_HIGH) {
 103                                         sun4c_grow_kernel_ring();
 104                                 }
 105                         }
 106                         local_irq_enable();
 107                 }
 108
 109                 if (pm_idle) {
 110                         while (!need_resched())
 111                                 (*pm_idle)();
 112                 } else {
 113                         while (!need_resched())
 114                                 cpu_relax();
 115                 }
 116                 preempt_enable_no_resched();
 117                 schedule();
 118                 preempt_disable();
 119                 check_pgt_cache();
 120         }
 121 }
 122
 123 #else
 124
 125 /* This is being executed in task 0 'user space'. */
 126 void cpu_idle(void)
 127 {
 128         set_thread_flag(TIF_POLLING_NRFLAG);
 129         /* endless idle loop with no priority at all */
 130         while(1) {
 131                 while (!need_resched())
 132                         cpu_relax();
 133                 preempt_enable_no_resched();
 134                 schedule();
 135                 preempt_disable();
 136                 check_pgt_cache();
 137         }
 138 }
 139
 140 #endif
 141
 142 extern char reboot_command [];
 143
 144 /* XXX cli/sti -> local_irq_xxx here, check this works once SMP is fixed. */
 145 void machine_halt(void)
 146 {
 147         local_irq_enable();
 148         mdelay(8);
 149         local_irq_disable();
 150         prom_halt();
 151         panic("Halt failed!");
 152 }
 153
 154 void machine_restart(char * cmd)
 155 {
 156         char *p;
 157
 158         local_irq_enable();
 159         mdelay(8);
 160         local_irq_disable();
 161
 162         p = strchr (reboot_command, '\n');
 163         if (p) *p = 0;
 164         if (cmd)
 165                 prom_reboot(cmd);
 166         if (*reboot_command)
 167                 prom_reboot(reboot_command);
 168         prom_feval ("reset");
 169         panic("Reboot failed!");
 170 }
 171
 172 void machine_power_off(void)
 173 {
 174 #ifdef CONFIG_SUN_AUXIO
 175         if (auxio_power_register &&
 176             (strcmp(of_console_device->type, "serial") || scons_pwroff))
 177                 *auxio_power_register |= AUXIO_POWER_OFF;
 178 #endif
 179         machine_halt();
 180 }
 181
 182 static DEFINE_SPINLOCK(sparc_backtrace_lock);
 183
 184 void __show_backtrace(unsigned long fp)
 185 {
 186         struct reg_window *rw;
 187         unsigned long flags;
 188         int cpu = smp_processor_id();
 189
 190         spin_lock_irqsave(&sparc_backtrace_lock, flags);
 191
 192         rw = (struct reg_window *)fp;
 193         while(rw && (((unsigned long) rw) >= PAGE_OFFSET) &&
 194             !(((unsigned long) rw) & 0x7)) {
 195                 printk("CPU[%d]: ARGS[%08lx,%08lx,%08lx,%08lx,%08lx,%08lx] "
 196                        "FP[%08lx] CALLER[%08lx]: ", cpu,
 197                        rw->ins[0], rw->ins[1], rw->ins[2], rw->ins[3],
 198                        rw->ins[4], rw->ins[5],
 199                        rw->ins[6],
 200                        rw->ins[7]);
 201                 print_symbol("%s\n", rw->ins[7]);
 202                 rw = (struct reg_window *) rw->ins[6];
 203         }
 204         spin_unlock_irqrestore(&sparc_backtrace_lock, flags);
 205 }
 206
 207 #define __SAVE __asm__ __volatile__("save %sp, -0x40, %sp\n\t")
 208 #define __RESTORE __asm__ __volatile__("restore %g0, %g0, %g0\n\t")
 209 #define __GET_FP(fp) __asm__ __volatile__("mov %%i6, %0" : "=r" (fp))
 210
 211 void show_backtrace(void)
 212 {
 213         unsigned long fp;
 214
 215         __SAVE; __SAVE; __SAVE; __SAVE;
 216         __SAVE; __SAVE; __SAVE; __SAVE;
 217         __RESTORE; __RESTORE; __RESTORE; __RESTORE;
 218         __RESTORE; __RESTORE; __RESTORE; __RESTORE;
 219
 220         __GET_FP(fp);
 221
 222         __show_backtrace(fp);
 223 }
 224
 225 #ifdef CONFIG_SMP
 226 void smp_show_backtrace_all_cpus(void)
 227 {
 228         xc0((smpfunc_t) show_backtrace);
 229         show_backtrace();
 230 }
 231 #endif
 232
 233 #if 0
 234 void show_stackframe(struct sparc_stackf *sf)
 235 {
 236         unsigned long size;
 237         unsigned long *stk;
 238         int i;
 239
 240         printk("l0: %08lx l1: %08lx l2: %08lx l3: %08lx "
 241                "l4: %08lx l5: %08lx l6: %08lx l7: %08lx\n",
 242                sf->locals[0], sf->locals[1], sf->locals[2], sf->locals[3],
 243                sf->locals[4], sf->locals[5], sf->locals[6], sf->locals[7]);
 244         printk("i0: %08lx i1: %08lx i2: %08lx i3: %08lx "
 245                "i4: %08lx i5: %08lx fp: %08lx i7: %08lx\n",
 246                sf->ins[0], sf->ins[1], sf->ins[2], sf->ins[3],
 247                sf->ins[4], sf->ins[5], (unsigned long)sf->fp, sf->callers_pc);
 248         printk("sp: %08lx x0: %08lx x1: %08lx x2: %08lx "
 249                "x3: %08lx x4: %08lx x5: %08lx xx: %08lx\n",
 250                (unsigned long)sf->structptr, sf->xargs[0], sf->xargs[1],
 251                sf->xargs[2], sf->xargs[3], sf->xargs[4], sf->xargs[5],
 252                sf->xxargs[0]);
 253         size = ((unsigned long)sf->fp) - ((unsigned long)sf);
 254         size -= STACKFRAME_SZ;
 255         stk = (unsigned long *)((unsigned long)sf + STACKFRAME_SZ);
 256         i = 0;
 257         do {
 258                 printk("s%d: %08lx\n", i++, *stk++);
 259         } while ((size -= sizeof(unsigned long)));
 260 }
 261 #endif
 262
 263 void show_regs(struct pt_regs *r)
 264 {
 265         struct reg_window *rw = (struct reg_window *) r->u_regs[14];
 266
 267         printk("PSR: %08lx PC: %08lx NPC: %08lx Y: %08lx    %s\n",
 268                r->psr, r->pc, r->npc, r->y, print_tainted());
 269         print_symbol("PC: <%s>\n", r->pc);
 270         printk("%%G: %08lx %08lx  %08lx %08lx  %08lx %08lx  %08lx %08lx\n",
 271                r->u_regs[0], r->u_regs[1], r->u_regs[2], r->u_regs[3],
 272                r->u_regs[4], r->u_regs[5], r->u_regs[6], r->u_regs[7]);
 273         printk("%%O: %08lx %08lx  %08lx %08lx  %08lx %08lx  %08lx %08lx\n",
 274                r->u_regs[8], r->u_regs[9], r->u_regs[10], r->u_regs[11],
 275                r->u_regs[12], r->u_regs[13], r->u_regs[14], r->u_regs[15]);
 276         print_symbol("RPC: <%s>\n", r->u_regs[15]);
 277
 278         printk("%%L: %08lx %08lx  %08lx %08lx  %08lx %08lx  %08lx %08lx\n",
 279                rw->locals[0], rw->locals[1], rw->locals[2], rw->locals[3],
 280                rw->locals[4], rw->locals[5], rw->locals[6], rw->locals[7]);
 281         printk("%%I: %08lx %08lx  %08lx %08lx  %08lx %08lx  %08lx %08lx\n",
 282                rw->ins[0], rw->ins[1], rw->ins[2], rw->ins[3],
 283                rw->ins[4], rw->ins[5], rw->ins[6], rw->ins[7]);
 284 }
 285
 286 /*
 287  * The show_stack is an external API which we do not use ourselves.
 288  * The oops is printed in die_if_kernel.
 289  */
 290 void show_stack(struct task_struct *tsk, unsigned long *_ksp)
 291 {
 292         unsigned long pc, fp;
 293         unsigned long task_base;
 294         struct reg_window *rw;
 295         int count = 0;
 296
 297         if (tsk != NULL)
 298                 task_base = (unsigned long) task_stack_page(tsk);
 299         else
 300                 task_base = (unsigned long) current_thread_info();
 301
 302         fp = (unsigned long) _ksp;
 303         do {
 304                 /* Bogus frame pointer? */
 305                 if (fp < (task_base + sizeof(struct thread_info)) ||
 306                     fp >= (task_base + (PAGE_SIZE << 1)))
 307                         break;
 308                 rw = (struct reg_window *) fp;
 309                 pc = rw->ins[7];
 310                 printk("[%08lx : ", pc);
 311                 print_symbol("%s ] ", pc);
 312                 fp = rw->ins[6];
 313         } while (++count < 16);
 314         printk("\n");
 315 }
 316
 317 void dump_stack(void)
 318 {
 319         unsigned long *ksp;
 320
 321         __asm__ __volatile__("mov       %%fp, %0"
 322                              : "=r" (ksp));
 323         show_stack(current, ksp);
 324 }
 325
 326 EXPORT_SYMBOL(dump_stack);
 327
 328 /*
 329  * Note: sparc64 has a pretty intricated thread_saved_pc, check it out.
 330  */
 331 unsigned long thread_saved_pc(struct task_struct *tsk)
 332 {
 333         return task_thread_info(tsk)->kpc;
 334 }
 335
 336 /*
 337  * Free current thread data structures etc..
 338  */
 339 void exit_thread(void)
 340 {
 341 #ifndef CONFIG_SMP
 342         if(last_task_used_math == current) {
 343 #else
 344         if (test_thread_flag(TIF_USEDFPU)) {
 345 #endif
 346                 /* Keep process from leaving FPU in a bogon state. */
 347                 put_psr(get_psr() | PSR_EF);
 348                 fpsave(&current->thread.float_regs[0], &current->thread.fsr,
 349                        &current->thread.fpqueue[0], &current->thread.fpqdepth);
 350 #ifndef CONFIG_SMP
 351                 last_task_used_math = NULL;
 352 #else
 353                 clear_thread_flag(TIF_USEDFPU);
 354 #endif
 355         }
 356 }
 357
 358 void flush_thread(void)
 359 {
 360         current_thread_info()->w_saved = 0;
 361
 362         /* No new signal delivery by default */
 363         current->thread.new_signal = 0;
 364 #ifndef CONFIG_SMP
 365         if(last_task_used_math == current) {
 366 #else
 367         if (test_thread_flag(TIF_USEDFPU)) {
 368 #endif
 369                 /* Clean the fpu. */
 370                 put_psr(get_psr() | PSR_EF);
 371                 fpsave(&current->thread.float_regs[0], &current->thread.fsr,
 372                        &current->thread.fpqueue[0], &current->thread.fpqdepth);
 373 #ifndef CONFIG_SMP
 374                 last_task_used_math = NULL;
 375 #else
 376                 clear_thread_flag(TIF_USEDFPU);
 377 #endif
 378         }
 379
 380         /* Now, this task is no longer a kernel thread. */
 381         current->thread.current_ds = USER_DS;
 382         if (current->thread.flags & SPARC_FLAG_KTHREAD) {
 383                 current->thread.flags &= ~SPARC_FLAG_KTHREAD;
 384
 385                 /* We must fixup kregs as well. */
 386                 /* XXX This was not fixed for ti for a while, worked. Unused? */
 387                 current->thread.kregs = (struct pt_regs *)
 388                     (task_stack_page(current) + (THREAD_SIZE - TRACEREG_SZ));
 389         }
 390 }
 391
 392 static inline struct sparc_stackf __user *
 393 clone_stackframe(struct sparc_stackf __user *dst,
 394                  struct sparc_stackf __user *src)
 395 {
 396         unsigned long size, fp;
 397         struct sparc_stackf *tmp;
 398         struct sparc_stackf __user *sp;
 399
 400         if (get_user(tmp, &src->fp))
 401                 return NULL;
 402
 403         fp = (unsigned long) tmp;
 404         size = (fp - ((unsigned long) src));
 405         fp = (unsigned long) dst;
 406         sp = (struct sparc_stackf __user *)(fp - size);
 407
 408         /* do_fork() grabs the parent semaphore, we must release it
 409          * temporarily so we can build the child clone stack frame
 410          * without deadlocking.
 411          */
 412         if (__copy_user(sp, src, size))
 413                 sp = NULL;
 414         else if (put_user(fp, &sp->fp))
 415                 sp = NULL;
 416
 417         return sp;
 418 }
 419
 420 asmlinkage int sparc_do_fork(unsigned long clone_flags,
 421                              unsigned long stack_start,
 422                              struct pt_regs *regs,
 423                              unsigned long stack_size)
 424 {
 425         unsigned long parent_tid_ptr, child_tid_ptr;
 426
 427         parent_tid_ptr = regs->u_regs[UREG_I2];
 428         child_tid_ptr = regs->u_regs[UREG_I4];
 429
 430         return do_fork(clone_flags, stack_start,
 431                        regs, stack_size,
 432                        (int __user *) parent_tid_ptr,
 433                        (int __user *) child_tid_ptr);
 434 }
 435
 436 /* Copy a Sparc thread.  The fork() return value conventions
 437  * under SunOS are nothing short of bletcherous:
 438  * Parent -->  %o0 == childs  pid, %o1 == 0
 439  * Child  -->  %o0 == parents pid, %o1 == 1
 440  *
 441  * NOTE: We have a separate fork kpsr/kwim because
 442  *       the parent could change these values between
 443  *       sys_fork invocation and when we reach here
 444  *       if the parent should sleep while trying to
 445  *       allocate the task_struct and kernel stack in
 446  *       do_fork().
 447  * XXX See comment above sys_vfork in sparc64. todo.
 448  */
 449 extern void ret_from_fork(void);
 450
 451 int copy_thread(int nr, unsigned long clone_flags, unsigned long sp,
 452                 unsigned long unused,
 453                 struct task_struct *p, struct pt_regs *regs)
 454 {
 455         struct thread_info *ti = task_thread_info(p);
 456         struct pt_regs *childregs;
 457         char *new_stack;
 458
 459 #ifndef CONFIG_SMP
 460         if(last_task_used_math == current) {
 461 #else
 462         if (test_thread_flag(TIF_USEDFPU)) {
 463 #endif
 464                 put_psr(get_psr() | PSR_EF);
 465                 fpsave(&p->thread.float_regs[0], &p->thread.fsr,
 466                        &p->thread.fpqueue[0], &p->thread.fpqdepth);
 467 #ifdef CONFIG_SMP
 468                 clear_thread_flag(TIF_USEDFPU);
 469 #endif
 470         }
 471
 472         /*
 473          *  p->thread_info         new_stack   childregs
 474          *  !                      !           !             {if(PSR_PS) }
 475          *  V                      V (stk.fr.) V  (pt_regs)  { (stk.fr.) }
 476          *  +----- - - - - - ------+===========+============={+==========}+
 477          */
 478         new_stack = task_stack_page(p) + THREAD_SIZE;
 479         if (regs->psr & PSR_PS)
 480                 new_stack -= STACKFRAME_SZ;
 481         new_stack -= STACKFRAME_SZ + TRACEREG_SZ;
 482         memcpy(new_stack, (char *)regs - STACKFRAME_SZ, STACKFRAME_SZ + TRACEREG_SZ);
 483         childregs = (struct pt_regs *) (new_stack + STACKFRAME_SZ);
 484
 485         /*
 486          * A new process must start with interrupts closed in 2.5,
 487          * because this is how Mingo's scheduler works (see schedule_tail
 488          * and finish_arch_switch). If we do not do it, a timer interrupt hits
 489          * before we unlock, attempts to re-take the rq->lock, and then we die.
 490          * Thus, kpsr|=PSR_PIL.
 491          */
 492         ti->ksp = (unsigned long) new_stack;
 493         ti->kpc = (((unsigned long) ret_from_fork) - 0x8);
 494         ti->kpsr = current->thread.fork_kpsr | PSR_PIL;
 495         ti->kwim = current->thread.fork_kwim;
 496
 497         if(regs->psr & PSR_PS) {
 498                 extern struct pt_regs fake_swapper_regs;
 499
 500                 p->thread.kregs = &fake_swapper_regs;
 501                 new_stack += STACKFRAME_SZ + TRACEREG_SZ;
 502                 childregs->u_regs[UREG_FP] = (unsigned long) new_stack;
 503                 p->thread.flags |= SPARC_FLAG_KTHREAD;
 504                 p->thread.current_ds = KERNEL_DS;
 505                 memcpy(new_stack, (void *)regs->u_regs[UREG_FP], STACKFRAME_SZ);
 506                 childregs->u_regs[UREG_G6] = (unsigned long) ti;
 507         } else {
 508                 p->thread.kregs = childregs;
 509                 childregs->u_regs[UREG_FP] = sp;
 510                 p->thread.flags &= ~SPARC_FLAG_KTHREAD;
 511                 p->thread.current_ds = USER_DS;
 512
 513                 if (sp != regs->u_regs[UREG_FP]) {
 514                         struct sparc_stackf __user *childstack;
 515                         struct sparc_stackf __user *parentstack;
 516
 517                         /*
 518                          * This is a clone() call with supplied user stack.
 519                          * Set some valid stack frames to give to the child.
 520                          */
 521                         childstack = (struct sparc_stackf __user *)
 522                                 (sp & ~0x7UL);
 523                         parentstack = (struct sparc_stackf __user *)
 524                                 regs->u_regs[UREG_FP];
 525
 526 #if 0
 527                         printk("clone: parent stack:\n");
 528                         show_stackframe(parentstack);
 529 #endif
 530
 531                         childstack = clone_stackframe(childstack, parentstack);
 532                         if (!childstack)
 533                                 return -EFAULT;
 534
 535 #if 0
 536                         printk("clone: child stack:\n");
 537                         show_stackframe(childstack);
 538 #endif
 539
 540                         childregs->u_regs[UREG_FP] = (unsigned long)childstack;
 541                 }
 542         }
 543
 544 #ifdef CONFIG_SMP
 545         /* FPU must be disabled on SMP. */
 546         childregs->psr &= ~PSR_EF;
 547 #endif
 548
 549         /* Set the return value for the child. */
 550         childregs->u_regs[UREG_I0] = current->pid;
 551         childregs->u_regs[UREG_I1] = 1;
 552
 553         /* Set the return value for the parent. */
 554         regs->u_regs[UREG_I1] = 0;
 555
 556         if (clone_flags & CLONE_SETTLS)
 557                 childregs->u_regs[UREG_G7] = regs->u_regs[UREG_I3];
 558
 559         return 0;
 560 }
 561
 562 /*
 563  * fill in the fpu structure for a core dump.
 564  */
 565 int dump_fpu (struct pt_regs * regs, elf_fpregset_t * fpregs)
 566 {
 567         if (used_math()) {
 568                 memset(fpregs, 0, sizeof(*fpregs));
 569                 fpregs->pr_q_entrysize = 8;
 570                 return 1;
 571         }
 572 #ifdef CONFIG_SMP
 573         if (test_thread_flag(TIF_USEDFPU)) {
 574                 put_psr(get_psr() | PSR_EF);
 575                 fpsave(&current->thread.float_regs[0], &current->thread.fsr,
 576                        &current->thread.fpqueue[0], &current->thread.fpqdepth);
 577                 if (regs != NULL) {
 578                         regs->psr &= ~(PSR_EF);
 579                         clear_thread_flag(TIF_USEDFPU);
 580                 }
 581         }
 582 #else
 583         if (current == last_task_used_math) {
 584                 put_psr(get_psr() | PSR_EF);
 585                 fpsave(&current->thread.float_regs[0], &current->thread.fsr,
 586                        &current->thread.fpqueue[0], &current->thread.fpqdepth);
 587                 if (regs != NULL) {
 588                         regs->psr &= ~(PSR_EF);
 589                         last_task_used_math = NULL;
 590                 }
 591         }
 592 #endif
 593         memcpy(&fpregs->pr_fr.pr_regs[0],
 594                &current->thread.float_regs[0],
 595                (sizeof(unsigned long) * 32));
 596         fpregs->pr_fsr = current->thread.fsr;
 597         fpregs->pr_qcnt = current->thread.fpqdepth;
 598         fpregs->pr_q_entrysize = 8;
 599         fpregs->pr_en = 1;
 600         if(fpregs->pr_qcnt != 0) {
 601                 memcpy(&fpregs->pr_q[0],
 602                        &current->thread.fpqueue[0],
 603                        sizeof(struct fpq) * fpregs->pr_qcnt);
 604         }
 605         /* Zero out the rest. */
 606         memset(&fpregs->pr_q[fpregs->pr_qcnt], 0,
 607                sizeof(struct fpq) * (32 - fpregs->pr_qcnt));
 608         return 1;
 609 }
 610
 611 /*
 612  * sparc_execve() executes a new program after the asm stub has set
 613  * things up for us.  This should basically do what I want it to.
 614  */
 615 asmlinkage int sparc_execve(struct pt_regs *regs)
 616 {
 617         int error, base = 0;
 618         char *filename;
 619
 620         /* Check for indirect call. */
 621         if(regs->u_regs[UREG_G1] == 0)
 622                 base = 1;
 623
 624         filename = getname((char __user *)regs->u_regs[base + UREG_I0]);
 625         error = PTR_ERR(filename);
 626         if(IS_ERR(filename))
 627                 goto out;
 628         error = do_execve(filename,
 629                           (char __user * __user *)regs->u_regs[base + UREG_I1],
 630                           (char __user * __user *)regs->u_regs[base + UREG_I2],
 631                           regs);
 632         putname(filename);
 633         if (error == 0) {
 634                 task_lock(current);
 635                 current->ptrace &= ~PT_DTRACE;
 636                 task_unlock(current);
 637         }
 638 out:
 639         return error;
 640 }
 641
 642 /*
 643  * This is the mechanism for creating a new kernel thread.
 644  *
 645  * NOTE! Only a kernel-only process(ie the swapper or direct descendants
 646  * who haven't done an "execve()") should use this: it will work within
 647  * a system call from a "real" process, but the process memory space will
 648  * not be freed until both the parent and the child have exited.
 649  */
 650 pid_t kernel_thread(int (*fn)(void *), void * arg, unsigned long flags)
 651 {
 652         long retval;
 653
 654         __asm__ __volatile__("mov %4, %%g2\n\t"    /* Set aside fn ptr... */
 655                              "mov %5, %%g3\n\t"    /* and arg. */
 656                              "mov %1, %%g1\n\t"
 657                              "mov %2, %%o0\n\t"    /* Clone flags. */
 658                              "mov 0, %%o1\n\t"     /* usp arg == 0 */
 659                              "t 0x10\n\t"          /* Linux/Sparc clone(). */
 660                              "cmp %%o1, 0\n\t"
 661                              "be 1f\n\t"           /* The parent, just return. */
 662                              " nop\n\t"            /* Delay slot. */
 663                              "jmpl %%g2, %%o7\n\t" /* Call the function. */
 664                              " mov %%g3, %%o0\n\t" /* Get back the arg in delay. */
 665                              "mov %3, %%g1\n\t"
 666                              "t 0x10\n\t"          /* Linux/Sparc exit(). */
 667                              /* Notreached by child. */
 668                              "1: mov %%o0, %0\n\t" :
 669                              "=r" (retval) :
 670                              "i" (__NR_clone), "r" (flags | CLONE_VM | CLONE_UNTRACED),
 671                              "i" (__NR_exit),  "r" (fn), "r" (arg) :
 672                              "g1", "g2", "g3", "o0", "o1", "memory", "cc");
 673         return retval;
 674 }
 675
 676 unsigned long get_wchan(struct task_struct *task)
 677 {
 678         unsigned long pc, fp, bias = 0;
 679         unsigned long task_base = (unsigned long) task;
 680         unsigned long ret = 0;
 681         struct reg_window *rw;
 682         int count = 0;
 683
 684         if (!task || task == current ||
 685             task->state == TASK_RUNNING)
 686                 goto out;
 687
 688         fp = task_thread_info(task)->ksp + bias;
 689         do {
 690                 /* Bogus frame pointer? */
 691                 if (fp < (task_base + sizeof(struct thread_info)) ||
 692                     fp >= (task_base + (2 * PAGE_SIZE)))
 693                         break;
 694                 rw = (struct reg_window *) fp;
 695                 pc = rw->ins[7];
 696                 if (!in_sched_functions(pc)) {
 697                         ret = pc;
 698                         goto out;
 699                 }
 700                 fp = rw->ins[6] + bias;
 701         } while (++count < 16);
 702
 703 out:
 704         return ret;
 705 }
 706