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

   1 /*
   2  *  arch/ppc/kernel/process.c
   3  *
   4  *  Derived from "arch/i386/kernel/process.c"
   5  *    Copyright (C) 1995  Linus Torvalds
   6  *
   7  *  Updated and modified by Cort Dougan (cort@cs.nmt.edu) and
   8  *  Paul Mackerras (paulus@cs.anu.edu.au)
   9  *
  10  *  PowerPC version
  11  *    Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org)
  12  *
  13  *  This program is free software; you can redistribute it and/or
  14  *  modify it under the terms of the GNU General Public License
  15  *  as published by the Free Software Foundation; either version
  16  *  2 of the License, or (at your option) any later version.
  17  *
  18  */
  19
  20 #include <linux/config.h>
  21 #include <linux/errno.h>
  22 #include <linux/sched.h>
  23 #include <linux/kernel.h>
  24 #include <linux/mm.h>
  25 #include <linux/smp.h>
  26 #include <linux/smp_lock.h>
  27 #include <linux/stddef.h>
  28 #include <linux/unistd.h>
  29 #include <linux/ptrace.h>
  30 #include <linux/slab.h>
  31 #include <linux/user.h>
  32 #include <linux/elf.h>
  33 #include <linux/init.h>
  34 #include <linux/prctl.h>
  35 #include <linux/init_task.h>
  36 #include <linux/module.h>
  37 #include <linux/kallsyms.h>
  38 #include <linux/mqueue.h>
  39 #include <linux/hardirq.h>
  40
  41 #include <asm/pgtable.h>
  42 #include <asm/uaccess.h>
  43 #include <asm/system.h>
  44 #include <asm/io.h>
  45 #include <asm/processor.h>
  46 #include <asm/mmu.h>
  47 #include <asm/prom.h>
  48
  49 extern unsigned long _get_SP(void);
  50
  51 struct task_struct *last_task_used_math = NULL;
  52 struct task_struct *last_task_used_altivec = NULL;
  53 struct task_struct *last_task_used_spe = NULL;
  54
  55 static struct fs_struct init_fs = INIT_FS;
  56 static struct files_struct init_files = INIT_FILES;
  57 static struct signal_struct init_signals = INIT_SIGNALS(init_signals);
  58 static struct sighand_struct init_sighand = INIT_SIGHAND(init_sighand);
  59 struct mm_struct init_mm = INIT_MM(init_mm);
  60 EXPORT_SYMBOL(init_mm);
  61
  62 /* this is 8kB-aligned so we can get to the thread_info struct
  63    at the base of it from the stack pointer with 1 integer instruction. */
  64 union thread_union init_thread_union
  65         __attribute__((__section__(".data.init_task"))) =
  66 { INIT_THREAD_INFO(init_task) };
  67
  68 /* initial task structure */
  69 struct task_struct init_task = INIT_TASK(init_task);
  70 EXPORT_SYMBOL(init_task);
  71
  72 /* only used to get secondary processor up */
  73 struct task_struct *current_set[NR_CPUS] = {&init_task, };
  74
  75 #undef SHOW_TASK_SWITCHES
  76 #undef CHECK_STACK
  77
  78 #if defined(CHECK_STACK)
  79 unsigned long
  80 kernel_stack_top(struct task_struct *tsk)
  81 {
  82         return ((unsigned long)tsk) + sizeof(union task_union);
  83 }
  84
  85 unsigned long
  86 task_top(struct task_struct *tsk)
  87 {
  88         return ((unsigned long)tsk) + sizeof(struct thread_info);
  89 }
  90
  91 /* check to make sure the kernel stack is healthy */
  92 int check_stack(struct task_struct *tsk)
  93 {
  94         unsigned long stack_top = kernel_stack_top(tsk);
  95         unsigned long tsk_top = task_top(tsk);
  96         int ret = 0;
  97
  98 #if 0
  99         /* check thread magic */
 100         if ( tsk->thread.magic != THREAD_MAGIC )
 101         {
 102                 ret |= 1;
 103                 printk("thread.magic bad: %08x\n", tsk->thread.magic);
 104         }
 105 #endif
 106
 107         if ( !tsk )
 108                 printk("check_stack(): tsk bad tsk %p\n",tsk);
 109
 110         /* check if stored ksp is bad */
 111         if ( (tsk->thread.ksp > stack_top) || (tsk->thread.ksp < tsk_top) )
 112         {
 113                 printk("stack out of bounds: %s/%d\n"
 114                        " tsk_top %08lx ksp %08lx stack_top %08lx\n",
 115                        tsk->comm,tsk->pid,
 116                        tsk_top, tsk->thread.ksp, stack_top);
 117                 ret |= 2;
 118         }
 119
 120         /* check if stack ptr RIGHT NOW is bad */
 121         if ( (tsk == current) && ((_get_SP() > stack_top ) || (_get_SP() < tsk_top)) )
 122         {
 123                 printk("current stack ptr out of bounds: %s/%d\n"
 124                        " tsk_top %08lx sp %08lx stack_top %08lx\n",
 125                        current->comm,current->pid,
 126                        tsk_top, _get_SP(), stack_top);
 127                 ret |= 4;
 128         }
 129
 130 #if 0
 131         /* check amount of free stack */
 132         for ( i = (unsigned long *)task_top(tsk) ; i < kernel_stack_top(tsk) ; i++ )
 133         {
 134                 if ( !i )
 135                         printk("check_stack(): i = %p\n", i);
 136                 if ( *i != 0 )
 137                 {
 138                         /* only notify if it's less than 900 bytes */
 139                         if ( (i - (unsigned long *)task_top(tsk))  < 900 )
 140                                 printk("%d bytes free on stack\n",
 141                                        i - task_top(tsk));
 142                         break;
 143                 }
 144         }
 145 #endif
 146
 147         if (ret)
 148         {
 149                 panic("bad kernel stack");
 150         }
 151         return(ret);
 152 }
 153 #endif /* defined(CHECK_STACK) */
 154
 155 /*
 156  * Make sure the floating-point register state in the
 157  * the thread_struct is up to date for task tsk.
 158  */
 159 void flush_fp_to_thread(struct task_struct *tsk)
 160 {
 161         if (tsk->thread.regs) {
 162                 /*
 163                  * We need to disable preemption here because if we didn't,
 164                  * another process could get scheduled after the regs->msr
 165                  * test but before we have finished saving the FP registers
 166                  * to the thread_struct.  That process could take over the
 167                  * FPU, and then when we get scheduled again we would store
 168                  * bogus values for the remaining FP registers.
 169                  */
 170                 preempt_disable();
 171                 if (tsk->thread.regs->msr & MSR_FP) {
 172 #ifdef CONFIG_SMP
 173                         /*
 174                          * This should only ever be called for current or
 175                          * for a stopped child process.  Since we save away
 176                          * the FP register state on context switch on SMP,
 177                          * there is something wrong if a stopped child appears
 178                          * to still have its FP state in the CPU registers.
 179                          */
 180                         BUG_ON(tsk != current);
 181 #endif
 182                         giveup_fpu(current);
 183                 }
 184                 preempt_enable();
 185         }
 186 }
 187
 188 void enable_kernel_fp(void)
 189 {
 190         WARN_ON(preemptible());
 191
 192 #ifdef CONFIG_SMP
 193         if (current->thread.regs && (current->thread.regs->msr & MSR_FP))
 194                 giveup_fpu(current);
 195         else
 196                 giveup_fpu(NULL);       /* just enables FP for kernel */
 197 #else
 198         giveup_fpu(last_task_used_math);
 199 #endif /* CONFIG_SMP */
 200 }
 201 EXPORT_SYMBOL(enable_kernel_fp);
 202
 203 int dump_task_fpu(struct task_struct *tsk, elf_fpregset_t *fpregs)
 204 {
 205         preempt_disable();
 206         if (tsk->thread.regs && (tsk->thread.regs->msr & MSR_FP))
 207                 giveup_fpu(tsk);
 208         preempt_enable();
 209         memcpy(fpregs, &tsk->thread.fpr[0], sizeof(*fpregs));
 210         return 1;
 211 }
 212
 213 #ifdef CONFIG_ALTIVEC
 214 void enable_kernel_altivec(void)
 215 {
 216         WARN_ON(preemptible());
 217
 218 #ifdef CONFIG_SMP
 219         if (current->thread.regs && (current->thread.regs->msr & MSR_VEC))
 220                 giveup_altivec(current);
 221         else
 222                 giveup_altivec(NULL);   /* just enable AltiVec for kernel - force */
 223 #else
 224         giveup_altivec(last_task_used_altivec);
 225 #endif /* __SMP __ */
 226 }
 227 EXPORT_SYMBOL(enable_kernel_altivec);
 228
 229 /*
 230  * Make sure the VMX/Altivec register state in the
 231  * the thread_struct is up to date for task tsk.
 232  */
 233 void flush_altivec_to_thread(struct task_struct *tsk)
 234 {
 235         if (tsk->thread.regs) {
 236                 preempt_disable();
 237                 if (tsk->thread.regs->msr & MSR_VEC) {
 238 #ifdef CONFIG_SMP
 239                         BUG_ON(tsk != current);
 240 #endif
 241                         giveup_altivec(current);
 242                 }
 243                 preempt_enable();
 244         }
 245 }
 246
 247 int dump_altivec(struct pt_regs *regs, elf_vrregset_t *vrregs)
 248 {
 249         if (regs->msr & MSR_VEC)
 250                 giveup_altivec(current);
 251         memcpy(vrregs, &current->thread.vr[0], sizeof(*vrregs));
 252         return 1;
 253 }
 254 #endif /* CONFIG_ALTIVEC */
 255
 256 #ifdef CONFIG_SPE
 257 void
 258 enable_kernel_spe(void)
 259 {
 260         WARN_ON(preemptible());
 261
 262 #ifdef CONFIG_SMP
 263         if (current->thread.regs && (current->thread.regs->msr & MSR_SPE))
 264                 giveup_spe(current);
 265         else
 266                 giveup_spe(NULL);       /* just enable SPE for kernel - force */
 267 #else
 268         giveup_spe(last_task_used_spe);
 269 #endif /* __SMP __ */
 270 }
 271 EXPORT_SYMBOL(enable_kernel_spe);
 272
 273 void flush_spe_to_thread(struct task_struct *tsk)
 274 {
 275         if (tsk->thread.regs) {
 276                 preempt_disable();
 277                 if (tsk->thread.regs->msr & MSR_SPE) {
 278 #ifdef CONFIG_SMP
 279                         BUG_ON(tsk != current);
 280 #endif
 281                         giveup_spe(current);
 282                 }
 283                 preempt_enable();
 284         }
 285 }
 286
 287 int dump_spe(struct pt_regs *regs, elf_vrregset_t *evrregs)
 288 {
 289         if (regs->msr & MSR_SPE)
 290                 giveup_spe(current);
 291         /* We copy u32 evr[32] + u64 acc + u32 spefscr -> 35 */
 292         memcpy(evrregs, &current->thread.evr[0], sizeof(u32) * 35);
 293         return 1;
 294 }
 295 #endif /* CONFIG_SPE */
 296
 297 struct task_struct *__switch_to(struct task_struct *prev,
 298         struct task_struct *new)
 299 {
 300         struct thread_struct *new_thread, *old_thread;
 301         unsigned long s;
 302         struct task_struct *last;
 303
 304         local_irq_save(s);
 305 #ifdef CHECK_STACK
 306         check_stack(prev);
 307         check_stack(new);
 308 #endif
 309
 310 #ifdef CONFIG_SMP
 311         /* avoid complexity of lazy save/restore of fpu
 312          * by just saving it every time we switch out if
 313          * this task used the fpu during the last quantum.
 314          *
 315          * If it tries to use the fpu again, it'll trap and
 316          * reload its fp regs.  So we don't have to do a restore
 317          * every switch, just a save.
 318          *  -- Cort
 319          */
 320         if (prev->thread.regs && (prev->thread.regs->msr & MSR_FP))
 321                 giveup_fpu(prev);
 322 #ifdef CONFIG_ALTIVEC
 323         /*
 324          * If the previous thread used altivec in the last quantum
 325          * (thus changing altivec regs) then save them.
 326          * We used to check the VRSAVE register but not all apps
 327          * set it, so we don't rely on it now (and in fact we need
 328          * to save & restore VSCR even if VRSAVE == 0).  -- paulus
 329          *
 330          * On SMP we always save/restore altivec regs just to avoid the
 331          * complexity of changing processors.
 332          *  -- Cort
 333          */
 334         if ((prev->thread.regs && (prev->thread.regs->msr & MSR_VEC)))
 335                 giveup_altivec(prev);
 336 #endif /* CONFIG_ALTIVEC */
 337 #ifdef CONFIG_SPE
 338         /*
 339          * If the previous thread used spe in the last quantum
 340          * (thus changing spe regs) then save them.
 341          *
 342          * On SMP we always save/restore spe regs just to avoid the
 343          * complexity of changing processors.
 344          */
 345         if ((prev->thread.regs && (prev->thread.regs->msr & MSR_SPE)))
 346                 giveup_spe(prev);
 347 #endif /* CONFIG_SPE */
 348 #endif /* CONFIG_SMP */
 349
 350 #ifdef CONFIG_ALTIVEC
 351         /* Avoid the trap.  On smp this this never happens since
 352          * we don't set last_task_used_altivec -- Cort
 353          */
 354         if (new->thread.regs && last_task_used_altivec == new)
 355                 new->thread.regs->msr |= MSR_VEC;
 356 #endif
 357 #ifdef CONFIG_SPE
 358         /* Avoid the trap.  On smp this this never happens since
 359          * we don't set last_task_used_spe
 360          */
 361         if (new->thread.regs && last_task_used_spe == new)
 362                 new->thread.regs->msr |= MSR_SPE;
 363 #endif /* CONFIG_SPE */
 364         new_thread = &new->thread;
 365         old_thread = &current->thread;
 366         last = _switch(old_thread, new_thread);
 367         local_irq_restore(s);
 368         return last;
 369 }
 370
 371 void show_regs(struct pt_regs * regs)
 372 {
 373         int i, trap;
 374
 375         printk("NIP: %08lX LR: %08lX SP: %08lX REGS: %p TRAP: %04lx    %s\n",
 376                regs->nip, regs->link, regs->gpr[1], regs, regs->trap,
 377                print_tainted());
 378         printk("MSR: %08lx EE: %01x PR: %01x FP: %01x ME: %01x IR/DR: %01x%01x\n",
 379                regs->msr, regs->msr&MSR_EE ? 1 : 0, regs->msr&MSR_PR ? 1 : 0,
 380                regs->msr & MSR_FP ? 1 : 0,regs->msr&MSR_ME ? 1 : 0,
 381                regs->msr&MSR_IR ? 1 : 0,
 382                regs->msr&MSR_DR ? 1 : 0);
 383         trap = TRAP(regs);
 384         if (trap == 0x300 || trap == 0x600)
 385                 printk("DAR: %08lX, DSISR: %08lX\n", regs->dar, regs->dsisr);
 386         printk("TASK = %p[%d] '%s' THREAD: %p\n",
 387                current, current->pid, current->comm, current->thread_info);
 388         printk("Last syscall: %ld ", current->thread.last_syscall);
 389
 390 #ifdef CONFIG_SMP
 391         printk(" CPU: %d", smp_processor_id());
 392 #endif /* CONFIG_SMP */
 393
 394         for (i = 0;  i < 32;  i++) {
 395                 long r;
 396                 if ((i % 8) == 0)
 397                         printk("\n" KERN_INFO "GPR%02d: ", i);
 398                 if (__get_user(r, &regs->gpr[i]))
 399                         break;
 400                 printk("%08lX ", r);
 401                 if (i == 12 && !FULL_REGS(regs))
 402                         break;
 403         }
 404         printk("\n");
 405 #ifdef CONFIG_KALLSYMS
 406         /*
 407          * Lookup NIP late so we have the best change of getting the
 408          * above info out without failing
 409          */
 410         printk("NIP [%08lx] ", regs->nip);
 411         print_symbol("%s\n", regs->nip);
 412         printk("LR [%08lx] ", regs->link);
 413         print_symbol("%s\n", regs->link);
 414 #endif
 415         show_stack(current, (unsigned long *) regs->gpr[1]);
 416 }
 417
 418 void exit_thread(void)
 419 {
 420         if (last_task_used_math == current)
 421                 last_task_used_math = NULL;
 422         if (last_task_used_altivec == current)
 423                 last_task_used_altivec = NULL;
 424 #ifdef CONFIG_SPE
 425         if (last_task_used_spe == current)
 426                 last_task_used_spe = NULL;
 427 #endif
 428 }
 429
 430 void flush_thread(void)
 431 {
 432         if (last_task_used_math == current)
 433                 last_task_used_math = NULL;
 434         if (last_task_used_altivec == current)
 435                 last_task_used_altivec = NULL;
 436 #ifdef CONFIG_SPE
 437         if (last_task_used_spe == current)
 438                 last_task_used_spe = NULL;
 439 #endif
 440 }
 441
 442 void
 443 release_thread(struct task_struct *t)
 444 {
 445 }
 446
 447 /*
 448  * This gets called before we allocate a new thread and copy
 449  * the current task into it.
 450  */
 451 void prepare_to_copy(struct task_struct *tsk)
 452 {
 453         struct pt_regs *regs = tsk->thread.regs;
 454
 455         if (regs == NULL)
 456                 return;
 457         preempt_disable();
 458         if (regs->msr & MSR_FP)
 459                 giveup_fpu(current);
 460 #ifdef CONFIG_ALTIVEC
 461         if (regs->msr & MSR_VEC)
 462                 giveup_altivec(current);
 463 #endif /* CONFIG_ALTIVEC */
 464 #ifdef CONFIG_SPE
 465         if (regs->msr & MSR_SPE)
 466                 giveup_spe(current);
 467 #endif /* CONFIG_SPE */
 468         preempt_enable();
 469 }
 470
 471 /*
 472  * Copy a thread..
 473  */
 474 int
 475 copy_thread(int nr, unsigned long clone_flags, unsigned long usp,
 476             unsigned long unused,
 477             struct task_struct *p, struct pt_regs *regs)
 478 {
 479         struct pt_regs *childregs, *kregs;
 480         extern void ret_from_fork(void);
 481         unsigned long sp = (unsigned long)p->thread_info + THREAD_SIZE;
 482         unsigned long childframe;
 483
 484         CHECK_FULL_REGS(regs);
 485         /* Copy registers */
 486         sp -= sizeof(struct pt_regs);
 487         childregs = (struct pt_regs *) sp;
 488         *childregs = *regs;
 489         if ((childregs->msr & MSR_PR) == 0) {
 490                 /* for kernel thread, set `current' and stackptr in new task */
 491                 childregs->gpr[1] = sp + sizeof(struct pt_regs);
 492                 childregs->gpr[2] = (unsigned long) p;
 493                 p->thread.regs = NULL;  /* no user register state */
 494         } else {
 495                 childregs->gpr[1] = usp;
 496                 p->thread.regs = childregs;
 497                 if (clone_flags & CLONE_SETTLS)
 498                         childregs->gpr[2] = childregs->gpr[6];
 499         }
 500         childregs->gpr[3] = 0;  /* Result from fork() */
 501         sp -= STACK_FRAME_OVERHEAD;
 502         childframe = sp;
 503
 504         /*
 505          * The way this works is that at some point in the future
 506          * some task will call _switch to switch to the new task.
 507          * That will pop off the stack frame created below and start
 508          * the new task running at ret_from_fork.  The new task will
 509          * do some house keeping and then return from the fork or clone
 510          * system call, using the stack frame created above.
 511          */
 512         sp -= sizeof(struct pt_regs);
 513         kregs = (struct pt_regs *) sp;
 514         sp -= STACK_FRAME_OVERHEAD;
 515         p->thread.ksp = sp;
 516         kregs->nip = (unsigned long)ret_from_fork;
 517
 518         p->thread.last_syscall = -1;
 519
 520         return 0;
 521 }
 522
 523 /*
 524  * Set up a thread for executing a new program
 525  */
 526 void start_thread(struct pt_regs *regs, unsigned long nip, unsigned long sp)
 527 {
 528         set_fs(USER_DS);
 529         memset(regs->gpr, 0, sizeof(regs->gpr));
 530         regs->ctr = 0;
 531         regs->link = 0;
 532         regs->xer = 0;
 533         regs->ccr = 0;
 534         regs->mq = 0;
 535         regs->nip = nip;
 536         regs->gpr[1] = sp;
 537         regs->msr = MSR_USER;
 538         if (last_task_used_math == current)
 539                 last_task_used_math = NULL;
 540         if (last_task_used_altivec == current)
 541                 last_task_used_altivec = NULL;
 542 #ifdef CONFIG_SPE
 543         if (last_task_used_spe == current)
 544                 last_task_used_spe = NULL;
 545 #endif
 546         memset(current->thread.fpr, 0, sizeof(current->thread.fpr));
 547         current->thread.fpscr.val = 0;
 548 #ifdef CONFIG_ALTIVEC
 549         memset(current->thread.vr, 0, sizeof(current->thread.vr));
 550         memset(&current->thread.vscr, 0, sizeof(current->thread.vscr));
 551         current->thread.vrsave = 0;
 552         current->thread.used_vr = 0;
 553 #endif /* CONFIG_ALTIVEC */
 554 #ifdef CONFIG_SPE
 555         memset(current->thread.evr, 0, sizeof(current->thread.evr));
 556         current->thread.acc = 0;
 557         current->thread.spefscr = 0;
 558         current->thread.used_spe = 0;
 559 #endif /* CONFIG_SPE */
 560 }
 561
 562 #define PR_FP_ALL_EXCEPT (PR_FP_EXC_DIV | PR_FP_EXC_OVF | PR_FP_EXC_UND \
 563                 | PR_FP_EXC_RES | PR_FP_EXC_INV)
 564
 565 int set_fpexc_mode(struct task_struct *tsk, unsigned int val)
 566 {
 567         struct pt_regs *regs = tsk->thread.regs;
 568
 569         /* This is a bit hairy.  If we are an SPE enabled  processor
 570          * (have embedded fp) we store the IEEE exception enable flags in
 571          * fpexc_mode.  fpexc_mode is also used for setting FP exception
 572          * mode (asyn, precise, disabled) for 'Classic' FP. */
 573         if (val & PR_FP_EXC_SW_ENABLE) {
 574 #ifdef CONFIG_SPE
 575                 tsk->thread.fpexc_mode = val &
 576                         (PR_FP_EXC_SW_ENABLE | PR_FP_ALL_EXCEPT);
 577 #else
 578                 return -EINVAL;
 579 #endif
 580         } else {
 581                 /* on a CONFIG_SPE this does not hurt us.  The bits that
 582                  * __pack_fe01 use do not overlap with bits used for
 583                  * PR_FP_EXC_SW_ENABLE.  Additionally, the MSR[FE0,FE1] bits
 584                  * on CONFIG_SPE implementations are reserved so writing to
 585                  * them does not change anything */
 586                 if (val > PR_FP_EXC_PRECISE)
 587                         return -EINVAL;
 588                 tsk->thread.fpexc_mode = __pack_fe01(val);
 589                 if (regs != NULL && (regs->msr & MSR_FP) != 0)
 590                         regs->msr = (regs->msr & ~(MSR_FE0|MSR_FE1))
 591                                 | tsk->thread.fpexc_mode;
 592         }
 593         return 0;
 594 }
 595
 596 int get_fpexc_mode(struct task_struct *tsk, unsigned long adr)
 597 {
 598         unsigned int val;
 599
 600         if (tsk->thread.fpexc_mode & PR_FP_EXC_SW_ENABLE)
 601 #ifdef CONFIG_SPE
 602                 val = tsk->thread.fpexc_mode;
 603 #else
 604                 return -EINVAL;
 605 #endif
 606         else
 607                 val = __unpack_fe01(tsk->thread.fpexc_mode);
 608         return put_user(val, (unsigned int __user *) adr);
 609 }
 610
 611 int sys_clone(unsigned long clone_flags, unsigned long usp,
 612               int __user *parent_tidp, void __user *child_threadptr,
 613               int __user *child_tidp, int p6,
 614               struct pt_regs *regs)
 615 {
 616         CHECK_FULL_REGS(regs);
 617         if (usp == 0)
 618                 usp = regs->gpr[1];     /* stack pointer for child */
 619         return do_fork(clone_flags, usp, regs, 0, parent_tidp, child_tidp);
 620 }
 621
 622 int sys_fork(unsigned long p1, unsigned long p2, unsigned long p3,
 623              unsigned long p4, unsigned long p5, unsigned long p6,
 624              struct pt_regs *regs)
 625 {
 626         CHECK_FULL_REGS(regs);
 627         return do_fork(SIGCHLD, regs->gpr[1], regs, 0, NULL, NULL);
 628 }
 629
 630 int sys_vfork(unsigned long p1, unsigned long p2, unsigned long p3,
 631               unsigned long p4, unsigned long p5, unsigned long p6,
 632               struct pt_regs *regs)
 633 {
 634         CHECK_FULL_REGS(regs);
 635         return do_fork(CLONE_VFORK | CLONE_VM | SIGCHLD, regs->gpr[1],
 636                         regs, 0, NULL, NULL);
 637 }
 638
 639 int sys_execve(unsigned long a0, unsigned long a1, unsigned long a2,
 640                unsigned long a3, unsigned long a4, unsigned long a5,
 641                struct pt_regs *regs)
 642 {
 643         int error;
 644         char * filename;
 645
 646         filename = getname((char __user *) a0);
 647         error = PTR_ERR(filename);
 648         if (IS_ERR(filename))
 649                 goto out;
 650         preempt_disable();
 651         if (regs->msr & MSR_FP)
 652                 giveup_fpu(current);
 653 #ifdef CONFIG_ALTIVEC
 654         if (regs->msr & MSR_VEC)
 655                 giveup_altivec(current);
 656 #endif /* CONFIG_ALTIVEC */
 657 #ifdef CONFIG_SPE
 658         if (regs->msr & MSR_SPE)
 659                 giveup_spe(current);
 660 #endif /* CONFIG_SPE */
 661         preempt_enable();
 662         error = do_execve(filename, (char __user *__user *) a1,
 663                           (char __user *__user *) a2, regs);
 664         if (error == 0) {
 665                 task_lock(current);
 666                 current->ptrace &= ~PT_DTRACE;
 667                 task_unlock(current);
 668         }
 669         putname(filename);
 670 out:
 671         return error;
 672 }
 673
 674 void dump_stack(void)
 675 {
 676         show_stack(current, NULL);
 677 }
 678
 679 EXPORT_SYMBOL(dump_stack);
 680
 681 void show_stack(struct task_struct *tsk, unsigned long *stack)
 682 {
 683         unsigned long sp, stack_top, prev_sp, ret;
 684         int count = 0;
 685         unsigned long next_exc = 0;
 686         struct pt_regs *regs;
 687         extern char ret_from_except, ret_from_except_full, ret_from_syscall;
 688
 689         sp = (unsigned long) stack;
 690         if (tsk == NULL)
 691                 tsk = current;
 692         if (sp == 0) {
 693                 if (tsk == current)
 694                         asm("mr %0,1" : "=r" (sp));
 695                 else
 696                         sp = tsk->thread.ksp;
 697         }
 698
 699         prev_sp = (unsigned long) (tsk->thread_info + 1);
 700         stack_top = (unsigned long) tsk->thread_info + THREAD_SIZE;
 701         while (count < 16 && sp > prev_sp && sp < stack_top && (sp & 3) == 0) {
 702                 if (count == 0) {
 703                         printk("Call trace:");
 704 #ifdef CONFIG_KALLSYMS
 705                         printk("\n");
 706 #endif
 707                 } else {
 708                         if (next_exc) {
 709                                 ret = next_exc;
 710                                 next_exc = 0;
 711                         } else
 712                                 ret = *(unsigned long *)(sp + 4);
 713                         printk(" [%08lx] ", ret);
 714 #ifdef CONFIG_KALLSYMS
 715                         print_symbol("%s", ret);
 716                         printk("\n");
 717 #endif
 718                         if (ret == (unsigned long) &ret_from_except
 719                             || ret == (unsigned long) &ret_from_except_full
 720                             || ret == (unsigned long) &ret_from_syscall) {
 721                                 /* sp + 16 points to an exception frame */
 722                                 regs = (struct pt_regs *) (sp + 16);
 723                                 if (sp + 16 + sizeof(*regs) <= stack_top)
 724                                         next_exc = regs->nip;
 725                         }
 726                 }
 727                 ++count;
 728                 sp = *(unsigned long *)sp;
 729         }
 730 #ifndef CONFIG_KALLSYMS
 731         if (count > 0)
 732                 printk("\n");
 733 #endif
 734 }
 735
 736 #if 0
 737 /*
 738  * Low level print for debugging - Cort
 739  */
 740 int __init ll_printk(const char *fmt, ...)
 741 {
 742         va_list args;
 743         char buf[256];
 744         int i;
 745
 746         va_start(args, fmt);
 747         i=vsprintf(buf,fmt,args);
 748         ll_puts(buf);
 749         va_end(args);
 750         return i;
 751 }
 752
 753 int lines = 24, cols = 80;
 754 int orig_x = 0, orig_y = 0;
 755
 756 void puthex(unsigned long val)
 757 {
 758         unsigned char buf[10];
 759         int i;
 760         for (i = 7;  i >= 0;  i--)
 761         {
 762                 buf[i] = "0123456789ABCDEF"[val & 0x0F];
 763                 val >>= 4;
 764         }
 765         buf[8] = '\0';
 766         prom_print(buf);
 767 }
 768
 769 void __init ll_puts(const char *s)
 770 {
 771         int x,y;
 772         char *vidmem = (char *)/*(_ISA_MEM_BASE + 0xB8000) */0xD00B8000;
 773         char c;
 774         extern int mem_init_done;
 775
 776         if ( mem_init_done ) /* assume this means we can printk */
 777         {
 778                 printk(s);
 779                 return;
 780         }
 781
 782 #if 0
 783         if ( have_of )
 784         {
 785                 prom_print(s);
 786                 return;
 787         }
 788 #endif
 789
 790         /*
 791          * can't ll_puts on chrp without openfirmware yet.
 792          * vidmem just needs to be setup for it.
 793          * -- Cort
 794          */
 795         if ( _machine != _MACH_prep )
 796                 return;
 797         x = orig_x;
 798         y = orig_y;
 799
 800         while ( ( c = *s++ ) != '\0' ) {
 801                 if ( c == '\n' ) {
 802                         x = 0;
 803                         if ( ++y >= lines ) {
 804                                 /*scroll();*/
 805                                 /*y--;*/
 806                                 y = 0;
 807                         }
 808                 } else {
 809                         vidmem [ ( x + cols * y ) * 2 ] = c;
 810                         if ( ++x >= cols ) {
 811                                 x = 0;
 812                                 if ( ++y >= lines ) {
 813                                         /*scroll();*/
 814                                         /*y--;*/
 815                                         y = 0;
 816                                 }
 817                         }
 818                 }
 819         }
 820
 821         orig_x = x;
 822         orig_y = y;
 823 }
 824 #endif
 825
 826 unsigned long get_wchan(struct task_struct *p)
 827 {
 828         unsigned long ip, sp;
 829         unsigned long stack_page = (unsigned long) p->thread_info;
 830         int count = 0;
 831         if (!p || p == current || p->state == TASK_RUNNING)
 832                 return 0;
 833         sp = p->thread.ksp;
 834         do {
 835                 sp = *(unsigned long *)sp;
 836                 if (sp < stack_page || sp >= stack_page + 8188)
 837                         return 0;
 838                 if (count > 0) {
 839                         ip = *(unsigned long *)(sp + 4);
 840                         if (!in_sched_functions(ip))
 841                                 return ip;
 842                 }
 843         } while (count++ < 16);
 844         return 0;
 845 }