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   1 /*  $Id: process.c,v 1.131 2002/02/09 19:49:30 davem Exp $
   2  *  arch/sparc64/kernel/process.c
   3  *
   4  *  Copyright (C) 1995, 1996 David S. Miller (davem@caip.rutgers.edu)
   5  *  Copyright (C) 1996       Eddie C. Dost   (ecd@skynet.be)
   6  *  Copyright (C) 1997, 1998 Jakub Jelinek   (jj@sunsite.mff.cuni.cz)
   7  */
   8
   9 /*
  10  * This file handles the architecture-dependent parts of process handling..
  11  */
  12
  13 #include <stdarg.h>
  14
  15 #include <linux/errno.h>
  16 #include <linux/module.h>
  17 #include <linux/sched.h>
  18 #include <linux/kernel.h>
  19 #include <linux/kallsyms.h>
  20 #include <linux/mm.h>
  21 #include <linux/fs.h>
  22 #include <linux/smp.h>
  23 #include <linux/stddef.h>
  24 #include <linux/ptrace.h>
  25 #include <linux/slab.h>
  26 #include <linux/user.h>
  27 #include <linux/reboot.h>
  28 #include <linux/delay.h>
  29 #include <linux/compat.h>
  30 #include <linux/tick.h>
  31 #include <linux/init.h>
  32 #include <linux/cpu.h>
  33 #include <linux/elfcore.h>
  34
  35 #include <asm/oplib.h>
  36 #include <asm/uaccess.h>
  37 #include <asm/system.h>
  38 #include <asm/page.h>
  39 #include <asm/pgalloc.h>
  40 #include <asm/pgtable.h>
  41 #include <asm/processor.h>
  42 #include <asm/pstate.h>
  43 #include <asm/elf.h>
  44 #include <asm/fpumacro.h>
  45 #include <asm/head.h>
  46 #include <asm/cpudata.h>
  47 #include <asm/mmu_context.h>
  48 #include <asm/unistd.h>
  49 #include <asm/hypervisor.h>
  50 #include <asm/sstate.h>
  51 #include <asm/reboot.h>
  52 #include <asm/syscalls.h>
  53
  54 /* #define VERBOSE_SHOWREGS */
  55
  56 static void sparc64_yield(int cpu)
  57 {
  58         if (tlb_type != hypervisor)
  59                 return;
  60
  61         clear_thread_flag(TIF_POLLING_NRFLAG);
  62         smp_mb__after_clear_bit();
  63
  64         while (!need_resched() && !cpu_is_offline(cpu)) {
  65                 unsigned long pstate;
  66
  67                 /* Disable interrupts. */
  68                 __asm__ __volatile__(
  69                         "rdpr %%pstate, %0\n\t"
  70                         "andn %0, %1, %0\n\t"
  71                         "wrpr %0, %%g0, %%pstate"
  72                         : "=&r" (pstate)
  73                         : "i" (PSTATE_IE));
  74
  75                 if (!need_resched() && !cpu_is_offline(cpu))
  76                         sun4v_cpu_yield();
  77
  78                 /* Re-enable interrupts. */
  79                 __asm__ __volatile__(
  80                         "rdpr %%pstate, %0\n\t"
  81                         "or %0, %1, %0\n\t"
  82                         "wrpr %0, %%g0, %%pstate"
  83                         : "=&r" (pstate)
  84                         : "i" (PSTATE_IE));
  85         }
  86
  87         set_thread_flag(TIF_POLLING_NRFLAG);
  88 }
  89
  90 /* The idle loop on sparc64. */
  91 void cpu_idle(void)
  92 {
  93         int cpu = smp_processor_id();
  94
  95         set_thread_flag(TIF_POLLING_NRFLAG);
  96
  97         while(1) {
  98                 tick_nohz_stop_sched_tick();
  99
 100                 while (!need_resched() && !cpu_is_offline(cpu))
 101                         sparc64_yield(cpu);
 102
 103                 tick_nohz_restart_sched_tick();
 104
 105                 preempt_enable_no_resched();
 106
 107 #ifdef CONFIG_HOTPLUG_CPU
 108                 if (cpu_is_offline(cpu))
 109                         cpu_play_dead();
 110 #endif
 111
 112                 schedule();
 113                 preempt_disable();
 114         }
 115 }
 116
 117 void machine_halt(void)
 118 {
 119         sstate_halt();
 120         prom_halt();
 121         panic("Halt failed!");
 122 }
 123
 124 void machine_alt_power_off(void)
 125 {
 126         sstate_poweroff();
 127         prom_halt_power_off();
 128         panic("Power-off failed!");
 129 }
 130
 131 void machine_restart(char * cmd)
 132 {
 133         char *p;
 134
 135         sstate_reboot();
 136         p = strchr (reboot_command, '\n');
 137         if (p) *p = 0;
 138         if (cmd)
 139                 prom_reboot(cmd);
 140         if (*reboot_command)
 141                 prom_reboot(reboot_command);
 142         prom_reboot("");
 143         panic("Reboot failed!");
 144 }
 145
 146 #ifdef CONFIG_COMPAT
 147 static void show_regwindow32(struct pt_regs *regs)
 148 {
 149         struct reg_window32 __user *rw;
 150         struct reg_window32 r_w;
 151         mm_segment_t old_fs;
 152
 153         __asm__ __volatile__ ("flushw");
 154         rw = compat_ptr((unsigned)regs->u_regs[14]);
 155         old_fs = get_fs();
 156         set_fs (USER_DS);
 157         if (copy_from_user (&r_w, rw, sizeof(r_w))) {
 158                 set_fs (old_fs);
 159                 return;
 160         }
 161
 162         set_fs (old_fs);
 163         printk("l0: %08x l1: %08x l2: %08x l3: %08x "
 164                "l4: %08x l5: %08x l6: %08x l7: %08x\n",
 165                r_w.locals[0], r_w.locals[1], r_w.locals[2], r_w.locals[3],
 166                r_w.locals[4], r_w.locals[5], r_w.locals[6], r_w.locals[7]);
 167         printk("i0: %08x i1: %08x i2: %08x i3: %08x "
 168                "i4: %08x i5: %08x i6: %08x i7: %08x\n",
 169                r_w.ins[0], r_w.ins[1], r_w.ins[2], r_w.ins[3],
 170                r_w.ins[4], r_w.ins[5], r_w.ins[6], r_w.ins[7]);
 171 }
 172 #else
 173 #define show_regwindow32(regs)  do { } while (0)
 174 #endif
 175
 176 static void show_regwindow(struct pt_regs *regs)
 177 {
 178         struct reg_window __user *rw;
 179         struct reg_window *rwk;
 180         struct reg_window r_w;
 181         mm_segment_t old_fs;
 182
 183         if ((regs->tstate & TSTATE_PRIV) || !(test_thread_flag(TIF_32BIT))) {
 184                 __asm__ __volatile__ ("flushw");
 185                 rw = (struct reg_window __user *)
 186                         (regs->u_regs[14] + STACK_BIAS);
 187                 rwk = (struct reg_window *)
 188                         (regs->u_regs[14] + STACK_BIAS);
 189                 if (!(regs->tstate & TSTATE_PRIV)) {
 190                         old_fs = get_fs();
 191                         set_fs (USER_DS);
 192                         if (copy_from_user (&r_w, rw, sizeof(r_w))) {
 193                                 set_fs (old_fs);
 194                                 return;
 195                         }
 196                         rwk = &r_w;
 197                         set_fs (old_fs);
 198                 }
 199         } else {
 200                 show_regwindow32(regs);
 201                 return;
 202         }
 203         printk("l0: %016lx l1: %016lx l2: %016lx l3: %016lx\n",
 204                rwk->locals[0], rwk->locals[1], rwk->locals[2], rwk->locals[3]);
 205         printk("l4: %016lx l5: %016lx l6: %016lx l7: %016lx\n",
 206                rwk->locals[4], rwk->locals[5], rwk->locals[6], rwk->locals[7]);
 207         printk("i0: %016lx i1: %016lx i2: %016lx i3: %016lx\n",
 208                rwk->ins[0], rwk->ins[1], rwk->ins[2], rwk->ins[3]);
 209         printk("i4: %016lx i5: %016lx i6: %016lx i7: %016lx\n",
 210                rwk->ins[4], rwk->ins[5], rwk->ins[6], rwk->ins[7]);
 211         if (regs->tstate & TSTATE_PRIV)
 212                 print_symbol("I7: <%s>\n", rwk->ins[7]);
 213 }
 214
 215 #ifdef CONFIG_SMP
 216 static DEFINE_SPINLOCK(regdump_lock);
 217 #endif
 218
 219 void __show_regs(struct pt_regs * regs)
 220 {
 221 #ifdef CONFIG_SMP
 222         unsigned long flags;
 223
 224         /* Protect against xcall ipis which might lead to livelock on the lock */
 225         __asm__ __volatile__("rdpr      %%pstate, %0\n\t"
 226                              "wrpr      %0, %1, %%pstate"
 227                              : "=r" (flags)
 228                              : "i" (PSTATE_IE));
 229         spin_lock(&regdump_lock);
 230 #endif
 231         printk("TSTATE: %016lx TPC: %016lx TNPC: %016lx Y: %08x    %s\n", regs->tstate,
 232                regs->tpc, regs->tnpc, regs->y, print_tainted());
 233         print_symbol("TPC: <%s>\n", regs->tpc);
 234         printk("g0: %016lx g1: %016lx g2: %016lx g3: %016lx\n",
 235                regs->u_regs[0], regs->u_regs[1], regs->u_regs[2],
 236                regs->u_regs[3]);
 237         printk("g4: %016lx g5: %016lx g6: %016lx g7: %016lx\n",
 238                regs->u_regs[4], regs->u_regs[5], regs->u_regs[6],
 239                regs->u_regs[7]);
 240         printk("o0: %016lx o1: %016lx o2: %016lx o3: %016lx\n",
 241                regs->u_regs[8], regs->u_regs[9], regs->u_regs[10],
 242                regs->u_regs[11]);
 243         printk("o4: %016lx o5: %016lx sp: %016lx ret_pc: %016lx\n",
 244                regs->u_regs[12], regs->u_regs[13], regs->u_regs[14],
 245                regs->u_regs[15]);
 246         print_symbol("RPC: <%s>\n", regs->u_regs[15]);
 247         show_regwindow(regs);
 248 #ifdef CONFIG_SMP
 249         spin_unlock(&regdump_lock);
 250         __asm__ __volatile__("wrpr      %0, 0, %%pstate"
 251                              : : "r" (flags));
 252 #endif
 253 }
 254
 255 #ifdef VERBOSE_SHOWREGS
 256 static void idump_from_user (unsigned int *pc)
 257 {
 258         int i;
 259         int code;
 260
 261         if((((unsigned long) pc) & 3))
 262                 return;
 263
 264         pc -= 3;
 265         for(i = -3; i < 6; i++) {
 266                 get_user(code, pc);
 267                 printk("%c%08x%c",i?' ':'<',code,i?' ':'>');
 268                 pc++;
 269         }
 270         printk("\n");
 271 }
 272 #endif
 273
 274 void show_regs(struct pt_regs *regs)
 275 {
 276 #ifdef VERBOSE_SHOWREGS
 277         extern long etrap, etraptl1;
 278 #endif
 279         __show_regs(regs);
 280 #if 0
 281 #ifdef CONFIG_SMP
 282         {
 283                 extern void smp_report_regs(void);
 284
 285                 smp_report_regs();
 286         }
 287 #endif
 288 #endif
 289
 290 #ifdef VERBOSE_SHOWREGS
 291         if (regs->tpc >= &etrap && regs->tpc < &etraptl1 &&
 292             regs->u_regs[14] >= (long)current - PAGE_SIZE &&
 293             regs->u_regs[14] < (long)current + 6 * PAGE_SIZE) {
 294                 printk ("*********parent**********\n");
 295                 __show_regs((struct pt_regs *)(regs->u_regs[14] + PTREGS_OFF));
 296                 idump_from_user(((struct pt_regs *)(regs->u_regs[14] + PTREGS_OFF))->tpc);
 297                 printk ("*********endpar**********\n");
 298         }
 299 #endif
 300 }
 301
 302 unsigned long thread_saved_pc(struct task_struct *tsk)
 303 {
 304         struct thread_info *ti = task_thread_info(tsk);
 305         unsigned long ret = 0xdeadbeefUL;
 306
 307         if (ti && ti->ksp) {
 308                 unsigned long *sp;
 309                 sp = (unsigned long *)(ti->ksp + STACK_BIAS);
 310                 if (((unsigned long)sp & (sizeof(long) - 1)) == 0UL &&
 311                     sp[14]) {
 312                         unsigned long *fp;
 313                         fp = (unsigned long *)(sp[14] + STACK_BIAS);
 314                         if (((unsigned long)fp & (sizeof(long) - 1)) == 0UL)
 315                                 ret = fp[15];
 316                 }
 317         }
 318         return ret;
 319 }
 320
 321 /* Free current thread data structures etc.. */
 322 void exit_thread(void)
 323 {
 324         struct thread_info *t = current_thread_info();
 325
 326         if (t->utraps) {
 327                 if (t->utraps[0] < 2)
 328                         kfree (t->utraps);
 329                 else
 330                         t->utraps[0]--;
 331         }
 332
 333         if (test_and_clear_thread_flag(TIF_PERFCTR)) {
 334                 t->user_cntd0 = t->user_cntd1 = NULL;
 335                 t->pcr_reg = 0;
 336                 write_pcr(0);
 337         }
 338 }
 339
 340 void flush_thread(void)
 341 {
 342         struct thread_info *t = current_thread_info();
 343         struct mm_struct *mm;
 344
 345         if (test_ti_thread_flag(t, TIF_ABI_PENDING)) {
 346                 clear_ti_thread_flag(t, TIF_ABI_PENDING);
 347                 if (test_ti_thread_flag(t, TIF_32BIT))
 348                         clear_ti_thread_flag(t, TIF_32BIT);
 349                 else
 350                         set_ti_thread_flag(t, TIF_32BIT);
 351         }
 352
 353         mm = t->task->mm;
 354         if (mm)
 355                 tsb_context_switch(mm);
 356
 357         set_thread_wsaved(0);
 358
 359         /* Turn off performance counters if on. */
 360         if (test_and_clear_thread_flag(TIF_PERFCTR)) {
 361                 t->user_cntd0 = t->user_cntd1 = NULL;
 362                 t->pcr_reg = 0;
 363                 write_pcr(0);
 364         }
 365
 366         /* Clear FPU register state. */
 367         t->fpsaved[0] = 0;
 368
 369         if (get_thread_current_ds() != ASI_AIUS)
 370                 set_fs(USER_DS);
 371
 372         /* Init new signal delivery disposition. */
 373         clear_thread_flag(TIF_NEWSIGNALS);
 374 }
 375
 376 /* It's a bit more tricky when 64-bit tasks are involved... */
 377 static unsigned long clone_stackframe(unsigned long csp, unsigned long psp)
 378 {
 379         unsigned long fp, distance, rval;
 380
 381         if (!(test_thread_flag(TIF_32BIT))) {
 382                 csp += STACK_BIAS;
 383                 psp += STACK_BIAS;
 384                 __get_user(fp, &(((struct reg_window __user *)psp)->ins[6]));
 385                 fp += STACK_BIAS;
 386         } else
 387                 __get_user(fp, &(((struct reg_window32 __user *)psp)->ins[6]));
 388
 389         /* Now 8-byte align the stack as this is mandatory in the
 390          * Sparc ABI due to how register windows work.  This hides
 391          * the restriction from thread libraries etc.  -DaveM
 392          */
 393         csp &= ~7UL;
 394
 395         distance = fp - psp;
 396         rval = (csp - distance);
 397         if (copy_in_user((void __user *) rval, (void __user *) psp, distance))
 398                 rval = 0;
 399         else if (test_thread_flag(TIF_32BIT)) {
 400                 if (put_user(((u32)csp),
 401                              &(((struct reg_window32 __user *)rval)->ins[6])))
 402                         rval = 0;
 403         } else {
 404                 if (put_user(((u64)csp - STACK_BIAS),
 405                              &(((struct reg_window __user *)rval)->ins[6])))
 406                         rval = 0;
 407                 else
 408                         rval = rval - STACK_BIAS;
 409         }
 410
 411         return rval;
 412 }
 413
 414 /* Standard stuff. */
 415 static inline void shift_window_buffer(int first_win, int last_win,
 416                                        struct thread_info *t)
 417 {
 418         int i;
 419
 420         for (i = first_win; i < last_win; i++) {
 421                 t->rwbuf_stkptrs[i] = t->rwbuf_stkptrs[i+1];
 422                 memcpy(&t->reg_window[i], &t->reg_window[i+1],
 423                        sizeof(struct reg_window));
 424         }
 425 }
 426
 427 void synchronize_user_stack(void)
 428 {
 429         struct thread_info *t = current_thread_info();
 430         unsigned long window;
 431
 432         flush_user_windows();
 433         if ((window = get_thread_wsaved()) != 0) {
 434                 int winsize = sizeof(struct reg_window);
 435                 int bias = 0;
 436
 437                 if (test_thread_flag(TIF_32BIT))
 438                         winsize = sizeof(struct reg_window32);
 439                 else
 440                         bias = STACK_BIAS;
 441
 442                 window -= 1;
 443                 do {
 444                         unsigned long sp = (t->rwbuf_stkptrs[window] + bias);
 445                         struct reg_window *rwin = &t->reg_window[window];
 446
 447                         if (!copy_to_user((char __user *)sp, rwin, winsize)) {
 448                                 shift_window_buffer(window, get_thread_wsaved() - 1, t);
 449                                 set_thread_wsaved(get_thread_wsaved() - 1);
 450                         }
 451                 } while (window--);
 452         }
 453 }
 454
 455 static void stack_unaligned(unsigned long sp)
 456 {
 457         siginfo_t info;
 458
 459         info.si_signo = SIGBUS;
 460         info.si_errno = 0;
 461         info.si_code = BUS_ADRALN;
 462         info.si_addr = (void __user *) sp;
 463         info.si_trapno = 0;
 464         force_sig_info(SIGBUS, &info, current);
 465 }
 466
 467 void fault_in_user_windows(void)
 468 {
 469         struct thread_info *t = current_thread_info();
 470         unsigned long window;
 471         int winsize = sizeof(struct reg_window);
 472         int bias = 0;
 473
 474         if (test_thread_flag(TIF_32BIT))
 475                 winsize = sizeof(struct reg_window32);
 476         else
 477                 bias = STACK_BIAS;
 478
 479         flush_user_windows();
 480         window = get_thread_wsaved();
 481
 482         if (likely(window != 0)) {
 483                 window -= 1;
 484                 do {
 485                         unsigned long sp = (t->rwbuf_stkptrs[window] + bias);
 486                         struct reg_window *rwin = &t->reg_window[window];
 487
 488                         if (unlikely(sp & 0x7UL))
 489                                 stack_unaligned(sp);
 490
 491                         if (unlikely(copy_to_user((char __user *)sp,
 492                                                   rwin, winsize)))
 493                                 goto barf;
 494                 } while (window--);
 495         }
 496         set_thread_wsaved(0);
 497         return;
 498
 499 barf:
 500         set_thread_wsaved(window + 1);
 501         do_exit(SIGILL);
 502 }
 503
 504 asmlinkage long sparc_do_fork(unsigned long clone_flags,
 505                               unsigned long stack_start,
 506                               struct pt_regs *regs,
 507                               unsigned long stack_size)
 508 {
 509         int __user *parent_tid_ptr, *child_tid_ptr;
 510
 511 #ifdef CONFIG_COMPAT
 512         if (test_thread_flag(TIF_32BIT)) {
 513                 parent_tid_ptr = compat_ptr(regs->u_regs[UREG_I2]);
 514                 child_tid_ptr = compat_ptr(regs->u_regs[UREG_I4]);
 515         } else
 516 #endif
 517         {
 518                 parent_tid_ptr = (int __user *) regs->u_regs[UREG_I2];
 519                 child_tid_ptr = (int __user *) regs->u_regs[UREG_I4];
 520         }
 521
 522         return do_fork(clone_flags, stack_start,
 523                        regs, stack_size,
 524                        parent_tid_ptr, child_tid_ptr);
 525 }
 526
 527 /* Copy a Sparc thread.  The fork() return value conventions
 528  * under SunOS are nothing short of bletcherous:
 529  * Parent -->  %o0 == childs  pid, %o1 == 0
 530  * Child  -->  %o0 == parents pid, %o1 == 1
 531  */
 532 int copy_thread(int nr, unsigned long clone_flags, unsigned long sp,
 533                 unsigned long unused,
 534                 struct task_struct *p, struct pt_regs *regs)
 535 {
 536         struct thread_info *t = task_thread_info(p);
 537         char *child_trap_frame;
 538
 539         /* Calculate offset to stack_frame & pt_regs */
 540         child_trap_frame = task_stack_page(p) + (THREAD_SIZE - (TRACEREG_SZ+STACKFRAME_SZ));
 541         memcpy(child_trap_frame, (((struct sparc_stackf *)regs)-1), (TRACEREG_SZ+STACKFRAME_SZ));
 542
 543         t->flags = (t->flags & ~((0xffUL << TI_FLAG_CWP_SHIFT) | (0xffUL << TI_FLAG_CURRENT_DS_SHIFT))) |
 544                 (((regs->tstate + 1) & TSTATE_CWP) << TI_FLAG_CWP_SHIFT);
 545         t->new_child = 1;
 546         t->ksp = ((unsigned long) child_trap_frame) - STACK_BIAS;
 547         t->kregs = (struct pt_regs *)(child_trap_frame+sizeof(struct sparc_stackf));
 548         t->fpsaved[0] = 0;
 549
 550         if (regs->tstate & TSTATE_PRIV) {
 551                 /* Special case, if we are spawning a kernel thread from
 552                  * a userspace task (via KMOD, NFS, or similar) we must
 553                  * disable performance counters in the child because the
 554                  * address space and protection realm are changing.
 555                  */
 556                 if (t->flags & _TIF_PERFCTR) {
 557                         t->user_cntd0 = t->user_cntd1 = NULL;
 558                         t->pcr_reg = 0;
 559                         t->flags &= ~_TIF_PERFCTR;
 560                 }
 561                 t->kregs->u_regs[UREG_FP] = t->ksp;
 562                 t->flags |= ((long)ASI_P << TI_FLAG_CURRENT_DS_SHIFT);
 563                 flush_register_windows();
 564                 memcpy((void *)(t->ksp + STACK_BIAS),
 565                        (void *)(regs->u_regs[UREG_FP] + STACK_BIAS),
 566                        sizeof(struct sparc_stackf));
 567                 t->kregs->u_regs[UREG_G6] = (unsigned long) t;
 568                 t->kregs->u_regs[UREG_G4] = (unsigned long) t->task;
 569         } else {
 570                 if (t->flags & _TIF_32BIT) {
 571                         sp &= 0x00000000ffffffffUL;
 572                         regs->u_regs[UREG_FP] &= 0x00000000ffffffffUL;
 573                 }
 574                 t->kregs->u_regs[UREG_FP] = sp;
 575                 t->flags |= ((long)ASI_AIUS << TI_FLAG_CURRENT_DS_SHIFT);
 576                 if (sp != regs->u_regs[UREG_FP]) {
 577                         unsigned long csp;
 578
 579                         csp = clone_stackframe(sp, regs->u_regs[UREG_FP]);
 580                         if (!csp)
 581                                 return -EFAULT;
 582                         t->kregs->u_regs[UREG_FP] = csp;
 583                 }
 584                 if (t->utraps)
 585                         t->utraps[0]++;
 586         }
 587
 588         /* Set the return value for the child. */
 589         t->kregs->u_regs[UREG_I0] = current->pid;
 590         t->kregs->u_regs[UREG_I1] = 1;
 591
 592         /* Set the second return value for the parent. */
 593         regs->u_regs[UREG_I1] = 0;
 594
 595         if (clone_flags & CLONE_SETTLS)
 596                 t->kregs->u_regs[UREG_G7] = regs->u_regs[UREG_I3];
 597
 598         return 0;
 599 }
 600
 601 /*
 602  * This is the mechanism for creating a new kernel thread.
 603  *
 604  * NOTE! Only a kernel-only process(ie the swapper or direct descendants
 605  * who haven't done an "execve()") should use this: it will work within
 606  * a system call from a "real" process, but the process memory space will
 607  * not be freed until both the parent and the child have exited.
 608  */
 609 pid_t kernel_thread(int (*fn)(void *), void * arg, unsigned long flags)
 610 {
 611         long retval;
 612
 613         /* If the parent runs before fn(arg) is called by the child,
 614          * the input registers of this function can be clobbered.
 615          * So we stash 'fn' and 'arg' into global registers which
 616          * will not be modified by the parent.
 617          */
 618         __asm__ __volatile__("mov %4, %%g2\n\t"    /* Save FN into global */
 619                              "mov %5, %%g3\n\t"    /* Save ARG into global */
 620                              "mov %1, %%g1\n\t"    /* Clone syscall nr. */
 621                              "mov %2, %%o0\n\t"    /* Clone flags. */
 622                              "mov 0, %%o1\n\t"     /* usp arg == 0 */
 623                              "t 0x6d\n\t"          /* Linux/Sparc clone(). */
 624                              "brz,a,pn %%o1, 1f\n\t" /* Parent, just return. */
 625                              " mov %%o0, %0\n\t"
 626                              "jmpl %%g2, %%o7\n\t"   /* Call the function. */
 627                              " mov %%g3, %%o0\n\t"   /* Set arg in delay. */
 628                              "mov %3, %%g1\n\t"
 629                              "t 0x6d\n\t"          /* Linux/Sparc exit(). */
 630                              /* Notreached by child. */
 631                              "1:" :
 632                              "=r" (retval) :
 633                              "i" (__NR_clone), "r" (flags | CLONE_VM | CLONE_UNTRACED),
 634                              "i" (__NR_exit),  "r" (fn), "r" (arg) :
 635                              "g1", "g2", "g3", "o0", "o1", "memory", "cc");
 636         return retval;
 637 }
 638
 639 typedef struct {
 640         union {
 641                 unsigned int    pr_regs[32];
 642                 unsigned long   pr_dregs[16];
 643         } pr_fr;
 644         unsigned int __unused;
 645         unsigned int    pr_fsr;
 646         unsigned char   pr_qcnt;
 647         unsigned char   pr_q_entrysize;
 648         unsigned char   pr_en;
 649         unsigned int    pr_q[64];
 650 } elf_fpregset_t32;
 651
 652 /*
 653  * fill in the fpu structure for a core dump.
 654  */
 655 int dump_fpu (struct pt_regs * regs, elf_fpregset_t * fpregs)
 656 {
 657         unsigned long *kfpregs = current_thread_info()->fpregs;
 658         unsigned long fprs = current_thread_info()->fpsaved[0];
 659
 660         if (test_thread_flag(TIF_32BIT)) {
 661                 elf_fpregset_t32 *fpregs32 = (elf_fpregset_t32 *)fpregs;
 662
 663                 if (fprs & FPRS_DL)
 664                         memcpy(&fpregs32->pr_fr.pr_regs[0], kfpregs,
 665                                sizeof(unsigned int) * 32);
 666                 else
 667                         memset(&fpregs32->pr_fr.pr_regs[0], 0,
 668                                sizeof(unsigned int) * 32);
 669                 fpregs32->pr_qcnt = 0;
 670                 fpregs32->pr_q_entrysize = 8;
 671                 memset(&fpregs32->pr_q[0], 0,
 672                        (sizeof(unsigned int) * 64));
 673                 if (fprs & FPRS_FEF) {
 674                         fpregs32->pr_fsr = (unsigned int) current_thread_info()->xfsr[0];
 675                         fpregs32->pr_en = 1;
 676                 } else {
 677                         fpregs32->pr_fsr = 0;
 678                         fpregs32->pr_en = 0;
 679                 }
 680         } else {
 681                 if(fprs & FPRS_DL)
 682                         memcpy(&fpregs->pr_regs[0], kfpregs,
 683                                sizeof(unsigned int) * 32);
 684                 else
 685                         memset(&fpregs->pr_regs[0], 0,
 686                                sizeof(unsigned int) * 32);
 687                 if(fprs & FPRS_DU)
 688                         memcpy(&fpregs->pr_regs[16], kfpregs+16,
 689                                sizeof(unsigned int) * 32);
 690                 else
 691                         memset(&fpregs->pr_regs[16], 0,
 692                                sizeof(unsigned int) * 32);
 693                 if(fprs & FPRS_FEF) {
 694                         fpregs->pr_fsr = current_thread_info()->xfsr[0];
 695                         fpregs->pr_gsr = current_thread_info()->gsr[0];
 696                 } else {
 697                         fpregs->pr_fsr = fpregs->pr_gsr = 0;
 698                 }
 699                 fpregs->pr_fprs = fprs;
 700         }
 701         return 1;
 702 }
 703
 704 /*
 705  * sparc_execve() executes a new program after the asm stub has set
 706  * things up for us.  This should basically do what I want it to.
 707  */
 708 asmlinkage int sparc_execve(struct pt_regs *regs)
 709 {
 710         int error, base = 0;
 711         char *filename;
 712
 713         /* User register window flush is done by entry.S */
 714
 715         /* Check for indirect call. */
 716         if (regs->u_regs[UREG_G1] == 0)
 717                 base = 1;
 718
 719         filename = getname((char __user *)regs->u_regs[base + UREG_I0]);
 720         error = PTR_ERR(filename);
 721         if (IS_ERR(filename))
 722                 goto out;
 723         error = do_execve(filename,
 724                           (char __user * __user *)
 725                           regs->u_regs[base + UREG_I1],
 726                           (char __user * __user *)
 727                           regs->u_regs[base + UREG_I2], regs);
 728         putname(filename);
 729         if (!error) {
 730                 fprs_write(0);
 731                 current_thread_info()->xfsr[0] = 0;
 732                 current_thread_info()->fpsaved[0] = 0;
 733                 regs->tstate &= ~TSTATE_PEF;
 734                 task_lock(current);
 735                 current->ptrace &= ~PT_DTRACE;
 736                 task_unlock(current);
 737         }
 738 out:
 739         return error;
 740 }
 741
 742 unsigned long get_wchan(struct task_struct *task)
 743 {
 744         unsigned long pc, fp, bias = 0;
 745         unsigned long thread_info_base;
 746         struct reg_window *rw;
 747         unsigned long ret = 0;
 748         int count = 0;
 749
 750         if (!task || task == current ||
 751             task->state == TASK_RUNNING)
 752                 goto out;
 753
 754         thread_info_base = (unsigned long) task_stack_page(task);
 755         bias = STACK_BIAS;
 756         fp = task_thread_info(task)->ksp + bias;
 757
 758         do {
 759                 /* Bogus frame pointer? */
 760                 if (fp < (thread_info_base + sizeof(struct thread_info)) ||
 761                     fp >= (thread_info_base + THREAD_SIZE))
 762                         break;
 763                 rw = (struct reg_window *) fp;
 764                 pc = rw->ins[7];
 765                 if (!in_sched_functions(pc)) {
 766                         ret = pc;
 767                         goto out;
 768                 }
 769                 fp = rw->ins[6] + bias;
 770         } while (++count < 16);
 771
 772 out:
 773         return ret;
 774 }