arch/sparc/kernel/process_64.c

   1 /*  arch/sparc64/kernel/process.c
   2  *
   3  *  Copyright (C) 1995, 1996, 2008 David S. Miller (davem@davemloft.net)
   4  *  Copyright (C) 1996       Eddie C. Dost   (ecd@skynet.be)
   5  *  Copyright (C) 1997, 1998 Jakub Jelinek   (jj@sunsite.mff.cuni.cz)
   6  */
   7
   8 /*
   9  * This file handles the architecture-dependent parts of process handling..
  10  */
  11
  12 #include <stdarg.h>
  13
  14 #include <linux/errno.h>
  15 #include <linux/export.h>
  16 #include <linux/sched.h>
  17 #include <linux/sched/debug.h>
  18 #include <linux/sched/task.h>
  19 #include <linux/sched/task_stack.h>
  20 #include <linux/kernel.h>
  21 #include <linux/mm.h>
  22 #include <linux/fs.h>
  23 #include <linux/smp.h>
  24 #include <linux/stddef.h>
  25 #include <linux/ptrace.h>
  26 #include <linux/slab.h>
  27 #include <linux/user.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/perf_event.h>
  34 #include <linux/elfcore.h>
  35 #include <linux/sysrq.h>
  36 #include <linux/nmi.h>
  37 #include <linux/context_tracking.h>
  38
  39 #include <linux/uaccess.h>
  40 #include <asm/page.h>
  41 #include <asm/pgalloc.h>
  42 #include <asm/pgtable.h>
  43 #include <asm/processor.h>
  44 #include <asm/pstate.h>
  45 #include <asm/elf.h>
  46 #include <asm/fpumacro.h>
  47 #include <asm/head.h>
  48 #include <asm/cpudata.h>
  49 #include <asm/mmu_context.h>
  50 #include <asm/unistd.h>
  51 #include <asm/hypervisor.h>
  52 #include <asm/syscalls.h>
  53 #include <asm/irq_regs.h>
  54 #include <asm/smp.h>
  55 #include <asm/pcr.h>
  56
  57 #include "kstack.h"
  58
  59 /* Idle loop support on sparc64. */
  60 void arch_cpu_idle(void)
  61 {
  62         if (tlb_type != hypervisor) {
  63                 touch_nmi_watchdog();
  64                 local_irq_enable();
  65         } else {
  66                 unsigned long pstate;
  67
  68                 local_irq_enable();
  69
  70                 /* The sun4v sleeping code requires that we have PSTATE.IE cleared over
  71                  * the cpu sleep hypervisor call.
  72                  */
  73                 __asm__ __volatile__(
  74                         "rdpr %%pstate, %0\n\t"
  75                         "andn %0, %1, %0\n\t"
  76                         "wrpr %0, %%g0, %%pstate"
  77                         : "=&r" (pstate)
  78                         : "i" (PSTATE_IE));
  79
  80                 if (!need_resched() && !cpu_is_offline(smp_processor_id()))
  81                         sun4v_cpu_yield();
  82
  83                 /* Re-enable interrupts. */
  84                 __asm__ __volatile__(
  85                         "rdpr %%pstate, %0\n\t"
  86                         "or %0, %1, %0\n\t"
  87                         "wrpr %0, %%g0, %%pstate"
  88                         : "=&r" (pstate)
  89                         : "i" (PSTATE_IE));
  90         }
  91 }
  92
  93 #ifdef CONFIG_HOTPLUG_CPU
  94 void arch_cpu_idle_dead(void)
  95 {
  96         sched_preempt_enable_no_resched();
  97         cpu_play_dead();
  98 }
  99 #endif
 100
 101 #ifdef CONFIG_COMPAT
 102 static void show_regwindow32(struct pt_regs *regs)
 103 {
 104         struct reg_window32 __user *rw;
 105         struct reg_window32 r_w;
 106         mm_segment_t old_fs;
 107
 108         __asm__ __volatile__ ("flushw");
 109         rw = compat_ptr((unsigned int)regs->u_regs[14]);
 110         old_fs = get_fs();
 111         set_fs (USER_DS);
 112         if (copy_from_user (&r_w, rw, sizeof(r_w))) {
 113                 set_fs (old_fs);
 114                 return;
 115         }
 116
 117         set_fs (old_fs);
 118         printk("l0: %08x l1: %08x l2: %08x l3: %08x "
 119                "l4: %08x l5: %08x l6: %08x l7: %08x\n",
 120                r_w.locals[0], r_w.locals[1], r_w.locals[2], r_w.locals[3],
 121                r_w.locals[4], r_w.locals[5], r_w.locals[6], r_w.locals[7]);
 122         printk("i0: %08x i1: %08x i2: %08x i3: %08x "
 123                "i4: %08x i5: %08x i6: %08x i7: %08x\n",
 124                r_w.ins[0], r_w.ins[1], r_w.ins[2], r_w.ins[3],
 125                r_w.ins[4], r_w.ins[5], r_w.ins[6], r_w.ins[7]);
 126 }
 127 #else
 128 #define show_regwindow32(regs)  do { } while (0)
 129 #endif
 130
 131 static void show_regwindow(struct pt_regs *regs)
 132 {
 133         struct reg_window __user *rw;
 134         struct reg_window *rwk;
 135         struct reg_window r_w;
 136         mm_segment_t old_fs;
 137
 138         if ((regs->tstate & TSTATE_PRIV) || !(test_thread_flag(TIF_32BIT))) {
 139                 __asm__ __volatile__ ("flushw");
 140                 rw = (struct reg_window __user *)
 141                         (regs->u_regs[14] + STACK_BIAS);
 142                 rwk = (struct reg_window *)
 143                         (regs->u_regs[14] + STACK_BIAS);
 144                 if (!(regs->tstate & TSTATE_PRIV)) {
 145                         old_fs = get_fs();
 146                         set_fs (USER_DS);
 147                         if (copy_from_user (&r_w, rw, sizeof(r_w))) {
 148                                 set_fs (old_fs);
 149                                 return;
 150                         }
 151                         rwk = &r_w;
 152                         set_fs (old_fs);
 153                 }
 154         } else {
 155                 show_regwindow32(regs);
 156                 return;
 157         }
 158         printk("l0: %016lx l1: %016lx l2: %016lx l3: %016lx\n",
 159                rwk->locals[0], rwk->locals[1], rwk->locals[2], rwk->locals[3]);
 160         printk("l4: %016lx l5: %016lx l6: %016lx l7: %016lx\n",
 161                rwk->locals[4], rwk->locals[5], rwk->locals[6], rwk->locals[7]);
 162         printk("i0: %016lx i1: %016lx i2: %016lx i3: %016lx\n",
 163                rwk->ins[0], rwk->ins[1], rwk->ins[2], rwk->ins[3]);
 164         printk("i4: %016lx i5: %016lx i6: %016lx i7: %016lx\n",
 165                rwk->ins[4], rwk->ins[5], rwk->ins[6], rwk->ins[7]);
 166         if (regs->tstate & TSTATE_PRIV)
 167                 printk("I7: <%pS>\n", (void *) rwk->ins[7]);
 168 }
 169
 170 void show_regs(struct pt_regs *regs)
 171 {
 172         show_regs_print_info(KERN_DEFAULT);
 173
 174         printk("TSTATE: %016lx TPC: %016lx TNPC: %016lx Y: %08x    %s\n", regs->tstate,
 175                regs->tpc, regs->tnpc, regs->y, print_tainted());
 176         printk("TPC: <%pS>\n", (void *) regs->tpc);
 177         printk("g0: %016lx g1: %016lx g2: %016lx g3: %016lx\n",
 178                regs->u_regs[0], regs->u_regs[1], regs->u_regs[2],
 179                regs->u_regs[3]);
 180         printk("g4: %016lx g5: %016lx g6: %016lx g7: %016lx\n",
 181                regs->u_regs[4], regs->u_regs[5], regs->u_regs[6],
 182                regs->u_regs[7]);
 183         printk("o0: %016lx o1: %016lx o2: %016lx o3: %016lx\n",
 184                regs->u_regs[8], regs->u_regs[9], regs->u_regs[10],
 185                regs->u_regs[11]);
 186         printk("o4: %016lx o5: %016lx sp: %016lx ret_pc: %016lx\n",
 187                regs->u_regs[12], regs->u_regs[13], regs->u_regs[14],
 188                regs->u_regs[15]);
 189         printk("RPC: <%pS>\n", (void *) regs->u_regs[15]);
 190         show_regwindow(regs);
 191         show_stack(current, (unsigned long *) regs->u_regs[UREG_FP]);
 192 }
 193
 194 union global_cpu_snapshot global_cpu_snapshot[NR_CPUS];
 195 static DEFINE_SPINLOCK(global_cpu_snapshot_lock);
 196
 197 static void __global_reg_self(struct thread_info *tp, struct pt_regs *regs,
 198                               int this_cpu)
 199 {
 200         struct global_reg_snapshot *rp;
 201
 202         flushw_all();
 203
 204         rp = &global_cpu_snapshot[this_cpu].reg;
 205
 206         rp->tstate = regs->tstate;
 207         rp->tpc = regs->tpc;
 208         rp->tnpc = regs->tnpc;
 209         rp->o7 = regs->u_regs[UREG_I7];
 210
 211         if (regs->tstate & TSTATE_PRIV) {
 212                 struct reg_window *rw;
 213
 214                 rw = (struct reg_window *)
 215                         (regs->u_regs[UREG_FP] + STACK_BIAS);
 216                 if (kstack_valid(tp, (unsigned long) rw)) {
 217                         rp->i7 = rw->ins[7];
 218                         rw = (struct reg_window *)
 219                                 (rw->ins[6] + STACK_BIAS);
 220                         if (kstack_valid(tp, (unsigned long) rw))
 221                                 rp->rpc = rw->ins[7];
 222                 }
 223         } else {
 224                 rp->i7 = 0;
 225                 rp->rpc = 0;
 226         }
 227         rp->thread = tp;
 228 }
 229
 230 /* In order to avoid hangs we do not try to synchronize with the
 231  * global register dump client cpus.  The last store they make is to
 232  * the thread pointer, so do a short poll waiting for that to become
 233  * non-NULL.
 234  */
 235 static void __global_reg_poll(struct global_reg_snapshot *gp)
 236 {
 237         int limit = 0;
 238
 239         while (!gp->thread && ++limit < 100) {
 240                 barrier();
 241                 udelay(1);
 242         }
 243 }
 244
 245 void arch_trigger_cpumask_backtrace(const cpumask_t *mask, bool exclude_self)
 246 {
 247         struct thread_info *tp = current_thread_info();
 248         struct pt_regs *regs = get_irq_regs();
 249         unsigned long flags;
 250         int this_cpu, cpu;
 251
 252         if (!regs)
 253                 regs = tp->kregs;
 254
 255         spin_lock_irqsave(&global_cpu_snapshot_lock, flags);
 256
 257         this_cpu = raw_smp_processor_id();
 258
 259         memset(global_cpu_snapshot, 0, sizeof(global_cpu_snapshot));
 260
 261         if (cpumask_test_cpu(this_cpu, mask) && !exclude_self)
 262                 __global_reg_self(tp, regs, this_cpu);
 263
 264         smp_fetch_global_regs();
 265
 266         for_each_cpu(cpu, mask) {
 267                 struct global_reg_snapshot *gp;
 268
 269                 if (exclude_self && cpu == this_cpu)
 270                         continue;
 271
 272                 gp = &global_cpu_snapshot[cpu].reg;
 273
 274                 __global_reg_poll(gp);
 275
 276                 tp = gp->thread;
 277                 printk("%c CPU[%3d]: TSTATE[%016lx] TPC[%016lx] TNPC[%016lx] TASK[%s:%d]\n",
 278                        (cpu == this_cpu ? '*' : ' '), cpu,
 279                        gp->tstate, gp->tpc, gp->tnpc,
 280                        ((tp && tp->task) ? tp->task->comm : "NULL"),
 281                        ((tp && tp->task) ? tp->task->pid : -1));
 282
 283                 if (gp->tstate & TSTATE_PRIV) {
 284                         printk("             TPC[%pS] O7[%pS] I7[%pS] RPC[%pS]\n",
 285                                (void *) gp->tpc,
 286                                (void *) gp->o7,
 287                                (void *) gp->i7,
 288                                (void *) gp->rpc);
 289                 } else {
 290                         printk("             TPC[%lx] O7[%lx] I7[%lx] RPC[%lx]\n",
 291                                gp->tpc, gp->o7, gp->i7, gp->rpc);
 292                 }
 293
 294                 touch_nmi_watchdog();
 295         }
 296
 297         memset(global_cpu_snapshot, 0, sizeof(global_cpu_snapshot));
 298
 299         spin_unlock_irqrestore(&global_cpu_snapshot_lock, flags);
 300 }
 301
 302 #ifdef CONFIG_MAGIC_SYSRQ
 303
 304 static void sysrq_handle_globreg(int key)
 305 {
 306         trigger_all_cpu_backtrace();
 307 }
 308
 309 static struct sysrq_key_op sparc_globalreg_op = {
 310         .handler        = sysrq_handle_globreg,
 311         .help_msg       = "global-regs(y)",
 312         .action_msg     = "Show Global CPU Regs",
 313 };
 314
 315 static void __global_pmu_self(int this_cpu)
 316 {
 317         struct global_pmu_snapshot *pp;
 318         int i, num;
 319
 320         if (!pcr_ops)
 321                 return;
 322
 323         pp = &global_cpu_snapshot[this_cpu].pmu;
 324
 325         num = 1;
 326         if (tlb_type == hypervisor &&
 327             sun4v_chip_type >= SUN4V_CHIP_NIAGARA4)
 328                 num = 4;
 329
 330         for (i = 0; i < num; i++) {
 331                 pp->pcr[i] = pcr_ops->read_pcr(i);
 332                 pp->pic[i] = pcr_ops->read_pic(i);
 333         }
 334 }
 335
 336 static void __global_pmu_poll(struct global_pmu_snapshot *pp)
 337 {
 338         int limit = 0;
 339
 340         while (!pp->pcr[0] && ++limit < 100) {
 341                 barrier();
 342                 udelay(1);
 343         }
 344 }
 345
 346 static void pmu_snapshot_all_cpus(void)
 347 {
 348         unsigned long flags;
 349         int this_cpu, cpu;
 350
 351         spin_lock_irqsave(&global_cpu_snapshot_lock, flags);
 352
 353         memset(global_cpu_snapshot, 0, sizeof(global_cpu_snapshot));
 354
 355         this_cpu = raw_smp_processor_id();
 356
 357         __global_pmu_self(this_cpu);
 358
 359         smp_fetch_global_pmu();
 360
 361         for_each_online_cpu(cpu) {
 362                 struct global_pmu_snapshot *pp = &global_cpu_snapshot[cpu].pmu;
 363
 364                 __global_pmu_poll(pp);
 365
 366                 printk("%c CPU[%3d]: PCR[%08lx:%08lx:%08lx:%08lx] PIC[%08lx:%08lx:%08lx:%08lx]\n",
 367                        (cpu == this_cpu ? '*' : ' '), cpu,
 368                        pp->pcr[0], pp->pcr[1], pp->pcr[2], pp->pcr[3],
 369                        pp->pic[0], pp->pic[1], pp->pic[2], pp->pic[3]);
 370
 371                 touch_nmi_watchdog();
 372         }
 373
 374         memset(global_cpu_snapshot, 0, sizeof(global_cpu_snapshot));
 375
 376         spin_unlock_irqrestore(&global_cpu_snapshot_lock, flags);
 377 }
 378
 379 static void sysrq_handle_globpmu(int key)
 380 {
 381         pmu_snapshot_all_cpus();
 382 }
 383
 384 static struct sysrq_key_op sparc_globalpmu_op = {
 385         .handler        = sysrq_handle_globpmu,
 386         .help_msg       = "global-pmu(x)",
 387         .action_msg     = "Show Global PMU Regs",
 388 };
 389
 390 static int __init sparc_sysrq_init(void)
 391 {
 392         int ret = register_sysrq_key('y', &sparc_globalreg_op);
 393
 394         if (!ret)
 395                 ret = register_sysrq_key('x', &sparc_globalpmu_op);
 396         return ret;
 397 }
 398
 399 core_initcall(sparc_sysrq_init);
 400
 401 #endif
 402
 403 /* Free current thread data structures etc.. */
 404 void exit_thread(struct task_struct *tsk)
 405 {
 406         struct thread_info *t = task_thread_info(tsk);
 407
 408         if (t->utraps) {
 409                 if (t->utraps[0] < 2)
 410                         kfree (t->utraps);
 411                 else
 412                         t->utraps[0]--;
 413         }
 414 }
 415
 416 void flush_thread(void)
 417 {
 418         struct thread_info *t = current_thread_info();
 419         struct mm_struct *mm;
 420
 421         mm = t->task->mm;
 422         if (mm)
 423                 tsb_context_switch(mm);
 424
 425         set_thread_wsaved(0);
 426
 427         /* Clear FPU register state. */
 428         t->fpsaved[0] = 0;
 429 }
 430
 431 /* It's a bit more tricky when 64-bit tasks are involved... */
 432 static unsigned long clone_stackframe(unsigned long csp, unsigned long psp)
 433 {
 434         bool stack_64bit = test_thread_64bit_stack(psp);
 435         unsigned long fp, distance, rval;
 436
 437         if (stack_64bit) {
 438                 csp += STACK_BIAS;
 439                 psp += STACK_BIAS;
 440                 __get_user(fp, &(((struct reg_window __user *)psp)->ins[6]));
 441                 fp += STACK_BIAS;
 442                 if (test_thread_flag(TIF_32BIT))
 443                         fp &= 0xffffffff;
 444         } else
 445                 __get_user(fp, &(((struct reg_window32 __user *)psp)->ins[6]));
 446
 447         /* Now align the stack as this is mandatory in the Sparc ABI
 448          * due to how register windows work.  This hides the
 449          * restriction from thread libraries etc.
 450          */
 451         csp &= ~15UL;
 452
 453         distance = fp - psp;
 454         rval = (csp - distance);
 455         if (copy_in_user((void __user *) rval, (void __user *) psp, distance))
 456                 rval = 0;
 457         else if (!stack_64bit) {
 458                 if (put_user(((u32)csp),
 459                              &(((struct reg_window32 __user *)rval)->ins[6])))
 460                         rval = 0;
 461         } else {
 462                 if (put_user(((u64)csp - STACK_BIAS),
 463                              &(((struct reg_window __user *)rval)->ins[6])))
 464                         rval = 0;
 465                 else
 466                         rval = rval - STACK_BIAS;
 467         }
 468
 469         return rval;
 470 }
 471
 472 /* Standard stuff. */
 473 static inline void shift_window_buffer(int first_win, int last_win,
 474                                        struct thread_info *t)
 475 {
 476         int i;
 477
 478         for (i = first_win; i < last_win; i++) {
 479                 t->rwbuf_stkptrs[i] = t->rwbuf_stkptrs[i+1];
 480                 memcpy(&t->reg_window[i], &t->reg_window[i+1],
 481                        sizeof(struct reg_window));
 482         }
 483 }
 484
 485 void synchronize_user_stack(void)
 486 {
 487         struct thread_info *t = current_thread_info();
 488         unsigned long window;
 489
 490         flush_user_windows();
 491         if ((window = get_thread_wsaved()) != 0) {
 492                 window -= 1;
 493                 do {
 494                         struct reg_window *rwin = &t->reg_window[window];
 495                         int winsize = sizeof(struct reg_window);
 496                         unsigned long sp;
 497
 498                         sp = t->rwbuf_stkptrs[window];
 499
 500                         if (test_thread_64bit_stack(sp))
 501                                 sp += STACK_BIAS;
 502                         else
 503                                 winsize = sizeof(struct reg_window32);
 504
 505                         if (!copy_to_user((char __user *)sp, rwin, winsize)) {
 506                                 shift_window_buffer(window, get_thread_wsaved() - 1, t);
 507                                 set_thread_wsaved(get_thread_wsaved() - 1);
 508                         }
 509                 } while (window--);
 510         }
 511 }
 512
 513 static void stack_unaligned(unsigned long sp)
 514 {
 515         siginfo_t info;
 516
 517         info.si_signo = SIGBUS;
 518         info.si_errno = 0;
 519         info.si_code = BUS_ADRALN;
 520         info.si_addr = (void __user *) sp;
 521         info.si_trapno = 0;
 522         force_sig_info(SIGBUS, &info, current);
 523 }
 524
 525 void fault_in_user_windows(void)
 526 {
 527         struct thread_info *t = current_thread_info();
 528         unsigned long window;
 529
 530         flush_user_windows();
 531         window = get_thread_wsaved();
 532
 533         if (likely(window != 0)) {
 534                 window -= 1;
 535                 do {
 536                         struct reg_window *rwin = &t->reg_window[window];
 537                         int winsize = sizeof(struct reg_window);
 538                         unsigned long sp;
 539
 540                         sp = t->rwbuf_stkptrs[window];
 541
 542                         if (test_thread_64bit_stack(sp))
 543                                 sp += STACK_BIAS;
 544                         else
 545                                 winsize = sizeof(struct reg_window32);
 546
 547                         if (unlikely(sp & 0x7UL))
 548                                 stack_unaligned(sp);
 549
 550                         if (unlikely(copy_to_user((char __user *)sp,
 551                                                   rwin, winsize)))
 552                                 goto barf;
 553                 } while (window--);
 554         }
 555         set_thread_wsaved(0);
 556         return;
 557
 558 barf:
 559         set_thread_wsaved(window + 1);
 560         user_exit();
 561         do_exit(SIGILL);
 562 }
 563
 564 asmlinkage long sparc_do_fork(unsigned long clone_flags,
 565                               unsigned long stack_start,
 566                               struct pt_regs *regs,
 567                               unsigned long stack_size)
 568 {
 569         int __user *parent_tid_ptr, *child_tid_ptr;
 570         unsigned long orig_i1 = regs->u_regs[UREG_I1];
 571         long ret;
 572
 573 #ifdef CONFIG_COMPAT
 574         if (test_thread_flag(TIF_32BIT)) {
 575                 parent_tid_ptr = compat_ptr(regs->u_regs[UREG_I2]);
 576                 child_tid_ptr = compat_ptr(regs->u_regs[UREG_I4]);
 577         } else
 578 #endif
 579         {
 580                 parent_tid_ptr = (int __user *) regs->u_regs[UREG_I2];
 581                 child_tid_ptr = (int __user *) regs->u_regs[UREG_I4];
 582         }
 583
 584         ret = do_fork(clone_flags, stack_start, stack_size,
 585                       parent_tid_ptr, child_tid_ptr);
 586
 587         /* If we get an error and potentially restart the system
 588          * call, we're screwed because copy_thread() clobbered
 589          * the parent's %o1.  So detect that case and restore it
 590          * here.
 591          */
 592         if ((unsigned long)ret >= -ERESTART_RESTARTBLOCK)
 593                 regs->u_regs[UREG_I1] = orig_i1;
 594
 595         return ret;
 596 }
 597
 598 /* Copy a Sparc thread.  The fork() return value conventions
 599  * under SunOS are nothing short of bletcherous:
 600  * Parent -->  %o0 == childs  pid, %o1 == 0
 601  * Child  -->  %o0 == parents pid, %o1 == 1
 602  */
 603 int copy_thread(unsigned long clone_flags, unsigned long sp,
 604                 unsigned long arg, struct task_struct *p)
 605 {
 606         struct thread_info *t = task_thread_info(p);
 607         struct pt_regs *regs = current_pt_regs();
 608         struct sparc_stackf *parent_sf;
 609         unsigned long child_stack_sz;
 610         char *child_trap_frame;
 611
 612         /* Calculate offset to stack_frame & pt_regs */
 613         child_stack_sz = (STACKFRAME_SZ + TRACEREG_SZ);
 614         child_trap_frame = (task_stack_page(p) +
 615                             (THREAD_SIZE - child_stack_sz));
 616
 617         t->new_child = 1;
 618         t->ksp = ((unsigned long) child_trap_frame) - STACK_BIAS;
 619         t->kregs = (struct pt_regs *) (child_trap_frame +
 620                                        sizeof(struct sparc_stackf));
 621         t->fpsaved[0] = 0;
 622
 623         if (unlikely(p->flags & PF_KTHREAD)) {
 624                 memset(child_trap_frame, 0, child_stack_sz);
 625                 __thread_flag_byte_ptr(t)[TI_FLAG_BYTE_CWP] =
 626                         (current_pt_regs()->tstate + 1) & TSTATE_CWP;
 627                 t->current_ds = ASI_P;
 628                 t->kregs->u_regs[UREG_G1] = sp; /* function */
 629                 t->kregs->u_regs[UREG_G2] = arg;
 630                 return 0;
 631         }
 632
 633         parent_sf = ((struct sparc_stackf *) regs) - 1;
 634         memcpy(child_trap_frame, parent_sf, child_stack_sz);
 635         if (t->flags & _TIF_32BIT) {
 636                 sp &= 0x00000000ffffffffUL;
 637                 regs->u_regs[UREG_FP] &= 0x00000000ffffffffUL;
 638         }
 639         t->kregs->u_regs[UREG_FP] = sp;
 640         __thread_flag_byte_ptr(t)[TI_FLAG_BYTE_CWP] =
 641                 (regs->tstate + 1) & TSTATE_CWP;
 642         t->current_ds = ASI_AIUS;
 643         if (sp != regs->u_regs[UREG_FP]) {
 644                 unsigned long csp;
 645
 646                 csp = clone_stackframe(sp, regs->u_regs[UREG_FP]);
 647                 if (!csp)
 648                         return -EFAULT;
 649                 t->kregs->u_regs[UREG_FP] = csp;
 650         }
 651         if (t->utraps)
 652                 t->utraps[0]++;
 653
 654         /* Set the return value for the child. */
 655         t->kregs->u_regs[UREG_I0] = current->pid;
 656         t->kregs->u_regs[UREG_I1] = 1;
 657
 658         /* Set the second return value for the parent. */
 659         regs->u_regs[UREG_I1] = 0;
 660
 661         if (clone_flags & CLONE_SETTLS)
 662                 t->kregs->u_regs[UREG_G7] = regs->u_regs[UREG_I3];
 663
 664         return 0;
 665 }
 666
 667 typedef struct {
 668         union {
 669                 unsigned int    pr_regs[32];
 670                 unsigned long   pr_dregs[16];
 671         } pr_fr;
 672         unsigned int __unused;
 673         unsigned int    pr_fsr;
 674         unsigned char   pr_qcnt;
 675         unsigned char   pr_q_entrysize;
 676         unsigned char   pr_en;
 677         unsigned int    pr_q[64];
 678 } elf_fpregset_t32;
 679
 680 /*
 681  * fill in the fpu structure for a core dump.
 682  */
 683 int dump_fpu (struct pt_regs * regs, elf_fpregset_t * fpregs)
 684 {
 685         unsigned long *kfpregs = current_thread_info()->fpregs;
 686         unsigned long fprs = current_thread_info()->fpsaved[0];
 687
 688         if (test_thread_flag(TIF_32BIT)) {
 689                 elf_fpregset_t32 *fpregs32 = (elf_fpregset_t32 *)fpregs;
 690
 691                 if (fprs & FPRS_DL)
 692                         memcpy(&fpregs32->pr_fr.pr_regs[0], kfpregs,
 693                                sizeof(unsigned int) * 32);
 694                 else
 695                         memset(&fpregs32->pr_fr.pr_regs[0], 0,
 696                                sizeof(unsigned int) * 32);
 697                 fpregs32->pr_qcnt = 0;
 698                 fpregs32->pr_q_entrysize = 8;
 699                 memset(&fpregs32->pr_q[0], 0,
 700                        (sizeof(unsigned int) * 64));
 701                 if (fprs & FPRS_FEF) {
 702                         fpregs32->pr_fsr = (unsigned int) current_thread_info()->xfsr[0];
 703                         fpregs32->pr_en = 1;
 704                 } else {
 705                         fpregs32->pr_fsr = 0;
 706                         fpregs32->pr_en = 0;
 707                 }
 708         } else {
 709                 if(fprs & FPRS_DL)
 710                         memcpy(&fpregs->pr_regs[0], kfpregs,
 711                                sizeof(unsigned int) * 32);
 712                 else
 713                         memset(&fpregs->pr_regs[0], 0,
 714                                sizeof(unsigned int) * 32);
 715                 if(fprs & FPRS_DU)
 716                         memcpy(&fpregs->pr_regs[16], kfpregs+16,
 717                                sizeof(unsigned int) * 32);
 718                 else
 719                         memset(&fpregs->pr_regs[16], 0,
 720                                sizeof(unsigned int) * 32);
 721                 if(fprs & FPRS_FEF) {
 722                         fpregs->pr_fsr = current_thread_info()->xfsr[0];
 723                         fpregs->pr_gsr = current_thread_info()->gsr[0];
 724                 } else {
 725                         fpregs->pr_fsr = fpregs->pr_gsr = 0;
 726                 }
 727                 fpregs->pr_fprs = fprs;
 728         }
 729         return 1;
 730 }
 731 EXPORT_SYMBOL(dump_fpu);
 732
 733 unsigned long get_wchan(struct task_struct *task)
 734 {
 735         unsigned long pc, fp, bias = 0;
 736         struct thread_info *tp;
 737         struct reg_window *rw;
 738         unsigned long ret = 0;
 739         int count = 0;
 740
 741         if (!task || task == current ||
 742             task->state == TASK_RUNNING)
 743                 goto out;
 744
 745         tp = task_thread_info(task);
 746         bias = STACK_BIAS;
 747         fp = task_thread_info(task)->ksp + bias;
 748
 749         do {
 750                 if (!kstack_valid(tp, fp))
 751                         break;
 752                 rw = (struct reg_window *) fp;
 753                 pc = rw->ins[7];
 754                 if (!in_sched_functions(pc)) {
 755                         ret = pc;
 756                         goto out;
 757                 }
 758                 fp = rw->ins[6] + bias;
 759         } while (++count < 16);
 760
 761 out:
 762         return ret;
 763 }