arch/sparc/kernel/process_64.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*  arch/sparc64/kernel/process.c
   3  *
   4  *  Copyright (C) 1995, 1996, 2008 David S. Miller (davem@davemloft.net)
   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/export.h>
  17 #include <linux/sched.h>
  18 #include <linux/sched/debug.h>
  19 #include <linux/sched/task.h>
  20 #include <linux/sched/task_stack.h>
  21 #include <linux/kernel.h>
  22 #include <linux/mm.h>
  23 #include <linux/fs.h>
  24 #include <linux/smp.h>
  25 #include <linux/stddef.h>
  26 #include <linux/ptrace.h>
  27 #include <linux/slab.h>
  28 #include <linux/user.h>
  29 #include <linux/delay.h>
  30 #include <linux/compat.h>
  31 #include <linux/tick.h>
  32 #include <linux/init.h>
  33 #include <linux/cpu.h>
  34 #include <linux/perf_event.h>
  35 #include <linux/elfcore.h>
  36 #include <linux/sysrq.h>
  37 #include <linux/nmi.h>
  38 #include <linux/context_tracking.h>
  39 #include <linux/signal.h>
  40
  41 #include <linux/uaccess.h>
  42 #include <asm/page.h>
  43 #include <asm/pgalloc.h>
  44 #include <asm/pgtable.h>
  45 #include <asm/processor.h>
  46 #include <asm/pstate.h>
  47 #include <asm/elf.h>
  48 #include <asm/fpumacro.h>
  49 #include <asm/head.h>
  50 #include <asm/cpudata.h>
  51 #include <asm/mmu_context.h>
  52 #include <asm/unistd.h>
  53 #include <asm/hypervisor.h>
  54 #include <asm/syscalls.h>
  55 #include <asm/irq_regs.h>
  56 #include <asm/smp.h>
  57 #include <asm/pcr.h>
  58
  59 #include "kstack.h"
  60
  61 /* Idle loop support on sparc64. */
  62 void arch_cpu_idle(void)
  63 {
  64         if (tlb_type != hypervisor) {
  65                 touch_nmi_watchdog();
  66                 local_irq_enable();
  67         } else {
  68                 unsigned long pstate;
  69
  70                 local_irq_enable();
  71
  72                 /* The sun4v sleeping code requires that we have PSTATE.IE cleared over
  73                  * the cpu sleep hypervisor call.
  74                  */
  75                 __asm__ __volatile__(
  76                         "rdpr %%pstate, %0\n\t"
  77                         "andn %0, %1, %0\n\t"
  78                         "wrpr %0, %%g0, %%pstate"
  79                         : "=&r" (pstate)
  80                         : "i" (PSTATE_IE));
  81
  82                 if (!need_resched() && !cpu_is_offline(smp_processor_id())) {
  83                         sun4v_cpu_yield();
  84                         /* If resumed by cpu_poke then we need to explicitly
  85                          * call scheduler_ipi().
  86                          */
  87                         scheduler_poke();
  88                 }
  89
  90                 /* Re-enable interrupts. */
  91                 __asm__ __volatile__(
  92                         "rdpr %%pstate, %0\n\t"
  93                         "or %0, %1, %0\n\t"
  94                         "wrpr %0, %%g0, %%pstate"
  95                         : "=&r" (pstate)
  96                         : "i" (PSTATE_IE));
  97         }
  98 }
  99
 100 #ifdef CONFIG_HOTPLUG_CPU
 101 void arch_cpu_idle_dead(void)
 102 {
 103         sched_preempt_enable_no_resched();
 104         cpu_play_dead();
 105 }
 106 #endif
 107
 108 #ifdef CONFIG_COMPAT
 109 static void show_regwindow32(struct pt_regs *regs)
 110 {
 111         struct reg_window32 __user *rw;
 112         struct reg_window32 r_w;
 113         mm_segment_t old_fs;
 114
 115         __asm__ __volatile__ ("flushw");
 116         rw = compat_ptr((unsigned int)regs->u_regs[14]);
 117         old_fs = get_fs();
 118         set_fs (USER_DS);
 119         if (copy_from_user (&r_w, rw, sizeof(r_w))) {
 120                 set_fs (old_fs);
 121                 return;
 122         }
 123
 124         set_fs (old_fs);
 125         printk("l0: %08x l1: %08x l2: %08x l3: %08x "
 126                "l4: %08x l5: %08x l6: %08x l7: %08x\n",
 127                r_w.locals[0], r_w.locals[1], r_w.locals[2], r_w.locals[3],
 128                r_w.locals[4], r_w.locals[5], r_w.locals[6], r_w.locals[7]);
 129         printk("i0: %08x i1: %08x i2: %08x i3: %08x "
 130                "i4: %08x i5: %08x i6: %08x i7: %08x\n",
 131                r_w.ins[0], r_w.ins[1], r_w.ins[2], r_w.ins[3],
 132                r_w.ins[4], r_w.ins[5], r_w.ins[6], r_w.ins[7]);
 133 }
 134 #else
 135 #define show_regwindow32(regs)  do { } while (0)
 136 #endif
 137
 138 static void show_regwindow(struct pt_regs *regs)
 139 {
 140         struct reg_window __user *rw;
 141         struct reg_window *rwk;
 142         struct reg_window r_w;
 143         mm_segment_t old_fs;
 144
 145         if ((regs->tstate & TSTATE_PRIV) || !(test_thread_flag(TIF_32BIT))) {
 146                 __asm__ __volatile__ ("flushw");
 147                 rw = (struct reg_window __user *)
 148                         (regs->u_regs[14] + STACK_BIAS);
 149                 rwk = (struct reg_window *)
 150                         (regs->u_regs[14] + STACK_BIAS);
 151                 if (!(regs->tstate & TSTATE_PRIV)) {
 152                         old_fs = get_fs();
 153                         set_fs (USER_DS);
 154                         if (copy_from_user (&r_w, rw, sizeof(r_w))) {
 155                                 set_fs (old_fs);
 156                                 return;
 157                         }
 158                         rwk = &r_w;
 159                         set_fs (old_fs);
 160                 }
 161         } else {
 162                 show_regwindow32(regs);
 163                 return;
 164         }
 165         printk("l0: %016lx l1: %016lx l2: %016lx l3: %016lx\n",
 166                rwk->locals[0], rwk->locals[1], rwk->locals[2], rwk->locals[3]);
 167         printk("l4: %016lx l5: %016lx l6: %016lx l7: %016lx\n",
 168                rwk->locals[4], rwk->locals[5], rwk->locals[6], rwk->locals[7]);
 169         printk("i0: %016lx i1: %016lx i2: %016lx i3: %016lx\n",
 170                rwk->ins[0], rwk->ins[1], rwk->ins[2], rwk->ins[3]);
 171         printk("i4: %016lx i5: %016lx i6: %016lx i7: %016lx\n",
 172                rwk->ins[4], rwk->ins[5], rwk->ins[6], rwk->ins[7]);
 173         if (regs->tstate & TSTATE_PRIV)
 174                 printk("I7: <%pS>\n", (void *) rwk->ins[7]);
 175 }
 176
 177 void show_regs(struct pt_regs *regs)
 178 {
 179         show_regs_print_info(KERN_DEFAULT);
 180
 181         printk("TSTATE: %016lx TPC: %016lx TNPC: %016lx Y: %08x    %s\n", regs->tstate,
 182                regs->tpc, regs->tnpc, regs->y, print_tainted());
 183         printk("TPC: <%pS>\n", (void *) regs->tpc);
 184         printk("g0: %016lx g1: %016lx g2: %016lx g3: %016lx\n",
 185                regs->u_regs[0], regs->u_regs[1], regs->u_regs[2],
 186                regs->u_regs[3]);
 187         printk("g4: %016lx g5: %016lx g6: %016lx g7: %016lx\n",
 188                regs->u_regs[4], regs->u_regs[5], regs->u_regs[6],
 189                regs->u_regs[7]);
 190         printk("o0: %016lx o1: %016lx o2: %016lx o3: %016lx\n",
 191                regs->u_regs[8], regs->u_regs[9], regs->u_regs[10],
 192                regs->u_regs[11]);
 193         printk("o4: %016lx o5: %016lx sp: %016lx ret_pc: %016lx\n",
 194                regs->u_regs[12], regs->u_regs[13], regs->u_regs[14],
 195                regs->u_regs[15]);
 196         printk("RPC: <%pS>\n", (void *) regs->u_regs[15]);
 197         show_regwindow(regs);
 198         show_stack(current, (unsigned long *) regs->u_regs[UREG_FP]);
 199 }
 200
 201 union global_cpu_snapshot global_cpu_snapshot[NR_CPUS];
 202 static DEFINE_SPINLOCK(global_cpu_snapshot_lock);
 203
 204 static void __global_reg_self(struct thread_info *tp, struct pt_regs *regs,
 205                               int this_cpu)
 206 {
 207         struct global_reg_snapshot *rp;
 208
 209         flushw_all();
 210
 211         rp = &global_cpu_snapshot[this_cpu].reg;
 212
 213         rp->tstate = regs->tstate;
 214         rp->tpc = regs->tpc;
 215         rp->tnpc = regs->tnpc;
 216         rp->o7 = regs->u_regs[UREG_I7];
 217
 218         if (regs->tstate & TSTATE_PRIV) {
 219                 struct reg_window *rw;
 220
 221                 rw = (struct reg_window *)
 222                         (regs->u_regs[UREG_FP] + STACK_BIAS);
 223                 if (kstack_valid(tp, (unsigned long) rw)) {
 224                         rp->i7 = rw->ins[7];
 225                         rw = (struct reg_window *)
 226                                 (rw->ins[6] + STACK_BIAS);
 227                         if (kstack_valid(tp, (unsigned long) rw))
 228                                 rp->rpc = rw->ins[7];
 229                 }
 230         } else {
 231                 rp->i7 = 0;
 232                 rp->rpc = 0;
 233         }
 234         rp->thread = tp;
 235 }
 236
 237 /* In order to avoid hangs we do not try to synchronize with the
 238  * global register dump client cpus.  The last store they make is to
 239  * the thread pointer, so do a short poll waiting for that to become
 240  * non-NULL.
 241  */
 242 static void __global_reg_poll(struct global_reg_snapshot *gp)
 243 {
 244         int limit = 0;
 245
 246         while (!gp->thread && ++limit < 100) {
 247                 barrier();
 248                 udelay(1);
 249         }
 250 }
 251
 252 void arch_trigger_cpumask_backtrace(const cpumask_t *mask, bool exclude_self)
 253 {
 254         struct thread_info *tp = current_thread_info();
 255         struct pt_regs *regs = get_irq_regs();
 256         unsigned long flags;
 257         int this_cpu, cpu;
 258
 259         if (!regs)
 260                 regs = tp->kregs;
 261
 262         spin_lock_irqsave(&global_cpu_snapshot_lock, flags);
 263
 264         this_cpu = raw_smp_processor_id();
 265
 266         memset(global_cpu_snapshot, 0, sizeof(global_cpu_snapshot));
 267
 268         if (cpumask_test_cpu(this_cpu, mask) && !exclude_self)
 269                 __global_reg_self(tp, regs, this_cpu);
 270
 271         smp_fetch_global_regs();
 272
 273         for_each_cpu(cpu, mask) {
 274                 struct global_reg_snapshot *gp;
 275
 276                 if (exclude_self && cpu == this_cpu)
 277                         continue;
 278
 279                 gp = &global_cpu_snapshot[cpu].reg;
 280
 281                 __global_reg_poll(gp);
 282
 283                 tp = gp->thread;
 284                 printk("%c CPU[%3d]: TSTATE[%016lx] TPC[%016lx] TNPC[%016lx] TASK[%s:%d]\n",
 285                        (cpu == this_cpu ? '*' : ' '), cpu,
 286                        gp->tstate, gp->tpc, gp->tnpc,
 287                        ((tp && tp->task) ? tp->task->comm : "NULL"),
 288                        ((tp && tp->task) ? tp->task->pid : -1));
 289
 290                 if (gp->tstate & TSTATE_PRIV) {
 291                         printk("             TPC[%pS] O7[%pS] I7[%pS] RPC[%pS]\n",
 292                                (void *) gp->tpc,
 293                                (void *) gp->o7,
 294                                (void *) gp->i7,
 295                                (void *) gp->rpc);
 296                 } else {
 297                         printk("             TPC[%lx] O7[%lx] I7[%lx] RPC[%lx]\n",
 298                                gp->tpc, gp->o7, gp->i7, gp->rpc);
 299                 }
 300
 301                 touch_nmi_watchdog();
 302         }
 303
 304         memset(global_cpu_snapshot, 0, sizeof(global_cpu_snapshot));
 305
 306         spin_unlock_irqrestore(&global_cpu_snapshot_lock, flags);
 307 }
 308
 309 #ifdef CONFIG_MAGIC_SYSRQ
 310
 311 static void sysrq_handle_globreg(int key)
 312 {
 313         trigger_all_cpu_backtrace();
 314 }
 315
 316 static struct sysrq_key_op sparc_globalreg_op = {
 317         .handler        = sysrq_handle_globreg,
 318         .help_msg       = "global-regs(y)",
 319         .action_msg     = "Show Global CPU Regs",
 320 };
 321
 322 static void __global_pmu_self(int this_cpu)
 323 {
 324         struct global_pmu_snapshot *pp;
 325         int i, num;
 326
 327         if (!pcr_ops)
 328                 return;
 329
 330         pp = &global_cpu_snapshot[this_cpu].pmu;
 331
 332         num = 1;
 333         if (tlb_type == hypervisor &&
 334             sun4v_chip_type >= SUN4V_CHIP_NIAGARA4)
 335                 num = 4;
 336
 337         for (i = 0; i < num; i++) {
 338                 pp->pcr[i] = pcr_ops->read_pcr(i);
 339                 pp->pic[i] = pcr_ops->read_pic(i);
 340         }
 341 }
 342
 343 static void __global_pmu_poll(struct global_pmu_snapshot *pp)
 344 {
 345         int limit = 0;
 346
 347         while (!pp->pcr[0] && ++limit < 100) {
 348                 barrier();
 349                 udelay(1);
 350         }
 351 }
 352
 353 static void pmu_snapshot_all_cpus(void)
 354 {
 355         unsigned long flags;
 356         int this_cpu, cpu;
 357
 358         spin_lock_irqsave(&global_cpu_snapshot_lock, flags);
 359
 360         memset(global_cpu_snapshot, 0, sizeof(global_cpu_snapshot));
 361
 362         this_cpu = raw_smp_processor_id();
 363
 364         __global_pmu_self(this_cpu);
 365
 366         smp_fetch_global_pmu();
 367
 368         for_each_online_cpu(cpu) {
 369                 struct global_pmu_snapshot *pp = &global_cpu_snapshot[cpu].pmu;
 370
 371                 __global_pmu_poll(pp);
 372
 373                 printk("%c CPU[%3d]: PCR[%08lx:%08lx:%08lx:%08lx] PIC[%08lx:%08lx:%08lx:%08lx]\n",
 374                        (cpu == this_cpu ? '*' : ' '), cpu,
 375                        pp->pcr[0], pp->pcr[1], pp->pcr[2], pp->pcr[3],
 376                        pp->pic[0], pp->pic[1], pp->pic[2], pp->pic[3]);
 377
 378                 touch_nmi_watchdog();
 379         }
 380
 381         memset(global_cpu_snapshot, 0, sizeof(global_cpu_snapshot));
 382
 383         spin_unlock_irqrestore(&global_cpu_snapshot_lock, flags);
 384 }
 385
 386 static void sysrq_handle_globpmu(int key)
 387 {
 388         pmu_snapshot_all_cpus();
 389 }
 390
 391 static struct sysrq_key_op sparc_globalpmu_op = {
 392         .handler        = sysrq_handle_globpmu,
 393         .help_msg       = "global-pmu(x)",
 394         .action_msg     = "Show Global PMU Regs",
 395 };
 396
 397 static int __init sparc_sysrq_init(void)
 398 {
 399         int ret = register_sysrq_key('y', &sparc_globalreg_op);
 400
 401         if (!ret)
 402                 ret = register_sysrq_key('x', &sparc_globalpmu_op);
 403         return ret;
 404 }
 405
 406 core_initcall(sparc_sysrq_init);
 407
 408 #endif
 409
 410 /* Free current thread data structures etc.. */
 411 void exit_thread(struct task_struct *tsk)
 412 {
 413         struct thread_info *t = task_thread_info(tsk);
 414
 415         if (t->utraps) {
 416                 if (t->utraps[0] < 2)
 417                         kfree (t->utraps);
 418                 else
 419                         t->utraps[0]--;
 420         }
 421 }
 422
 423 void flush_thread(void)
 424 {
 425         struct thread_info *t = current_thread_info();
 426         struct mm_struct *mm;
 427
 428         mm = t->task->mm;
 429         if (mm)
 430                 tsb_context_switch(mm);
 431
 432         set_thread_wsaved(0);
 433
 434         /* Clear FPU register state. */
 435         t->fpsaved[0] = 0;
 436 }
 437
 438 /* It's a bit more tricky when 64-bit tasks are involved... */
 439 static unsigned long clone_stackframe(unsigned long csp, unsigned long psp)
 440 {
 441         bool stack_64bit = test_thread_64bit_stack(psp);
 442         unsigned long fp, distance, rval;
 443
 444         if (stack_64bit) {
 445                 csp += STACK_BIAS;
 446                 psp += STACK_BIAS;
 447                 __get_user(fp, &(((struct reg_window __user *)psp)->ins[6]));
 448                 fp += STACK_BIAS;
 449                 if (test_thread_flag(TIF_32BIT))
 450                         fp &= 0xffffffff;
 451         } else
 452                 __get_user(fp, &(((struct reg_window32 __user *)psp)->ins[6]));
 453
 454         /* Now align the stack as this is mandatory in the Sparc ABI
 455          * due to how register windows work.  This hides the
 456          * restriction from thread libraries etc.
 457          */
 458         csp &= ~15UL;
 459
 460         distance = fp - psp;
 461         rval = (csp - distance);
 462         if (copy_in_user((void __user *) rval, (void __user *) psp, distance))
 463                 rval = 0;
 464         else if (!stack_64bit) {
 465                 if (put_user(((u32)csp),
 466                              &(((struct reg_window32 __user *)rval)->ins[6])))
 467                         rval = 0;
 468         } else {
 469                 if (put_user(((u64)csp - STACK_BIAS),
 470                              &(((struct reg_window __user *)rval)->ins[6])))
 471                         rval = 0;
 472                 else
 473                         rval = rval - STACK_BIAS;
 474         }
 475
 476         return rval;
 477 }
 478
 479 /* Standard stuff. */
 480 static inline void shift_window_buffer(int first_win, int last_win,
 481                                        struct thread_info *t)
 482 {
 483         int i;
 484
 485         for (i = first_win; i < last_win; i++) {
 486                 t->rwbuf_stkptrs[i] = t->rwbuf_stkptrs[i+1];
 487                 memcpy(&t->reg_window[i], &t->reg_window[i+1],
 488                        sizeof(struct reg_window));
 489         }
 490 }
 491
 492 void synchronize_user_stack(void)
 493 {
 494         struct thread_info *t = current_thread_info();
 495         unsigned long window;
 496
 497         flush_user_windows();
 498         if ((window = get_thread_wsaved()) != 0) {
 499                 window -= 1;
 500                 do {
 501                         struct reg_window *rwin = &t->reg_window[window];
 502                         int winsize = sizeof(struct reg_window);
 503                         unsigned long sp;
 504
 505                         sp = t->rwbuf_stkptrs[window];
 506
 507                         if (test_thread_64bit_stack(sp))
 508                                 sp += STACK_BIAS;
 509                         else
 510                                 winsize = sizeof(struct reg_window32);
 511
 512                         if (!copy_to_user((char __user *)sp, rwin, winsize)) {
 513                                 shift_window_buffer(window, get_thread_wsaved() - 1, t);
 514                                 set_thread_wsaved(get_thread_wsaved() - 1);
 515                         }
 516                 } while (window--);
 517         }
 518 }
 519
 520 static void stack_unaligned(unsigned long sp)
 521 {
 522         siginfo_t info;
 523
 524         info.si_signo = SIGBUS;
 525         info.si_errno = 0;
 526         info.si_code = BUS_ADRALN;
 527         info.si_addr = (void __user *) sp;
 528         info.si_trapno = 0;
 529         force_sig_info(SIGBUS, &info, current);
 530 }
 531
 532 static const char uwfault32[] = KERN_INFO \
 533         "%s[%d]: bad register window fault: SP %08lx (orig_sp %08lx) TPC %08lx O7 %08lx\n";
 534 static const char uwfault64[] = KERN_INFO \
 535         "%s[%d]: bad register window fault: SP %016lx (orig_sp %016lx) TPC %08lx O7 %016lx\n";
 536
 537 void fault_in_user_windows(struct pt_regs *regs)
 538 {
 539         struct thread_info *t = current_thread_info();
 540         unsigned long window;
 541
 542         flush_user_windows();
 543         window = get_thread_wsaved();
 544
 545         if (likely(window != 0)) {
 546                 window -= 1;
 547                 do {
 548                         struct reg_window *rwin = &t->reg_window[window];
 549                         int winsize = sizeof(struct reg_window);
 550                         unsigned long sp, orig_sp;
 551
 552                         orig_sp = sp = t->rwbuf_stkptrs[window];
 553
 554                         if (test_thread_64bit_stack(sp))
 555                                 sp += STACK_BIAS;
 556                         else
 557                                 winsize = sizeof(struct reg_window32);
 558
 559                         if (unlikely(sp & 0x7UL))
 560                                 stack_unaligned(sp);
 561
 562                         if (unlikely(copy_to_user((char __user *)sp,
 563                                                   rwin, winsize))) {
 564                                 if (show_unhandled_signals)
 565                                         printk_ratelimited(is_compat_task() ?
 566                                                            uwfault32 : uwfault64,
 567                                                            current->comm, current->pid,
 568                                                            sp, orig_sp,
 569                                                            regs->tpc,
 570                                                            regs->u_regs[UREG_I7]);
 571                                 goto barf;
 572                         }
 573                 } while (window--);
 574         }
 575         set_thread_wsaved(0);
 576         return;
 577
 578 barf:
 579         set_thread_wsaved(window + 1);
 580         force_sig(SIGSEGV, current);
 581 }
 582
 583 asmlinkage long sparc_do_fork(unsigned long clone_flags,
 584                               unsigned long stack_start,
 585                               struct pt_regs *regs,
 586                               unsigned long stack_size)
 587 {
 588         int __user *parent_tid_ptr, *child_tid_ptr;
 589         unsigned long orig_i1 = regs->u_regs[UREG_I1];
 590         long ret;
 591
 592 #ifdef CONFIG_COMPAT
 593         if (test_thread_flag(TIF_32BIT)) {
 594                 parent_tid_ptr = compat_ptr(regs->u_regs[UREG_I2]);
 595                 child_tid_ptr = compat_ptr(regs->u_regs[UREG_I4]);
 596         } else
 597 #endif
 598         {
 599                 parent_tid_ptr = (int __user *) regs->u_regs[UREG_I2];
 600                 child_tid_ptr = (int __user *) regs->u_regs[UREG_I4];
 601         }
 602
 603         ret = do_fork(clone_flags, stack_start, stack_size,
 604                       parent_tid_ptr, child_tid_ptr);
 605
 606         /* If we get an error and potentially restart the system
 607          * call, we're screwed because copy_thread() clobbered
 608          * the parent's %o1.  So detect that case and restore it
 609          * here.
 610          */
 611         if ((unsigned long)ret >= -ERESTART_RESTARTBLOCK)
 612                 regs->u_regs[UREG_I1] = orig_i1;
 613
 614         return ret;
 615 }
 616
 617 /* Copy a Sparc thread.  The fork() return value conventions
 618  * under SunOS are nothing short of bletcherous:
 619  * Parent -->  %o0 == childs  pid, %o1 == 0
 620  * Child  -->  %o0 == parents pid, %o1 == 1
 621  */
 622 int copy_thread(unsigned long clone_flags, unsigned long sp,
 623                 unsigned long arg, struct task_struct *p)
 624 {
 625         struct thread_info *t = task_thread_info(p);
 626         struct pt_regs *regs = current_pt_regs();
 627         struct sparc_stackf *parent_sf;
 628         unsigned long child_stack_sz;
 629         char *child_trap_frame;
 630
 631         /* Calculate offset to stack_frame & pt_regs */
 632         child_stack_sz = (STACKFRAME_SZ + TRACEREG_SZ);
 633         child_trap_frame = (task_stack_page(p) +
 634                             (THREAD_SIZE - child_stack_sz));
 635
 636         t->new_child = 1;
 637         t->ksp = ((unsigned long) child_trap_frame) - STACK_BIAS;
 638         t->kregs = (struct pt_regs *) (child_trap_frame +
 639                                        sizeof(struct sparc_stackf));
 640         t->fpsaved[0] = 0;
 641
 642         if (unlikely(p->flags & PF_KTHREAD)) {
 643                 memset(child_trap_frame, 0, child_stack_sz);
 644                 __thread_flag_byte_ptr(t)[TI_FLAG_BYTE_CWP] =
 645                         (current_pt_regs()->tstate + 1) & TSTATE_CWP;
 646                 t->current_ds = ASI_P;
 647                 t->kregs->u_regs[UREG_G1] = sp; /* function */
 648                 t->kregs->u_regs[UREG_G2] = arg;
 649                 return 0;
 650         }
 651
 652         parent_sf = ((struct sparc_stackf *) regs) - 1;
 653         memcpy(child_trap_frame, parent_sf, child_stack_sz);
 654         if (t->flags & _TIF_32BIT) {
 655                 sp &= 0x00000000ffffffffUL;
 656                 regs->u_regs[UREG_FP] &= 0x00000000ffffffffUL;
 657         }
 658         t->kregs->u_regs[UREG_FP] = sp;
 659         __thread_flag_byte_ptr(t)[TI_FLAG_BYTE_CWP] =
 660                 (regs->tstate + 1) & TSTATE_CWP;
 661         t->current_ds = ASI_AIUS;
 662         if (sp != regs->u_regs[UREG_FP]) {
 663                 unsigned long csp;
 664
 665                 csp = clone_stackframe(sp, regs->u_regs[UREG_FP]);
 666                 if (!csp)
 667                         return -EFAULT;
 668                 t->kregs->u_regs[UREG_FP] = csp;
 669         }
 670         if (t->utraps)
 671                 t->utraps[0]++;
 672
 673         /* Set the return value for the child. */
 674         t->kregs->u_regs[UREG_I0] = current->pid;
 675         t->kregs->u_regs[UREG_I1] = 1;
 676
 677         /* Set the second return value for the parent. */
 678         regs->u_regs[UREG_I1] = 0;
 679
 680         if (clone_flags & CLONE_SETTLS)
 681                 t->kregs->u_regs[UREG_G7] = regs->u_regs[UREG_I3];
 682
 683         return 0;
 684 }
 685
 686 typedef struct {
 687         union {
 688                 unsigned int    pr_regs[32];
 689                 unsigned long   pr_dregs[16];
 690         } pr_fr;
 691         unsigned int __unused;
 692         unsigned int    pr_fsr;
 693         unsigned char   pr_qcnt;
 694         unsigned char   pr_q_entrysize;
 695         unsigned char   pr_en;
 696         unsigned int    pr_q[64];
 697 } elf_fpregset_t32;
 698
 699 /*
 700  * fill in the fpu structure for a core dump.
 701  */
 702 int dump_fpu (struct pt_regs * regs, elf_fpregset_t * fpregs)
 703 {
 704         unsigned long *kfpregs = current_thread_info()->fpregs;
 705         unsigned long fprs = current_thread_info()->fpsaved[0];
 706
 707         if (test_thread_flag(TIF_32BIT)) {
 708                 elf_fpregset_t32 *fpregs32 = (elf_fpregset_t32 *)fpregs;
 709
 710                 if (fprs & FPRS_DL)
 711                         memcpy(&fpregs32->pr_fr.pr_regs[0], kfpregs,
 712                                sizeof(unsigned int) * 32);
 713                 else
 714                         memset(&fpregs32->pr_fr.pr_regs[0], 0,
 715                                sizeof(unsigned int) * 32);
 716                 fpregs32->pr_qcnt = 0;
 717                 fpregs32->pr_q_entrysize = 8;
 718                 memset(&fpregs32->pr_q[0], 0,
 719                        (sizeof(unsigned int) * 64));
 720                 if (fprs & FPRS_FEF) {
 721                         fpregs32->pr_fsr = (unsigned int) current_thread_info()->xfsr[0];
 722                         fpregs32->pr_en = 1;
 723                 } else {
 724                         fpregs32->pr_fsr = 0;
 725                         fpregs32->pr_en = 0;
 726                 }
 727         } else {
 728                 if(fprs & FPRS_DL)
 729                         memcpy(&fpregs->pr_regs[0], kfpregs,
 730                                sizeof(unsigned int) * 32);
 731                 else
 732                         memset(&fpregs->pr_regs[0], 0,
 733                                sizeof(unsigned int) * 32);
 734                 if(fprs & FPRS_DU)
 735                         memcpy(&fpregs->pr_regs[16], kfpregs+16,
 736                                sizeof(unsigned int) * 32);
 737                 else
 738                         memset(&fpregs->pr_regs[16], 0,
 739                                sizeof(unsigned int) * 32);
 740                 if(fprs & FPRS_FEF) {
 741                         fpregs->pr_fsr = current_thread_info()->xfsr[0];
 742                         fpregs->pr_gsr = current_thread_info()->gsr[0];
 743                 } else {
 744                         fpregs->pr_fsr = fpregs->pr_gsr = 0;
 745                 }
 746                 fpregs->pr_fprs = fprs;
 747         }
 748         return 1;
 749 }
 750 EXPORT_SYMBOL(dump_fpu);
 751
 752 unsigned long get_wchan(struct task_struct *task)
 753 {
 754         unsigned long pc, fp, bias = 0;
 755         struct thread_info *tp;
 756         struct reg_window *rw;
 757         unsigned long ret = 0;
 758         int count = 0;
 759
 760         if (!task || task == current ||
 761             task->state == TASK_RUNNING)
 762                 goto out;
 763
 764         tp = task_thread_info(task);
 765         bias = STACK_BIAS;
 766         fp = task_thread_info(task)->ksp + bias;
 767
 768         do {
 769                 if (!kstack_valid(tp, fp))
 770                         break;
 771                 rw = (struct reg_window *) fp;
 772                 pc = rw->ins[7];
 773                 if (!in_sched_functions(pc)) {
 774                         ret = pc;
 775                         goto out;
 776                 }
 777                 fp = rw->ins[6] + bias;
 778         } while (++count < 16);
 779
 780 out:
 781         return ret;
 782 }