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/module.h> 16 #include <linux/sched.h> 17 #include <linux/kernel.h> 18 #include <linux/mm.h> 19 #include <linux/fs.h> 20 #include <linux/smp.h> 21 #include <linux/stddef.h> 22 #include <linux/ptrace.h> 23 #include <linux/slab.h> 24 #include <linux/user.h> 25 #include <linux/delay.h> 26 #include <linux/compat.h> 27 #include <linux/tick.h> 28 #include <linux/init.h> 29 #include <linux/cpu.h> 30 #include <linux/elfcore.h> 31 #include <linux/sysrq.h> 32 33 #include <asm/uaccess.h> 34 #include <asm/system.h> 35 #include <asm/page.h> 36 #include <asm/pgalloc.h> 37 #include <asm/pgtable.h> 38 #include <asm/processor.h> 39 #include <asm/pstate.h> 40 #include <asm/elf.h> 41 #include <asm/fpumacro.h> 42 #include <asm/head.h> 43 #include <asm/cpudata.h> 44 #include <asm/mmu_context.h> 45 #include <asm/unistd.h> 46 #include <asm/hypervisor.h> 47 #include <asm/syscalls.h> 48 #include <asm/irq_regs.h> 49 #include <asm/smp.h> 50 51 #include "kstack.h" 52 53 static void sparc64_yield(int cpu) 54 { 55 if (tlb_type != hypervisor) 56 return; 57 58 clear_thread_flag(TIF_POLLING_NRFLAG); 59 smp_mb__after_clear_bit(); 60 61 while (!need_resched() && !cpu_is_offline(cpu)) { 62 unsigned long pstate; 63 64 /* Disable interrupts. */ 65 __asm__ __volatile__( 66 "rdpr %%pstate, %0\n\t" 67 "andn %0, %1, %0\n\t" 68 "wrpr %0, %%g0, %%pstate" 69 : "=&r" (pstate) 70 : "i" (PSTATE_IE)); 71 72 if (!need_resched() && !cpu_is_offline(cpu)) 73 sun4v_cpu_yield(); 74 75 /* Re-enable interrupts. */ 76 __asm__ __volatile__( 77 "rdpr %%pstate, %0\n\t" 78 "or %0, %1, %0\n\t" 79 "wrpr %0, %%g0, %%pstate" 80 : "=&r" (pstate) 81 : "i" (PSTATE_IE)); 82 } 83 84 set_thread_flag(TIF_POLLING_NRFLAG); 85 } 86 87 /* The idle loop on sparc64. */ 88 void cpu_idle(void) 89 { 90 int cpu = smp_processor_id(); 91 92 set_thread_flag(TIF_POLLING_NRFLAG); 93 94 while(1) { 95 tick_nohz_stop_sched_tick(1); 96 97 while (!need_resched() && !cpu_is_offline(cpu)) 98 sparc64_yield(cpu); 99 100 tick_nohz_restart_sched_tick(); 101 102 preempt_enable_no_resched(); 103 104 #ifdef CONFIG_HOTPLUG_CPU 105 if (cpu_is_offline(cpu)) 106 cpu_play_dead(); 107 #endif 108 109 schedule(); 110 preempt_disable(); 111 } 112 } 113 114 #ifdef CONFIG_COMPAT 115 static void show_regwindow32(struct pt_regs *regs) 116 { 117 struct reg_window32 __user *rw; 118 struct reg_window32 r_w; 119 mm_segment_t old_fs; 120 121 __asm__ __volatile__ ("flushw"); 122 rw = compat_ptr((unsigned)regs->u_regs[14]); 123 old_fs = get_fs(); 124 set_fs (USER_DS); 125 if (copy_from_user (&r_w, rw, sizeof(r_w))) { 126 set_fs (old_fs); 127 return; 128 } 129 130 set_fs (old_fs); 131 printk("l0: %08x l1: %08x l2: %08x l3: %08x " 132 "l4: %08x l5: %08x l6: %08x l7: %08x\n", 133 r_w.locals[0], r_w.locals[1], r_w.locals[2], r_w.locals[3], 134 r_w.locals[4], r_w.locals[5], r_w.locals[6], r_w.locals[7]); 135 printk("i0: %08x i1: %08x i2: %08x i3: %08x " 136 "i4: %08x i5: %08x i6: %08x i7: %08x\n", 137 r_w.ins[0], r_w.ins[1], r_w.ins[2], r_w.ins[3], 138 r_w.ins[4], r_w.ins[5], r_w.ins[6], r_w.ins[7]); 139 } 140 #else 141 #define show_regwindow32(regs) do { } while (0) 142 #endif 143 144 static void show_regwindow(struct pt_regs *regs) 145 { 146 struct reg_window __user *rw; 147 struct reg_window *rwk; 148 struct reg_window r_w; 149 mm_segment_t old_fs; 150 151 if ((regs->tstate & TSTATE_PRIV) || !(test_thread_flag(TIF_32BIT))) { 152 __asm__ __volatile__ ("flushw"); 153 rw = (struct reg_window __user *) 154 (regs->u_regs[14] + STACK_BIAS); 155 rwk = (struct reg_window *) 156 (regs->u_regs[14] + STACK_BIAS); 157 if (!(regs->tstate & TSTATE_PRIV)) { 158 old_fs = get_fs(); 159 set_fs (USER_DS); 160 if (copy_from_user (&r_w, rw, sizeof(r_w))) { 161 set_fs (old_fs); 162 return; 163 } 164 rwk = &r_w; 165 set_fs (old_fs); 166 } 167 } else { 168 show_regwindow32(regs); 169 return; 170 } 171 printk("l0: %016lx l1: %016lx l2: %016lx l3: %016lx\n", 172 rwk->locals[0], rwk->locals[1], rwk->locals[2], rwk->locals[3]); 173 printk("l4: %016lx l5: %016lx l6: %016lx l7: %016lx\n", 174 rwk->locals[4], rwk->locals[5], rwk->locals[6], rwk->locals[7]); 175 printk("i0: %016lx i1: %016lx i2: %016lx i3: %016lx\n", 176 rwk->ins[0], rwk->ins[1], rwk->ins[2], rwk->ins[3]); 177 printk("i4: %016lx i5: %016lx i6: %016lx i7: %016lx\n", 178 rwk->ins[4], rwk->ins[5], rwk->ins[6], rwk->ins[7]); 179 if (regs->tstate & TSTATE_PRIV) 180 printk("I7: <%pS>\n", (void *) rwk->ins[7]); 181 } 182 183 void show_regs(struct pt_regs *regs) 184 { 185 printk("TSTATE: %016lx TPC: %016lx TNPC: %016lx Y: %08x %s\n", regs->tstate, 186 regs->tpc, regs->tnpc, regs->y, print_tainted()); 187 printk("TPC: <%pS>\n", (void *) regs->tpc); 188 printk("g0: %016lx g1: %016lx g2: %016lx g3: %016lx\n", 189 regs->u_regs[0], regs->u_regs[1], regs->u_regs[2], 190 regs->u_regs[3]); 191 printk("g4: %016lx g5: %016lx g6: %016lx g7: %016lx\n", 192 regs->u_regs[4], regs->u_regs[5], regs->u_regs[6], 193 regs->u_regs[7]); 194 printk("o0: %016lx o1: %016lx o2: %016lx o3: %016lx\n", 195 regs->u_regs[8], regs->u_regs[9], regs->u_regs[10], 196 regs->u_regs[11]); 197 printk("o4: %016lx o5: %016lx sp: %016lx ret_pc: %016lx\n", 198 regs->u_regs[12], regs->u_regs[13], regs->u_regs[14], 199 regs->u_regs[15]); 200 printk("RPC: <%pS>\n", (void *) regs->u_regs[15]); 201 show_regwindow(regs); 202 } 203 204 struct global_reg_snapshot global_reg_snapshot[NR_CPUS]; 205 static DEFINE_SPINLOCK(global_reg_snapshot_lock); 206 207 static void __global_reg_self(struct thread_info *tp, struct pt_regs *regs, 208 int this_cpu) 209 { 210 flushw_all(); 211 212 global_reg_snapshot[this_cpu].tstate = regs->tstate; 213 global_reg_snapshot[this_cpu].tpc = regs->tpc; 214 global_reg_snapshot[this_cpu].tnpc = regs->tnpc; 215 global_reg_snapshot[this_cpu].o7 = regs->u_regs[UREG_I7]; 216 217 if (regs->tstate & TSTATE_PRIV) { 218 struct reg_window *rw; 219 220 rw = (struct reg_window *) 221 (regs->u_regs[UREG_FP] + STACK_BIAS); 222 if (kstack_valid(tp, (unsigned long) rw)) { 223 global_reg_snapshot[this_cpu].i7 = rw->ins[7]; 224 rw = (struct reg_window *) 225 (rw->ins[6] + STACK_BIAS); 226 if (kstack_valid(tp, (unsigned long) rw)) 227 global_reg_snapshot[this_cpu].rpc = rw->ins[7]; 228 } 229 } else { 230 global_reg_snapshot[this_cpu].i7 = 0; 231 global_reg_snapshot[this_cpu].rpc = 0; 232 } 233 global_reg_snapshot[this_cpu].thread = tp; 234 } 235 236 /* In order to avoid hangs we do not try to synchronize with the 237 * global register dump client cpus. The last store they make is to 238 * the thread pointer, so do a short poll waiting for that to become 239 * non-NULL. 240 */ 241 static void __global_reg_poll(struct global_reg_snapshot *gp) 242 { 243 int limit = 0; 244 245 while (!gp->thread && ++limit < 100) { 246 barrier(); 247 udelay(1); 248 } 249 } 250 251 void __trigger_all_cpu_backtrace(void) 252 { 253 struct thread_info *tp = current_thread_info(); 254 struct pt_regs *regs = get_irq_regs(); 255 unsigned long flags; 256 int this_cpu, cpu; 257 258 if (!regs) 259 regs = tp->kregs; 260 261 spin_lock_irqsave(&global_reg_snapshot_lock, flags); 262 263 memset(global_reg_snapshot, 0, sizeof(global_reg_snapshot)); 264 265 this_cpu = raw_smp_processor_id(); 266 267 __global_reg_self(tp, regs, this_cpu); 268 269 smp_fetch_global_regs(); 270 271 for_each_online_cpu(cpu) { 272 struct global_reg_snapshot *gp = &global_reg_snapshot[cpu]; 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 } 294 295 memset(global_reg_snapshot, 0, sizeof(global_reg_snapshot)); 296 297 spin_unlock_irqrestore(&global_reg_snapshot_lock, flags); 298 } 299 300 #ifdef CONFIG_MAGIC_SYSRQ 301 302 static void sysrq_handle_globreg(int key, struct tty_struct *tty) 303 { 304 __trigger_all_cpu_backtrace(); 305 } 306 307 static struct sysrq_key_op sparc_globalreg_op = { 308 .handler = sysrq_handle_globreg, 309 .help_msg = "Globalregs", 310 .action_msg = "Show Global CPU Regs", 311 }; 312 313 static int __init sparc_globreg_init(void) 314 { 315 return register_sysrq_key('y', &sparc_globalreg_op); 316 } 317 318 core_initcall(sparc_globreg_init); 319 320 #endif 321 322 unsigned long thread_saved_pc(struct task_struct *tsk) 323 { 324 struct thread_info *ti = task_thread_info(tsk); 325 unsigned long ret = 0xdeadbeefUL; 326 327 if (ti && ti->ksp) { 328 unsigned long *sp; 329 sp = (unsigned long *)(ti->ksp + STACK_BIAS); 330 if (((unsigned long)sp & (sizeof(long) - 1)) == 0UL && 331 sp[14]) { 332 unsigned long *fp; 333 fp = (unsigned long *)(sp[14] + STACK_BIAS); 334 if (((unsigned long)fp & (sizeof(long) - 1)) == 0UL) 335 ret = fp[15]; 336 } 337 } 338 return ret; 339 } 340 341 /* Free current thread data structures etc.. */ 342 void exit_thread(void) 343 { 344 struct thread_info *t = current_thread_info(); 345 346 if (t->utraps) { 347 if (t->utraps[0] < 2) 348 kfree (t->utraps); 349 else 350 t->utraps[0]--; 351 } 352 353 if (test_and_clear_thread_flag(TIF_PERFCTR)) { 354 t->user_cntd0 = t->user_cntd1 = NULL; 355 t->pcr_reg = 0; 356 write_pcr(0); 357 } 358 } 359 360 void flush_thread(void) 361 { 362 struct thread_info *t = current_thread_info(); 363 struct mm_struct *mm; 364 365 if (test_ti_thread_flag(t, TIF_ABI_PENDING)) { 366 clear_ti_thread_flag(t, TIF_ABI_PENDING); 367 if (test_ti_thread_flag(t, TIF_32BIT)) 368 clear_ti_thread_flag(t, TIF_32BIT); 369 else 370 set_ti_thread_flag(t, TIF_32BIT); 371 } 372 373 mm = t->task->mm; 374 if (mm) 375 tsb_context_switch(mm); 376 377 set_thread_wsaved(0); 378 379 /* Turn off performance counters if on. */ 380 if (test_and_clear_thread_flag(TIF_PERFCTR)) { 381 t->user_cntd0 = t->user_cntd1 = NULL; 382 t->pcr_reg = 0; 383 write_pcr(0); 384 } 385 386 /* Clear FPU register state. */ 387 t->fpsaved[0] = 0; 388 389 if (get_thread_current_ds() != ASI_AIUS) 390 set_fs(USER_DS); 391 } 392 393 /* It's a bit more tricky when 64-bit tasks are involved... */ 394 static unsigned long clone_stackframe(unsigned long csp, unsigned long psp) 395 { 396 unsigned long fp, distance, rval; 397 398 if (!(test_thread_flag(TIF_32BIT))) { 399 csp += STACK_BIAS; 400 psp += STACK_BIAS; 401 __get_user(fp, &(((struct reg_window __user *)psp)->ins[6])); 402 fp += STACK_BIAS; 403 } else 404 __get_user(fp, &(((struct reg_window32 __user *)psp)->ins[6])); 405 406 /* Now 8-byte align the stack as this is mandatory in the 407 * Sparc ABI due to how register windows work. This hides 408 * the restriction from thread libraries etc. -DaveM 409 */ 410 csp &= ~7UL; 411 412 distance = fp - psp; 413 rval = (csp - distance); 414 if (copy_in_user((void __user *) rval, (void __user *) psp, distance)) 415 rval = 0; 416 else if (test_thread_flag(TIF_32BIT)) { 417 if (put_user(((u32)csp), 418 &(((struct reg_window32 __user *)rval)->ins[6]))) 419 rval = 0; 420 } else { 421 if (put_user(((u64)csp - STACK_BIAS), 422 &(((struct reg_window __user *)rval)->ins[6]))) 423 rval = 0; 424 else 425 rval = rval - STACK_BIAS; 426 } 427 428 return rval; 429 } 430 431 /* Standard stuff. */ 432 static inline void shift_window_buffer(int first_win, int last_win, 433 struct thread_info *t) 434 { 435 int i; 436 437 for (i = first_win; i < last_win; i++) { 438 t->rwbuf_stkptrs[i] = t->rwbuf_stkptrs[i+1]; 439 memcpy(&t->reg_window[i], &t->reg_window[i+1], 440 sizeof(struct reg_window)); 441 } 442 } 443 444 void synchronize_user_stack(void) 445 { 446 struct thread_info *t = current_thread_info(); 447 unsigned long window; 448 449 flush_user_windows(); 450 if ((window = get_thread_wsaved()) != 0) { 451 int winsize = sizeof(struct reg_window); 452 int bias = 0; 453 454 if (test_thread_flag(TIF_32BIT)) 455 winsize = sizeof(struct reg_window32); 456 else 457 bias = STACK_BIAS; 458 459 window -= 1; 460 do { 461 unsigned long sp = (t->rwbuf_stkptrs[window] + bias); 462 struct reg_window *rwin = &t->reg_window[window]; 463 464 if (!copy_to_user((char __user *)sp, rwin, winsize)) { 465 shift_window_buffer(window, get_thread_wsaved() - 1, t); 466 set_thread_wsaved(get_thread_wsaved() - 1); 467 } 468 } while (window--); 469 } 470 } 471 472 static void stack_unaligned(unsigned long sp) 473 { 474 siginfo_t info; 475 476 info.si_signo = SIGBUS; 477 info.si_errno = 0; 478 info.si_code = BUS_ADRALN; 479 info.si_addr = (void __user *) sp; 480 info.si_trapno = 0; 481 force_sig_info(SIGBUS, &info, current); 482 } 483 484 void fault_in_user_windows(void) 485 { 486 struct thread_info *t = current_thread_info(); 487 unsigned long window; 488 int winsize = sizeof(struct reg_window); 489 int bias = 0; 490 491 if (test_thread_flag(TIF_32BIT)) 492 winsize = sizeof(struct reg_window32); 493 else 494 bias = STACK_BIAS; 495 496 flush_user_windows(); 497 window = get_thread_wsaved(); 498 499 if (likely(window != 0)) { 500 window -= 1; 501 do { 502 unsigned long sp = (t->rwbuf_stkptrs[window] + bias); 503 struct reg_window *rwin = &t->reg_window[window]; 504 505 if (unlikely(sp & 0x7UL)) 506 stack_unaligned(sp); 507 508 if (unlikely(copy_to_user((char __user *)sp, 509 rwin, winsize))) 510 goto barf; 511 } while (window--); 512 } 513 set_thread_wsaved(0); 514 return; 515 516 barf: 517 set_thread_wsaved(window + 1); 518 do_exit(SIGILL); 519 } 520 521 asmlinkage long sparc_do_fork(unsigned long clone_flags, 522 unsigned long stack_start, 523 struct pt_regs *regs, 524 unsigned long stack_size) 525 { 526 int __user *parent_tid_ptr, *child_tid_ptr; 527 unsigned long orig_i1 = regs->u_regs[UREG_I1]; 528 long ret; 529 530 #ifdef CONFIG_COMPAT 531 if (test_thread_flag(TIF_32BIT)) { 532 parent_tid_ptr = compat_ptr(regs->u_regs[UREG_I2]); 533 child_tid_ptr = compat_ptr(regs->u_regs[UREG_I4]); 534 } else 535 #endif 536 { 537 parent_tid_ptr = (int __user *) regs->u_regs[UREG_I2]; 538 child_tid_ptr = (int __user *) regs->u_regs[UREG_I4]; 539 } 540 541 ret = do_fork(clone_flags, stack_start, 542 regs, stack_size, 543 parent_tid_ptr, child_tid_ptr); 544 545 /* If we get an error and potentially restart the system 546 * call, we're screwed because copy_thread() clobbered 547 * the parent's %o1. So detect that case and restore it 548 * here. 549 */ 550 if ((unsigned long)ret >= -ERESTART_RESTARTBLOCK) 551 regs->u_regs[UREG_I1] = orig_i1; 552 553 return ret; 554 } 555 556 /* Copy a Sparc thread. The fork() return value conventions 557 * under SunOS are nothing short of bletcherous: 558 * Parent --> %o0 == childs pid, %o1 == 0 559 * Child --> %o0 == parents pid, %o1 == 1 560 */ 561 int copy_thread(int nr, unsigned long clone_flags, unsigned long sp, 562 unsigned long unused, 563 struct task_struct *p, struct pt_regs *regs) 564 { 565 struct thread_info *t = task_thread_info(p); 566 struct sparc_stackf *parent_sf; 567 unsigned long child_stack_sz; 568 char *child_trap_frame; 569 int kernel_thread; 570 571 kernel_thread = (regs->tstate & TSTATE_PRIV) ? 1 : 0; 572 parent_sf = ((struct sparc_stackf *) regs) - 1; 573 574 /* Calculate offset to stack_frame & pt_regs */ 575 child_stack_sz = ((STACKFRAME_SZ + TRACEREG_SZ) + 576 (kernel_thread ? STACKFRAME_SZ : 0)); 577 child_trap_frame = (task_stack_page(p) + 578 (THREAD_SIZE - child_stack_sz)); 579 memcpy(child_trap_frame, parent_sf, child_stack_sz); 580 581 t->flags = (t->flags & ~((0xffUL << TI_FLAG_CWP_SHIFT) | 582 (0xffUL << TI_FLAG_CURRENT_DS_SHIFT))) | 583 (((regs->tstate + 1) & TSTATE_CWP) << TI_FLAG_CWP_SHIFT); 584 t->new_child = 1; 585 t->ksp = ((unsigned long) child_trap_frame) - STACK_BIAS; 586 t->kregs = (struct pt_regs *) (child_trap_frame + 587 sizeof(struct sparc_stackf)); 588 t->fpsaved[0] = 0; 589 590 if (kernel_thread) { 591 struct sparc_stackf *child_sf = (struct sparc_stackf *) 592 (child_trap_frame + (STACKFRAME_SZ + TRACEREG_SZ)); 593 594 /* Zero terminate the stack backtrace. */ 595 child_sf->fp = NULL; 596 t->kregs->u_regs[UREG_FP] = 597 ((unsigned long) child_sf) - STACK_BIAS; 598 599 /* Special case, if we are spawning a kernel thread from 600 * a userspace task (usermode helper, NFS or similar), we 601 * must disable performance counters in the child because 602 * the address space and protection realm are changing. 603 */ 604 if (t->flags & _TIF_PERFCTR) { 605 t->user_cntd0 = t->user_cntd1 = NULL; 606 t->pcr_reg = 0; 607 t->flags &= ~_TIF_PERFCTR; 608 } 609 t->flags |= ((long)ASI_P << TI_FLAG_CURRENT_DS_SHIFT); 610 t->kregs->u_regs[UREG_G6] = (unsigned long) t; 611 t->kregs->u_regs[UREG_G4] = (unsigned long) t->task; 612 } else { 613 if (t->flags & _TIF_32BIT) { 614 sp &= 0x00000000ffffffffUL; 615 regs->u_regs[UREG_FP] &= 0x00000000ffffffffUL; 616 } 617 t->kregs->u_regs[UREG_FP] = sp; 618 t->flags |= ((long)ASI_AIUS << TI_FLAG_CURRENT_DS_SHIFT); 619 if (sp != regs->u_regs[UREG_FP]) { 620 unsigned long csp; 621 622 csp = clone_stackframe(sp, regs->u_regs[UREG_FP]); 623 if (!csp) 624 return -EFAULT; 625 t->kregs->u_regs[UREG_FP] = csp; 626 } 627 if (t->utraps) 628 t->utraps[0]++; 629 } 630 631 /* Set the return value for the child. */ 632 t->kregs->u_regs[UREG_I0] = current->pid; 633 t->kregs->u_regs[UREG_I1] = 1; 634 635 /* Set the second return value for the parent. */ 636 regs->u_regs[UREG_I1] = 0; 637 638 if (clone_flags & CLONE_SETTLS) 639 t->kregs->u_regs[UREG_G7] = regs->u_regs[UREG_I3]; 640 641 return 0; 642 } 643 644 /* 645 * This is the mechanism for creating a new kernel thread. 646 * 647 * NOTE! Only a kernel-only process(ie the swapper or direct descendants 648 * who haven't done an "execve()") should use this: it will work within 649 * a system call from a "real" process, but the process memory space will 650 * not be freed until both the parent and the child have exited. 651 */ 652 pid_t kernel_thread(int (*fn)(void *), void * arg, unsigned long flags) 653 { 654 long retval; 655 656 /* If the parent runs before fn(arg) is called by the child, 657 * the input registers of this function can be clobbered. 658 * So we stash 'fn' and 'arg' into global registers which 659 * will not be modified by the parent. 660 */ 661 __asm__ __volatile__("mov %4, %%g2\n\t" /* Save FN into global */ 662 "mov %5, %%g3\n\t" /* Save ARG into global */ 663 "mov %1, %%g1\n\t" /* Clone syscall nr. */ 664 "mov %2, %%o0\n\t" /* Clone flags. */ 665 "mov 0, %%o1\n\t" /* usp arg == 0 */ 666 "t 0x6d\n\t" /* Linux/Sparc clone(). */ 667 "brz,a,pn %%o1, 1f\n\t" /* Parent, just return. */ 668 " mov %%o0, %0\n\t" 669 "jmpl %%g2, %%o7\n\t" /* Call the function. */ 670 " mov %%g3, %%o0\n\t" /* Set arg in delay. */ 671 "mov %3, %%g1\n\t" 672 "t 0x6d\n\t" /* Linux/Sparc exit(). */ 673 /* Notreached by child. */ 674 "1:" : 675 "=r" (retval) : 676 "i" (__NR_clone), "r" (flags | CLONE_VM | CLONE_UNTRACED), 677 "i" (__NR_exit), "r" (fn), "r" (arg) : 678 "g1", "g2", "g3", "o0", "o1", "memory", "cc"); 679 return retval; 680 } 681 682 typedef struct { 683 union { 684 unsigned int pr_regs[32]; 685 unsigned long pr_dregs[16]; 686 } pr_fr; 687 unsigned int __unused; 688 unsigned int pr_fsr; 689 unsigned char pr_qcnt; 690 unsigned char pr_q_entrysize; 691 unsigned char pr_en; 692 unsigned int pr_q[64]; 693 } elf_fpregset_t32; 694 695 /* 696 * fill in the fpu structure for a core dump. 697 */ 698 int dump_fpu (struct pt_regs * regs, elf_fpregset_t * fpregs) 699 { 700 unsigned long *kfpregs = current_thread_info()->fpregs; 701 unsigned long fprs = current_thread_info()->fpsaved[0]; 702 703 if (test_thread_flag(TIF_32BIT)) { 704 elf_fpregset_t32 *fpregs32 = (elf_fpregset_t32 *)fpregs; 705 706 if (fprs & FPRS_DL) 707 memcpy(&fpregs32->pr_fr.pr_regs[0], kfpregs, 708 sizeof(unsigned int) * 32); 709 else 710 memset(&fpregs32->pr_fr.pr_regs[0], 0, 711 sizeof(unsigned int) * 32); 712 fpregs32->pr_qcnt = 0; 713 fpregs32->pr_q_entrysize = 8; 714 memset(&fpregs32->pr_q[0], 0, 715 (sizeof(unsigned int) * 64)); 716 if (fprs & FPRS_FEF) { 717 fpregs32->pr_fsr = (unsigned int) current_thread_info()->xfsr[0]; 718 fpregs32->pr_en = 1; 719 } else { 720 fpregs32->pr_fsr = 0; 721 fpregs32->pr_en = 0; 722 } 723 } else { 724 if(fprs & FPRS_DL) 725 memcpy(&fpregs->pr_regs[0], kfpregs, 726 sizeof(unsigned int) * 32); 727 else 728 memset(&fpregs->pr_regs[0], 0, 729 sizeof(unsigned int) * 32); 730 if(fprs & FPRS_DU) 731 memcpy(&fpregs->pr_regs[16], kfpregs+16, 732 sizeof(unsigned int) * 32); 733 else 734 memset(&fpregs->pr_regs[16], 0, 735 sizeof(unsigned int) * 32); 736 if(fprs & FPRS_FEF) { 737 fpregs->pr_fsr = current_thread_info()->xfsr[0]; 738 fpregs->pr_gsr = current_thread_info()->gsr[0]; 739 } else { 740 fpregs->pr_fsr = fpregs->pr_gsr = 0; 741 } 742 fpregs->pr_fprs = fprs; 743 } 744 return 1; 745 } 746 747 /* 748 * sparc_execve() executes a new program after the asm stub has set 749 * things up for us. This should basically do what I want it to. 750 */ 751 asmlinkage int sparc_execve(struct pt_regs *regs) 752 { 753 int error, base = 0; 754 char *filename; 755 756 /* User register window flush is done by entry.S */ 757 758 /* Check for indirect call. */ 759 if (regs->u_regs[UREG_G1] == 0) 760 base = 1; 761 762 filename = getname((char __user *)regs->u_regs[base + UREG_I0]); 763 error = PTR_ERR(filename); 764 if (IS_ERR(filename)) 765 goto out; 766 error = do_execve(filename, 767 (char __user * __user *) 768 regs->u_regs[base + UREG_I1], 769 (char __user * __user *) 770 regs->u_regs[base + UREG_I2], regs); 771 putname(filename); 772 if (!error) { 773 fprs_write(0); 774 current_thread_info()->xfsr[0] = 0; 775 current_thread_info()->fpsaved[0] = 0; 776 regs->tstate &= ~TSTATE_PEF; 777 } 778 out: 779 return error; 780 } 781 782 unsigned long get_wchan(struct task_struct *task) 783 { 784 unsigned long pc, fp, bias = 0; 785 struct thread_info *tp; 786 struct reg_window *rw; 787 unsigned long ret = 0; 788 int count = 0; 789 790 if (!task || task == current || 791 task->state == TASK_RUNNING) 792 goto out; 793 794 tp = task_thread_info(task); 795 bias = STACK_BIAS; 796 fp = task_thread_info(task)->ksp + bias; 797 798 do { 799 if (!kstack_valid(tp, fp)) 800 break; 801 rw = (struct reg_window *) fp; 802 pc = rw->ins[7]; 803 if (!in_sched_functions(pc)) { 804 ret = pc; 805 goto out; 806 } 807 fp = rw->ins[6] + bias; 808 } while (++count < 16); 809 810 out: 811 return ret; 812 } 813