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v4.17
  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
 40#include <linux/uaccess.h>
 41#include <asm/page.h>
 42#include <asm/pgalloc.h>
 43#include <asm/pgtable.h>
 44#include <asm/processor.h>
 45#include <asm/pstate.h>
 46#include <asm/elf.h>
 47#include <asm/fpumacro.h>
 48#include <asm/head.h>
 49#include <asm/cpudata.h>
 50#include <asm/mmu_context.h>
 51#include <asm/unistd.h>
 52#include <asm/hypervisor.h>
 53#include <asm/syscalls.h>
 54#include <asm/irq_regs.h>
 55#include <asm/smp.h>
 56#include <asm/pcr.h>
 57
 58#include "kstack.h"
 59
 60/* Idle loop support on sparc64. */
 61void arch_cpu_idle(void)
 62{
 63	if (tlb_type != hypervisor) {
 64		touch_nmi_watchdog();
 65		local_irq_enable();
 66	} else {
 67		unsigned long pstate;
 68
 69		local_irq_enable();
 70
 71                /* The sun4v sleeping code requires that we have PSTATE.IE cleared over
 72                 * the cpu sleep hypervisor call.
 73                 */
 74		__asm__ __volatile__(
 75			"rdpr %%pstate, %0\n\t"
 76			"andn %0, %1, %0\n\t"
 77			"wrpr %0, %%g0, %%pstate"
 78			: "=&r" (pstate)
 79			: "i" (PSTATE_IE));
 80
 81		if (!need_resched() && !cpu_is_offline(smp_processor_id())) {
 82			sun4v_cpu_yield();
 83			/* If resumed by cpu_poke then we need to explicitly
 84			 * call scheduler_ipi().
 85			 */
 86			scheduler_poke();
 87		}
 88
 89		/* Re-enable interrupts. */
 90		__asm__ __volatile__(
 91			"rdpr %%pstate, %0\n\t"
 92			"or %0, %1, %0\n\t"
 93			"wrpr %0, %%g0, %%pstate"
 94			: "=&r" (pstate)
 95			: "i" (PSTATE_IE));
 96	}
 97}
 98
 99#ifdef CONFIG_HOTPLUG_CPU
100void arch_cpu_idle_dead(void)
101{
102	sched_preempt_enable_no_resched();
103	cpu_play_dead();
104}
105#endif
106
107#ifdef CONFIG_COMPAT
108static void show_regwindow32(struct pt_regs *regs)
109{
110	struct reg_window32 __user *rw;
111	struct reg_window32 r_w;
112	mm_segment_t old_fs;
113	
114	__asm__ __volatile__ ("flushw");
115	rw = compat_ptr((unsigned int)regs->u_regs[14]);
116	old_fs = get_fs();
117	set_fs (USER_DS);
118	if (copy_from_user (&r_w, rw, sizeof(r_w))) {
119		set_fs (old_fs);
120		return;
121	}
122
123	set_fs (old_fs);			
124	printk("l0: %08x l1: %08x l2: %08x l3: %08x "
125	       "l4: %08x l5: %08x l6: %08x l7: %08x\n",
126	       r_w.locals[0], r_w.locals[1], r_w.locals[2], r_w.locals[3],
127	       r_w.locals[4], r_w.locals[5], r_w.locals[6], r_w.locals[7]);
128	printk("i0: %08x i1: %08x i2: %08x i3: %08x "
129	       "i4: %08x i5: %08x i6: %08x i7: %08x\n",
130	       r_w.ins[0], r_w.ins[1], r_w.ins[2], r_w.ins[3],
131	       r_w.ins[4], r_w.ins[5], r_w.ins[6], r_w.ins[7]);
132}
133#else
134#define show_regwindow32(regs)	do { } while (0)
135#endif
136
137static void show_regwindow(struct pt_regs *regs)
138{
139	struct reg_window __user *rw;
140	struct reg_window *rwk;
141	struct reg_window r_w;
142	mm_segment_t old_fs;
143
144	if ((regs->tstate & TSTATE_PRIV) || !(test_thread_flag(TIF_32BIT))) {
145		__asm__ __volatile__ ("flushw");
146		rw = (struct reg_window __user *)
147			(regs->u_regs[14] + STACK_BIAS);
148		rwk = (struct reg_window *)
149			(regs->u_regs[14] + STACK_BIAS);
150		if (!(regs->tstate & TSTATE_PRIV)) {
151			old_fs = get_fs();
152			set_fs (USER_DS);
153			if (copy_from_user (&r_w, rw, sizeof(r_w))) {
154				set_fs (old_fs);
155				return;
156			}
157			rwk = &r_w;
158			set_fs (old_fs);			
159		}
160	} else {
161		show_regwindow32(regs);
162		return;
163	}
164	printk("l0: %016lx l1: %016lx l2: %016lx l3: %016lx\n",
165	       rwk->locals[0], rwk->locals[1], rwk->locals[2], rwk->locals[3]);
166	printk("l4: %016lx l5: %016lx l6: %016lx l7: %016lx\n",
167	       rwk->locals[4], rwk->locals[5], rwk->locals[6], rwk->locals[7]);
168	printk("i0: %016lx i1: %016lx i2: %016lx i3: %016lx\n",
169	       rwk->ins[0], rwk->ins[1], rwk->ins[2], rwk->ins[3]);
170	printk("i4: %016lx i5: %016lx i6: %016lx i7: %016lx\n",
171	       rwk->ins[4], rwk->ins[5], rwk->ins[6], rwk->ins[7]);
172	if (regs->tstate & TSTATE_PRIV)
173		printk("I7: <%pS>\n", (void *) rwk->ins[7]);
174}
175
176void show_regs(struct pt_regs *regs)
177{
178	show_regs_print_info(KERN_DEFAULT);
179
180	printk("TSTATE: %016lx TPC: %016lx TNPC: %016lx Y: %08x    %s\n", regs->tstate,
181	       regs->tpc, regs->tnpc, regs->y, print_tainted());
182	printk("TPC: <%pS>\n", (void *) regs->tpc);
183	printk("g0: %016lx g1: %016lx g2: %016lx g3: %016lx\n",
184	       regs->u_regs[0], regs->u_regs[1], regs->u_regs[2],
185	       regs->u_regs[3]);
186	printk("g4: %016lx g5: %016lx g6: %016lx g7: %016lx\n",
187	       regs->u_regs[4], regs->u_regs[5], regs->u_regs[6],
188	       regs->u_regs[7]);
189	printk("o0: %016lx o1: %016lx o2: %016lx o3: %016lx\n",
190	       regs->u_regs[8], regs->u_regs[9], regs->u_regs[10],
191	       regs->u_regs[11]);
192	printk("o4: %016lx o5: %016lx sp: %016lx ret_pc: %016lx\n",
193	       regs->u_regs[12], regs->u_regs[13], regs->u_regs[14],
194	       regs->u_regs[15]);
195	printk("RPC: <%pS>\n", (void *) regs->u_regs[15]);
196	show_regwindow(regs);
197	show_stack(current, (unsigned long *) regs->u_regs[UREG_FP]);
198}
199
200union global_cpu_snapshot global_cpu_snapshot[NR_CPUS];
201static DEFINE_SPINLOCK(global_cpu_snapshot_lock);
202
203static void __global_reg_self(struct thread_info *tp, struct pt_regs *regs,
204			      int this_cpu)
205{
206	struct global_reg_snapshot *rp;
207
208	flushw_all();
209
210	rp = &global_cpu_snapshot[this_cpu].reg;
211
212	rp->tstate = regs->tstate;
213	rp->tpc = regs->tpc;
214	rp->tnpc = regs->tnpc;
215	rp->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			rp->i7 = rw->ins[7];
224			rw = (struct reg_window *)
225				(rw->ins[6] + STACK_BIAS);
226			if (kstack_valid(tp, (unsigned long) rw))
227				rp->rpc = rw->ins[7];
228		}
229	} else {
230		rp->i7 = 0;
231		rp->rpc = 0;
232	}
233	rp->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 */
241static 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
251void arch_trigger_cpumask_backtrace(const cpumask_t *mask, bool exclude_self)
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_cpu_snapshot_lock, flags);
262
263	this_cpu = raw_smp_processor_id();
264
265	memset(global_cpu_snapshot, 0, sizeof(global_cpu_snapshot));
266
267	if (cpumask_test_cpu(this_cpu, mask) && !exclude_self)
268		__global_reg_self(tp, regs, this_cpu);
269
270	smp_fetch_global_regs();
271
272	for_each_cpu(cpu, mask) {
273		struct global_reg_snapshot *gp;
274
275		if (exclude_self && cpu == this_cpu)
276			continue;
277
278		gp = &global_cpu_snapshot[cpu].reg;
279
280		__global_reg_poll(gp);
281
282		tp = gp->thread;
283		printk("%c CPU[%3d]: TSTATE[%016lx] TPC[%016lx] TNPC[%016lx] TASK[%s:%d]\n",
284		       (cpu == this_cpu ? '*' : ' '), cpu,
285		       gp->tstate, gp->tpc, gp->tnpc,
286		       ((tp && tp->task) ? tp->task->comm : "NULL"),
287		       ((tp && tp->task) ? tp->task->pid : -1));
288
289		if (gp->tstate & TSTATE_PRIV) {
290			printk("             TPC[%pS] O7[%pS] I7[%pS] RPC[%pS]\n",
291			       (void *) gp->tpc,
292			       (void *) gp->o7,
293			       (void *) gp->i7,
294			       (void *) gp->rpc);
295		} else {
296			printk("             TPC[%lx] O7[%lx] I7[%lx] RPC[%lx]\n",
297			       gp->tpc, gp->o7, gp->i7, gp->rpc);
298		}
299
300		touch_nmi_watchdog();
301	}
302
303	memset(global_cpu_snapshot, 0, sizeof(global_cpu_snapshot));
304
305	spin_unlock_irqrestore(&global_cpu_snapshot_lock, flags);
306}
307
308#ifdef CONFIG_MAGIC_SYSRQ
309
310static void sysrq_handle_globreg(int key)
311{
312	trigger_all_cpu_backtrace();
313}
314
315static struct sysrq_key_op sparc_globalreg_op = {
316	.handler	= sysrq_handle_globreg,
317	.help_msg	= "global-regs(y)",
318	.action_msg	= "Show Global CPU Regs",
319};
320
321static void __global_pmu_self(int this_cpu)
322{
323	struct global_pmu_snapshot *pp;
324	int i, num;
325
326	if (!pcr_ops)
327		return;
328
329	pp = &global_cpu_snapshot[this_cpu].pmu;
330
331	num = 1;
332	if (tlb_type == hypervisor &&
333	    sun4v_chip_type >= SUN4V_CHIP_NIAGARA4)
334		num = 4;
335
336	for (i = 0; i < num; i++) {
337		pp->pcr[i] = pcr_ops->read_pcr(i);
338		pp->pic[i] = pcr_ops->read_pic(i);
339	}
340}
341
342static void __global_pmu_poll(struct global_pmu_snapshot *pp)
343{
344	int limit = 0;
345
346	while (!pp->pcr[0] && ++limit < 100) {
347		barrier();
348		udelay(1);
349	}
350}
351
352static void pmu_snapshot_all_cpus(void)
353{
354	unsigned long flags;
355	int this_cpu, cpu;
356
357	spin_lock_irqsave(&global_cpu_snapshot_lock, flags);
358
359	memset(global_cpu_snapshot, 0, sizeof(global_cpu_snapshot));
360
361	this_cpu = raw_smp_processor_id();
362
363	__global_pmu_self(this_cpu);
364
365	smp_fetch_global_pmu();
366
367	for_each_online_cpu(cpu) {
368		struct global_pmu_snapshot *pp = &global_cpu_snapshot[cpu].pmu;
369
370		__global_pmu_poll(pp);
371
372		printk("%c CPU[%3d]: PCR[%08lx:%08lx:%08lx:%08lx] PIC[%08lx:%08lx:%08lx:%08lx]\n",
373		       (cpu == this_cpu ? '*' : ' '), cpu,
374		       pp->pcr[0], pp->pcr[1], pp->pcr[2], pp->pcr[3],
375		       pp->pic[0], pp->pic[1], pp->pic[2], pp->pic[3]);
376
377		touch_nmi_watchdog();
378	}
379
380	memset(global_cpu_snapshot, 0, sizeof(global_cpu_snapshot));
381
382	spin_unlock_irqrestore(&global_cpu_snapshot_lock, flags);
383}
384
385static void sysrq_handle_globpmu(int key)
386{
387	pmu_snapshot_all_cpus();
388}
389
390static struct sysrq_key_op sparc_globalpmu_op = {
391	.handler	= sysrq_handle_globpmu,
392	.help_msg	= "global-pmu(x)",
393	.action_msg	= "Show Global PMU Regs",
394};
395
396static int __init sparc_sysrq_init(void)
397{
398	int ret = register_sysrq_key('y', &sparc_globalreg_op);
399
400	if (!ret)
401		ret = register_sysrq_key('x', &sparc_globalpmu_op);
402	return ret;
403}
404
405core_initcall(sparc_sysrq_init);
406
407#endif
408
409/* Free current thread data structures etc.. */
410void exit_thread(struct task_struct *tsk)
411{
412	struct thread_info *t = task_thread_info(tsk);
413
414	if (t->utraps) {
415		if (t->utraps[0] < 2)
416			kfree (t->utraps);
417		else
418			t->utraps[0]--;
419	}
420}
421
422void flush_thread(void)
423{
424	struct thread_info *t = current_thread_info();
425	struct mm_struct *mm;
426
427	mm = t->task->mm;
428	if (mm)
429		tsb_context_switch(mm);
430
431	set_thread_wsaved(0);
432
433	/* Clear FPU register state. */
434	t->fpsaved[0] = 0;
435}
436
437/* It's a bit more tricky when 64-bit tasks are involved... */
438static unsigned long clone_stackframe(unsigned long csp, unsigned long psp)
439{
440	bool stack_64bit = test_thread_64bit_stack(psp);
441	unsigned long fp, distance, rval;
442
443	if (stack_64bit) {
444		csp += STACK_BIAS;
445		psp += STACK_BIAS;
446		__get_user(fp, &(((struct reg_window __user *)psp)->ins[6]));
447		fp += STACK_BIAS;
448		if (test_thread_flag(TIF_32BIT))
449			fp &= 0xffffffff;
450	} else
451		__get_user(fp, &(((struct reg_window32 __user *)psp)->ins[6]));
452
453	/* Now align the stack as this is mandatory in the Sparc ABI
454	 * due to how register windows work.  This hides the
455	 * restriction from thread libraries etc.
456	 */
457	csp &= ~15UL;
458
459	distance = fp - psp;
460	rval = (csp - distance);
461	if (copy_in_user((void __user *) rval, (void __user *) psp, distance))
462		rval = 0;
463	else if (!stack_64bit) {
464		if (put_user(((u32)csp),
465			     &(((struct reg_window32 __user *)rval)->ins[6])))
466			rval = 0;
467	} else {
468		if (put_user(((u64)csp - STACK_BIAS),
469			     &(((struct reg_window __user *)rval)->ins[6])))
470			rval = 0;
471		else
472			rval = rval - STACK_BIAS;
473	}
474
475	return rval;
476}
477
478/* Standard stuff. */
479static inline void shift_window_buffer(int first_win, int last_win,
480				       struct thread_info *t)
481{
482	int i;
483
484	for (i = first_win; i < last_win; i++) {
485		t->rwbuf_stkptrs[i] = t->rwbuf_stkptrs[i+1];
486		memcpy(&t->reg_window[i], &t->reg_window[i+1],
487		       sizeof(struct reg_window));
488	}
489}
490
491void synchronize_user_stack(void)
492{
493	struct thread_info *t = current_thread_info();
494	unsigned long window;
495
496	flush_user_windows();
497	if ((window = get_thread_wsaved()) != 0) {
498		window -= 1;
499		do {
500			struct reg_window *rwin = &t->reg_window[window];
501			int winsize = sizeof(struct reg_window);
502			unsigned long sp;
503
504			sp = t->rwbuf_stkptrs[window];
505
506			if (test_thread_64bit_stack(sp))
507				sp += STACK_BIAS;
508			else
509				winsize = sizeof(struct reg_window32);
510
511			if (!copy_to_user((char __user *)sp, rwin, winsize)) {
512				shift_window_buffer(window, get_thread_wsaved() - 1, t);
513				set_thread_wsaved(get_thread_wsaved() - 1);
514			}
515		} while (window--);
516	}
517}
518
519static void stack_unaligned(unsigned long sp)
520{
521	siginfo_t info;
522
523	info.si_signo = SIGBUS;
524	info.si_errno = 0;
525	info.si_code = BUS_ADRALN;
526	info.si_addr = (void __user *) sp;
527	info.si_trapno = 0;
528	force_sig_info(SIGBUS, &info, current);
529}
530
531void fault_in_user_windows(void)
 
 
 
 
 
532{
533	struct thread_info *t = current_thread_info();
534	unsigned long window;
535
536	flush_user_windows();
537	window = get_thread_wsaved();
538
539	if (likely(window != 0)) {
540		window -= 1;
541		do {
542			struct reg_window *rwin = &t->reg_window[window];
543			int winsize = sizeof(struct reg_window);
544			unsigned long sp;
545
546			sp = t->rwbuf_stkptrs[window];
547
548			if (test_thread_64bit_stack(sp))
549				sp += STACK_BIAS;
550			else
551				winsize = sizeof(struct reg_window32);
552
553			if (unlikely(sp & 0x7UL))
554				stack_unaligned(sp);
555
556			if (unlikely(copy_to_user((char __user *)sp,
557						  rwin, winsize)))
 
 
 
 
 
 
 
558				goto barf;
 
559		} while (window--);
560	}
561	set_thread_wsaved(0);
562	return;
563
564barf:
565	set_thread_wsaved(window + 1);
566	user_exit();
567	do_exit(SIGILL);
568}
569
570asmlinkage long sparc_do_fork(unsigned long clone_flags,
571			      unsigned long stack_start,
572			      struct pt_regs *regs,
573			      unsigned long stack_size)
574{
575	int __user *parent_tid_ptr, *child_tid_ptr;
576	unsigned long orig_i1 = regs->u_regs[UREG_I1];
577	long ret;
578
579#ifdef CONFIG_COMPAT
580	if (test_thread_flag(TIF_32BIT)) {
581		parent_tid_ptr = compat_ptr(regs->u_regs[UREG_I2]);
582		child_tid_ptr = compat_ptr(regs->u_regs[UREG_I4]);
583	} else
584#endif
585	{
586		parent_tid_ptr = (int __user *) regs->u_regs[UREG_I2];
587		child_tid_ptr = (int __user *) regs->u_regs[UREG_I4];
588	}
589
590	ret = do_fork(clone_flags, stack_start, stack_size,
591		      parent_tid_ptr, child_tid_ptr);
592
593	/* If we get an error and potentially restart the system
594	 * call, we're screwed because copy_thread() clobbered
595	 * the parent's %o1.  So detect that case and restore it
596	 * here.
597	 */
598	if ((unsigned long)ret >= -ERESTART_RESTARTBLOCK)
599		regs->u_regs[UREG_I1] = orig_i1;
600
601	return ret;
602}
603
604/* Copy a Sparc thread.  The fork() return value conventions
605 * under SunOS are nothing short of bletcherous:
606 * Parent -->  %o0 == childs  pid, %o1 == 0
607 * Child  -->  %o0 == parents pid, %o1 == 1
608 */
609int copy_thread(unsigned long clone_flags, unsigned long sp,
610		unsigned long arg, struct task_struct *p)
611{
 
 
 
612	struct thread_info *t = task_thread_info(p);
613	struct pt_regs *regs = current_pt_regs();
614	struct sparc_stackf *parent_sf;
615	unsigned long child_stack_sz;
616	char *child_trap_frame;
617
618	/* Calculate offset to stack_frame & pt_regs */
619	child_stack_sz = (STACKFRAME_SZ + TRACEREG_SZ);
620	child_trap_frame = (task_stack_page(p) +
621			    (THREAD_SIZE - child_stack_sz));
622
623	t->new_child = 1;
624	t->ksp = ((unsigned long) child_trap_frame) - STACK_BIAS;
625	t->kregs = (struct pt_regs *) (child_trap_frame +
626				       sizeof(struct sparc_stackf));
627	t->fpsaved[0] = 0;
628
629	if (unlikely(p->flags & PF_KTHREAD)) {
630		memset(child_trap_frame, 0, child_stack_sz);
631		__thread_flag_byte_ptr(t)[TI_FLAG_BYTE_CWP] = 
632			(current_pt_regs()->tstate + 1) & TSTATE_CWP;
633		t->current_ds = ASI_P;
634		t->kregs->u_regs[UREG_G1] = sp; /* function */
635		t->kregs->u_regs[UREG_G2] = arg;
636		return 0;
637	}
638
639	parent_sf = ((struct sparc_stackf *) regs) - 1;
640	memcpy(child_trap_frame, parent_sf, child_stack_sz);
641	if (t->flags & _TIF_32BIT) {
642		sp &= 0x00000000ffffffffUL;
643		regs->u_regs[UREG_FP] &= 0x00000000ffffffffUL;
644	}
645	t->kregs->u_regs[UREG_FP] = sp;
646	__thread_flag_byte_ptr(t)[TI_FLAG_BYTE_CWP] = 
647		(regs->tstate + 1) & TSTATE_CWP;
648	t->current_ds = ASI_AIUS;
649	if (sp != regs->u_regs[UREG_FP]) {
650		unsigned long csp;
651
652		csp = clone_stackframe(sp, regs->u_regs[UREG_FP]);
653		if (!csp)
654			return -EFAULT;
655		t->kregs->u_regs[UREG_FP] = csp;
656	}
657	if (t->utraps)
658		t->utraps[0]++;
659
660	/* Set the return value for the child. */
661	t->kregs->u_regs[UREG_I0] = current->pid;
662	t->kregs->u_regs[UREG_I1] = 1;
663
664	/* Set the second return value for the parent. */
665	regs->u_regs[UREG_I1] = 0;
666
667	if (clone_flags & CLONE_SETTLS)
668		t->kregs->u_regs[UREG_G7] = regs->u_regs[UREG_I3];
669
670	return 0;
671}
672
673/* TIF_MCDPER in thread info flags for current task is updated lazily upon
674 * a context switch. Update this flag in current task's thread flags
675 * before dup so the dup'd task will inherit the current TIF_MCDPER flag.
676 */
677int arch_dup_task_struct(struct task_struct *dst, struct task_struct *src)
678{
679	if (adi_capable()) {
680		register unsigned long tmp_mcdper;
681
682		__asm__ __volatile__(
683			".word 0x83438000\n\t"	/* rd  %mcdper, %g1 */
684			"mov %%g1, %0\n\t"
685			: "=r" (tmp_mcdper)
686			:
687			: "g1");
688		if (tmp_mcdper)
689			set_thread_flag(TIF_MCDPER);
690		else
691			clear_thread_flag(TIF_MCDPER);
692	}
693
694	*dst = *src;
695	return 0;
696}
697
698typedef struct {
699	union {
700		unsigned int	pr_regs[32];
701		unsigned long	pr_dregs[16];
702	} pr_fr;
703	unsigned int __unused;
704	unsigned int	pr_fsr;
705	unsigned char	pr_qcnt;
706	unsigned char	pr_q_entrysize;
707	unsigned char	pr_en;
708	unsigned int	pr_q[64];
709} elf_fpregset_t32;
710
711/*
712 * fill in the fpu structure for a core dump.
713 */
714int dump_fpu (struct pt_regs * regs, elf_fpregset_t * fpregs)
715{
716	unsigned long *kfpregs = current_thread_info()->fpregs;
717	unsigned long fprs = current_thread_info()->fpsaved[0];
718
719	if (test_thread_flag(TIF_32BIT)) {
720		elf_fpregset_t32 *fpregs32 = (elf_fpregset_t32 *)fpregs;
721
722		if (fprs & FPRS_DL)
723			memcpy(&fpregs32->pr_fr.pr_regs[0], kfpregs,
724			       sizeof(unsigned int) * 32);
725		else
726			memset(&fpregs32->pr_fr.pr_regs[0], 0,
727			       sizeof(unsigned int) * 32);
728		fpregs32->pr_qcnt = 0;
729		fpregs32->pr_q_entrysize = 8;
730		memset(&fpregs32->pr_q[0], 0,
731		       (sizeof(unsigned int) * 64));
732		if (fprs & FPRS_FEF) {
733			fpregs32->pr_fsr = (unsigned int) current_thread_info()->xfsr[0];
734			fpregs32->pr_en = 1;
735		} else {
736			fpregs32->pr_fsr = 0;
737			fpregs32->pr_en = 0;
738		}
739	} else {
740		if(fprs & FPRS_DL)
741			memcpy(&fpregs->pr_regs[0], kfpregs,
742			       sizeof(unsigned int) * 32);
743		else
744			memset(&fpregs->pr_regs[0], 0,
745			       sizeof(unsigned int) * 32);
746		if(fprs & FPRS_DU)
747			memcpy(&fpregs->pr_regs[16], kfpregs+16,
748			       sizeof(unsigned int) * 32);
749		else
750			memset(&fpregs->pr_regs[16], 0,
751			       sizeof(unsigned int) * 32);
752		if(fprs & FPRS_FEF) {
753			fpregs->pr_fsr = current_thread_info()->xfsr[0];
754			fpregs->pr_gsr = current_thread_info()->gsr[0];
755		} else {
756			fpregs->pr_fsr = fpregs->pr_gsr = 0;
757		}
758		fpregs->pr_fprs = fprs;
759	}
760	return 1;
761}
762EXPORT_SYMBOL(dump_fpu);
763
764unsigned long get_wchan(struct task_struct *task)
765{
766	unsigned long pc, fp, bias = 0;
767	struct thread_info *tp;
768	struct reg_window *rw;
769        unsigned long ret = 0;
770	int count = 0; 
771
772	if (!task || task == current ||
773            task->state == TASK_RUNNING)
774		goto out;
775
776	tp = task_thread_info(task);
777	bias = STACK_BIAS;
778	fp = task_thread_info(task)->ksp + bias;
779
780	do {
781		if (!kstack_valid(tp, fp))
782			break;
783		rw = (struct reg_window *) fp;
784		pc = rw->ins[7];
785		if (!in_sched_functions(pc)) {
786			ret = pc;
787			goto out;
788		}
789		fp = rw->ins[6] + bias;
790	} while (++count < 16);
791
792out:
793	return ret;
794}
v6.2
  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#include <linux/errno.h>
 13#include <linux/export.h>
 14#include <linux/sched.h>
 15#include <linux/sched/debug.h>
 16#include <linux/sched/task.h>
 17#include <linux/sched/task_stack.h>
 18#include <linux/kernel.h>
 19#include <linux/mm.h>
 20#include <linux/fs.h>
 21#include <linux/smp.h>
 22#include <linux/stddef.h>
 23#include <linux/ptrace.h>
 24#include <linux/slab.h>
 25#include <linux/user.h>
 26#include <linux/delay.h>
 27#include <linux/compat.h>
 28#include <linux/tick.h>
 29#include <linux/init.h>
 30#include <linux/cpu.h>
 31#include <linux/perf_event.h>
 32#include <linux/elfcore.h>
 33#include <linux/sysrq.h>
 34#include <linux/nmi.h>
 35#include <linux/context_tracking.h>
 36#include <linux/signal.h>
 37
 38#include <linux/uaccess.h>
 39#include <asm/page.h>
 40#include <asm/pgalloc.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/syscalls.h>
 51#include <asm/irq_regs.h>
 52#include <asm/smp.h>
 53#include <asm/pcr.h>
 54
 55#include "kstack.h"
 56
 57/* Idle loop support on sparc64. */
 58void arch_cpu_idle(void)
 59{
 60	if (tlb_type != hypervisor) {
 61		touch_nmi_watchdog();
 62		raw_local_irq_enable();
 63	} else {
 64		unsigned long pstate;
 65
 66		raw_local_irq_enable();
 67
 68                /* The sun4v sleeping code requires that we have PSTATE.IE cleared over
 69                 * the cpu sleep hypervisor call.
 70                 */
 71		__asm__ __volatile__(
 72			"rdpr %%pstate, %0\n\t"
 73			"andn %0, %1, %0\n\t"
 74			"wrpr %0, %%g0, %%pstate"
 75			: "=&r" (pstate)
 76			: "i" (PSTATE_IE));
 77
 78		if (!need_resched() && !cpu_is_offline(smp_processor_id())) {
 79			sun4v_cpu_yield();
 80			/* If resumed by cpu_poke then we need to explicitly
 81			 * call scheduler_ipi().
 82			 */
 83			scheduler_poke();
 84		}
 85
 86		/* Re-enable interrupts. */
 87		__asm__ __volatile__(
 88			"rdpr %%pstate, %0\n\t"
 89			"or %0, %1, %0\n\t"
 90			"wrpr %0, %%g0, %%pstate"
 91			: "=&r" (pstate)
 92			: "i" (PSTATE_IE));
 93	}
 94}
 95
 96#ifdef CONFIG_HOTPLUG_CPU
 97void arch_cpu_idle_dead(void)
 98{
 99	sched_preempt_enable_no_resched();
100	cpu_play_dead();
101}
102#endif
103
104#ifdef CONFIG_COMPAT
105static void show_regwindow32(struct pt_regs *regs)
106{
107	struct reg_window32 __user *rw;
108	struct reg_window32 r_w;
 
109	
110	__asm__ __volatile__ ("flushw");
111	rw = compat_ptr((unsigned int)regs->u_regs[14]);
 
 
112	if (copy_from_user (&r_w, rw, sizeof(r_w))) {
 
113		return;
114	}
115
 
116	printk("l0: %08x l1: %08x l2: %08x l3: %08x "
117	       "l4: %08x l5: %08x l6: %08x l7: %08x\n",
118	       r_w.locals[0], r_w.locals[1], r_w.locals[2], r_w.locals[3],
119	       r_w.locals[4], r_w.locals[5], r_w.locals[6], r_w.locals[7]);
120	printk("i0: %08x i1: %08x i2: %08x i3: %08x "
121	       "i4: %08x i5: %08x i6: %08x i7: %08x\n",
122	       r_w.ins[0], r_w.ins[1], r_w.ins[2], r_w.ins[3],
123	       r_w.ins[4], r_w.ins[5], r_w.ins[6], r_w.ins[7]);
124}
125#else
126#define show_regwindow32(regs)	do { } while (0)
127#endif
128
129static void show_regwindow(struct pt_regs *regs)
130{
131	struct reg_window __user *rw;
132	struct reg_window *rwk;
133	struct reg_window r_w;
 
134
135	if ((regs->tstate & TSTATE_PRIV) || !(test_thread_flag(TIF_32BIT))) {
136		__asm__ __volatile__ ("flushw");
137		rw = (struct reg_window __user *)
138			(regs->u_regs[14] + STACK_BIAS);
139		rwk = (struct reg_window *)
140			(regs->u_regs[14] + STACK_BIAS);
141		if (!(regs->tstate & TSTATE_PRIV)) {
 
 
142			if (copy_from_user (&r_w, rw, sizeof(r_w))) {
 
143				return;
144			}
145			rwk = &r_w;
 
146		}
147	} else {
148		show_regwindow32(regs);
149		return;
150	}
151	printk("l0: %016lx l1: %016lx l2: %016lx l3: %016lx\n",
152	       rwk->locals[0], rwk->locals[1], rwk->locals[2], rwk->locals[3]);
153	printk("l4: %016lx l5: %016lx l6: %016lx l7: %016lx\n",
154	       rwk->locals[4], rwk->locals[5], rwk->locals[6], rwk->locals[7]);
155	printk("i0: %016lx i1: %016lx i2: %016lx i3: %016lx\n",
156	       rwk->ins[0], rwk->ins[1], rwk->ins[2], rwk->ins[3]);
157	printk("i4: %016lx i5: %016lx i6: %016lx i7: %016lx\n",
158	       rwk->ins[4], rwk->ins[5], rwk->ins[6], rwk->ins[7]);
159	if (regs->tstate & TSTATE_PRIV)
160		printk("I7: <%pS>\n", (void *) rwk->ins[7]);
161}
162
163void show_regs(struct pt_regs *regs)
164{
165	show_regs_print_info(KERN_DEFAULT);
166
167	printk("TSTATE: %016lx TPC: %016lx TNPC: %016lx Y: %08x    %s\n", regs->tstate,
168	       regs->tpc, regs->tnpc, regs->y, print_tainted());
169	printk("TPC: <%pS>\n", (void *) regs->tpc);
170	printk("g0: %016lx g1: %016lx g2: %016lx g3: %016lx\n",
171	       regs->u_regs[0], regs->u_regs[1], regs->u_regs[2],
172	       regs->u_regs[3]);
173	printk("g4: %016lx g5: %016lx g6: %016lx g7: %016lx\n",
174	       regs->u_regs[4], regs->u_regs[5], regs->u_regs[6],
175	       regs->u_regs[7]);
176	printk("o0: %016lx o1: %016lx o2: %016lx o3: %016lx\n",
177	       regs->u_regs[8], regs->u_regs[9], regs->u_regs[10],
178	       regs->u_regs[11]);
179	printk("o4: %016lx o5: %016lx sp: %016lx ret_pc: %016lx\n",
180	       regs->u_regs[12], regs->u_regs[13], regs->u_regs[14],
181	       regs->u_regs[15]);
182	printk("RPC: <%pS>\n", (void *) regs->u_regs[15]);
183	show_regwindow(regs);
184	show_stack(current, (unsigned long *)regs->u_regs[UREG_FP], KERN_DEFAULT);
185}
186
187union global_cpu_snapshot global_cpu_snapshot[NR_CPUS];
188static DEFINE_SPINLOCK(global_cpu_snapshot_lock);
189
190static void __global_reg_self(struct thread_info *tp, struct pt_regs *regs,
191			      int this_cpu)
192{
193	struct global_reg_snapshot *rp;
194
195	flushw_all();
196
197	rp = &global_cpu_snapshot[this_cpu].reg;
198
199	rp->tstate = regs->tstate;
200	rp->tpc = regs->tpc;
201	rp->tnpc = regs->tnpc;
202	rp->o7 = regs->u_regs[UREG_I7];
203
204	if (regs->tstate & TSTATE_PRIV) {
205		struct reg_window *rw;
206
207		rw = (struct reg_window *)
208			(regs->u_regs[UREG_FP] + STACK_BIAS);
209		if (kstack_valid(tp, (unsigned long) rw)) {
210			rp->i7 = rw->ins[7];
211			rw = (struct reg_window *)
212				(rw->ins[6] + STACK_BIAS);
213			if (kstack_valid(tp, (unsigned long) rw))
214				rp->rpc = rw->ins[7];
215		}
216	} else {
217		rp->i7 = 0;
218		rp->rpc = 0;
219	}
220	rp->thread = tp;
221}
222
223/* In order to avoid hangs we do not try to synchronize with the
224 * global register dump client cpus.  The last store they make is to
225 * the thread pointer, so do a short poll waiting for that to become
226 * non-NULL.
227 */
228static void __global_reg_poll(struct global_reg_snapshot *gp)
229{
230	int limit = 0;
231
232	while (!gp->thread && ++limit < 100) {
233		barrier();
234		udelay(1);
235	}
236}
237
238void arch_trigger_cpumask_backtrace(const cpumask_t *mask, bool exclude_self)
239{
240	struct thread_info *tp = current_thread_info();
241	struct pt_regs *regs = get_irq_regs();
242	unsigned long flags;
243	int this_cpu, cpu;
244
245	if (!regs)
246		regs = tp->kregs;
247
248	spin_lock_irqsave(&global_cpu_snapshot_lock, flags);
249
250	this_cpu = raw_smp_processor_id();
251
252	memset(global_cpu_snapshot, 0, sizeof(global_cpu_snapshot));
253
254	if (cpumask_test_cpu(this_cpu, mask) && !exclude_self)
255		__global_reg_self(tp, regs, this_cpu);
256
257	smp_fetch_global_regs();
258
259	for_each_cpu(cpu, mask) {
260		struct global_reg_snapshot *gp;
261
262		if (exclude_self && cpu == this_cpu)
263			continue;
264
265		gp = &global_cpu_snapshot[cpu].reg;
266
267		__global_reg_poll(gp);
268
269		tp = gp->thread;
270		printk("%c CPU[%3d]: TSTATE[%016lx] TPC[%016lx] TNPC[%016lx] TASK[%s:%d]\n",
271		       (cpu == this_cpu ? '*' : ' '), cpu,
272		       gp->tstate, gp->tpc, gp->tnpc,
273		       ((tp && tp->task) ? tp->task->comm : "NULL"),
274		       ((tp && tp->task) ? tp->task->pid : -1));
275
276		if (gp->tstate & TSTATE_PRIV) {
277			printk("             TPC[%pS] O7[%pS] I7[%pS] RPC[%pS]\n",
278			       (void *) gp->tpc,
279			       (void *) gp->o7,
280			       (void *) gp->i7,
281			       (void *) gp->rpc);
282		} else {
283			printk("             TPC[%lx] O7[%lx] I7[%lx] RPC[%lx]\n",
284			       gp->tpc, gp->o7, gp->i7, gp->rpc);
285		}
286
287		touch_nmi_watchdog();
288	}
289
290	memset(global_cpu_snapshot, 0, sizeof(global_cpu_snapshot));
291
292	spin_unlock_irqrestore(&global_cpu_snapshot_lock, flags);
293}
294
295#ifdef CONFIG_MAGIC_SYSRQ
296
297static void sysrq_handle_globreg(int key)
298{
299	trigger_all_cpu_backtrace();
300}
301
302static const struct sysrq_key_op sparc_globalreg_op = {
303	.handler	= sysrq_handle_globreg,
304	.help_msg	= "global-regs(y)",
305	.action_msg	= "Show Global CPU Regs",
306};
307
308static void __global_pmu_self(int this_cpu)
309{
310	struct global_pmu_snapshot *pp;
311	int i, num;
312
313	if (!pcr_ops)
314		return;
315
316	pp = &global_cpu_snapshot[this_cpu].pmu;
317
318	num = 1;
319	if (tlb_type == hypervisor &&
320	    sun4v_chip_type >= SUN4V_CHIP_NIAGARA4)
321		num = 4;
322
323	for (i = 0; i < num; i++) {
324		pp->pcr[i] = pcr_ops->read_pcr(i);
325		pp->pic[i] = pcr_ops->read_pic(i);
326	}
327}
328
329static void __global_pmu_poll(struct global_pmu_snapshot *pp)
330{
331	int limit = 0;
332
333	while (!pp->pcr[0] && ++limit < 100) {
334		barrier();
335		udelay(1);
336	}
337}
338
339static void pmu_snapshot_all_cpus(void)
340{
341	unsigned long flags;
342	int this_cpu, cpu;
343
344	spin_lock_irqsave(&global_cpu_snapshot_lock, flags);
345
346	memset(global_cpu_snapshot, 0, sizeof(global_cpu_snapshot));
347
348	this_cpu = raw_smp_processor_id();
349
350	__global_pmu_self(this_cpu);
351
352	smp_fetch_global_pmu();
353
354	for_each_online_cpu(cpu) {
355		struct global_pmu_snapshot *pp = &global_cpu_snapshot[cpu].pmu;
356
357		__global_pmu_poll(pp);
358
359		printk("%c CPU[%3d]: PCR[%08lx:%08lx:%08lx:%08lx] PIC[%08lx:%08lx:%08lx:%08lx]\n",
360		       (cpu == this_cpu ? '*' : ' '), cpu,
361		       pp->pcr[0], pp->pcr[1], pp->pcr[2], pp->pcr[3],
362		       pp->pic[0], pp->pic[1], pp->pic[2], pp->pic[3]);
363
364		touch_nmi_watchdog();
365	}
366
367	memset(global_cpu_snapshot, 0, sizeof(global_cpu_snapshot));
368
369	spin_unlock_irqrestore(&global_cpu_snapshot_lock, flags);
370}
371
372static void sysrq_handle_globpmu(int key)
373{
374	pmu_snapshot_all_cpus();
375}
376
377static const struct sysrq_key_op sparc_globalpmu_op = {
378	.handler	= sysrq_handle_globpmu,
379	.help_msg	= "global-pmu(x)",
380	.action_msg	= "Show Global PMU Regs",
381};
382
383static int __init sparc_sysrq_init(void)
384{
385	int ret = register_sysrq_key('y', &sparc_globalreg_op);
386
387	if (!ret)
388		ret = register_sysrq_key('x', &sparc_globalpmu_op);
389	return ret;
390}
391
392core_initcall(sparc_sysrq_init);
393
394#endif
395
396/* Free current thread data structures etc.. */
397void exit_thread(struct task_struct *tsk)
398{
399	struct thread_info *t = task_thread_info(tsk);
400
401	if (t->utraps) {
402		if (t->utraps[0] < 2)
403			kfree (t->utraps);
404		else
405			t->utraps[0]--;
406	}
407}
408
409void flush_thread(void)
410{
411	struct thread_info *t = current_thread_info();
412	struct mm_struct *mm;
413
414	mm = t->task->mm;
415	if (mm)
416		tsb_context_switch(mm);
417
418	set_thread_wsaved(0);
419
420	/* Clear FPU register state. */
421	t->fpsaved[0] = 0;
422}
423
424/* It's a bit more tricky when 64-bit tasks are involved... */
425static unsigned long clone_stackframe(unsigned long csp, unsigned long psp)
426{
427	bool stack_64bit = test_thread_64bit_stack(psp);
428	unsigned long fp, distance, rval;
429
430	if (stack_64bit) {
431		csp += STACK_BIAS;
432		psp += STACK_BIAS;
433		__get_user(fp, &(((struct reg_window __user *)psp)->ins[6]));
434		fp += STACK_BIAS;
435		if (test_thread_flag(TIF_32BIT))
436			fp &= 0xffffffff;
437	} else
438		__get_user(fp, &(((struct reg_window32 __user *)psp)->ins[6]));
439
440	/* Now align the stack as this is mandatory in the Sparc ABI
441	 * due to how register windows work.  This hides the
442	 * restriction from thread libraries etc.
443	 */
444	csp &= ~15UL;
445
446	distance = fp - psp;
447	rval = (csp - distance);
448	if (raw_copy_in_user((void __user *)rval, (void __user *)psp, distance))
449		rval = 0;
450	else if (!stack_64bit) {
451		if (put_user(((u32)csp),
452			     &(((struct reg_window32 __user *)rval)->ins[6])))
453			rval = 0;
454	} else {
455		if (put_user(((u64)csp - STACK_BIAS),
456			     &(((struct reg_window __user *)rval)->ins[6])))
457			rval = 0;
458		else
459			rval = rval - STACK_BIAS;
460	}
461
462	return rval;
463}
464
465/* Standard stuff. */
466static inline void shift_window_buffer(int first_win, int last_win,
467				       struct thread_info *t)
468{
469	int i;
470
471	for (i = first_win; i < last_win; i++) {
472		t->rwbuf_stkptrs[i] = t->rwbuf_stkptrs[i+1];
473		memcpy(&t->reg_window[i], &t->reg_window[i+1],
474		       sizeof(struct reg_window));
475	}
476}
477
478void synchronize_user_stack(void)
479{
480	struct thread_info *t = current_thread_info();
481	unsigned long window;
482
483	flush_user_windows();
484	if ((window = get_thread_wsaved()) != 0) {
485		window -= 1;
486		do {
487			struct reg_window *rwin = &t->reg_window[window];
488			int winsize = sizeof(struct reg_window);
489			unsigned long sp;
490
491			sp = t->rwbuf_stkptrs[window];
492
493			if (test_thread_64bit_stack(sp))
494				sp += STACK_BIAS;
495			else
496				winsize = sizeof(struct reg_window32);
497
498			if (!copy_to_user((char __user *)sp, rwin, winsize)) {
499				shift_window_buffer(window, get_thread_wsaved() - 1, t);
500				set_thread_wsaved(get_thread_wsaved() - 1);
501			}
502		} while (window--);
503	}
504}
505
506static void stack_unaligned(unsigned long sp)
507{
508	force_sig_fault(SIGBUS, BUS_ADRALN, (void __user *) sp);
 
 
 
 
 
 
 
509}
510
511static const char uwfault32[] = KERN_INFO \
512	"%s[%d]: bad register window fault: SP %08lx (orig_sp %08lx) TPC %08lx O7 %08lx\n";
513static const char uwfault64[] = KERN_INFO \
514	"%s[%d]: bad register window fault: SP %016lx (orig_sp %016lx) TPC %08lx O7 %016lx\n";
515
516void fault_in_user_windows(struct pt_regs *regs)
517{
518	struct thread_info *t = current_thread_info();
519	unsigned long window;
520
521	flush_user_windows();
522	window = get_thread_wsaved();
523
524	if (likely(window != 0)) {
525		window -= 1;
526		do {
527			struct reg_window *rwin = &t->reg_window[window];
528			int winsize = sizeof(struct reg_window);
529			unsigned long sp, orig_sp;
530
531			orig_sp = sp = t->rwbuf_stkptrs[window];
532
533			if (test_thread_64bit_stack(sp))
534				sp += STACK_BIAS;
535			else
536				winsize = sizeof(struct reg_window32);
537
538			if (unlikely(sp & 0x7UL))
539				stack_unaligned(sp);
540
541			if (unlikely(copy_to_user((char __user *)sp,
542						  rwin, winsize))) {
543				if (show_unhandled_signals)
544					printk_ratelimited(is_compat_task() ?
545							   uwfault32 : uwfault64,
546							   current->comm, current->pid,
547							   sp, orig_sp,
548							   regs->tpc,
549							   regs->u_regs[UREG_I7]);
550				goto barf;
551			}
552		} while (window--);
553	}
554	set_thread_wsaved(0);
555	return;
556
557barf:
558	set_thread_wsaved(window + 1);
559	force_sig(SIGSEGV);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
560}
561
562/* Copy a Sparc thread.  The fork() return value conventions
563 * under SunOS are nothing short of bletcherous:
564 * Parent -->  %o0 == childs  pid, %o1 == 0
565 * Child  -->  %o0 == parents pid, %o1 == 1
566 */
567int copy_thread(struct task_struct *p, const struct kernel_clone_args *args)
 
568{
569	unsigned long clone_flags = args->flags;
570	unsigned long sp = args->stack;
571	unsigned long tls = args->tls;
572	struct thread_info *t = task_thread_info(p);
573	struct pt_regs *regs = current_pt_regs();
574	struct sparc_stackf *parent_sf;
575	unsigned long child_stack_sz;
576	char *child_trap_frame;
577
578	/* Calculate offset to stack_frame & pt_regs */
579	child_stack_sz = (STACKFRAME_SZ + TRACEREG_SZ);
580	child_trap_frame = (task_stack_page(p) +
581			    (THREAD_SIZE - child_stack_sz));
582
583	t->new_child = 1;
584	t->ksp = ((unsigned long) child_trap_frame) - STACK_BIAS;
585	t->kregs = (struct pt_regs *) (child_trap_frame +
586				       sizeof(struct sparc_stackf));
587	t->fpsaved[0] = 0;
588
589	if (unlikely(args->fn)) {
590		memset(child_trap_frame, 0, child_stack_sz);
591		__thread_flag_byte_ptr(t)[TI_FLAG_BYTE_CWP] = 
592			(current_pt_regs()->tstate + 1) & TSTATE_CWP;
593		t->kregs->u_regs[UREG_G1] = (unsigned long) args->fn;
594		t->kregs->u_regs[UREG_G2] = (unsigned long) args->fn_arg;
 
595		return 0;
596	}
597
598	parent_sf = ((struct sparc_stackf *) regs) - 1;
599	memcpy(child_trap_frame, parent_sf, child_stack_sz);
600	if (t->flags & _TIF_32BIT) {
601		sp &= 0x00000000ffffffffUL;
602		regs->u_regs[UREG_FP] &= 0x00000000ffffffffUL;
603	}
604	t->kregs->u_regs[UREG_FP] = sp;
605	__thread_flag_byte_ptr(t)[TI_FLAG_BYTE_CWP] = 
606		(regs->tstate + 1) & TSTATE_CWP;
 
607	if (sp != regs->u_regs[UREG_FP]) {
608		unsigned long csp;
609
610		csp = clone_stackframe(sp, regs->u_regs[UREG_FP]);
611		if (!csp)
612			return -EFAULT;
613		t->kregs->u_regs[UREG_FP] = csp;
614	}
615	if (t->utraps)
616		t->utraps[0]++;
617
618	/* Set the return value for the child. */
619	t->kregs->u_regs[UREG_I0] = current->pid;
620	t->kregs->u_regs[UREG_I1] = 1;
621
622	/* Set the second return value for the parent. */
623	regs->u_regs[UREG_I1] = 0;
624
625	if (clone_flags & CLONE_SETTLS)
626		t->kregs->u_regs[UREG_G7] = tls;
627
628	return 0;
629}
630
631/* TIF_MCDPER in thread info flags for current task is updated lazily upon
632 * a context switch. Update this flag in current task's thread flags
633 * before dup so the dup'd task will inherit the current TIF_MCDPER flag.
634 */
635int arch_dup_task_struct(struct task_struct *dst, struct task_struct *src)
636{
637	if (adi_capable()) {
638		register unsigned long tmp_mcdper;
639
640		__asm__ __volatile__(
641			".word 0x83438000\n\t"	/* rd  %mcdper, %g1 */
642			"mov %%g1, %0\n\t"
643			: "=r" (tmp_mcdper)
644			:
645			: "g1");
646		if (tmp_mcdper)
647			set_thread_flag(TIF_MCDPER);
648		else
649			clear_thread_flag(TIF_MCDPER);
650	}
651
652	*dst = *src;
653	return 0;
654}
655
656unsigned long __get_wchan(struct task_struct *task)
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
657{
658	unsigned long pc, fp, bias = 0;
659	struct thread_info *tp;
660	struct reg_window *rw;
661        unsigned long ret = 0;
662	int count = 0; 
 
 
 
 
663
664	tp = task_thread_info(task);
665	bias = STACK_BIAS;
666	fp = task_thread_info(task)->ksp + bias;
667
668	do {
669		if (!kstack_valid(tp, fp))
670			break;
671		rw = (struct reg_window *) fp;
672		pc = rw->ins[7];
673		if (!in_sched_functions(pc)) {
674			ret = pc;
675			goto out;
676		}
677		fp = rw->ins[6] + bias;
678	} while (++count < 16);
679
680out:
681	return ret;
682}