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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}
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 } else {
63 unsigned long pstate;
64
65 raw_local_irq_enable();
66
67 /* The sun4v sleeping code requires that we have PSTATE.IE cleared over
68 * the cpu sleep hypervisor call.
69 */
70 __asm__ __volatile__(
71 "rdpr %%pstate, %0\n\t"
72 "andn %0, %1, %0\n\t"
73 "wrpr %0, %%g0, %%pstate"
74 : "=&r" (pstate)
75 : "i" (PSTATE_IE));
76
77 if (!need_resched() && !cpu_is_offline(smp_processor_id())) {
78 sun4v_cpu_yield();
79 /* If resumed by cpu_poke then we need to explicitly
80 * call scheduler_ipi().
81 */
82 scheduler_poke();
83 }
84
85 /* Re-enable interrupts. */
86 __asm__ __volatile__(
87 "rdpr %%pstate, %0\n\t"
88 "or %0, %1, %0\n\t"
89 "wrpr %0, %%g0, %%pstate"
90 : "=&r" (pstate)
91 : "i" (PSTATE_IE));
92
93 raw_local_irq_disable();
94 }
95}
96
97#ifdef CONFIG_HOTPLUG_CPU
98void __noreturn arch_cpu_idle_dead(void)
99{
100 sched_preempt_enable_no_resched();
101 cpu_play_dead();
102}
103#endif
104
105#ifdef CONFIG_COMPAT
106static void show_regwindow32(struct pt_regs *regs)
107{
108 struct reg_window32 __user *rw;
109 struct reg_window32 r_w;
110
111 __asm__ __volatile__ ("flushw");
112 rw = compat_ptr((unsigned int)regs->u_regs[14]);
113 if (copy_from_user (&r_w, rw, sizeof(r_w))) {
114 return;
115 }
116
117 printk("l0: %08x l1: %08x l2: %08x l3: %08x "
118 "l4: %08x l5: %08x l6: %08x l7: %08x\n",
119 r_w.locals[0], r_w.locals[1], r_w.locals[2], r_w.locals[3],
120 r_w.locals[4], r_w.locals[5], r_w.locals[6], r_w.locals[7]);
121 printk("i0: %08x i1: %08x i2: %08x i3: %08x "
122 "i4: %08x i5: %08x i6: %08x i7: %08x\n",
123 r_w.ins[0], r_w.ins[1], r_w.ins[2], r_w.ins[3],
124 r_w.ins[4], r_w.ins[5], r_w.ins[6], r_w.ins[7]);
125}
126#else
127#define show_regwindow32(regs) do { } while (0)
128#endif
129
130static void show_regwindow(struct pt_regs *regs)
131{
132 struct reg_window __user *rw;
133 struct reg_window *rwk;
134 struct reg_window r_w;
135
136 if ((regs->tstate & TSTATE_PRIV) || !(test_thread_flag(TIF_32BIT))) {
137 __asm__ __volatile__ ("flushw");
138 rw = (struct reg_window __user *)
139 (regs->u_regs[14] + STACK_BIAS);
140 rwk = (struct reg_window *)
141 (regs->u_regs[14] + STACK_BIAS);
142 if (!(regs->tstate & TSTATE_PRIV)) {
143 if (copy_from_user (&r_w, rw, sizeof(r_w))) {
144 return;
145 }
146 rwk = &r_w;
147 }
148 } else {
149 show_regwindow32(regs);
150 return;
151 }
152 printk("l0: %016lx l1: %016lx l2: %016lx l3: %016lx\n",
153 rwk->locals[0], rwk->locals[1], rwk->locals[2], rwk->locals[3]);
154 printk("l4: %016lx l5: %016lx l6: %016lx l7: %016lx\n",
155 rwk->locals[4], rwk->locals[5], rwk->locals[6], rwk->locals[7]);
156 printk("i0: %016lx i1: %016lx i2: %016lx i3: %016lx\n",
157 rwk->ins[0], rwk->ins[1], rwk->ins[2], rwk->ins[3]);
158 printk("i4: %016lx i5: %016lx i6: %016lx i7: %016lx\n",
159 rwk->ins[4], rwk->ins[5], rwk->ins[6], rwk->ins[7]);
160 if (regs->tstate & TSTATE_PRIV)
161 printk("I7: <%pS>\n", (void *) rwk->ins[7]);
162}
163
164void show_regs(struct pt_regs *regs)
165{
166 show_regs_print_info(KERN_DEFAULT);
167
168 printk("TSTATE: %016lx TPC: %016lx TNPC: %016lx Y: %08x %s\n", regs->tstate,
169 regs->tpc, regs->tnpc, regs->y, print_tainted());
170 printk("TPC: <%pS>\n", (void *) regs->tpc);
171 printk("g0: %016lx g1: %016lx g2: %016lx g3: %016lx\n",
172 regs->u_regs[0], regs->u_regs[1], regs->u_regs[2],
173 regs->u_regs[3]);
174 printk("g4: %016lx g5: %016lx g6: %016lx g7: %016lx\n",
175 regs->u_regs[4], regs->u_regs[5], regs->u_regs[6],
176 regs->u_regs[7]);
177 printk("o0: %016lx o1: %016lx o2: %016lx o3: %016lx\n",
178 regs->u_regs[8], regs->u_regs[9], regs->u_regs[10],
179 regs->u_regs[11]);
180 printk("o4: %016lx o5: %016lx sp: %016lx ret_pc: %016lx\n",
181 regs->u_regs[12], regs->u_regs[13], regs->u_regs[14],
182 regs->u_regs[15]);
183 printk("RPC: <%pS>\n", (void *) regs->u_regs[15]);
184 show_regwindow(regs);
185 show_stack(current, (unsigned long *)regs->u_regs[UREG_FP], KERN_DEFAULT);
186}
187
188union global_cpu_snapshot global_cpu_snapshot[NR_CPUS];
189static DEFINE_SPINLOCK(global_cpu_snapshot_lock);
190
191static void __global_reg_self(struct thread_info *tp, struct pt_regs *regs,
192 int this_cpu)
193{
194 struct global_reg_snapshot *rp;
195
196 flushw_all();
197
198 rp = &global_cpu_snapshot[this_cpu].reg;
199
200 rp->tstate = regs->tstate;
201 rp->tpc = regs->tpc;
202 rp->tnpc = regs->tnpc;
203 rp->o7 = regs->u_regs[UREG_I7];
204
205 if (regs->tstate & TSTATE_PRIV) {
206 struct reg_window *rw;
207
208 rw = (struct reg_window *)
209 (regs->u_regs[UREG_FP] + STACK_BIAS);
210 if (kstack_valid(tp, (unsigned long) rw)) {
211 rp->i7 = rw->ins[7];
212 rw = (struct reg_window *)
213 (rw->ins[6] + STACK_BIAS);
214 if (kstack_valid(tp, (unsigned long) rw))
215 rp->rpc = rw->ins[7];
216 }
217 } else {
218 rp->i7 = 0;
219 rp->rpc = 0;
220 }
221 rp->thread = tp;
222}
223
224/* In order to avoid hangs we do not try to synchronize with the
225 * global register dump client cpus. The last store they make is to
226 * the thread pointer, so do a short poll waiting for that to become
227 * non-NULL.
228 */
229static void __global_reg_poll(struct global_reg_snapshot *gp)
230{
231 int limit = 0;
232
233 while (!gp->thread && ++limit < 100) {
234 barrier();
235 udelay(1);
236 }
237}
238
239void arch_trigger_cpumask_backtrace(const cpumask_t *mask, int exclude_cpu)
240{
241 struct thread_info *tp = current_thread_info();
242 struct pt_regs *regs = get_irq_regs();
243 unsigned long flags;
244 int this_cpu, cpu;
245
246 if (!regs)
247 regs = tp->kregs;
248
249 spin_lock_irqsave(&global_cpu_snapshot_lock, flags);
250
251 this_cpu = raw_smp_processor_id();
252
253 memset(global_cpu_snapshot, 0, sizeof(global_cpu_snapshot));
254
255 if (cpumask_test_cpu(this_cpu, mask) && this_cpu != exclude_cpu)
256 __global_reg_self(tp, regs, this_cpu);
257
258 smp_fetch_global_regs();
259
260 for_each_cpu(cpu, mask) {
261 struct global_reg_snapshot *gp;
262
263 if (cpu == exclude_cpu)
264 continue;
265
266 gp = &global_cpu_snapshot[cpu].reg;
267
268 __global_reg_poll(gp);
269
270 tp = gp->thread;
271 printk("%c CPU[%3d]: TSTATE[%016lx] TPC[%016lx] TNPC[%016lx] TASK[%s:%d]\n",
272 (cpu == this_cpu ? '*' : ' '), cpu,
273 gp->tstate, gp->tpc, gp->tnpc,
274 ((tp && tp->task) ? tp->task->comm : "NULL"),
275 ((tp && tp->task) ? tp->task->pid : -1));
276
277 if (gp->tstate & TSTATE_PRIV) {
278 printk(" TPC[%pS] O7[%pS] I7[%pS] RPC[%pS]\n",
279 (void *) gp->tpc,
280 (void *) gp->o7,
281 (void *) gp->i7,
282 (void *) gp->rpc);
283 } else {
284 printk(" TPC[%lx] O7[%lx] I7[%lx] RPC[%lx]\n",
285 gp->tpc, gp->o7, gp->i7, gp->rpc);
286 }
287
288 touch_nmi_watchdog();
289 }
290
291 memset(global_cpu_snapshot, 0, sizeof(global_cpu_snapshot));
292
293 spin_unlock_irqrestore(&global_cpu_snapshot_lock, flags);
294}
295
296#ifdef CONFIG_MAGIC_SYSRQ
297
298static void sysrq_handle_globreg(u8 key)
299{
300 trigger_all_cpu_backtrace();
301}
302
303static const struct sysrq_key_op sparc_globalreg_op = {
304 .handler = sysrq_handle_globreg,
305 .help_msg = "global-regs(y)",
306 .action_msg = "Show Global CPU Regs",
307};
308
309static void __global_pmu_self(int this_cpu)
310{
311 struct global_pmu_snapshot *pp;
312 int i, num;
313
314 if (!pcr_ops)
315 return;
316
317 pp = &global_cpu_snapshot[this_cpu].pmu;
318
319 num = 1;
320 if (tlb_type == hypervisor &&
321 sun4v_chip_type >= SUN4V_CHIP_NIAGARA4)
322 num = 4;
323
324 for (i = 0; i < num; i++) {
325 pp->pcr[i] = pcr_ops->read_pcr(i);
326 pp->pic[i] = pcr_ops->read_pic(i);
327 }
328}
329
330static void __global_pmu_poll(struct global_pmu_snapshot *pp)
331{
332 int limit = 0;
333
334 while (!pp->pcr[0] && ++limit < 100) {
335 barrier();
336 udelay(1);
337 }
338}
339
340static void pmu_snapshot_all_cpus(void)
341{
342 unsigned long flags;
343 int this_cpu, cpu;
344
345 spin_lock_irqsave(&global_cpu_snapshot_lock, flags);
346
347 memset(global_cpu_snapshot, 0, sizeof(global_cpu_snapshot));
348
349 this_cpu = raw_smp_processor_id();
350
351 __global_pmu_self(this_cpu);
352
353 smp_fetch_global_pmu();
354
355 for_each_online_cpu(cpu) {
356 struct global_pmu_snapshot *pp = &global_cpu_snapshot[cpu].pmu;
357
358 __global_pmu_poll(pp);
359
360 printk("%c CPU[%3d]: PCR[%08lx:%08lx:%08lx:%08lx] PIC[%08lx:%08lx:%08lx:%08lx]\n",
361 (cpu == this_cpu ? '*' : ' '), cpu,
362 pp->pcr[0], pp->pcr[1], pp->pcr[2], pp->pcr[3],
363 pp->pic[0], pp->pic[1], pp->pic[2], pp->pic[3]);
364
365 touch_nmi_watchdog();
366 }
367
368 memset(global_cpu_snapshot, 0, sizeof(global_cpu_snapshot));
369
370 spin_unlock_irqrestore(&global_cpu_snapshot_lock, flags);
371}
372
373static void sysrq_handle_globpmu(u8 key)
374{
375 pmu_snapshot_all_cpus();
376}
377
378static const struct sysrq_key_op sparc_globalpmu_op = {
379 .handler = sysrq_handle_globpmu,
380 .help_msg = "global-pmu(x)",
381 .action_msg = "Show Global PMU Regs",
382};
383
384static int __init sparc_sysrq_init(void)
385{
386 int ret = register_sysrq_key('y', &sparc_globalreg_op);
387
388 if (!ret)
389 ret = register_sysrq_key('x', &sparc_globalpmu_op);
390 return ret;
391}
392
393core_initcall(sparc_sysrq_init);
394
395#endif
396
397/* Free current thread data structures etc.. */
398void exit_thread(struct task_struct *tsk)
399{
400 struct thread_info *t = task_thread_info(tsk);
401
402 if (t->utraps) {
403 if (t->utraps[0] < 2)
404 kfree (t->utraps);
405 else
406 t->utraps[0]--;
407 }
408}
409
410void flush_thread(void)
411{
412 struct thread_info *t = current_thread_info();
413 struct mm_struct *mm;
414
415 mm = t->task->mm;
416 if (mm)
417 tsb_context_switch(mm);
418
419 set_thread_wsaved(0);
420
421 /* Clear FPU register state. */
422 t->fpsaved[0] = 0;
423}
424
425/* It's a bit more tricky when 64-bit tasks are involved... */
426static unsigned long clone_stackframe(unsigned long csp, unsigned long psp)
427{
428 bool stack_64bit = test_thread_64bit_stack(psp);
429 unsigned long fp, distance, rval;
430
431 if (stack_64bit) {
432 csp += STACK_BIAS;
433 psp += STACK_BIAS;
434 __get_user(fp, &(((struct reg_window __user *)psp)->ins[6]));
435 fp += STACK_BIAS;
436 if (test_thread_flag(TIF_32BIT))
437 fp &= 0xffffffff;
438 } else
439 __get_user(fp, &(((struct reg_window32 __user *)psp)->ins[6]));
440
441 /* Now align the stack as this is mandatory in the Sparc ABI
442 * due to how register windows work. This hides the
443 * restriction from thread libraries etc.
444 */
445 csp &= ~15UL;
446
447 distance = fp - psp;
448 rval = (csp - distance);
449 if (raw_copy_in_user((void __user *)rval, (void __user *)psp, distance))
450 rval = 0;
451 else if (!stack_64bit) {
452 if (put_user(((u32)csp),
453 &(((struct reg_window32 __user *)rval)->ins[6])))
454 rval = 0;
455 } else {
456 if (put_user(((u64)csp - STACK_BIAS),
457 &(((struct reg_window __user *)rval)->ins[6])))
458 rval = 0;
459 else
460 rval = rval - STACK_BIAS;
461 }
462
463 return rval;
464}
465
466/* Standard stuff. */
467static inline void shift_window_buffer(int first_win, int last_win,
468 struct thread_info *t)
469{
470 int i;
471
472 for (i = first_win; i < last_win; i++) {
473 t->rwbuf_stkptrs[i] = t->rwbuf_stkptrs[i+1];
474 memcpy(&t->reg_window[i], &t->reg_window[i+1],
475 sizeof(struct reg_window));
476 }
477}
478
479void synchronize_user_stack(void)
480{
481 struct thread_info *t = current_thread_info();
482 unsigned long window;
483
484 flush_user_windows();
485 if ((window = get_thread_wsaved()) != 0) {
486 window -= 1;
487 do {
488 struct reg_window *rwin = &t->reg_window[window];
489 int winsize = sizeof(struct reg_window);
490 unsigned long sp;
491
492 sp = t->rwbuf_stkptrs[window];
493
494 if (test_thread_64bit_stack(sp))
495 sp += STACK_BIAS;
496 else
497 winsize = sizeof(struct reg_window32);
498
499 if (!copy_to_user((char __user *)sp, rwin, winsize)) {
500 shift_window_buffer(window, get_thread_wsaved() - 1, t);
501 set_thread_wsaved(get_thread_wsaved() - 1);
502 }
503 } while (window--);
504 }
505}
506
507static void stack_unaligned(unsigned long sp)
508{
509 force_sig_fault(SIGBUS, BUS_ADRALN, (void __user *) sp);
510}
511
512static const char uwfault32[] = KERN_INFO \
513 "%s[%d]: bad register window fault: SP %08lx (orig_sp %08lx) TPC %08lx O7 %08lx\n";
514static const char uwfault64[] = KERN_INFO \
515 "%s[%d]: bad register window fault: SP %016lx (orig_sp %016lx) TPC %08lx O7 %016lx\n";
516
517void fault_in_user_windows(struct pt_regs *regs)
518{
519 struct thread_info *t = current_thread_info();
520 unsigned long window;
521
522 flush_user_windows();
523 window = get_thread_wsaved();
524
525 if (likely(window != 0)) {
526 window -= 1;
527 do {
528 struct reg_window *rwin = &t->reg_window[window];
529 int winsize = sizeof(struct reg_window);
530 unsigned long sp, orig_sp;
531
532 orig_sp = sp = t->rwbuf_stkptrs[window];
533
534 if (test_thread_64bit_stack(sp))
535 sp += STACK_BIAS;
536 else
537 winsize = sizeof(struct reg_window32);
538
539 if (unlikely(sp & 0x7UL))
540 stack_unaligned(sp);
541
542 if (unlikely(copy_to_user((char __user *)sp,
543 rwin, winsize))) {
544 if (show_unhandled_signals)
545 printk_ratelimited(is_compat_task() ?
546 uwfault32 : uwfault64,
547 current->comm, current->pid,
548 sp, orig_sp,
549 regs->tpc,
550 regs->u_regs[UREG_I7]);
551 goto barf;
552 }
553 } while (window--);
554 }
555 set_thread_wsaved(0);
556 return;
557
558barf:
559 set_thread_wsaved(window + 1);
560 force_sig(SIGSEGV);
561}
562
563/* Copy a Sparc thread. The fork() return value conventions
564 * under SunOS are nothing short of bletcherous:
565 * Parent --> %o0 == childs pid, %o1 == 0
566 * Child --> %o0 == parents pid, %o1 == 1
567 */
568int copy_thread(struct task_struct *p, const struct kernel_clone_args *args)
569{
570 unsigned long clone_flags = args->flags;
571 unsigned long sp = args->stack;
572 unsigned long tls = args->tls;
573 struct thread_info *t = task_thread_info(p);
574 struct pt_regs *regs = current_pt_regs();
575 struct sparc_stackf *parent_sf;
576 unsigned long child_stack_sz;
577 char *child_trap_frame;
578
579 /* Calculate offset to stack_frame & pt_regs */
580 child_stack_sz = (STACKFRAME_SZ + TRACEREG_SZ);
581 child_trap_frame = (task_stack_page(p) +
582 (THREAD_SIZE - child_stack_sz));
583
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 (unlikely(args->fn)) {
591 memset(child_trap_frame, 0, child_stack_sz);
592 __thread_flag_byte_ptr(t)[TI_FLAG_BYTE_CWP] =
593 (current_pt_regs()->tstate + 1) & TSTATE_CWP;
594 t->kregs->u_regs[UREG_G1] = (unsigned long) args->fn;
595 t->kregs->u_regs[UREG_G2] = (unsigned long) args->fn_arg;
596 return 0;
597 }
598
599 parent_sf = ((struct sparc_stackf *) regs) - 1;
600 memcpy(child_trap_frame, parent_sf, child_stack_sz);
601 if (t->flags & _TIF_32BIT) {
602 sp &= 0x00000000ffffffffUL;
603 regs->u_regs[UREG_FP] &= 0x00000000ffffffffUL;
604 }
605 t->kregs->u_regs[UREG_FP] = sp;
606 __thread_flag_byte_ptr(t)[TI_FLAG_BYTE_CWP] =
607 (regs->tstate + 1) & TSTATE_CWP;
608 if (sp != regs->u_regs[UREG_FP]) {
609 unsigned long csp;
610
611 csp = clone_stackframe(sp, regs->u_regs[UREG_FP]);
612 if (!csp)
613 return -EFAULT;
614 t->kregs->u_regs[UREG_FP] = csp;
615 }
616 if (t->utraps)
617 t->utraps[0]++;
618
619 /* Set the return value for the child. */
620 t->kregs->u_regs[UREG_I0] = current->pid;
621 t->kregs->u_regs[UREG_I1] = 1;
622
623 /* Set the second return value for the parent. */
624 regs->u_regs[UREG_I1] = 0;
625
626 if (clone_flags & CLONE_SETTLS)
627 t->kregs->u_regs[UREG_G7] = tls;
628
629 return 0;
630}
631
632/* TIF_MCDPER in thread info flags for current task is updated lazily upon
633 * a context switch. Update this flag in current task's thread flags
634 * before dup so the dup'd task will inherit the current TIF_MCDPER flag.
635 */
636int arch_dup_task_struct(struct task_struct *dst, struct task_struct *src)
637{
638 if (adi_capable()) {
639 register unsigned long tmp_mcdper;
640
641 __asm__ __volatile__(
642 ".word 0x83438000\n\t" /* rd %mcdper, %g1 */
643 "mov %%g1, %0\n\t"
644 : "=r" (tmp_mcdper)
645 :
646 : "g1");
647 if (tmp_mcdper)
648 set_thread_flag(TIF_MCDPER);
649 else
650 clear_thread_flag(TIF_MCDPER);
651 }
652
653 *dst = *src;
654 return 0;
655}
656
657unsigned long __get_wchan(struct task_struct *task)
658{
659 unsigned long pc, fp, bias = 0;
660 struct thread_info *tp;
661 struct reg_window *rw;
662 unsigned long ret = 0;
663 int count = 0;
664
665 tp = task_thread_info(task);
666 bias = STACK_BIAS;
667 fp = task_thread_info(task)->ksp + bias;
668
669 do {
670 if (!kstack_valid(tp, fp))
671 break;
672 rw = (struct reg_window *) fp;
673 pc = rw->ins[7];
674 if (!in_sched_functions(pc)) {
675 ret = pc;
676 goto out;
677 }
678 fp = rw->ins[6] + bias;
679 } while (++count < 16);
680
681out:
682 return ret;
683}