1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 * Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org)
4 * Copyright 2007-2010 Freescale Semiconductor, Inc.
5 *
6 * Modified by Cort Dougan (cort@cs.nmt.edu)
7 * and Paul Mackerras (paulus@samba.org)
8 */
9
10 /*
11 * This file handles the architecture-dependent parts of hardware exceptions
12 */
13
14 #include <linux/errno.h>
15 #include <linux/sched.h>
16 #include <linux/sched/debug.h>
17 #include <linux/kernel.h>
18 #include <linux/mm.h>
19 #include <linux/pkeys.h>
20 #include <linux/stddef.h>
21 #include <linux/unistd.h>
22 #include <linux/ptrace.h>
23 #include <linux/user.h>
24 #include <linux/interrupt.h>
25 #include <linux/init.h>
26 #include <linux/extable.h>
27 #include <linux/module.h> /* print_modules */
28 #include <linux/prctl.h>
29 #include <linux/delay.h>
30 #include <linux/kprobes.h>
31 #include <linux/kexec.h>
32 #include <linux/backlight.h>
33 #include <linux/bug.h>
34 #include <linux/kdebug.h>
35 #include <linux/ratelimit.h>
36 #include <linux/context_tracking.h>
37 #include <linux/smp.h>
38 #include <linux/console.h>
39 #include <linux/kmsg_dump.h>
40 #include <linux/debugfs.h>
41
42 #include <asm/emulated_ops.h>
43 #include <linux/uaccess.h>
44 #include <asm/interrupt.h>
45 #include <asm/io.h>
46 #include <asm/machdep.h>
47 #include <asm/rtas.h>
48 #include <asm/pmc.h>
49 #include <asm/reg.h>
50 #ifdef CONFIG_PMAC_BACKLIGHT
51 #include <asm/backlight.h>
52 #endif
53 #ifdef CONFIG_PPC64
54 #include <asm/firmware.h>
55 #include <asm/processor.h>
56 #endif
57 #include <asm/kexec.h>
58 #include <asm/ppc-opcode.h>
59 #include <asm/rio.h>
60 #include <asm/fadump.h>
61 #include <asm/switch_to.h>
62 #include <asm/tm.h>
63 #include <asm/debug.h>
64 #include <asm/asm-prototypes.h>
65 #include <asm/hmi.h>
66 #include <sysdev/fsl_pci.h>
67 #include <asm/kprobes.h>
68 #include <asm/stacktrace.h>
69 #include <asm/nmi.h>
70 #include <asm/disassemble.h>
71 #include <asm/udbg.h>
72
73 #if defined(CONFIG_DEBUGGER) || defined(CONFIG_KEXEC_CORE)
74 int (*__debugger)(struct pt_regs *regs) __read_mostly;
75 int (*__debugger_ipi)(struct pt_regs *regs) __read_mostly;
76 int (*__debugger_bpt)(struct pt_regs *regs) __read_mostly;
77 int (*__debugger_sstep)(struct pt_regs *regs) __read_mostly;
78 int (*__debugger_iabr_match)(struct pt_regs *regs) __read_mostly;
79 int (*__debugger_break_match)(struct pt_regs *regs) __read_mostly;
80 int (*__debugger_fault_handler)(struct pt_regs *regs) __read_mostly;
81
82 EXPORT_SYMBOL(__debugger);
83 EXPORT_SYMBOL(__debugger_ipi);
84 EXPORT_SYMBOL(__debugger_bpt);
85 EXPORT_SYMBOL(__debugger_sstep);
86 EXPORT_SYMBOL(__debugger_iabr_match);
87 EXPORT_SYMBOL(__debugger_break_match);
88 EXPORT_SYMBOL(__debugger_fault_handler);
89 #endif
90
91 /* Transactional Memory trap debug */
92 #ifdef TM_DEBUG_SW
93 #define TM_DEBUG(x...) printk(KERN_INFO x)
94 #else
95 #define TM_DEBUG(x...) do { } while(0)
96 #endif
97
signame(int signr)98 static const char *signame(int signr)
99 {
100 switch (signr) {
101 case SIGBUS: return "bus error";
102 case SIGFPE: return "floating point exception";
103 case SIGILL: return "illegal instruction";
104 case SIGSEGV: return "segfault";
105 case SIGTRAP: return "unhandled trap";
106 }
107
108 return "unknown signal";
109 }
110
111 /*
112 * Trap & Exception support
113 */
114
115 #ifdef CONFIG_PMAC_BACKLIGHT
pmac_backlight_unblank(void)116 static void pmac_backlight_unblank(void)
117 {
118 mutex_lock(&pmac_backlight_mutex);
119 if (pmac_backlight) {
120 struct backlight_properties *props;
121
122 props = &pmac_backlight->props;
123 props->brightness = props->max_brightness;
124 props->power = BACKLIGHT_POWER_ON;
125 backlight_update_status(pmac_backlight);
126 }
127 mutex_unlock(&pmac_backlight_mutex);
128 }
129 #else
pmac_backlight_unblank(void)130 static inline void pmac_backlight_unblank(void) { }
131 #endif
132
133 /*
134 * If oops/die is expected to crash the machine, return true here.
135 *
136 * This should not be expected to be 100% accurate, there may be
137 * notifiers registered or other unexpected conditions that may bring
138 * down the kernel. Or if the current process in the kernel is holding
139 * locks or has other critical state, the kernel may become effectively
140 * unusable anyway.
141 */
die_will_crash(void)142 bool die_will_crash(void)
143 {
144 if (should_fadump_crash())
145 return true;
146 if (kexec_should_crash(current))
147 return true;
148 if (in_interrupt() || panic_on_oops ||
149 !current->pid || is_global_init(current))
150 return true;
151
152 return false;
153 }
154
155 static arch_spinlock_t die_lock = __ARCH_SPIN_LOCK_UNLOCKED;
156 static int die_owner = -1;
157 static unsigned int die_nest_count;
158 static int die_counter;
159
panic_flush_kmsg_start(void)160 void panic_flush_kmsg_start(void)
161 {
162 /*
163 * These are mostly taken from kernel/panic.c, but tries to do
164 * relatively minimal work. Don't use delay functions (TB may
165 * be broken), don't crash dump (need to set a firmware log),
166 * don't run notifiers. We do want to get some information to
167 * Linux console.
168 */
169 console_verbose();
170 bust_spinlocks(1);
171 }
172
panic_flush_kmsg_end(void)173 void panic_flush_kmsg_end(void)
174 {
175 kmsg_dump(KMSG_DUMP_PANIC);
176 bust_spinlocks(0);
177 debug_locks_off();
178 console_flush_on_panic(CONSOLE_FLUSH_PENDING);
179 }
180
oops_begin(struct pt_regs * regs)181 static unsigned long oops_begin(struct pt_regs *regs)
182 {
183 int cpu;
184 unsigned long flags;
185
186 oops_enter();
187
188 /* racy, but better than risking deadlock. */
189 raw_local_irq_save(flags);
190 cpu = smp_processor_id();
191 if (!arch_spin_trylock(&die_lock)) {
192 if (cpu == die_owner)
193 /* nested oops. should stop eventually */;
194 else
195 arch_spin_lock(&die_lock);
196 }
197 die_nest_count++;
198 die_owner = cpu;
199 console_verbose();
200 bust_spinlocks(1);
201 if (machine_is(powermac))
202 pmac_backlight_unblank();
203 return flags;
204 }
205 NOKPROBE_SYMBOL(oops_begin);
206
oops_end(unsigned long flags,struct pt_regs * regs,int signr)207 static void oops_end(unsigned long flags, struct pt_regs *regs,
208 int signr)
209 {
210 bust_spinlocks(0);
211 add_taint(TAINT_DIE, LOCKDEP_NOW_UNRELIABLE);
212 die_nest_count--;
213 oops_exit();
214 printk("\n");
215 if (!die_nest_count) {
216 /* Nest count reaches zero, release the lock. */
217 die_owner = -1;
218 arch_spin_unlock(&die_lock);
219 }
220 raw_local_irq_restore(flags);
221
222 /*
223 * system_reset_excption handles debugger, crash dump, panic, for 0x100
224 */
225 if (TRAP(regs) == INTERRUPT_SYSTEM_RESET)
226 return;
227
228 crash_fadump(regs, "die oops");
229
230 if (kexec_should_crash(current))
231 crash_kexec(regs);
232
233 if (!signr)
234 return;
235
236 /*
237 * While our oops output is serialised by a spinlock, output
238 * from panic() called below can race and corrupt it. If we
239 * know we are going to panic, delay for 1 second so we have a
240 * chance to get clean backtraces from all CPUs that are oopsing.
241 */
242 if (in_interrupt() || panic_on_oops || !current->pid ||
243 is_global_init(current)) {
244 mdelay(MSEC_PER_SEC);
245 }
246
247 if (panic_on_oops)
248 panic("Fatal exception");
249 make_task_dead(signr);
250 }
251 NOKPROBE_SYMBOL(oops_end);
252
get_mmu_str(void)253 static char *get_mmu_str(void)
254 {
255 if (early_radix_enabled())
256 return " MMU=Radix";
257 if (early_mmu_has_feature(MMU_FTR_HPTE_TABLE))
258 return " MMU=Hash";
259 return "";
260 }
261
__die(const char * str,struct pt_regs * regs,long err)262 static int __die(const char *str, struct pt_regs *regs, long err)
263 {
264 printk("Oops: %s, sig: %ld [#%d]\n", str, err, ++die_counter);
265
266 printk("%s PAGE_SIZE=%luK%s%s%s%s%s%s %s\n",
267 IS_ENABLED(CONFIG_CPU_LITTLE_ENDIAN) ? "LE" : "BE",
268 PAGE_SIZE / 1024, get_mmu_str(),
269 IS_ENABLED(CONFIG_PREEMPT) ? " PREEMPT" : "",
270 IS_ENABLED(CONFIG_SMP) ? " SMP" : "",
271 IS_ENABLED(CONFIG_SMP) ? (" NR_CPUS=" __stringify(NR_CPUS)) : "",
272 debug_pagealloc_enabled() ? " DEBUG_PAGEALLOC" : "",
273 IS_ENABLED(CONFIG_NUMA) ? " NUMA" : "",
274 ppc_md.name ? ppc_md.name : "");
275
276 if (notify_die(DIE_OOPS, str, regs, err, 255, SIGSEGV) == NOTIFY_STOP)
277 return 1;
278
279 print_modules();
280 show_regs(regs);
281
282 return 0;
283 }
284 NOKPROBE_SYMBOL(__die);
285
die(const char * str,struct pt_regs * regs,long err)286 void die(const char *str, struct pt_regs *regs, long err)
287 {
288 unsigned long flags;
289
290 /*
291 * system_reset_excption handles debugger, crash dump, panic, for 0x100
292 */
293 if (TRAP(regs) != INTERRUPT_SYSTEM_RESET) {
294 if (debugger(regs))
295 return;
296 }
297
298 flags = oops_begin(regs);
299 if (__die(str, regs, err))
300 err = 0;
301 oops_end(flags, regs, err);
302 }
303 NOKPROBE_SYMBOL(die);
304
user_single_step_report(struct pt_regs * regs)305 void user_single_step_report(struct pt_regs *regs)
306 {
307 force_sig_fault(SIGTRAP, TRAP_TRACE, (void __user *)regs->nip);
308 }
309
show_signal_msg(int signr,struct pt_regs * regs,int code,unsigned long addr)310 static void show_signal_msg(int signr, struct pt_regs *regs, int code,
311 unsigned long addr)
312 {
313 static DEFINE_RATELIMIT_STATE(rs, DEFAULT_RATELIMIT_INTERVAL,
314 DEFAULT_RATELIMIT_BURST);
315
316 if (!show_unhandled_signals)
317 return;
318
319 if (!unhandled_signal(current, signr))
320 return;
321
322 if (!__ratelimit(&rs))
323 return;
324
325 pr_info("%s[%d]: %s (%d) at %lx nip %lx lr %lx code %x",
326 current->comm, current->pid, signame(signr), signr,
327 addr, regs->nip, regs->link, code);
328
329 print_vma_addr(KERN_CONT " in ", regs->nip);
330
331 pr_cont("\n");
332
333 show_user_instructions(regs);
334 }
335
exception_common(int signr,struct pt_regs * regs,int code,unsigned long addr)336 static bool exception_common(int signr, struct pt_regs *regs, int code,
337 unsigned long addr)
338 {
339 if (!user_mode(regs)) {
340 die("Exception in kernel mode", regs, signr);
341 return false;
342 }
343
344 /*
345 * Must not enable interrupts even for user-mode exception, because
346 * this can be called from machine check, which may be a NMI or IRQ
347 * which don't like interrupts being enabled. Could check for
348 * in_hardirq || in_nmi perhaps, but there doesn't seem to be a good
349 * reason why _exception() should enable irqs for an exception handler,
350 * the handlers themselves do that directly.
351 */
352
353 show_signal_msg(signr, regs, code, addr);
354
355 current->thread.trap_nr = code;
356
357 return true;
358 }
359
_exception_pkey(struct pt_regs * regs,unsigned long addr,int key)360 void _exception_pkey(struct pt_regs *regs, unsigned long addr, int key)
361 {
362 if (!exception_common(SIGSEGV, regs, SEGV_PKUERR, addr))
363 return;
364
365 force_sig_pkuerr((void __user *) addr, key);
366 }
367
_exception(int signr,struct pt_regs * regs,int code,unsigned long addr)368 void _exception(int signr, struct pt_regs *regs, int code, unsigned long addr)
369 {
370 if (!exception_common(signr, regs, code, addr))
371 return;
372
373 force_sig_fault(signr, code, (void __user *)addr);
374 }
375
376 /*
377 * The interrupt architecture has a quirk in that the HV interrupts excluding
378 * the NMIs (0x100 and 0x200) do not clear MSR[RI] at entry. The first thing
379 * that an interrupt handler must do is save off a GPR into a scratch register,
380 * and all interrupts on POWERNV (HV=1) use the HSPRG1 register as scratch.
381 * Therefore an NMI can clobber an HV interrupt's live HSPRG1 without noticing
382 * that it is non-reentrant, which leads to random data corruption.
383 *
384 * The solution is for NMI interrupts in HV mode to check if they originated
385 * from these critical HV interrupt regions. If so, then mark them not
386 * recoverable.
387 *
388 * An alternative would be for HV NMIs to use SPRG for scratch to avoid the
389 * HSPRG1 clobber, however this would cause guest SPRG to be clobbered. Linux
390 * guests should always have MSR[RI]=0 when its scratch SPRG is in use, so
391 * that would work. However any other guest OS that may have the SPRG live
392 * and MSR[RI]=1 could encounter silent corruption.
393 *
394 * Builds that do not support KVM could take this second option to increase
395 * the recoverability of NMIs.
396 */
hv_nmi_check_nonrecoverable(struct pt_regs * regs)397 noinstr void hv_nmi_check_nonrecoverable(struct pt_regs *regs)
398 {
399 #ifdef CONFIG_PPC_POWERNV
400 unsigned long kbase = (unsigned long)_stext;
401 unsigned long nip = regs->nip;
402
403 if (!(regs->msr & MSR_RI))
404 return;
405 if (!(regs->msr & MSR_HV))
406 return;
407 if (user_mode(regs))
408 return;
409
410 /*
411 * Now test if the interrupt has hit a range that may be using
412 * HSPRG1 without having RI=0 (i.e., an HSRR interrupt). The
413 * problem ranges all run un-relocated. Test real and virt modes
414 * at the same time by dropping the high bit of the nip (virt mode
415 * entry points still have the +0x4000 offset).
416 */
417 nip &= ~0xc000000000000000ULL;
418 if ((nip >= 0x500 && nip < 0x600) || (nip >= 0x4500 && nip < 0x4600))
419 goto nonrecoverable;
420 if ((nip >= 0x980 && nip < 0xa00) || (nip >= 0x4980 && nip < 0x4a00))
421 goto nonrecoverable;
422 if ((nip >= 0xe00 && nip < 0xec0) || (nip >= 0x4e00 && nip < 0x4ec0))
423 goto nonrecoverable;
424 if ((nip >= 0xf80 && nip < 0xfa0) || (nip >= 0x4f80 && nip < 0x4fa0))
425 goto nonrecoverable;
426
427 /* Trampoline code runs un-relocated so subtract kbase. */
428 if (nip >= (unsigned long)(start_real_trampolines - kbase) &&
429 nip < (unsigned long)(end_real_trampolines - kbase))
430 goto nonrecoverable;
431 if (nip >= (unsigned long)(start_virt_trampolines - kbase) &&
432 nip < (unsigned long)(end_virt_trampolines - kbase))
433 goto nonrecoverable;
434 return;
435
436 nonrecoverable:
437 regs->msr &= ~MSR_RI;
438 local_paca->hsrr_valid = 0;
439 local_paca->srr_valid = 0;
440 #endif
441 }
DEFINE_INTERRUPT_HANDLER_NMI(system_reset_exception)442 DEFINE_INTERRUPT_HANDLER_NMI(system_reset_exception)
443 {
444 unsigned long hsrr0, hsrr1;
445 bool saved_hsrrs = false;
446
447 /*
448 * System reset can interrupt code where HSRRs are live and MSR[RI]=1.
449 * The system reset interrupt itself may clobber HSRRs (e.g., to call
450 * OPAL), so save them here and restore them before returning.
451 *
452 * Machine checks don't need to save HSRRs, as the real mode handler
453 * is careful to avoid them, and the regular handler is not delivered
454 * as an NMI.
455 */
456 if (cpu_has_feature(CPU_FTR_HVMODE)) {
457 hsrr0 = mfspr(SPRN_HSRR0);
458 hsrr1 = mfspr(SPRN_HSRR1);
459 saved_hsrrs = true;
460 }
461
462 hv_nmi_check_nonrecoverable(regs);
463
464 __this_cpu_inc(irq_stat.sreset_irqs);
465
466 /* See if any machine dependent calls */
467 if (ppc_md.system_reset_exception) {
468 if (ppc_md.system_reset_exception(regs))
469 goto out;
470 }
471
472 if (debugger(regs))
473 goto out;
474
475 kmsg_dump(KMSG_DUMP_OOPS);
476 /*
477 * A system reset is a request to dump, so we always send
478 * it through the crashdump code (if fadump or kdump are
479 * registered).
480 */
481 crash_fadump(regs, "System Reset");
482
483 crash_kexec(regs);
484
485 /*
486 * We aren't the primary crash CPU. We need to send it
487 * to a holding pattern to avoid it ending up in the panic
488 * code.
489 */
490 crash_kexec_secondary(regs);
491
492 /*
493 * No debugger or crash dump registered, print logs then
494 * panic.
495 */
496 die("System Reset", regs, SIGABRT);
497
498 mdelay(2*MSEC_PER_SEC); /* Wait a little while for others to print */
499 add_taint(TAINT_DIE, LOCKDEP_NOW_UNRELIABLE);
500 nmi_panic(regs, "System Reset");
501
502 out:
503 #ifdef CONFIG_PPC_BOOK3S_64
504 BUG_ON(get_paca()->in_nmi == 0);
505 if (get_paca()->in_nmi > 1)
506 die("Unrecoverable nested System Reset", regs, SIGABRT);
507 #endif
508 /* Must die if the interrupt is not recoverable */
509 if (regs_is_unrecoverable(regs)) {
510 /* For the reason explained in die_mce, nmi_exit before die */
511 nmi_exit();
512 die("Unrecoverable System Reset", regs, SIGABRT);
513 }
514
515 if (saved_hsrrs) {
516 mtspr(SPRN_HSRR0, hsrr0);
517 mtspr(SPRN_HSRR1, hsrr1);
518 }
519
520 /* What should we do here? We could issue a shutdown or hard reset. */
521
522 return 0;
523 }
524
525 /*
526 * I/O accesses can cause machine checks on powermacs.
527 * Check if the NIP corresponds to the address of a sync
528 * instruction for which there is an entry in the exception
529 * table.
530 * -- paulus.
531 */
check_io_access(struct pt_regs * regs)532 static inline int check_io_access(struct pt_regs *regs)
533 {
534 #ifdef CONFIG_PPC32
535 unsigned long msr = regs->msr;
536 const struct exception_table_entry *entry;
537 unsigned int *nip = (unsigned int *)regs->nip;
538
539 if (((msr & 0xffff0000) == 0 || (msr & (0x80000 | 0x40000)))
540 && (entry = search_exception_tables(regs->nip)) != NULL) {
541 /*
542 * Check that it's a sync instruction, or somewhere
543 * in the twi; isync; nop sequence that inb/inw/inl uses.
544 * As the address is in the exception table
545 * we should be able to read the instr there.
546 * For the debug message, we look at the preceding
547 * load or store.
548 */
549 if (*nip == PPC_RAW_NOP())
550 nip -= 2;
551 else if (*nip == PPC_RAW_ISYNC())
552 --nip;
553 if (*nip == PPC_RAW_SYNC() || get_op(*nip) == OP_TRAP) {
554 unsigned int rb;
555
556 --nip;
557 rb = (*nip >> 11) & 0x1f;
558 printk(KERN_DEBUG "%s bad port %lx at %p\n",
559 (*nip & 0x100)? "OUT to": "IN from",
560 regs->gpr[rb] - _IO_BASE, nip);
561 regs_set_recoverable(regs);
562 regs_set_return_ip(regs, extable_fixup(entry));
563 return 1;
564 }
565 }
566 #endif /* CONFIG_PPC32 */
567 return 0;
568 }
569
570 #ifdef CONFIG_PPC_ADV_DEBUG_REGS
571 /* On 4xx, the reason for the machine check or program exception
572 is in the ESR. */
573 #define get_reason(regs) ((regs)->esr)
574 #define REASON_FP ESR_FP
575 #define REASON_ILLEGAL (ESR_PIL | ESR_PUO)
576 #define REASON_PRIVILEGED ESR_PPR
577 #define REASON_TRAP ESR_PTR
578 #define REASON_PREFIXED 0
579 #define REASON_BOUNDARY 0
580
581 /* single-step stuff */
582 #define single_stepping(regs) (current->thread.debug.dbcr0 & DBCR0_IC)
583 #define clear_single_step(regs) (current->thread.debug.dbcr0 &= ~DBCR0_IC)
584 #define clear_br_trace(regs) do {} while(0)
585 #else
586 /* On non-4xx, the reason for the machine check or program
587 exception is in the MSR. */
588 #define get_reason(regs) ((regs)->msr)
589 #define REASON_TM SRR1_PROGTM
590 #define REASON_FP SRR1_PROGFPE
591 #define REASON_ILLEGAL SRR1_PROGILL
592 #define REASON_PRIVILEGED SRR1_PROGPRIV
593 #define REASON_TRAP SRR1_PROGTRAP
594 #define REASON_PREFIXED SRR1_PREFIXED
595 #define REASON_BOUNDARY SRR1_BOUNDARY
596
597 #define single_stepping(regs) ((regs)->msr & MSR_SE)
598 #define clear_single_step(regs) (regs_set_return_msr((regs), (regs)->msr & ~MSR_SE))
599 #define clear_br_trace(regs) (regs_set_return_msr((regs), (regs)->msr & ~MSR_BE))
600 #endif
601
602 #define inst_length(reason) (((reason) & REASON_PREFIXED) ? 8 : 4)
603
604 #if defined(CONFIG_PPC_E500)
machine_check_e500mc(struct pt_regs * regs)605 int machine_check_e500mc(struct pt_regs *regs)
606 {
607 unsigned long mcsr = mfspr(SPRN_MCSR);
608 unsigned long pvr = mfspr(SPRN_PVR);
609 unsigned long reason = mcsr;
610 int recoverable = 1;
611
612 if (reason & MCSR_LD) {
613 recoverable = fsl_rio_mcheck_exception(regs);
614 if (recoverable == 1)
615 goto silent_out;
616 }
617
618 printk("Machine check in kernel mode.\n");
619 printk("Caused by (from MCSR=%lx): ", reason);
620
621 if (reason & MCSR_MCP)
622 pr_cont("Machine Check Signal\n");
623
624 if (reason & MCSR_ICPERR) {
625 pr_cont("Instruction Cache Parity Error\n");
626
627 /*
628 * This is recoverable by invalidating the i-cache.
629 */
630 mtspr(SPRN_L1CSR1, mfspr(SPRN_L1CSR1) | L1CSR1_ICFI);
631 while (mfspr(SPRN_L1CSR1) & L1CSR1_ICFI)
632 ;
633
634 /*
635 * This will generally be accompanied by an instruction
636 * fetch error report -- only treat MCSR_IF as fatal
637 * if it wasn't due to an L1 parity error.
638 */
639 reason &= ~MCSR_IF;
640 }
641
642 if (reason & MCSR_DCPERR_MC) {
643 pr_cont("Data Cache Parity Error\n");
644
645 /*
646 * In write shadow mode we auto-recover from the error, but it
647 * may still get logged and cause a machine check. We should
648 * only treat the non-write shadow case as non-recoverable.
649 */
650 /* On e6500 core, L1 DCWS (Data cache write shadow mode) bit
651 * is not implemented but L1 data cache always runs in write
652 * shadow mode. Hence on data cache parity errors HW will
653 * automatically invalidate the L1 Data Cache.
654 */
655 if (PVR_VER(pvr) != PVR_VER_E6500) {
656 if (!(mfspr(SPRN_L1CSR2) & L1CSR2_DCWS))
657 recoverable = 0;
658 }
659 }
660
661 if (reason & MCSR_L2MMU_MHIT) {
662 pr_cont("Hit on multiple TLB entries\n");
663 recoverable = 0;
664 }
665
666 if (reason & MCSR_NMI)
667 pr_cont("Non-maskable interrupt\n");
668
669 if (reason & MCSR_IF) {
670 pr_cont("Instruction Fetch Error Report\n");
671 recoverable = 0;
672 }
673
674 if (reason & MCSR_LD) {
675 pr_cont("Load Error Report\n");
676 recoverable = 0;
677 }
678
679 if (reason & MCSR_ST) {
680 pr_cont("Store Error Report\n");
681 recoverable = 0;
682 }
683
684 if (reason & MCSR_LDG) {
685 pr_cont("Guarded Load Error Report\n");
686 recoverable = 0;
687 }
688
689 if (reason & MCSR_TLBSYNC)
690 pr_cont("Simultaneous tlbsync operations\n");
691
692 if (reason & MCSR_BSL2_ERR) {
693 pr_cont("Level 2 Cache Error\n");
694 recoverable = 0;
695 }
696
697 if (reason & MCSR_MAV) {
698 u64 addr;
699
700 addr = mfspr(SPRN_MCAR);
701 addr |= (u64)mfspr(SPRN_MCARU) << 32;
702
703 pr_cont("Machine Check %s Address: %#llx\n",
704 reason & MCSR_MEA ? "Effective" : "Physical", addr);
705 }
706
707 silent_out:
708 mtspr(SPRN_MCSR, mcsr);
709 return mfspr(SPRN_MCSR) == 0 && recoverable;
710 }
711
machine_check_e500(struct pt_regs * regs)712 int machine_check_e500(struct pt_regs *regs)
713 {
714 unsigned long reason = mfspr(SPRN_MCSR);
715
716 if (reason & MCSR_BUS_RBERR) {
717 if (fsl_rio_mcheck_exception(regs))
718 return 1;
719 if (fsl_pci_mcheck_exception(regs))
720 return 1;
721 }
722
723 printk("Machine check in kernel mode.\n");
724 printk("Caused by (from MCSR=%lx): ", reason);
725
726 if (reason & MCSR_MCP)
727 pr_cont("Machine Check Signal\n");
728 if (reason & MCSR_ICPERR)
729 pr_cont("Instruction Cache Parity Error\n");
730 if (reason & MCSR_DCP_PERR)
731 pr_cont("Data Cache Push Parity Error\n");
732 if (reason & MCSR_DCPERR)
733 pr_cont("Data Cache Parity Error\n");
734 if (reason & MCSR_BUS_IAERR)
735 pr_cont("Bus - Instruction Address Error\n");
736 if (reason & MCSR_BUS_RAERR)
737 pr_cont("Bus - Read Address Error\n");
738 if (reason & MCSR_BUS_WAERR)
739 pr_cont("Bus - Write Address Error\n");
740 if (reason & MCSR_BUS_IBERR)
741 pr_cont("Bus - Instruction Data Error\n");
742 if (reason & MCSR_BUS_RBERR)
743 pr_cont("Bus - Read Data Bus Error\n");
744 if (reason & MCSR_BUS_WBERR)
745 pr_cont("Bus - Write Data Bus Error\n");
746 if (reason & MCSR_BUS_IPERR)
747 pr_cont("Bus - Instruction Parity Error\n");
748 if (reason & MCSR_BUS_RPERR)
749 pr_cont("Bus - Read Parity Error\n");
750
751 return 0;
752 }
753
machine_check_generic(struct pt_regs * regs)754 int machine_check_generic(struct pt_regs *regs)
755 {
756 return 0;
757 }
758 #elif defined(CONFIG_PPC32)
machine_check_generic(struct pt_regs * regs)759 int machine_check_generic(struct pt_regs *regs)
760 {
761 unsigned long reason = regs->msr;
762
763 printk("Machine check in kernel mode.\n");
764 printk("Caused by (from SRR1=%lx): ", reason);
765 switch (reason & 0x601F0000) {
766 case 0x80000:
767 pr_cont("Machine check signal\n");
768 break;
769 case 0x40000:
770 case 0x140000: /* 7450 MSS error and TEA */
771 pr_cont("Transfer error ack signal\n");
772 break;
773 case 0x20000:
774 pr_cont("Data parity error signal\n");
775 break;
776 case 0x10000:
777 pr_cont("Address parity error signal\n");
778 break;
779 case 0x20000000:
780 pr_cont("L1 Data Cache error\n");
781 break;
782 case 0x40000000:
783 pr_cont("L1 Instruction Cache error\n");
784 break;
785 case 0x00100000:
786 pr_cont("L2 data cache parity error\n");
787 break;
788 default:
789 pr_cont("Unknown values in msr\n");
790 }
791 return 0;
792 }
793 #endif /* everything else */
794
die_mce(const char * str,struct pt_regs * regs,long err)795 void die_mce(const char *str, struct pt_regs *regs, long err)
796 {
797 /*
798 * The machine check wants to kill the interrupted context,
799 * but make_task_dead() checks for in_interrupt() and panics
800 * in that case, so exit the irq/nmi before calling die.
801 */
802 if (in_nmi())
803 nmi_exit();
804 else
805 irq_exit();
806 die(str, regs, err);
807 }
808
809 /*
810 * BOOK3S_64 does not usually call this handler as a non-maskable interrupt
811 * (it uses its own early real-mode handler to handle the MCE proper
812 * and then raises irq_work to call this handler when interrupts are
813 * enabled). The only time when this is not true is if the early handler
814 * is unrecoverable, then it does call this directly to try to get a
815 * message out.
816 */
__machine_check_exception(struct pt_regs * regs)817 static void __machine_check_exception(struct pt_regs *regs)
818 {
819 int recover = 0;
820
821 __this_cpu_inc(irq_stat.mce_exceptions);
822
823 add_taint(TAINT_MACHINE_CHECK, LOCKDEP_NOW_UNRELIABLE);
824
825 /* See if any machine dependent calls. In theory, we would want
826 * to call the CPU first, and call the ppc_md. one if the CPU
827 * one returns a positive number. However there is existing code
828 * that assumes the board gets a first chance, so let's keep it
829 * that way for now and fix things later. --BenH.
830 */
831 if (ppc_md.machine_check_exception)
832 recover = ppc_md.machine_check_exception(regs);
833 else if (cur_cpu_spec->machine_check)
834 recover = cur_cpu_spec->machine_check(regs);
835
836 if (recover > 0)
837 goto bail;
838
839 if (debugger_fault_handler(regs))
840 goto bail;
841
842 if (check_io_access(regs))
843 goto bail;
844
845 die_mce("Machine check", regs, SIGBUS);
846
847 bail:
848 /* Must die if the interrupt is not recoverable */
849 if (regs_is_unrecoverable(regs))
850 die_mce("Unrecoverable Machine check", regs, SIGBUS);
851 }
852
853 #ifdef CONFIG_PPC_BOOK3S_64
DEFINE_INTERRUPT_HANDLER_RAW(machine_check_early_boot)854 DEFINE_INTERRUPT_HANDLER_RAW(machine_check_early_boot)
855 {
856 udbg_printf("Machine check (early boot)\n");
857 udbg_printf("SRR0=0x%016lx SRR1=0x%016lx\n", regs->nip, regs->msr);
858 udbg_printf(" DAR=0x%016lx DSISR=0x%08lx\n", regs->dar, regs->dsisr);
859 udbg_printf(" LR=0x%016lx R1=0x%08lx\n", regs->link, regs->gpr[1]);
860 udbg_printf("------\n");
861 die("Machine check (early boot)", regs, SIGBUS);
862 for (;;)
863 ;
864 return 0;
865 }
866
DEFINE_INTERRUPT_HANDLER_ASYNC(machine_check_exception_async)867 DEFINE_INTERRUPT_HANDLER_ASYNC(machine_check_exception_async)
868 {
869 __machine_check_exception(regs);
870 }
871 #endif
DEFINE_INTERRUPT_HANDLER_NMI(machine_check_exception)872 DEFINE_INTERRUPT_HANDLER_NMI(machine_check_exception)
873 {
874 __machine_check_exception(regs);
875
876 return 0;
877 }
878
DEFINE_INTERRUPT_HANDLER(SMIException)879 DEFINE_INTERRUPT_HANDLER(SMIException) /* async? */
880 {
881 die("System Management Interrupt", regs, SIGABRT);
882 }
883
884 #ifdef CONFIG_VSX
p9_hmi_special_emu(struct pt_regs * regs)885 static void p9_hmi_special_emu(struct pt_regs *regs)
886 {
887 unsigned int ra, rb, t, i, sel, instr, rc;
888 const void __user *addr;
889 u8 vbuf[16] __aligned(16), *vdst;
890 unsigned long ea, msr, msr_mask;
891 bool swap;
892
893 if (__get_user(instr, (unsigned int __user *)regs->nip))
894 return;
895
896 /*
897 * lxvb16x opcode: 0x7c0006d8
898 * lxvd2x opcode: 0x7c000698
899 * lxvh8x opcode: 0x7c000658
900 * lxvw4x opcode: 0x7c000618
901 */
902 if ((instr & 0xfc00073e) != 0x7c000618) {
903 pr_devel("HMI vec emu: not vector CI %i:%s[%d] nip=%016lx"
904 " instr=%08x\n",
905 smp_processor_id(), current->comm, current->pid,
906 regs->nip, instr);
907 return;
908 }
909
910 /* Grab vector registers into the task struct */
911 msr = regs->msr; /* Grab msr before we flush the bits */
912 flush_vsx_to_thread(current);
913 enable_kernel_altivec();
914
915 /*
916 * Is userspace running with a different endian (this is rare but
917 * not impossible)
918 */
919 swap = (msr & MSR_LE) != (MSR_KERNEL & MSR_LE);
920
921 /* Decode the instruction */
922 ra = (instr >> 16) & 0x1f;
923 rb = (instr >> 11) & 0x1f;
924 t = (instr >> 21) & 0x1f;
925 if (instr & 1)
926 vdst = (u8 *)¤t->thread.vr_state.vr[t];
927 else
928 vdst = (u8 *)¤t->thread.fp_state.fpr[t][0];
929
930 /* Grab the vector address */
931 ea = regs->gpr[rb] + (ra ? regs->gpr[ra] : 0);
932 if (is_32bit_task())
933 ea &= 0xfffffffful;
934 addr = (__force const void __user *)ea;
935
936 /* Check it */
937 if (!access_ok(addr, 16)) {
938 pr_devel("HMI vec emu: bad access %i:%s[%d] nip=%016lx"
939 " instr=%08x addr=%016lx\n",
940 smp_processor_id(), current->comm, current->pid,
941 regs->nip, instr, (unsigned long)addr);
942 return;
943 }
944
945 /* Read the vector */
946 rc = 0;
947 if ((unsigned long)addr & 0xfUL)
948 /* unaligned case */
949 rc = __copy_from_user_inatomic(vbuf, addr, 16);
950 else
951 __get_user_atomic_128_aligned(vbuf, addr, rc);
952 if (rc) {
953 pr_devel("HMI vec emu: page fault %i:%s[%d] nip=%016lx"
954 " instr=%08x addr=%016lx\n",
955 smp_processor_id(), current->comm, current->pid,
956 regs->nip, instr, (unsigned long)addr);
957 return;
958 }
959
960 pr_devel("HMI vec emu: emulated vector CI %i:%s[%d] nip=%016lx"
961 " instr=%08x addr=%016lx\n",
962 smp_processor_id(), current->comm, current->pid, regs->nip,
963 instr, (unsigned long) addr);
964
965 /* Grab instruction "selector" */
966 sel = (instr >> 6) & 3;
967
968 /*
969 * Check to make sure the facility is actually enabled. This
970 * could happen if we get a false positive hit.
971 *
972 * lxvd2x/lxvw4x always check MSR VSX sel = 0,2
973 * lxvh8x/lxvb16x check MSR VSX or VEC depending on VSR used sel = 1,3
974 */
975 msr_mask = MSR_VSX;
976 if ((sel & 1) && (instr & 1)) /* lxvh8x & lxvb16x + VSR >= 32 */
977 msr_mask = MSR_VEC;
978 if (!(msr & msr_mask)) {
979 pr_devel("HMI vec emu: MSR fac clear %i:%s[%d] nip=%016lx"
980 " instr=%08x msr:%016lx\n",
981 smp_processor_id(), current->comm, current->pid,
982 regs->nip, instr, msr);
983 return;
984 }
985
986 /* Do logging here before we modify sel based on endian */
987 switch (sel) {
988 case 0: /* lxvw4x */
989 PPC_WARN_EMULATED(lxvw4x, regs);
990 break;
991 case 1: /* lxvh8x */
992 PPC_WARN_EMULATED(lxvh8x, regs);
993 break;
994 case 2: /* lxvd2x */
995 PPC_WARN_EMULATED(lxvd2x, regs);
996 break;
997 case 3: /* lxvb16x */
998 PPC_WARN_EMULATED(lxvb16x, regs);
999 break;
1000 }
1001
1002 #ifdef __LITTLE_ENDIAN__
1003 /*
1004 * An LE kernel stores the vector in the task struct as an LE
1005 * byte array (effectively swapping both the components and
1006 * the content of the components). Those instructions expect
1007 * the components to remain in ascending address order, so we
1008 * swap them back.
1009 *
1010 * If we are running a BE user space, the expectation is that
1011 * of a simple memcpy, so forcing the emulation to look like
1012 * a lxvb16x should do the trick.
1013 */
1014 if (swap)
1015 sel = 3;
1016
1017 switch (sel) {
1018 case 0: /* lxvw4x */
1019 for (i = 0; i < 4; i++)
1020 ((u32 *)vdst)[i] = ((u32 *)vbuf)[3-i];
1021 break;
1022 case 1: /* lxvh8x */
1023 for (i = 0; i < 8; i++)
1024 ((u16 *)vdst)[i] = ((u16 *)vbuf)[7-i];
1025 break;
1026 case 2: /* lxvd2x */
1027 for (i = 0; i < 2; i++)
1028 ((u64 *)vdst)[i] = ((u64 *)vbuf)[1-i];
1029 break;
1030 case 3: /* lxvb16x */
1031 for (i = 0; i < 16; i++)
1032 vdst[i] = vbuf[15-i];
1033 break;
1034 }
1035 #else /* __LITTLE_ENDIAN__ */
1036 /* On a big endian kernel, a BE userspace only needs a memcpy */
1037 if (!swap)
1038 sel = 3;
1039
1040 /* Otherwise, we need to swap the content of the components */
1041 switch (sel) {
1042 case 0: /* lxvw4x */
1043 for (i = 0; i < 4; i++)
1044 ((u32 *)vdst)[i] = cpu_to_le32(((u32 *)vbuf)[i]);
1045 break;
1046 case 1: /* lxvh8x */
1047 for (i = 0; i < 8; i++)
1048 ((u16 *)vdst)[i] = cpu_to_le16(((u16 *)vbuf)[i]);
1049 break;
1050 case 2: /* lxvd2x */
1051 for (i = 0; i < 2; i++)
1052 ((u64 *)vdst)[i] = cpu_to_le64(((u64 *)vbuf)[i]);
1053 break;
1054 case 3: /* lxvb16x */
1055 memcpy(vdst, vbuf, 16);
1056 break;
1057 }
1058 #endif /* !__LITTLE_ENDIAN__ */
1059
1060 /* Go to next instruction */
1061 regs_add_return_ip(regs, 4);
1062 }
1063 #endif /* CONFIG_VSX */
1064
DEFINE_INTERRUPT_HANDLER_ASYNC(handle_hmi_exception)1065 DEFINE_INTERRUPT_HANDLER_ASYNC(handle_hmi_exception)
1066 {
1067 struct pt_regs *old_regs;
1068
1069 old_regs = set_irq_regs(regs);
1070
1071 #ifdef CONFIG_VSX
1072 /* Real mode flagged P9 special emu is needed */
1073 if (local_paca->hmi_p9_special_emu) {
1074 local_paca->hmi_p9_special_emu = 0;
1075
1076 /*
1077 * We don't want to take page faults while doing the
1078 * emulation, we just replay the instruction if necessary.
1079 */
1080 pagefault_disable();
1081 p9_hmi_special_emu(regs);
1082 pagefault_enable();
1083 }
1084 #endif /* CONFIG_VSX */
1085
1086 if (ppc_md.handle_hmi_exception)
1087 ppc_md.handle_hmi_exception(regs);
1088
1089 set_irq_regs(old_regs);
1090 }
1091
DEFINE_INTERRUPT_HANDLER(unknown_exception)1092 DEFINE_INTERRUPT_HANDLER(unknown_exception)
1093 {
1094 printk("Bad trap at PC: %lx, SR: %lx, vector=%lx\n",
1095 regs->nip, regs->msr, regs->trap);
1096
1097 _exception(SIGTRAP, regs, TRAP_UNK, 0);
1098 }
1099
DEFINE_INTERRUPT_HANDLER_ASYNC(unknown_async_exception)1100 DEFINE_INTERRUPT_HANDLER_ASYNC(unknown_async_exception)
1101 {
1102 printk("Bad trap at PC: %lx, SR: %lx, vector=%lx\n",
1103 regs->nip, regs->msr, regs->trap);
1104
1105 _exception(SIGTRAP, regs, TRAP_UNK, 0);
1106 }
1107
DEFINE_INTERRUPT_HANDLER_NMI(unknown_nmi_exception)1108 DEFINE_INTERRUPT_HANDLER_NMI(unknown_nmi_exception)
1109 {
1110 printk("Bad trap at PC: %lx, SR: %lx, vector=%lx\n",
1111 regs->nip, regs->msr, regs->trap);
1112
1113 _exception(SIGTRAP, regs, TRAP_UNK, 0);
1114
1115 return 0;
1116 }
1117
DEFINE_INTERRUPT_HANDLER(instruction_breakpoint_exception)1118 DEFINE_INTERRUPT_HANDLER(instruction_breakpoint_exception)
1119 {
1120 if (notify_die(DIE_IABR_MATCH, "iabr_match", regs, 5,
1121 5, SIGTRAP) == NOTIFY_STOP)
1122 return;
1123 if (debugger_iabr_match(regs))
1124 return;
1125 _exception(SIGTRAP, regs, TRAP_BRKPT, regs->nip);
1126 }
1127
DEFINE_INTERRUPT_HANDLER(RunModeException)1128 DEFINE_INTERRUPT_HANDLER(RunModeException)
1129 {
1130 _exception(SIGTRAP, regs, TRAP_UNK, 0);
1131 }
1132
__single_step_exception(struct pt_regs * regs)1133 static void __single_step_exception(struct pt_regs *regs)
1134 {
1135 clear_single_step(regs);
1136 clear_br_trace(regs);
1137
1138 if (kprobe_post_handler(regs))
1139 return;
1140
1141 if (notify_die(DIE_SSTEP, "single_step", regs, 5,
1142 5, SIGTRAP) == NOTIFY_STOP)
1143 return;
1144 if (debugger_sstep(regs))
1145 return;
1146
1147 _exception(SIGTRAP, regs, TRAP_TRACE, regs->nip);
1148 }
1149
DEFINE_INTERRUPT_HANDLER(single_step_exception)1150 DEFINE_INTERRUPT_HANDLER(single_step_exception)
1151 {
1152 __single_step_exception(regs);
1153 }
1154
1155 /*
1156 * After we have successfully emulated an instruction, we have to
1157 * check if the instruction was being single-stepped, and if so,
1158 * pretend we got a single-step exception. This was pointed out
1159 * by Kumar Gala. -- paulus
1160 */
emulate_single_step(struct pt_regs * regs)1161 void emulate_single_step(struct pt_regs *regs)
1162 {
1163 if (single_stepping(regs))
1164 __single_step_exception(regs);
1165 }
1166
1167 #ifdef CONFIG_PPC_FPU_REGS
__parse_fpscr(unsigned long fpscr)1168 static inline int __parse_fpscr(unsigned long fpscr)
1169 {
1170 int ret = FPE_FLTUNK;
1171
1172 /* Invalid operation */
1173 if ((fpscr & FPSCR_VE) && (fpscr & FPSCR_VX))
1174 ret = FPE_FLTINV;
1175
1176 /* Overflow */
1177 else if ((fpscr & FPSCR_OE) && (fpscr & FPSCR_OX))
1178 ret = FPE_FLTOVF;
1179
1180 /* Underflow */
1181 else if ((fpscr & FPSCR_UE) && (fpscr & FPSCR_UX))
1182 ret = FPE_FLTUND;
1183
1184 /* Divide by zero */
1185 else if ((fpscr & FPSCR_ZE) && (fpscr & FPSCR_ZX))
1186 ret = FPE_FLTDIV;
1187
1188 /* Inexact result */
1189 else if ((fpscr & FPSCR_XE) && (fpscr & FPSCR_XX))
1190 ret = FPE_FLTRES;
1191
1192 return ret;
1193 }
1194 #endif
1195
parse_fpe(struct pt_regs * regs)1196 static void parse_fpe(struct pt_regs *regs)
1197 {
1198 int code = 0;
1199
1200 flush_fp_to_thread(current);
1201
1202 #ifdef CONFIG_PPC_FPU_REGS
1203 code = __parse_fpscr(current->thread.fp_state.fpscr);
1204 #endif
1205
1206 _exception(SIGFPE, regs, code, regs->nip);
1207 }
1208
1209 /*
1210 * Illegal instruction emulation support. Originally written to
1211 * provide the PVR to user applications using the mfspr rd, PVR.
1212 * Return non-zero if we can't emulate, or -EFAULT if the associated
1213 * memory access caused an access fault. Return zero on success.
1214 *
1215 * There are a couple of ways to do this, either "decode" the instruction
1216 * or directly match lots of bits. In this case, matching lots of
1217 * bits is faster and easier.
1218 *
1219 */
emulate_string_inst(struct pt_regs * regs,u32 instword)1220 static int emulate_string_inst(struct pt_regs *regs, u32 instword)
1221 {
1222 u8 rT = (instword >> 21) & 0x1f;
1223 u8 rA = (instword >> 16) & 0x1f;
1224 u8 NB_RB = (instword >> 11) & 0x1f;
1225 u32 num_bytes;
1226 unsigned long EA;
1227 int pos = 0;
1228
1229 /* Early out if we are an invalid form of lswx */
1230 if ((instword & PPC_INST_STRING_MASK) == PPC_INST_LSWX)
1231 if ((rT == rA) || (rT == NB_RB))
1232 return -EINVAL;
1233
1234 EA = (rA == 0) ? 0 : regs->gpr[rA];
1235
1236 switch (instword & PPC_INST_STRING_MASK) {
1237 case PPC_INST_LSWX:
1238 case PPC_INST_STSWX:
1239 EA += NB_RB;
1240 num_bytes = regs->xer & 0x7f;
1241 break;
1242 case PPC_INST_LSWI:
1243 case PPC_INST_STSWI:
1244 num_bytes = (NB_RB == 0) ? 32 : NB_RB;
1245 break;
1246 default:
1247 return -EINVAL;
1248 }
1249
1250 while (num_bytes != 0)
1251 {
1252 u8 val;
1253 u32 shift = 8 * (3 - (pos & 0x3));
1254
1255 /* if process is 32-bit, clear upper 32 bits of EA */
1256 if ((regs->msr & MSR_64BIT) == 0)
1257 EA &= 0xFFFFFFFF;
1258
1259 switch ((instword & PPC_INST_STRING_MASK)) {
1260 case PPC_INST_LSWX:
1261 case PPC_INST_LSWI:
1262 if (get_user(val, (u8 __user *)EA))
1263 return -EFAULT;
1264 /* first time updating this reg,
1265 * zero it out */
1266 if (pos == 0)
1267 regs->gpr[rT] = 0;
1268 regs->gpr[rT] |= val << shift;
1269 break;
1270 case PPC_INST_STSWI:
1271 case PPC_INST_STSWX:
1272 val = regs->gpr[rT] >> shift;
1273 if (put_user(val, (u8 __user *)EA))
1274 return -EFAULT;
1275 break;
1276 }
1277 /* move EA to next address */
1278 EA += 1;
1279 num_bytes--;
1280
1281 /* manage our position within the register */
1282 if (++pos == 4) {
1283 pos = 0;
1284 if (++rT == 32)
1285 rT = 0;
1286 }
1287 }
1288
1289 return 0;
1290 }
1291
emulate_popcntb_inst(struct pt_regs * regs,u32 instword)1292 static int emulate_popcntb_inst(struct pt_regs *regs, u32 instword)
1293 {
1294 u32 ra,rs;
1295 unsigned long tmp;
1296
1297 ra = (instword >> 16) & 0x1f;
1298 rs = (instword >> 21) & 0x1f;
1299
1300 tmp = regs->gpr[rs];
1301 tmp = tmp - ((tmp >> 1) & 0x5555555555555555ULL);
1302 tmp = (tmp & 0x3333333333333333ULL) + ((tmp >> 2) & 0x3333333333333333ULL);
1303 tmp = (tmp + (tmp >> 4)) & 0x0f0f0f0f0f0f0f0fULL;
1304 regs->gpr[ra] = tmp;
1305
1306 return 0;
1307 }
1308
emulate_isel(struct pt_regs * regs,u32 instword)1309 static int emulate_isel(struct pt_regs *regs, u32 instword)
1310 {
1311 u8 rT = (instword >> 21) & 0x1f;
1312 u8 rA = (instword >> 16) & 0x1f;
1313 u8 rB = (instword >> 11) & 0x1f;
1314 u8 BC = (instword >> 6) & 0x1f;
1315 u8 bit;
1316 unsigned long tmp;
1317
1318 tmp = (rA == 0) ? 0 : regs->gpr[rA];
1319 bit = (regs->ccr >> (31 - BC)) & 0x1;
1320
1321 regs->gpr[rT] = bit ? tmp : regs->gpr[rB];
1322
1323 return 0;
1324 }
1325
1326 #ifdef CONFIG_PPC_TRANSACTIONAL_MEM
tm_abort_check(struct pt_regs * regs,int cause)1327 static inline bool tm_abort_check(struct pt_regs *regs, int cause)
1328 {
1329 /* If we're emulating a load/store in an active transaction, we cannot
1330 * emulate it as the kernel operates in transaction suspended context.
1331 * We need to abort the transaction. This creates a persistent TM
1332 * abort so tell the user what caused it with a new code.
1333 */
1334 if (MSR_TM_TRANSACTIONAL(regs->msr)) {
1335 tm_enable();
1336 tm_abort(cause);
1337 return true;
1338 }
1339 return false;
1340 }
1341 #else
tm_abort_check(struct pt_regs * regs,int reason)1342 static inline bool tm_abort_check(struct pt_regs *regs, int reason)
1343 {
1344 return false;
1345 }
1346 #endif
1347
emulate_instruction(struct pt_regs * regs)1348 static int emulate_instruction(struct pt_regs *regs)
1349 {
1350 u32 instword;
1351 u32 rd;
1352
1353 if (!user_mode(regs))
1354 return -EINVAL;
1355
1356 if (get_user(instword, (u32 __user *)(regs->nip)))
1357 return -EFAULT;
1358
1359 /* Emulate the mfspr rD, PVR. */
1360 if ((instword & PPC_INST_MFSPR_PVR_MASK) == PPC_INST_MFSPR_PVR) {
1361 PPC_WARN_EMULATED(mfpvr, regs);
1362 rd = (instword >> 21) & 0x1f;
1363 regs->gpr[rd] = mfspr(SPRN_PVR);
1364 return 0;
1365 }
1366
1367 /* Emulating the dcba insn is just a no-op. */
1368 if ((instword & PPC_INST_DCBA_MASK) == PPC_INST_DCBA) {
1369 PPC_WARN_EMULATED(dcba, regs);
1370 return 0;
1371 }
1372
1373 /* Emulate the mcrxr insn. */
1374 if ((instword & PPC_INST_MCRXR_MASK) == PPC_INST_MCRXR) {
1375 int shift = (instword >> 21) & 0x1c;
1376 unsigned long msk = 0xf0000000UL >> shift;
1377
1378 PPC_WARN_EMULATED(mcrxr, regs);
1379 regs->ccr = (regs->ccr & ~msk) | ((regs->xer >> shift) & msk);
1380 regs->xer &= ~0xf0000000UL;
1381 return 0;
1382 }
1383
1384 /* Emulate load/store string insn. */
1385 if ((instword & PPC_INST_STRING_GEN_MASK) == PPC_INST_STRING) {
1386 if (tm_abort_check(regs,
1387 TM_CAUSE_EMULATE | TM_CAUSE_PERSISTENT))
1388 return -EINVAL;
1389 PPC_WARN_EMULATED(string, regs);
1390 return emulate_string_inst(regs, instword);
1391 }
1392
1393 /* Emulate the popcntb (Population Count Bytes) instruction. */
1394 if ((instword & PPC_INST_POPCNTB_MASK) == PPC_INST_POPCNTB) {
1395 PPC_WARN_EMULATED(popcntb, regs);
1396 return emulate_popcntb_inst(regs, instword);
1397 }
1398
1399 /* Emulate isel (Integer Select) instruction */
1400 if ((instword & PPC_INST_ISEL_MASK) == PPC_INST_ISEL) {
1401 PPC_WARN_EMULATED(isel, regs);
1402 return emulate_isel(regs, instword);
1403 }
1404
1405 /* Emulate sync instruction variants */
1406 if ((instword & PPC_INST_SYNC_MASK) == PPC_INST_SYNC) {
1407 PPC_WARN_EMULATED(sync, regs);
1408 asm volatile("sync");
1409 return 0;
1410 }
1411
1412 #ifdef CONFIG_PPC64
1413 /* Emulate the mfspr rD, DSCR. */
1414 if ((((instword & PPC_INST_MFSPR_DSCR_USER_MASK) ==
1415 PPC_INST_MFSPR_DSCR_USER) ||
1416 ((instword & PPC_INST_MFSPR_DSCR_MASK) ==
1417 PPC_INST_MFSPR_DSCR)) &&
1418 cpu_has_feature(CPU_FTR_DSCR)) {
1419 PPC_WARN_EMULATED(mfdscr, regs);
1420 rd = (instword >> 21) & 0x1f;
1421 regs->gpr[rd] = mfspr(SPRN_DSCR);
1422 return 0;
1423 }
1424 /* Emulate the mtspr DSCR, rD. */
1425 if ((((instword & PPC_INST_MTSPR_DSCR_USER_MASK) ==
1426 PPC_INST_MTSPR_DSCR_USER) ||
1427 ((instword & PPC_INST_MTSPR_DSCR_MASK) ==
1428 PPC_INST_MTSPR_DSCR)) &&
1429 cpu_has_feature(CPU_FTR_DSCR)) {
1430 PPC_WARN_EMULATED(mtdscr, regs);
1431 rd = (instword >> 21) & 0x1f;
1432 current->thread.dscr = regs->gpr[rd];
1433 current->thread.dscr_inherit = 1;
1434 mtspr(SPRN_DSCR, current->thread.dscr);
1435 return 0;
1436 }
1437 #endif
1438
1439 return -EINVAL;
1440 }
1441
1442 #ifdef CONFIG_GENERIC_BUG
is_valid_bugaddr(unsigned long addr)1443 int is_valid_bugaddr(unsigned long addr)
1444 {
1445 return is_kernel_addr(addr);
1446 }
1447 #endif
1448
1449 #ifdef CONFIG_MATH_EMULATION
emulate_math(struct pt_regs * regs)1450 static int emulate_math(struct pt_regs *regs)
1451 {
1452 int ret;
1453
1454 ret = do_mathemu(regs);
1455 if (ret >= 0)
1456 PPC_WARN_EMULATED(math, regs);
1457
1458 switch (ret) {
1459 case 0:
1460 emulate_single_step(regs);
1461 return 0;
1462 case 1: {
1463 int code = 0;
1464 code = __parse_fpscr(current->thread.fp_state.fpscr);
1465 _exception(SIGFPE, regs, code, regs->nip);
1466 return 0;
1467 }
1468 case -EFAULT:
1469 _exception(SIGSEGV, regs, SEGV_MAPERR, regs->nip);
1470 return 0;
1471 }
1472
1473 return -1;
1474 }
1475 #else
emulate_math(struct pt_regs * regs)1476 static inline int emulate_math(struct pt_regs *regs) { return -1; }
1477 #endif
1478
do_program_check(struct pt_regs * regs)1479 static void do_program_check(struct pt_regs *regs)
1480 {
1481 unsigned int reason = get_reason(regs);
1482
1483 /* We can now get here via a FP Unavailable exception if the core
1484 * has no FPU, in that case the reason flags will be 0 */
1485
1486 if (reason & REASON_FP) {
1487 /* IEEE FP exception */
1488 parse_fpe(regs);
1489 return;
1490 }
1491 if (reason & REASON_TRAP) {
1492 unsigned long bugaddr;
1493 /* Debugger is first in line to stop recursive faults in
1494 * rcu_lock, notify_die, or atomic_notifier_call_chain */
1495 if (debugger_bpt(regs))
1496 return;
1497
1498 if (kprobe_handler(regs))
1499 return;
1500
1501 /* trap exception */
1502 if (notify_die(DIE_BPT, "breakpoint", regs, 5, 5, SIGTRAP)
1503 == NOTIFY_STOP)
1504 return;
1505
1506 bugaddr = regs->nip;
1507 /*
1508 * Fixup bugaddr for BUG_ON() in real mode
1509 */
1510 if (!is_kernel_addr(bugaddr) && !(regs->msr & MSR_IR))
1511 bugaddr += PAGE_OFFSET;
1512
1513 if (!user_mode(regs) &&
1514 report_bug(bugaddr, regs) == BUG_TRAP_TYPE_WARN) {
1515 regs_add_return_ip(regs, 4);
1516 return;
1517 }
1518
1519 /* User mode considers other cases after enabling IRQs */
1520 if (!user_mode(regs)) {
1521 _exception(SIGTRAP, regs, TRAP_BRKPT, regs->nip);
1522 return;
1523 }
1524 }
1525 #ifdef CONFIG_PPC_TRANSACTIONAL_MEM
1526 if (reason & REASON_TM) {
1527 /* This is a TM "Bad Thing Exception" program check.
1528 * This occurs when:
1529 * - An rfid/hrfid/mtmsrd attempts to cause an illegal
1530 * transition in TM states.
1531 * - A trechkpt is attempted when transactional.
1532 * - A treclaim is attempted when non transactional.
1533 * - A tend is illegally attempted.
1534 * - writing a TM SPR when transactional.
1535 *
1536 * If usermode caused this, it's done something illegal and
1537 * gets a SIGILL slap on the wrist. We call it an illegal
1538 * operand to distinguish from the instruction just being bad
1539 * (e.g. executing a 'tend' on a CPU without TM!); it's an
1540 * illegal /placement/ of a valid instruction.
1541 */
1542 if (user_mode(regs)) {
1543 _exception(SIGILL, regs, ILL_ILLOPN, regs->nip);
1544 return;
1545 } else {
1546 printk(KERN_EMERG "Unexpected TM Bad Thing exception "
1547 "at %lx (msr 0x%lx) tm_scratch=%llx\n",
1548 regs->nip, regs->msr, get_paca()->tm_scratch);
1549 die("Unrecoverable exception", regs, SIGABRT);
1550 }
1551 }
1552 #endif
1553
1554 /*
1555 * If we took the program check in the kernel skip down to sending a
1556 * SIGILL. The subsequent cases all relate to user space, such as
1557 * emulating instructions which we should only do for user space. We
1558 * also do not want to enable interrupts for kernel faults because that
1559 * might lead to further faults, and loose the context of the original
1560 * exception.
1561 */
1562 if (!user_mode(regs))
1563 goto sigill;
1564
1565 interrupt_cond_local_irq_enable(regs);
1566
1567 /*
1568 * (reason & REASON_TRAP) is mostly handled before enabling IRQs,
1569 * except get_user_instr() can sleep so we cannot reliably inspect the
1570 * current instruction in that context. Now that we know we are
1571 * handling a user space trap and can sleep, we can check if the trap
1572 * was a hashchk failure.
1573 */
1574 if (reason & REASON_TRAP) {
1575 if (cpu_has_feature(CPU_FTR_DEXCR_NPHIE)) {
1576 ppc_inst_t insn;
1577
1578 if (get_user_instr(insn, (void __user *)regs->nip)) {
1579 _exception(SIGSEGV, regs, SEGV_MAPERR, regs->nip);
1580 return;
1581 }
1582
1583 if (ppc_inst_primary_opcode(insn) == 31 &&
1584 get_xop(ppc_inst_val(insn)) == OP_31_XOP_HASHCHK) {
1585 _exception(SIGILL, regs, ILL_ILLOPN, regs->nip);
1586 return;
1587 }
1588 }
1589
1590 _exception(SIGTRAP, regs, TRAP_BRKPT, regs->nip);
1591 return;
1592 }
1593
1594 /* (reason & REASON_ILLEGAL) would be the obvious thing here,
1595 * but there seems to be a hardware bug on the 405GP (RevD)
1596 * that means ESR is sometimes set incorrectly - either to
1597 * ESR_DST (!?) or 0. In the process of chasing this with the
1598 * hardware people - not sure if it can happen on any illegal
1599 * instruction or only on FP instructions, whether there is a
1600 * pattern to occurrences etc. -dgibson 31/Mar/2003
1601 */
1602 if (!emulate_math(regs))
1603 return;
1604
1605 /* Try to emulate it if we should. */
1606 if (reason & (REASON_ILLEGAL | REASON_PRIVILEGED)) {
1607 switch (emulate_instruction(regs)) {
1608 case 0:
1609 regs_add_return_ip(regs, 4);
1610 emulate_single_step(regs);
1611 return;
1612 case -EFAULT:
1613 _exception(SIGSEGV, regs, SEGV_MAPERR, regs->nip);
1614 return;
1615 }
1616 }
1617
1618 sigill:
1619 if (reason & REASON_PRIVILEGED)
1620 _exception(SIGILL, regs, ILL_PRVOPC, regs->nip);
1621 else
1622 _exception(SIGILL, regs, ILL_ILLOPC, regs->nip);
1623
1624 }
1625
DEFINE_INTERRUPT_HANDLER(program_check_exception)1626 DEFINE_INTERRUPT_HANDLER(program_check_exception)
1627 {
1628 do_program_check(regs);
1629 }
1630
1631 /*
1632 * This occurs when running in hypervisor mode on POWER6 or later
1633 * and an illegal instruction is encountered.
1634 */
DEFINE_INTERRUPT_HANDLER(emulation_assist_interrupt)1635 DEFINE_INTERRUPT_HANDLER(emulation_assist_interrupt)
1636 {
1637 regs_set_return_msr(regs, regs->msr | REASON_ILLEGAL);
1638 do_program_check(regs);
1639 }
1640
DEFINE_INTERRUPT_HANDLER(alignment_exception)1641 DEFINE_INTERRUPT_HANDLER(alignment_exception)
1642 {
1643 int sig, code, fixed = 0;
1644 unsigned long reason;
1645
1646 interrupt_cond_local_irq_enable(regs);
1647
1648 reason = get_reason(regs);
1649 if (reason & REASON_BOUNDARY) {
1650 sig = SIGBUS;
1651 code = BUS_ADRALN;
1652 goto bad;
1653 }
1654
1655 if (tm_abort_check(regs, TM_CAUSE_ALIGNMENT | TM_CAUSE_PERSISTENT))
1656 return;
1657
1658 /* we don't implement logging of alignment exceptions */
1659 if (!(current->thread.align_ctl & PR_UNALIGN_SIGBUS))
1660 fixed = fix_alignment(regs);
1661
1662 if (fixed == 1) {
1663 /* skip over emulated instruction */
1664 regs_add_return_ip(regs, inst_length(reason));
1665 emulate_single_step(regs);
1666 return;
1667 }
1668
1669 /* Operand address was bad */
1670 if (fixed == -EFAULT) {
1671 sig = SIGSEGV;
1672 code = SEGV_ACCERR;
1673 } else {
1674 sig = SIGBUS;
1675 code = BUS_ADRALN;
1676 }
1677 bad:
1678 if (user_mode(regs))
1679 _exception(sig, regs, code, regs->dar);
1680 else
1681 bad_page_fault(regs, sig);
1682 }
1683
DEFINE_INTERRUPT_HANDLER(stack_overflow_exception)1684 DEFINE_INTERRUPT_HANDLER(stack_overflow_exception)
1685 {
1686 die("Kernel stack overflow", regs, SIGSEGV);
1687 }
1688
DEFINE_INTERRUPT_HANDLER(kernel_fp_unavailable_exception)1689 DEFINE_INTERRUPT_HANDLER(kernel_fp_unavailable_exception)
1690 {
1691 printk(KERN_EMERG "Unrecoverable FP Unavailable Exception "
1692 "%lx at %lx\n", regs->trap, regs->nip);
1693 die("Unrecoverable FP Unavailable Exception", regs, SIGABRT);
1694 }
1695
DEFINE_INTERRUPT_HANDLER(altivec_unavailable_exception)1696 DEFINE_INTERRUPT_HANDLER(altivec_unavailable_exception)
1697 {
1698 if (user_mode(regs)) {
1699 /* A user program has executed an altivec instruction,
1700 but this kernel doesn't support altivec. */
1701 _exception(SIGILL, regs, ILL_ILLOPC, regs->nip);
1702 return;
1703 }
1704
1705 printk(KERN_EMERG "Unrecoverable VMX/Altivec Unavailable Exception "
1706 "%lx at %lx\n", regs->trap, regs->nip);
1707 die("Unrecoverable VMX/Altivec Unavailable Exception", regs, SIGABRT);
1708 }
1709
DEFINE_INTERRUPT_HANDLER(vsx_unavailable_exception)1710 DEFINE_INTERRUPT_HANDLER(vsx_unavailable_exception)
1711 {
1712 if (user_mode(regs)) {
1713 /* A user program has executed an vsx instruction,
1714 but this kernel doesn't support vsx. */
1715 _exception(SIGILL, regs, ILL_ILLOPC, regs->nip);
1716 return;
1717 }
1718
1719 printk(KERN_EMERG "Unrecoverable VSX Unavailable Exception "
1720 "%lx at %lx\n", regs->trap, regs->nip);
1721 die("Unrecoverable VSX Unavailable Exception", regs, SIGABRT);
1722 }
1723
1724 #ifdef CONFIG_PPC_BOOK3S_64
tm_unavailable(struct pt_regs * regs)1725 static void tm_unavailable(struct pt_regs *regs)
1726 {
1727 #ifdef CONFIG_PPC_TRANSACTIONAL_MEM
1728 if (user_mode(regs)) {
1729 current->thread.load_tm++;
1730 regs_set_return_msr(regs, regs->msr | MSR_TM);
1731 tm_enable();
1732 tm_restore_sprs(¤t->thread);
1733 return;
1734 }
1735 #endif
1736 pr_emerg("Unrecoverable TM Unavailable Exception "
1737 "%lx at %lx\n", regs->trap, regs->nip);
1738 die("Unrecoverable TM Unavailable Exception", regs, SIGABRT);
1739 }
1740
DEFINE_INTERRUPT_HANDLER(facility_unavailable_exception)1741 DEFINE_INTERRUPT_HANDLER(facility_unavailable_exception)
1742 {
1743 static char *facility_strings[] = {
1744 [FSCR_FP_LG] = "FPU",
1745 [FSCR_VECVSX_LG] = "VMX/VSX",
1746 [FSCR_DSCR_LG] = "DSCR",
1747 [FSCR_PM_LG] = "PMU SPRs",
1748 [FSCR_BHRB_LG] = "BHRB",
1749 [FSCR_TM_LG] = "TM",
1750 [FSCR_EBB_LG] = "EBB",
1751 [FSCR_TAR_LG] = "TAR",
1752 [FSCR_MSGP_LG] = "MSGP",
1753 [FSCR_SCV_LG] = "SCV",
1754 [FSCR_PREFIX_LG] = "PREFIX",
1755 };
1756 char *facility = "unknown";
1757 u64 value;
1758 u32 instword, rd;
1759 u8 status;
1760 bool hv;
1761
1762 hv = (TRAP(regs) == INTERRUPT_H_FAC_UNAVAIL);
1763 if (hv)
1764 value = mfspr(SPRN_HFSCR);
1765 else
1766 value = mfspr(SPRN_FSCR);
1767
1768 status = value >> 56;
1769 if ((hv || status >= 2) &&
1770 (status < ARRAY_SIZE(facility_strings)) &&
1771 facility_strings[status])
1772 facility = facility_strings[status];
1773
1774 /* We should not have taken this interrupt in kernel */
1775 if (!user_mode(regs)) {
1776 pr_emerg("Facility '%s' unavailable (%d) exception in kernel mode at %lx\n",
1777 facility, status, regs->nip);
1778 die("Unexpected facility unavailable exception", regs, SIGABRT);
1779 }
1780
1781 interrupt_cond_local_irq_enable(regs);
1782
1783 if (status == FSCR_DSCR_LG) {
1784 /*
1785 * User is accessing the DSCR register using the problem
1786 * state only SPR number (0x03) either through a mfspr or
1787 * a mtspr instruction. If it is a write attempt through
1788 * a mtspr, then we set the inherit bit. This also allows
1789 * the user to write or read the register directly in the
1790 * future by setting via the FSCR DSCR bit. But in case it
1791 * is a read DSCR attempt through a mfspr instruction, we
1792 * just emulate the instruction instead. This code path will
1793 * always emulate all the mfspr instructions till the user
1794 * has attempted at least one mtspr instruction. This way it
1795 * preserves the same behaviour when the user is accessing
1796 * the DSCR through privilege level only SPR number (0x11)
1797 * which is emulated through illegal instruction exception.
1798 * We always leave HFSCR DSCR set.
1799 */
1800 if (get_user(instword, (u32 __user *)(regs->nip))) {
1801 pr_err("Failed to fetch the user instruction\n");
1802 return;
1803 }
1804
1805 /* Write into DSCR (mtspr 0x03, RS) */
1806 if ((instword & PPC_INST_MTSPR_DSCR_USER_MASK)
1807 == PPC_INST_MTSPR_DSCR_USER) {
1808 rd = (instword >> 21) & 0x1f;
1809 current->thread.dscr = regs->gpr[rd];
1810 current->thread.dscr_inherit = 1;
1811 current->thread.fscr |= FSCR_DSCR;
1812 mtspr(SPRN_FSCR, current->thread.fscr);
1813 }
1814
1815 /* Read from DSCR (mfspr RT, 0x03) */
1816 if ((instword & PPC_INST_MFSPR_DSCR_USER_MASK)
1817 == PPC_INST_MFSPR_DSCR_USER) {
1818 if (emulate_instruction(regs)) {
1819 pr_err("DSCR based mfspr emulation failed\n");
1820 return;
1821 }
1822 regs_add_return_ip(regs, 4);
1823 emulate_single_step(regs);
1824 }
1825 return;
1826 }
1827
1828 if (status == FSCR_TM_LG) {
1829 /*
1830 * If we're here then the hardware is TM aware because it
1831 * generated an exception with FSRM_TM set.
1832 *
1833 * If cpu_has_feature(CPU_FTR_TM) is false, then either firmware
1834 * told us not to do TM, or the kernel is not built with TM
1835 * support.
1836 *
1837 * If both of those things are true, then userspace can spam the
1838 * console by triggering the printk() below just by continually
1839 * doing tbegin (or any TM instruction). So in that case just
1840 * send the process a SIGILL immediately.
1841 */
1842 if (!cpu_has_feature(CPU_FTR_TM))
1843 goto out;
1844
1845 tm_unavailable(regs);
1846 return;
1847 }
1848
1849 pr_err_ratelimited("%sFacility '%s' unavailable (%d), exception at 0x%lx, MSR=%lx\n",
1850 hv ? "Hypervisor " : "", facility, status, regs->nip, regs->msr);
1851
1852 out:
1853 _exception(SIGILL, regs, ILL_ILLOPC, regs->nip);
1854 }
1855 #endif
1856
1857 #ifdef CONFIG_PPC_TRANSACTIONAL_MEM
1858
DEFINE_INTERRUPT_HANDLER(fp_unavailable_tm)1859 DEFINE_INTERRUPT_HANDLER(fp_unavailable_tm)
1860 {
1861 /* Note: This does not handle any kind of FP laziness. */
1862
1863 TM_DEBUG("FP Unavailable trap whilst transactional at 0x%lx, MSR=%lx\n",
1864 regs->nip, regs->msr);
1865
1866 /* We can only have got here if the task started using FP after
1867 * beginning the transaction. So, the transactional regs are just a
1868 * copy of the checkpointed ones. But, we still need to recheckpoint
1869 * as we're enabling FP for the process; it will return, abort the
1870 * transaction, and probably retry but now with FP enabled. So the
1871 * checkpointed FP registers need to be loaded.
1872 */
1873 tm_reclaim_current(TM_CAUSE_FAC_UNAV);
1874
1875 /*
1876 * Reclaim initially saved out bogus (lazy) FPRs to ckfp_state, and
1877 * then it was overwrite by the thr->fp_state by tm_reclaim_thread().
1878 *
1879 * At this point, ck{fp,vr}_state contains the exact values we want to
1880 * recheckpoint.
1881 */
1882
1883 /* Enable FP for the task: */
1884 current->thread.load_fp = 1;
1885
1886 /*
1887 * Recheckpoint all the checkpointed ckpt, ck{fp, vr}_state registers.
1888 */
1889 tm_recheckpoint(¤t->thread);
1890 }
1891
DEFINE_INTERRUPT_HANDLER(altivec_unavailable_tm)1892 DEFINE_INTERRUPT_HANDLER(altivec_unavailable_tm)
1893 {
1894 /* See the comments in fp_unavailable_tm(). This function operates
1895 * the same way.
1896 */
1897
1898 TM_DEBUG("Vector Unavailable trap whilst transactional at 0x%lx,"
1899 "MSR=%lx\n",
1900 regs->nip, regs->msr);
1901 tm_reclaim_current(TM_CAUSE_FAC_UNAV);
1902 current->thread.load_vec = 1;
1903 tm_recheckpoint(¤t->thread);
1904 current->thread.used_vr = 1;
1905 }
1906
DEFINE_INTERRUPT_HANDLER(vsx_unavailable_tm)1907 DEFINE_INTERRUPT_HANDLER(vsx_unavailable_tm)
1908 {
1909 /* See the comments in fp_unavailable_tm(). This works similarly,
1910 * though we're loading both FP and VEC registers in here.
1911 *
1912 * If FP isn't in use, load FP regs. If VEC isn't in use, load VEC
1913 * regs. Either way, set MSR_VSX.
1914 */
1915
1916 TM_DEBUG("VSX Unavailable trap whilst transactional at 0x%lx,"
1917 "MSR=%lx\n",
1918 regs->nip, regs->msr);
1919
1920 current->thread.used_vsr = 1;
1921
1922 /* This reclaims FP and/or VR regs if they're already enabled */
1923 tm_reclaim_current(TM_CAUSE_FAC_UNAV);
1924
1925 current->thread.load_vec = 1;
1926 current->thread.load_fp = 1;
1927
1928 tm_recheckpoint(¤t->thread);
1929 }
1930 #endif /* CONFIG_PPC_TRANSACTIONAL_MEM */
1931
1932 #ifdef CONFIG_PPC64
1933 DECLARE_INTERRUPT_HANDLER_NMI(performance_monitor_exception_nmi);
DEFINE_INTERRUPT_HANDLER_NMI(performance_monitor_exception_nmi)1934 DEFINE_INTERRUPT_HANDLER_NMI(performance_monitor_exception_nmi)
1935 {
1936 __this_cpu_inc(irq_stat.pmu_irqs);
1937
1938 perf_irq(regs);
1939
1940 return 0;
1941 }
1942 #endif
1943
1944 DECLARE_INTERRUPT_HANDLER_ASYNC(performance_monitor_exception_async);
DEFINE_INTERRUPT_HANDLER_ASYNC(performance_monitor_exception_async)1945 DEFINE_INTERRUPT_HANDLER_ASYNC(performance_monitor_exception_async)
1946 {
1947 __this_cpu_inc(irq_stat.pmu_irqs);
1948
1949 perf_irq(regs);
1950 }
1951
DEFINE_INTERRUPT_HANDLER_RAW(performance_monitor_exception)1952 DEFINE_INTERRUPT_HANDLER_RAW(performance_monitor_exception)
1953 {
1954 /*
1955 * On 64-bit, if perf interrupts hit in a local_irq_disable
1956 * (soft-masked) region, we consider them as NMIs. This is required to
1957 * prevent hash faults on user addresses when reading callchains (and
1958 * looks better from an irq tracing perspective).
1959 */
1960 if (IS_ENABLED(CONFIG_PPC64) && unlikely(arch_irq_disabled_regs(regs)))
1961 performance_monitor_exception_nmi(regs);
1962 else
1963 performance_monitor_exception_async(regs);
1964
1965 return 0;
1966 }
1967
1968 #ifdef CONFIG_PPC_ADV_DEBUG_REGS
handle_debug(struct pt_regs * regs,unsigned long debug_status)1969 static void handle_debug(struct pt_regs *regs, unsigned long debug_status)
1970 {
1971 int changed = 0;
1972 /*
1973 * Determine the cause of the debug event, clear the
1974 * event flags and send a trap to the handler. Torez
1975 */
1976 if (debug_status & (DBSR_DAC1R | DBSR_DAC1W)) {
1977 dbcr_dac(current) &= ~(DBCR_DAC1R | DBCR_DAC1W);
1978 #ifdef CONFIG_PPC_ADV_DEBUG_DAC_RANGE
1979 current->thread.debug.dbcr2 &= ~DBCR2_DAC12MODE;
1980 #endif
1981 do_send_trap(regs, mfspr(SPRN_DAC1), debug_status,
1982 5);
1983 changed |= 0x01;
1984 } else if (debug_status & (DBSR_DAC2R | DBSR_DAC2W)) {
1985 dbcr_dac(current) &= ~(DBCR_DAC2R | DBCR_DAC2W);
1986 do_send_trap(regs, mfspr(SPRN_DAC2), debug_status,
1987 6);
1988 changed |= 0x01;
1989 } else if (debug_status & DBSR_IAC1) {
1990 current->thread.debug.dbcr0 &= ~DBCR0_IAC1;
1991 dbcr_iac_range(current) &= ~DBCR_IAC12MODE;
1992 do_send_trap(regs, mfspr(SPRN_IAC1), debug_status,
1993 1);
1994 changed |= 0x01;
1995 } else if (debug_status & DBSR_IAC2) {
1996 current->thread.debug.dbcr0 &= ~DBCR0_IAC2;
1997 do_send_trap(regs, mfspr(SPRN_IAC2), debug_status,
1998 2);
1999 changed |= 0x01;
2000 } else if (debug_status & DBSR_IAC3) {
2001 current->thread.debug.dbcr0 &= ~DBCR0_IAC3;
2002 dbcr_iac_range(current) &= ~DBCR_IAC34MODE;
2003 do_send_trap(regs, mfspr(SPRN_IAC3), debug_status,
2004 3);
2005 changed |= 0x01;
2006 } else if (debug_status & DBSR_IAC4) {
2007 current->thread.debug.dbcr0 &= ~DBCR0_IAC4;
2008 do_send_trap(regs, mfspr(SPRN_IAC4), debug_status,
2009 4);
2010 changed |= 0x01;
2011 }
2012 /*
2013 * At the point this routine was called, the MSR(DE) was turned off.
2014 * Check all other debug flags and see if that bit needs to be turned
2015 * back on or not.
2016 */
2017 if (DBCR_ACTIVE_EVENTS(current->thread.debug.dbcr0,
2018 current->thread.debug.dbcr1))
2019 regs_set_return_msr(regs, regs->msr | MSR_DE);
2020 else
2021 /* Make sure the IDM flag is off */
2022 current->thread.debug.dbcr0 &= ~DBCR0_IDM;
2023
2024 if (changed & 0x01)
2025 mtspr(SPRN_DBCR0, current->thread.debug.dbcr0);
2026 }
2027
DEFINE_INTERRUPT_HANDLER(DebugException)2028 DEFINE_INTERRUPT_HANDLER(DebugException)
2029 {
2030 unsigned long debug_status = regs->dsisr;
2031
2032 current->thread.debug.dbsr = debug_status;
2033
2034 /* Hack alert: On BookE, Branch Taken stops on the branch itself, while
2035 * on server, it stops on the target of the branch. In order to simulate
2036 * the server behaviour, we thus restart right away with a single step
2037 * instead of stopping here when hitting a BT
2038 */
2039 if (debug_status & DBSR_BT) {
2040 regs_set_return_msr(regs, regs->msr & ~MSR_DE);
2041
2042 /* Disable BT */
2043 mtspr(SPRN_DBCR0, mfspr(SPRN_DBCR0) & ~DBCR0_BT);
2044 /* Clear the BT event */
2045 mtspr(SPRN_DBSR, DBSR_BT);
2046
2047 /* Do the single step trick only when coming from userspace */
2048 if (user_mode(regs)) {
2049 current->thread.debug.dbcr0 &= ~DBCR0_BT;
2050 current->thread.debug.dbcr0 |= DBCR0_IDM | DBCR0_IC;
2051 regs_set_return_msr(regs, regs->msr | MSR_DE);
2052 return;
2053 }
2054
2055 if (kprobe_post_handler(regs))
2056 return;
2057
2058 if (notify_die(DIE_SSTEP, "block_step", regs, 5,
2059 5, SIGTRAP) == NOTIFY_STOP) {
2060 return;
2061 }
2062 if (debugger_sstep(regs))
2063 return;
2064 } else if (debug_status & DBSR_IC) { /* Instruction complete */
2065 regs_set_return_msr(regs, regs->msr & ~MSR_DE);
2066
2067 /* Disable instruction completion */
2068 mtspr(SPRN_DBCR0, mfspr(SPRN_DBCR0) & ~DBCR0_IC);
2069 /* Clear the instruction completion event */
2070 mtspr(SPRN_DBSR, DBSR_IC);
2071
2072 if (kprobe_post_handler(regs))
2073 return;
2074
2075 if (notify_die(DIE_SSTEP, "single_step", regs, 5,
2076 5, SIGTRAP) == NOTIFY_STOP) {
2077 return;
2078 }
2079
2080 if (debugger_sstep(regs))
2081 return;
2082
2083 if (user_mode(regs)) {
2084 current->thread.debug.dbcr0 &= ~DBCR0_IC;
2085 if (DBCR_ACTIVE_EVENTS(current->thread.debug.dbcr0,
2086 current->thread.debug.dbcr1))
2087 regs_set_return_msr(regs, regs->msr | MSR_DE);
2088 else
2089 /* Make sure the IDM bit is off */
2090 current->thread.debug.dbcr0 &= ~DBCR0_IDM;
2091 }
2092
2093 _exception(SIGTRAP, regs, TRAP_TRACE, regs->nip);
2094 } else
2095 handle_debug(regs, debug_status);
2096 }
2097 #endif /* CONFIG_PPC_ADV_DEBUG_REGS */
2098
2099 #ifdef CONFIG_ALTIVEC
DEFINE_INTERRUPT_HANDLER(altivec_assist_exception)2100 DEFINE_INTERRUPT_HANDLER(altivec_assist_exception)
2101 {
2102 int err;
2103
2104 if (!user_mode(regs)) {
2105 printk(KERN_EMERG "VMX/Altivec assist exception in kernel mode"
2106 " at %lx\n", regs->nip);
2107 die("Kernel VMX/Altivec assist exception", regs, SIGILL);
2108 }
2109
2110 flush_altivec_to_thread(current);
2111
2112 PPC_WARN_EMULATED(altivec, regs);
2113 err = emulate_altivec(regs);
2114 if (err == 0) {
2115 regs_add_return_ip(regs, 4); /* skip emulated instruction */
2116 emulate_single_step(regs);
2117 return;
2118 }
2119
2120 if (err == -EFAULT) {
2121 /* got an error reading the instruction */
2122 _exception(SIGSEGV, regs, SEGV_ACCERR, regs->nip);
2123 } else {
2124 /* didn't recognize the instruction */
2125 /* XXX quick hack for now: set the non-Java bit in the VSCR */
2126 printk_ratelimited(KERN_ERR "Unrecognized altivec instruction "
2127 "in %s at %lx\n", current->comm, regs->nip);
2128 current->thread.vr_state.vscr.u[3] |= 0x10000;
2129 }
2130 }
2131 #endif /* CONFIG_ALTIVEC */
2132
2133 #ifdef CONFIG_PPC_85xx
DEFINE_INTERRUPT_HANDLER(CacheLockingException)2134 DEFINE_INTERRUPT_HANDLER(CacheLockingException)
2135 {
2136 unsigned long error_code = regs->dsisr;
2137
2138 /* We treat cache locking instructions from the user
2139 * as priv ops, in the future we could try to do
2140 * something smarter
2141 */
2142 if (error_code & (ESR_DLK|ESR_ILK))
2143 _exception(SIGILL, regs, ILL_PRVOPC, regs->nip);
2144 return;
2145 }
2146 #endif /* CONFIG_PPC_85xx */
2147
2148 #ifdef CONFIG_SPE
DEFINE_INTERRUPT_HANDLER(SPEFloatingPointException)2149 DEFINE_INTERRUPT_HANDLER(SPEFloatingPointException)
2150 {
2151 unsigned long spefscr;
2152 int fpexc_mode;
2153 int code = FPE_FLTUNK;
2154 int err;
2155
2156 interrupt_cond_local_irq_enable(regs);
2157
2158 flush_spe_to_thread(current);
2159
2160 spefscr = current->thread.spefscr;
2161 fpexc_mode = current->thread.fpexc_mode;
2162
2163 if ((spefscr & SPEFSCR_FOVF) && (fpexc_mode & PR_FP_EXC_OVF)) {
2164 code = FPE_FLTOVF;
2165 }
2166 else if ((spefscr & SPEFSCR_FUNF) && (fpexc_mode & PR_FP_EXC_UND)) {
2167 code = FPE_FLTUND;
2168 }
2169 else if ((spefscr & SPEFSCR_FDBZ) && (fpexc_mode & PR_FP_EXC_DIV))
2170 code = FPE_FLTDIV;
2171 else if ((spefscr & SPEFSCR_FINV) && (fpexc_mode & PR_FP_EXC_INV)) {
2172 code = FPE_FLTINV;
2173 }
2174 else if ((spefscr & (SPEFSCR_FG | SPEFSCR_FX)) && (fpexc_mode & PR_FP_EXC_RES))
2175 code = FPE_FLTRES;
2176
2177 err = do_spe_mathemu(regs);
2178 if (err == 0) {
2179 regs_add_return_ip(regs, 4); /* skip emulated instruction */
2180 emulate_single_step(regs);
2181 return;
2182 }
2183
2184 if (err == -EFAULT) {
2185 /* got an error reading the instruction */
2186 _exception(SIGSEGV, regs, SEGV_ACCERR, regs->nip);
2187 } else if (err == -EINVAL) {
2188 /* didn't recognize the instruction */
2189 printk(KERN_ERR "unrecognized spe instruction "
2190 "in %s at %lx\n", current->comm, regs->nip);
2191 } else {
2192 _exception(SIGFPE, regs, code, regs->nip);
2193 }
2194
2195 return;
2196 }
2197
DEFINE_INTERRUPT_HANDLER(SPEFloatingPointRoundException)2198 DEFINE_INTERRUPT_HANDLER(SPEFloatingPointRoundException)
2199 {
2200 int err;
2201
2202 interrupt_cond_local_irq_enable(regs);
2203
2204 preempt_disable();
2205 if (regs->msr & MSR_SPE)
2206 giveup_spe(current);
2207 preempt_enable();
2208
2209 regs_add_return_ip(regs, -4);
2210 err = speround_handler(regs);
2211 if (err == 0) {
2212 regs_add_return_ip(regs, 4); /* skip emulated instruction */
2213 emulate_single_step(regs);
2214 return;
2215 }
2216
2217 if (err == -EFAULT) {
2218 /* got an error reading the instruction */
2219 _exception(SIGSEGV, regs, SEGV_ACCERR, regs->nip);
2220 } else if (err == -EINVAL) {
2221 /* didn't recognize the instruction */
2222 printk(KERN_ERR "unrecognized spe instruction "
2223 "in %s at %lx\n", current->comm, regs->nip);
2224 } else {
2225 _exception(SIGFPE, regs, FPE_FLTUNK, regs->nip);
2226 return;
2227 }
2228 }
2229 #endif
2230
2231 /*
2232 * We enter here if we get an unrecoverable exception, that is, one
2233 * that happened at a point where the RI (recoverable interrupt) bit
2234 * in the MSR is 0. This indicates that SRR0/1 are live, and that
2235 * we therefore lost state by taking this exception.
2236 */
unrecoverable_exception(struct pt_regs * regs)2237 void __noreturn unrecoverable_exception(struct pt_regs *regs)
2238 {
2239 pr_emerg("Unrecoverable exception %lx at %lx (msr=%lx)\n",
2240 regs->trap, regs->nip, regs->msr);
2241 die("Unrecoverable exception", regs, SIGABRT);
2242 /* die() should not return */
2243 for (;;)
2244 ;
2245 }
2246
2247 #ifdef CONFIG_BOOKE_WDT
DEFINE_INTERRUPT_HANDLER_NMI(WatchdogException)2248 DEFINE_INTERRUPT_HANDLER_NMI(WatchdogException)
2249 {
2250 printk (KERN_EMERG "PowerPC Book-E Watchdog Exception\n");
2251 mtspr(SPRN_TCR, mfspr(SPRN_TCR) & ~TCR_WIE);
2252 return 0;
2253 }
2254 #endif
2255
2256 /*
2257 * We enter here if we discover during exception entry that we are
2258 * running in supervisor mode with a userspace value in the stack pointer.
2259 */
DEFINE_INTERRUPT_HANDLER(kernel_bad_stack)2260 DEFINE_INTERRUPT_HANDLER(kernel_bad_stack)
2261 {
2262 printk(KERN_EMERG "Bad kernel stack pointer %lx at %lx\n",
2263 regs->gpr[1], regs->nip);
2264 die("Bad kernel stack pointer", regs, SIGABRT);
2265 }
2266
2267 #ifdef CONFIG_PPC_EMULATED_STATS
2268
2269 #define WARN_EMULATED_SETUP(type) .type = { .name = #type }
2270
2271 struct ppc_emulated ppc_emulated = {
2272 #ifdef CONFIG_ALTIVEC
2273 WARN_EMULATED_SETUP(altivec),
2274 #endif
2275 WARN_EMULATED_SETUP(dcba),
2276 WARN_EMULATED_SETUP(dcbz),
2277 WARN_EMULATED_SETUP(fp_pair),
2278 WARN_EMULATED_SETUP(isel),
2279 WARN_EMULATED_SETUP(mcrxr),
2280 WARN_EMULATED_SETUP(mfpvr),
2281 WARN_EMULATED_SETUP(multiple),
2282 WARN_EMULATED_SETUP(popcntb),
2283 WARN_EMULATED_SETUP(spe),
2284 WARN_EMULATED_SETUP(string),
2285 WARN_EMULATED_SETUP(sync),
2286 WARN_EMULATED_SETUP(unaligned),
2287 #ifdef CONFIG_MATH_EMULATION
2288 WARN_EMULATED_SETUP(math),
2289 #endif
2290 #ifdef CONFIG_VSX
2291 WARN_EMULATED_SETUP(vsx),
2292 #endif
2293 #ifdef CONFIG_PPC64
2294 WARN_EMULATED_SETUP(mfdscr),
2295 WARN_EMULATED_SETUP(mtdscr),
2296 WARN_EMULATED_SETUP(lq_stq),
2297 WARN_EMULATED_SETUP(lxvw4x),
2298 WARN_EMULATED_SETUP(lxvh8x),
2299 WARN_EMULATED_SETUP(lxvd2x),
2300 WARN_EMULATED_SETUP(lxvb16x),
2301 #endif
2302 };
2303
2304 u32 ppc_warn_emulated;
2305
ppc_warn_emulated_print(const char * type)2306 void ppc_warn_emulated_print(const char *type)
2307 {
2308 pr_warn_ratelimited("%s used emulated %s instruction\n", current->comm,
2309 type);
2310 }
2311
ppc_warn_emulated_init(void)2312 static int __init ppc_warn_emulated_init(void)
2313 {
2314 struct dentry *dir;
2315 unsigned int i;
2316 struct ppc_emulated_entry *entries = (void *)&ppc_emulated;
2317
2318 dir = debugfs_create_dir("emulated_instructions",
2319 arch_debugfs_dir);
2320
2321 debugfs_create_u32("do_warn", 0644, dir, &ppc_warn_emulated);
2322
2323 for (i = 0; i < sizeof(ppc_emulated)/sizeof(*entries); i++)
2324 debugfs_create_u32(entries[i].name, 0644, dir,
2325 (u32 *)&entries[i].val.counter);
2326
2327 return 0;
2328 }
2329
2330 device_initcall(ppc_warn_emulated_init);
2331
2332 #endif /* CONFIG_PPC_EMULATED_STATS */
2333