1 /*
2 * arch/sh/kernel/traps_64.c
3 *
4 * Copyright (C) 2000, 2001 Paolo Alberelli
5 * Copyright (C) 2003, 2004 Paul Mundt
6 * Copyright (C) 2003, 2004 Richard Curnow
7 *
8 * This file is subject to the terms and conditions of the GNU General Public
9 * License. See the file "COPYING" in the main directory of this archive
10 * for more details.
11 */
12 #include <linux/sched.h>
13 #include <linux/kernel.h>
14 #include <linux/string.h>
15 #include <linux/errno.h>
16 #include <linux/ptrace.h>
17 #include <linux/timer.h>
18 #include <linux/mm.h>
19 #include <linux/smp.h>
20 #include <linux/init.h>
21 #include <linux/delay.h>
22 #include <linux/spinlock.h>
23 #include <linux/kallsyms.h>
24 #include <linux/interrupt.h>
25 #include <linux/sysctl.h>
26 #include <linux/module.h>
27 #include <linux/perf_event.h>
28 #include <asm/system.h>
29 #include <asm/uaccess.h>
30 #include <asm/io.h>
31 #include <linux/atomic.h>
32 #include <asm/processor.h>
33 #include <asm/pgtable.h>
34 #include <asm/fpu.h>
35
36 #undef DEBUG_EXCEPTION
37 #ifdef DEBUG_EXCEPTION
38 /* implemented in ../lib/dbg.c */
39 extern void show_excp_regs(char *fname, int trapnr, int signr,
40 struct pt_regs *regs);
41 #else
42 #define show_excp_regs(a, b, c, d)
43 #endif
44
45 static void do_unhandled_exception(int trapnr, int signr, char *str, char *fn_name,
46 unsigned long error_code, struct pt_regs *regs, struct task_struct *tsk);
47
48 #define DO_ERROR(trapnr, signr, str, name, tsk) \
49 asmlinkage void do_##name(unsigned long error_code, struct pt_regs *regs) \
50 { \
51 do_unhandled_exception(trapnr, signr, str, __stringify(name), error_code, regs, current); \
52 }
53
54 static DEFINE_SPINLOCK(die_lock);
55
die(const char * str,struct pt_regs * regs,long err)56 void die(const char * str, struct pt_regs * regs, long err)
57 {
58 console_verbose();
59 spin_lock_irq(&die_lock);
60 printk("%s: %lx\n", str, (err & 0xffffff));
61 show_regs(regs);
62 spin_unlock_irq(&die_lock);
63 do_exit(SIGSEGV);
64 }
65
die_if_kernel(const char * str,struct pt_regs * regs,long err)66 static inline void die_if_kernel(const char * str, struct pt_regs * regs, long err)
67 {
68 if (!user_mode(regs))
69 die(str, regs, err);
70 }
71
die_if_no_fixup(const char * str,struct pt_regs * regs,long err)72 static void die_if_no_fixup(const char * str, struct pt_regs * regs, long err)
73 {
74 if (!user_mode(regs)) {
75 const struct exception_table_entry *fixup;
76 fixup = search_exception_tables(regs->pc);
77 if (fixup) {
78 regs->pc = fixup->fixup;
79 return;
80 }
81 die(str, regs, err);
82 }
83 }
84
85 DO_ERROR(13, SIGILL, "illegal slot instruction", illegal_slot_inst, current)
86 DO_ERROR(87, SIGSEGV, "address error (exec)", address_error_exec, current)
87
88
89 /* Implement misaligned load/store handling for kernel (and optionally for user
90 mode too). Limitation : only SHmedia mode code is handled - there is no
91 handling at all for misaligned accesses occurring in SHcompact code yet. */
92
93 static int misaligned_fixup(struct pt_regs *regs);
94
do_address_error_load(unsigned long error_code,struct pt_regs * regs)95 asmlinkage void do_address_error_load(unsigned long error_code, struct pt_regs *regs)
96 {
97 if (misaligned_fixup(regs) < 0) {
98 do_unhandled_exception(7, SIGSEGV, "address error(load)",
99 "do_address_error_load",
100 error_code, regs, current);
101 }
102 return;
103 }
104
do_address_error_store(unsigned long error_code,struct pt_regs * regs)105 asmlinkage void do_address_error_store(unsigned long error_code, struct pt_regs *regs)
106 {
107 if (misaligned_fixup(regs) < 0) {
108 do_unhandled_exception(8, SIGSEGV, "address error(store)",
109 "do_address_error_store",
110 error_code, regs, current);
111 }
112 return;
113 }
114
115 #if defined(CONFIG_SH64_ID2815_WORKAROUND)
116
117 #define OPCODE_INVALID 0
118 #define OPCODE_USER_VALID 1
119 #define OPCODE_PRIV_VALID 2
120
121 /* getcon/putcon - requires checking which control register is referenced. */
122 #define OPCODE_CTRL_REG 3
123
124 /* Table of valid opcodes for SHmedia mode.
125 Form a 10-bit value by concatenating the major/minor opcodes i.e.
126 opcode[31:26,20:16]. The 6 MSBs of this value index into the following
127 array. The 4 LSBs select the bit-pair in the entry (bits 1:0 correspond to
128 LSBs==4'b0000 etc). */
129 static unsigned long shmedia_opcode_table[64] = {
130 0x55554044,0x54445055,0x15141514,0x14541414,0x00000000,0x10001000,0x01110055,0x04050015,
131 0x00000444,0xc0000000,0x44545515,0x40405555,0x55550015,0x10005555,0x55555505,0x04050000,
132 0x00000555,0x00000404,0x00040445,0x15151414,0x00000000,0x00000000,0x00000000,0x00000000,
133 0x00000055,0x40404444,0x00000404,0xc0009495,0x00000000,0x00000000,0x00000000,0x00000000,
134 0x55555555,0x55555555,0x55555555,0x55555555,0x55555555,0x55555555,0x55555555,0x55555555,
135 0x55555555,0x55555555,0x55555555,0x55555555,0x55555555,0x55555555,0x55555555,0x55555555,
136 0x80005050,0x04005055,0x55555555,0x55555555,0x55555555,0x55555555,0x55555555,0x55555555,
137 0x81055554,0x00000404,0x55555555,0x55555555,0x00000000,0x00000000,0x00000000,0x00000000
138 };
139
do_reserved_inst(unsigned long error_code,struct pt_regs * regs)140 void do_reserved_inst(unsigned long error_code, struct pt_regs *regs)
141 {
142 /* Workaround SH5-101 cut2 silicon defect #2815 :
143 in some situations, inter-mode branches from SHcompact -> SHmedia
144 which should take ITLBMISS or EXECPROT exceptions at the target
145 falsely take RESINST at the target instead. */
146
147 unsigned long opcode = 0x6ff4fff0; /* guaranteed reserved opcode */
148 unsigned long pc, aligned_pc;
149 int get_user_error;
150 int trapnr = 12;
151 int signr = SIGILL;
152 char *exception_name = "reserved_instruction";
153
154 pc = regs->pc;
155 if ((pc & 3) == 1) {
156 /* SHmedia : check for defect. This requires executable vmas
157 to be readable too. */
158 aligned_pc = pc & ~3;
159 if (!access_ok(VERIFY_READ, aligned_pc, sizeof(unsigned long))) {
160 get_user_error = -EFAULT;
161 } else {
162 get_user_error = __get_user(opcode, (unsigned long *)aligned_pc);
163 }
164 if (get_user_error >= 0) {
165 unsigned long index, shift;
166 unsigned long major, minor, combined;
167 unsigned long reserved_field;
168 reserved_field = opcode & 0xf; /* These bits are currently reserved as zero in all valid opcodes */
169 major = (opcode >> 26) & 0x3f;
170 minor = (opcode >> 16) & 0xf;
171 combined = (major << 4) | minor;
172 index = major;
173 shift = minor << 1;
174 if (reserved_field == 0) {
175 int opcode_state = (shmedia_opcode_table[index] >> shift) & 0x3;
176 switch (opcode_state) {
177 case OPCODE_INVALID:
178 /* Trap. */
179 break;
180 case OPCODE_USER_VALID:
181 /* Restart the instruction : the branch to the instruction will now be from an RTE
182 not from SHcompact so the silicon defect won't be triggered. */
183 return;
184 case OPCODE_PRIV_VALID:
185 if (!user_mode(regs)) {
186 /* Should only ever get here if a module has
187 SHcompact code inside it. If so, the same fix up is needed. */
188 return; /* same reason */
189 }
190 /* Otherwise, user mode trying to execute a privileged instruction -
191 fall through to trap. */
192 break;
193 case OPCODE_CTRL_REG:
194 /* If in privileged mode, return as above. */
195 if (!user_mode(regs)) return;
196 /* In user mode ... */
197 if (combined == 0x9f) { /* GETCON */
198 unsigned long regno = (opcode >> 20) & 0x3f;
199 if (regno >= 62) {
200 return;
201 }
202 /* Otherwise, reserved or privileged control register, => trap */
203 } else if (combined == 0x1bf) { /* PUTCON */
204 unsigned long regno = (opcode >> 4) & 0x3f;
205 if (regno >= 62) {
206 return;
207 }
208 /* Otherwise, reserved or privileged control register, => trap */
209 } else {
210 /* Trap */
211 }
212 break;
213 default:
214 /* Fall through to trap. */
215 break;
216 }
217 }
218 /* fall through to normal resinst processing */
219 } else {
220 /* Error trying to read opcode. This typically means a
221 real fault, not a RESINST any more. So change the
222 codes. */
223 trapnr = 87;
224 exception_name = "address error (exec)";
225 signr = SIGSEGV;
226 }
227 }
228
229 do_unhandled_exception(trapnr, signr, exception_name, "do_reserved_inst", error_code, regs, current);
230 }
231
232 #else /* CONFIG_SH64_ID2815_WORKAROUND */
233
234 /* If the workaround isn't needed, this is just a straightforward reserved
235 instruction */
236 DO_ERROR(12, SIGILL, "reserved instruction", reserved_inst, current)
237
238 #endif /* CONFIG_SH64_ID2815_WORKAROUND */
239
240 /* Called with interrupts disabled */
do_exception_error(unsigned long ex,struct pt_regs * regs)241 asmlinkage void do_exception_error(unsigned long ex, struct pt_regs *regs)
242 {
243 show_excp_regs(__func__, -1, -1, regs);
244 die_if_kernel("exception", regs, ex);
245 }
246
do_unknown_trapa(unsigned long scId,struct pt_regs * regs)247 int do_unknown_trapa(unsigned long scId, struct pt_regs *regs)
248 {
249 /* Syscall debug */
250 printk("System call ID error: [0x1#args:8 #syscall:16 0x%lx]\n", scId);
251
252 die_if_kernel("unknown trapa", regs, scId);
253
254 return -ENOSYS;
255 }
256
show_stack(struct task_struct * tsk,unsigned long * sp)257 void show_stack(struct task_struct *tsk, unsigned long *sp)
258 {
259 #ifdef CONFIG_KALLSYMS
260 extern void sh64_unwind(struct pt_regs *regs);
261 struct pt_regs *regs;
262
263 regs = tsk ? tsk->thread.kregs : NULL;
264
265 sh64_unwind(regs);
266 #else
267 printk(KERN_ERR "Can't backtrace on sh64 without CONFIG_KALLSYMS\n");
268 #endif
269 }
270
show_task(unsigned long * sp)271 void show_task(unsigned long *sp)
272 {
273 show_stack(NULL, sp);
274 }
275
dump_stack(void)276 void dump_stack(void)
277 {
278 show_task(NULL);
279 }
280 /* Needed by any user of WARN_ON in view of the defn in include/asm-sh/bug.h */
281 EXPORT_SYMBOL(dump_stack);
282
do_unhandled_exception(int trapnr,int signr,char * str,char * fn_name,unsigned long error_code,struct pt_regs * regs,struct task_struct * tsk)283 static void do_unhandled_exception(int trapnr, int signr, char *str, char *fn_name,
284 unsigned long error_code, struct pt_regs *regs, struct task_struct *tsk)
285 {
286 show_excp_regs(fn_name, trapnr, signr, regs);
287 tsk->thread.error_code = error_code;
288 tsk->thread.trap_no = trapnr;
289
290 if (user_mode(regs))
291 force_sig(signr, tsk);
292
293 die_if_no_fixup(str, regs, error_code);
294 }
295
read_opcode(unsigned long long pc,unsigned long * result_opcode,int from_user_mode)296 static int read_opcode(unsigned long long pc, unsigned long *result_opcode, int from_user_mode)
297 {
298 int get_user_error;
299 unsigned long aligned_pc;
300 unsigned long opcode;
301
302 if ((pc & 3) == 1) {
303 /* SHmedia */
304 aligned_pc = pc & ~3;
305 if (from_user_mode) {
306 if (!access_ok(VERIFY_READ, aligned_pc, sizeof(unsigned long))) {
307 get_user_error = -EFAULT;
308 } else {
309 get_user_error = __get_user(opcode, (unsigned long *)aligned_pc);
310 *result_opcode = opcode;
311 }
312 return get_user_error;
313 } else {
314 /* If the fault was in the kernel, we can either read
315 * this directly, or if not, we fault.
316 */
317 *result_opcode = *(unsigned long *) aligned_pc;
318 return 0;
319 }
320 } else if ((pc & 1) == 0) {
321 /* SHcompact */
322 /* TODO : provide handling for this. We don't really support
323 user-mode SHcompact yet, and for a kernel fault, this would
324 have to come from a module built for SHcompact. */
325 return -EFAULT;
326 } else {
327 /* misaligned */
328 return -EFAULT;
329 }
330 }
331
address_is_sign_extended(__u64 a)332 static int address_is_sign_extended(__u64 a)
333 {
334 __u64 b;
335 #if (NEFF == 32)
336 b = (__u64)(__s64)(__s32)(a & 0xffffffffUL);
337 return (b == a) ? 1 : 0;
338 #else
339 #error "Sign extend check only works for NEFF==32"
340 #endif
341 }
342
generate_and_check_address(struct pt_regs * regs,__u32 opcode,int displacement_not_indexed,int width_shift,__u64 * address)343 static int generate_and_check_address(struct pt_regs *regs,
344 __u32 opcode,
345 int displacement_not_indexed,
346 int width_shift,
347 __u64 *address)
348 {
349 /* return -1 for fault, 0 for OK */
350
351 __u64 base_address, addr;
352 int basereg;
353
354 basereg = (opcode >> 20) & 0x3f;
355 base_address = regs->regs[basereg];
356 if (displacement_not_indexed) {
357 __s64 displacement;
358 displacement = (opcode >> 10) & 0x3ff;
359 displacement = ((displacement << 54) >> 54); /* sign extend */
360 addr = (__u64)((__s64)base_address + (displacement << width_shift));
361 } else {
362 __u64 offset;
363 int offsetreg;
364 offsetreg = (opcode >> 10) & 0x3f;
365 offset = regs->regs[offsetreg];
366 addr = base_address + offset;
367 }
368
369 /* Check sign extended */
370 if (!address_is_sign_extended(addr)) {
371 return -1;
372 }
373
374 /* Check accessible. For misaligned access in the kernel, assume the
375 address is always accessible (and if not, just fault when the
376 load/store gets done.) */
377 if (user_mode(regs)) {
378 if (addr >= TASK_SIZE) {
379 return -1;
380 }
381 /* Do access_ok check later - it depends on whether it's a load or a store. */
382 }
383
384 *address = addr;
385 return 0;
386 }
387
388 static int user_mode_unaligned_fixup_count = 10;
389 static int user_mode_unaligned_fixup_enable = 1;
390 static int kernel_mode_unaligned_fixup_count = 32;
391
misaligned_kernel_word_load(__u64 address,int do_sign_extend,__u64 * result)392 static void misaligned_kernel_word_load(__u64 address, int do_sign_extend, __u64 *result)
393 {
394 unsigned short x;
395 unsigned char *p, *q;
396 p = (unsigned char *) (int) address;
397 q = (unsigned char *) &x;
398 q[0] = p[0];
399 q[1] = p[1];
400
401 if (do_sign_extend) {
402 *result = (__u64)(__s64) *(short *) &x;
403 } else {
404 *result = (__u64) x;
405 }
406 }
407
misaligned_kernel_word_store(__u64 address,__u64 value)408 static void misaligned_kernel_word_store(__u64 address, __u64 value)
409 {
410 unsigned short x;
411 unsigned char *p, *q;
412 p = (unsigned char *) (int) address;
413 q = (unsigned char *) &x;
414
415 x = (__u16) value;
416 p[0] = q[0];
417 p[1] = q[1];
418 }
419
misaligned_load(struct pt_regs * regs,__u32 opcode,int displacement_not_indexed,int width_shift,int do_sign_extend)420 static int misaligned_load(struct pt_regs *regs,
421 __u32 opcode,
422 int displacement_not_indexed,
423 int width_shift,
424 int do_sign_extend)
425 {
426 /* Return -1 for a fault, 0 for OK */
427 int error;
428 int destreg;
429 __u64 address;
430
431 error = generate_and_check_address(regs, opcode,
432 displacement_not_indexed, width_shift, &address);
433 if (error < 0) {
434 return error;
435 }
436
437 perf_sw_event(PERF_COUNT_SW_ALIGNMENT_FAULTS, 1, regs, address);
438
439 destreg = (opcode >> 4) & 0x3f;
440 if (user_mode(regs)) {
441 __u64 buffer;
442
443 if (!access_ok(VERIFY_READ, (unsigned long) address, 1UL<<width_shift)) {
444 return -1;
445 }
446
447 if (__copy_user(&buffer, (const void *)(int)address, (1 << width_shift)) > 0) {
448 return -1; /* fault */
449 }
450 switch (width_shift) {
451 case 1:
452 if (do_sign_extend) {
453 regs->regs[destreg] = (__u64)(__s64) *(__s16 *) &buffer;
454 } else {
455 regs->regs[destreg] = (__u64) *(__u16 *) &buffer;
456 }
457 break;
458 case 2:
459 regs->regs[destreg] = (__u64)(__s64) *(__s32 *) &buffer;
460 break;
461 case 3:
462 regs->regs[destreg] = buffer;
463 break;
464 default:
465 printk("Unexpected width_shift %d in misaligned_load, PC=%08lx\n",
466 width_shift, (unsigned long) regs->pc);
467 break;
468 }
469 } else {
470 /* kernel mode - we can take short cuts since if we fault, it's a genuine bug */
471 __u64 lo, hi;
472
473 switch (width_shift) {
474 case 1:
475 misaligned_kernel_word_load(address, do_sign_extend, ®s->regs[destreg]);
476 break;
477 case 2:
478 asm ("ldlo.l %1, 0, %0" : "=r" (lo) : "r" (address));
479 asm ("ldhi.l %1, 3, %0" : "=r" (hi) : "r" (address));
480 regs->regs[destreg] = lo | hi;
481 break;
482 case 3:
483 asm ("ldlo.q %1, 0, %0" : "=r" (lo) : "r" (address));
484 asm ("ldhi.q %1, 7, %0" : "=r" (hi) : "r" (address));
485 regs->regs[destreg] = lo | hi;
486 break;
487
488 default:
489 printk("Unexpected width_shift %d in misaligned_load, PC=%08lx\n",
490 width_shift, (unsigned long) regs->pc);
491 break;
492 }
493 }
494
495 return 0;
496
497 }
498
misaligned_store(struct pt_regs * regs,__u32 opcode,int displacement_not_indexed,int width_shift)499 static int misaligned_store(struct pt_regs *regs,
500 __u32 opcode,
501 int displacement_not_indexed,
502 int width_shift)
503 {
504 /* Return -1 for a fault, 0 for OK */
505 int error;
506 int srcreg;
507 __u64 address;
508
509 error = generate_and_check_address(regs, opcode,
510 displacement_not_indexed, width_shift, &address);
511 if (error < 0) {
512 return error;
513 }
514
515 perf_sw_event(PERF_COUNT_SW_ALIGNMENT_FAULTS, 1, regs, address);
516
517 srcreg = (opcode >> 4) & 0x3f;
518 if (user_mode(regs)) {
519 __u64 buffer;
520
521 if (!access_ok(VERIFY_WRITE, (unsigned long) address, 1UL<<width_shift)) {
522 return -1;
523 }
524
525 switch (width_shift) {
526 case 1:
527 *(__u16 *) &buffer = (__u16) regs->regs[srcreg];
528 break;
529 case 2:
530 *(__u32 *) &buffer = (__u32) regs->regs[srcreg];
531 break;
532 case 3:
533 buffer = regs->regs[srcreg];
534 break;
535 default:
536 printk("Unexpected width_shift %d in misaligned_store, PC=%08lx\n",
537 width_shift, (unsigned long) regs->pc);
538 break;
539 }
540
541 if (__copy_user((void *)(int)address, &buffer, (1 << width_shift)) > 0) {
542 return -1; /* fault */
543 }
544 } else {
545 /* kernel mode - we can take short cuts since if we fault, it's a genuine bug */
546 __u64 val = regs->regs[srcreg];
547
548 switch (width_shift) {
549 case 1:
550 misaligned_kernel_word_store(address, val);
551 break;
552 case 2:
553 asm ("stlo.l %1, 0, %0" : : "r" (val), "r" (address));
554 asm ("sthi.l %1, 3, %0" : : "r" (val), "r" (address));
555 break;
556 case 3:
557 asm ("stlo.q %1, 0, %0" : : "r" (val), "r" (address));
558 asm ("sthi.q %1, 7, %0" : : "r" (val), "r" (address));
559 break;
560
561 default:
562 printk("Unexpected width_shift %d in misaligned_store, PC=%08lx\n",
563 width_shift, (unsigned long) regs->pc);
564 break;
565 }
566 }
567
568 return 0;
569
570 }
571
572 /* Never need to fix up misaligned FPU accesses within the kernel since that's a real
573 error. */
misaligned_fpu_load(struct pt_regs * regs,__u32 opcode,int displacement_not_indexed,int width_shift,int do_paired_load)574 static int misaligned_fpu_load(struct pt_regs *regs,
575 __u32 opcode,
576 int displacement_not_indexed,
577 int width_shift,
578 int do_paired_load)
579 {
580 /* Return -1 for a fault, 0 for OK */
581 int error;
582 int destreg;
583 __u64 address;
584
585 error = generate_and_check_address(regs, opcode,
586 displacement_not_indexed, width_shift, &address);
587 if (error < 0) {
588 return error;
589 }
590
591 perf_sw_event(PERF_COUNT_SW_EMULATION_FAULTS, 1, regs, address);
592
593 destreg = (opcode >> 4) & 0x3f;
594 if (user_mode(regs)) {
595 __u64 buffer;
596 __u32 buflo, bufhi;
597
598 if (!access_ok(VERIFY_READ, (unsigned long) address, 1UL<<width_shift)) {
599 return -1;
600 }
601
602 if (__copy_user(&buffer, (const void *)(int)address, (1 << width_shift)) > 0) {
603 return -1; /* fault */
604 }
605 /* 'current' may be the current owner of the FPU state, so
606 context switch the registers into memory so they can be
607 indexed by register number. */
608 if (last_task_used_math == current) {
609 enable_fpu();
610 save_fpu(current);
611 disable_fpu();
612 last_task_used_math = NULL;
613 regs->sr |= SR_FD;
614 }
615
616 buflo = *(__u32*) &buffer;
617 bufhi = *(1 + (__u32*) &buffer);
618
619 switch (width_shift) {
620 case 2:
621 current->thread.xstate->hardfpu.fp_regs[destreg] = buflo;
622 break;
623 case 3:
624 if (do_paired_load) {
625 current->thread.xstate->hardfpu.fp_regs[destreg] = buflo;
626 current->thread.xstate->hardfpu.fp_regs[destreg+1] = bufhi;
627 } else {
628 #if defined(CONFIG_CPU_LITTLE_ENDIAN)
629 current->thread.xstate->hardfpu.fp_regs[destreg] = bufhi;
630 current->thread.xstate->hardfpu.fp_regs[destreg+1] = buflo;
631 #else
632 current->thread.xstate->hardfpu.fp_regs[destreg] = buflo;
633 current->thread.xstate->hardfpu.fp_regs[destreg+1] = bufhi;
634 #endif
635 }
636 break;
637 default:
638 printk("Unexpected width_shift %d in misaligned_fpu_load, PC=%08lx\n",
639 width_shift, (unsigned long) regs->pc);
640 break;
641 }
642 return 0;
643 } else {
644 die ("Misaligned FPU load inside kernel", regs, 0);
645 return -1;
646 }
647
648
649 }
650
misaligned_fpu_store(struct pt_regs * regs,__u32 opcode,int displacement_not_indexed,int width_shift,int do_paired_load)651 static int misaligned_fpu_store(struct pt_regs *regs,
652 __u32 opcode,
653 int displacement_not_indexed,
654 int width_shift,
655 int do_paired_load)
656 {
657 /* Return -1 for a fault, 0 for OK */
658 int error;
659 int srcreg;
660 __u64 address;
661
662 error = generate_and_check_address(regs, opcode,
663 displacement_not_indexed, width_shift, &address);
664 if (error < 0) {
665 return error;
666 }
667
668 perf_sw_event(PERF_COUNT_SW_EMULATION_FAULTS, 1, regs, address);
669
670 srcreg = (opcode >> 4) & 0x3f;
671 if (user_mode(regs)) {
672 __u64 buffer;
673 /* Initialise these to NaNs. */
674 __u32 buflo=0xffffffffUL, bufhi=0xffffffffUL;
675
676 if (!access_ok(VERIFY_WRITE, (unsigned long) address, 1UL<<width_shift)) {
677 return -1;
678 }
679
680 /* 'current' may be the current owner of the FPU state, so
681 context switch the registers into memory so they can be
682 indexed by register number. */
683 if (last_task_used_math == current) {
684 enable_fpu();
685 save_fpu(current);
686 disable_fpu();
687 last_task_used_math = NULL;
688 regs->sr |= SR_FD;
689 }
690
691 switch (width_shift) {
692 case 2:
693 buflo = current->thread.xstate->hardfpu.fp_regs[srcreg];
694 break;
695 case 3:
696 if (do_paired_load) {
697 buflo = current->thread.xstate->hardfpu.fp_regs[srcreg];
698 bufhi = current->thread.xstate->hardfpu.fp_regs[srcreg+1];
699 } else {
700 #if defined(CONFIG_CPU_LITTLE_ENDIAN)
701 bufhi = current->thread.xstate->hardfpu.fp_regs[srcreg];
702 buflo = current->thread.xstate->hardfpu.fp_regs[srcreg+1];
703 #else
704 buflo = current->thread.xstate->hardfpu.fp_regs[srcreg];
705 bufhi = current->thread.xstate->hardfpu.fp_regs[srcreg+1];
706 #endif
707 }
708 break;
709 default:
710 printk("Unexpected width_shift %d in misaligned_fpu_store, PC=%08lx\n",
711 width_shift, (unsigned long) regs->pc);
712 break;
713 }
714
715 *(__u32*) &buffer = buflo;
716 *(1 + (__u32*) &buffer) = bufhi;
717 if (__copy_user((void *)(int)address, &buffer, (1 << width_shift)) > 0) {
718 return -1; /* fault */
719 }
720 return 0;
721 } else {
722 die ("Misaligned FPU load inside kernel", regs, 0);
723 return -1;
724 }
725 }
726
misaligned_fixup(struct pt_regs * regs)727 static int misaligned_fixup(struct pt_regs *regs)
728 {
729 unsigned long opcode;
730 int error;
731 int major, minor;
732
733 if (!user_mode_unaligned_fixup_enable)
734 return -1;
735
736 error = read_opcode(regs->pc, &opcode, user_mode(regs));
737 if (error < 0) {
738 return error;
739 }
740 major = (opcode >> 26) & 0x3f;
741 minor = (opcode >> 16) & 0xf;
742
743 if (user_mode(regs) && (user_mode_unaligned_fixup_count > 0)) {
744 --user_mode_unaligned_fixup_count;
745 /* Only do 'count' worth of these reports, to remove a potential DoS against syslog */
746 printk("Fixing up unaligned userspace access in \"%s\" pid=%d pc=0x%08x ins=0x%08lx\n",
747 current->comm, task_pid_nr(current), (__u32)regs->pc, opcode);
748 } else if (!user_mode(regs) && (kernel_mode_unaligned_fixup_count > 0)) {
749 --kernel_mode_unaligned_fixup_count;
750 if (in_interrupt()) {
751 printk("Fixing up unaligned kernelspace access in interrupt pc=0x%08x ins=0x%08lx\n",
752 (__u32)regs->pc, opcode);
753 } else {
754 printk("Fixing up unaligned kernelspace access in \"%s\" pid=%d pc=0x%08x ins=0x%08lx\n",
755 current->comm, task_pid_nr(current), (__u32)regs->pc, opcode);
756 }
757 }
758
759
760 switch (major) {
761 case (0x84>>2): /* LD.W */
762 error = misaligned_load(regs, opcode, 1, 1, 1);
763 break;
764 case (0xb0>>2): /* LD.UW */
765 error = misaligned_load(regs, opcode, 1, 1, 0);
766 break;
767 case (0x88>>2): /* LD.L */
768 error = misaligned_load(regs, opcode, 1, 2, 1);
769 break;
770 case (0x8c>>2): /* LD.Q */
771 error = misaligned_load(regs, opcode, 1, 3, 0);
772 break;
773
774 case (0xa4>>2): /* ST.W */
775 error = misaligned_store(regs, opcode, 1, 1);
776 break;
777 case (0xa8>>2): /* ST.L */
778 error = misaligned_store(regs, opcode, 1, 2);
779 break;
780 case (0xac>>2): /* ST.Q */
781 error = misaligned_store(regs, opcode, 1, 3);
782 break;
783
784 case (0x40>>2): /* indexed loads */
785 switch (minor) {
786 case 0x1: /* LDX.W */
787 error = misaligned_load(regs, opcode, 0, 1, 1);
788 break;
789 case 0x5: /* LDX.UW */
790 error = misaligned_load(regs, opcode, 0, 1, 0);
791 break;
792 case 0x2: /* LDX.L */
793 error = misaligned_load(regs, opcode, 0, 2, 1);
794 break;
795 case 0x3: /* LDX.Q */
796 error = misaligned_load(regs, opcode, 0, 3, 0);
797 break;
798 default:
799 error = -1;
800 break;
801 }
802 break;
803
804 case (0x60>>2): /* indexed stores */
805 switch (minor) {
806 case 0x1: /* STX.W */
807 error = misaligned_store(regs, opcode, 0, 1);
808 break;
809 case 0x2: /* STX.L */
810 error = misaligned_store(regs, opcode, 0, 2);
811 break;
812 case 0x3: /* STX.Q */
813 error = misaligned_store(regs, opcode, 0, 3);
814 break;
815 default:
816 error = -1;
817 break;
818 }
819 break;
820
821 case (0x94>>2): /* FLD.S */
822 error = misaligned_fpu_load(regs, opcode, 1, 2, 0);
823 break;
824 case (0x98>>2): /* FLD.P */
825 error = misaligned_fpu_load(regs, opcode, 1, 3, 1);
826 break;
827 case (0x9c>>2): /* FLD.D */
828 error = misaligned_fpu_load(regs, opcode, 1, 3, 0);
829 break;
830 case (0x1c>>2): /* floating indexed loads */
831 switch (minor) {
832 case 0x8: /* FLDX.S */
833 error = misaligned_fpu_load(regs, opcode, 0, 2, 0);
834 break;
835 case 0xd: /* FLDX.P */
836 error = misaligned_fpu_load(regs, opcode, 0, 3, 1);
837 break;
838 case 0x9: /* FLDX.D */
839 error = misaligned_fpu_load(regs, opcode, 0, 3, 0);
840 break;
841 default:
842 error = -1;
843 break;
844 }
845 break;
846 case (0xb4>>2): /* FLD.S */
847 error = misaligned_fpu_store(regs, opcode, 1, 2, 0);
848 break;
849 case (0xb8>>2): /* FLD.P */
850 error = misaligned_fpu_store(regs, opcode, 1, 3, 1);
851 break;
852 case (0xbc>>2): /* FLD.D */
853 error = misaligned_fpu_store(regs, opcode, 1, 3, 0);
854 break;
855 case (0x3c>>2): /* floating indexed stores */
856 switch (minor) {
857 case 0x8: /* FSTX.S */
858 error = misaligned_fpu_store(regs, opcode, 0, 2, 0);
859 break;
860 case 0xd: /* FSTX.P */
861 error = misaligned_fpu_store(regs, opcode, 0, 3, 1);
862 break;
863 case 0x9: /* FSTX.D */
864 error = misaligned_fpu_store(regs, opcode, 0, 3, 0);
865 break;
866 default:
867 error = -1;
868 break;
869 }
870 break;
871
872 default:
873 /* Fault */
874 error = -1;
875 break;
876 }
877
878 if (error < 0) {
879 return error;
880 } else {
881 regs->pc += 4; /* Skip the instruction that's just been emulated */
882 return 0;
883 }
884
885 }
886
887 static ctl_table unaligned_table[] = {
888 {
889 .procname = "kernel_reports",
890 .data = &kernel_mode_unaligned_fixup_count,
891 .maxlen = sizeof(int),
892 .mode = 0644,
893 .proc_handler = proc_dointvec
894 },
895 {
896 .procname = "user_reports",
897 .data = &user_mode_unaligned_fixup_count,
898 .maxlen = sizeof(int),
899 .mode = 0644,
900 .proc_handler = proc_dointvec
901 },
902 {
903 .procname = "user_enable",
904 .data = &user_mode_unaligned_fixup_enable,
905 .maxlen = sizeof(int),
906 .mode = 0644,
907 .proc_handler = proc_dointvec},
908 {}
909 };
910
911 static ctl_table unaligned_root[] = {
912 {
913 .procname = "unaligned_fixup",
914 .mode = 0555,
915 .child = unaligned_table
916 },
917 {}
918 };
919
920 static ctl_table sh64_root[] = {
921 {
922 .procname = "sh64",
923 .mode = 0555,
924 .child = unaligned_root
925 },
926 {}
927 };
928 static struct ctl_table_header *sysctl_header;
init_sysctl(void)929 static int __init init_sysctl(void)
930 {
931 sysctl_header = register_sysctl_table(sh64_root);
932 return 0;
933 }
934
935 __initcall(init_sysctl);
936
937
do_debug_interrupt(unsigned long code,struct pt_regs * regs)938 asmlinkage void do_debug_interrupt(unsigned long code, struct pt_regs *regs)
939 {
940 u64 peek_real_address_q(u64 addr);
941 u64 poke_real_address_q(u64 addr, u64 val);
942 unsigned long long DM_EXP_CAUSE_PHY = 0x0c100010;
943 unsigned long long exp_cause;
944 /* It's not worth ioremapping the debug module registers for the amount
945 of access we make to them - just go direct to their physical
946 addresses. */
947 exp_cause = peek_real_address_q(DM_EXP_CAUSE_PHY);
948 if (exp_cause & ~4) {
949 printk("DM.EXP_CAUSE had unexpected bits set (=%08lx)\n",
950 (unsigned long)(exp_cause & 0xffffffff));
951 }
952 show_state();
953 /* Clear all DEBUGINT causes */
954 poke_real_address_q(DM_EXP_CAUSE_PHY, 0x0);
955 }
956
per_cpu_trap_init(void)957 void __cpuinit per_cpu_trap_init(void)
958 {
959 /* Nothing to do for now, VBR initialization later. */
960 }
961