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v5.4
  1// SPDX-License-Identifier: GPL-2.0
  2/*
  3 * arch/sh/kernel/traps_64.c
  4 *
  5 * Copyright (C) 2000, 2001  Paolo Alberelli
  6 * Copyright (C) 2003, 2004  Paul Mundt
  7 * Copyright (C) 2003, 2004  Richard Curnow
 
 
 
 
  8 */
  9#include <linux/sched.h>
 10#include <linux/sched/debug.h>
 11#include <linux/kernel.h>
 12#include <linux/string.h>
 13#include <linux/errno.h>
 14#include <linux/ptrace.h>
 15#include <linux/timer.h>
 16#include <linux/mm.h>
 17#include <linux/smp.h>
 18#include <linux/init.h>
 19#include <linux/delay.h>
 20#include <linux/spinlock.h>
 21#include <linux/kallsyms.h>
 22#include <linux/interrupt.h>
 23#include <linux/sysctl.h>
 24#include <linux/module.h>
 25#include <linux/perf_event.h>
 26#include <linux/uaccess.h>
 
 27#include <asm/io.h>
 28#include <asm/alignment.h>
 29#include <asm/processor.h>
 30#include <asm/pgtable.h>
 31#include <asm/fpu.h>
 32
 33static int read_opcode(reg_size_t pc, insn_size_t *result_opcode, int from_user_mode)
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 34{
 35	int get_user_error;
 36	unsigned long aligned_pc;
 37	insn_size_t opcode;
 38
 39	if ((pc & 3) == 1) {
 40		/* SHmedia */
 41		aligned_pc = pc & ~3;
 42		if (from_user_mode) {
 43			if (!access_ok(aligned_pc, sizeof(insn_size_t))) {
 44				get_user_error = -EFAULT;
 45			} else {
 46				get_user_error = __get_user(opcode, (insn_size_t *)aligned_pc);
 47				*result_opcode = opcode;
 48			}
 49			return get_user_error;
 50		} else {
 51			/* If the fault was in the kernel, we can either read
 52			 * this directly, or if not, we fault.
 53			*/
 54			*result_opcode = *(insn_size_t *)aligned_pc;
 55			return 0;
 56		}
 57	} else if ((pc & 1) == 0) {
 58		/* SHcompact */
 59		/* TODO : provide handling for this.  We don't really support
 60		   user-mode SHcompact yet, and for a kernel fault, this would
 61		   have to come from a module built for SHcompact.  */
 62		return -EFAULT;
 63	} else {
 64		/* misaligned */
 65		return -EFAULT;
 66	}
 67}
 68
 69static int address_is_sign_extended(__u64 a)
 70{
 71	__u64 b;
 72#if (NEFF == 32)
 73	b = (__u64)(__s64)(__s32)(a & 0xffffffffUL);
 74	return (b == a) ? 1 : 0;
 75#else
 76#error "Sign extend check only works for NEFF==32"
 77#endif
 78}
 79
 80/* return -1 for fault, 0 for OK */
 81static int generate_and_check_address(struct pt_regs *regs,
 82				      insn_size_t opcode,
 83				      int displacement_not_indexed,
 84				      int width_shift,
 85				      __u64 *address)
 86{
 
 
 87	__u64 base_address, addr;
 88	int basereg;
 89
 90	switch (1 << width_shift) {
 91	case 1: inc_unaligned_byte_access(); break;
 92	case 2: inc_unaligned_word_access(); break;
 93	case 4: inc_unaligned_dword_access(); break;
 94	case 8: inc_unaligned_multi_access(); break;
 95	}
 96
 97	basereg = (opcode >> 20) & 0x3f;
 98	base_address = regs->regs[basereg];
 99	if (displacement_not_indexed) {
100		__s64 displacement;
101		displacement = (opcode >> 10) & 0x3ff;
102		displacement = sign_extend64(displacement, 9);
103		addr = (__u64)((__s64)base_address + (displacement << width_shift));
104	} else {
105		__u64 offset;
106		int offsetreg;
107		offsetreg = (opcode >> 10) & 0x3f;
108		offset = regs->regs[offsetreg];
109		addr = base_address + offset;
110	}
111
112	/* Check sign extended */
113	if (!address_is_sign_extended(addr))
114		return -1;
 
115
116	/* Check accessible.  For misaligned access in the kernel, assume the
117	   address is always accessible (and if not, just fault when the
118	   load/store gets done.) */
119	if (user_mode(regs)) {
120		inc_unaligned_user_access();
121
122		if (addr >= TASK_SIZE)
123			return -1;
124	} else
125		inc_unaligned_kernel_access();
 
126
127	*address = addr;
128
129	perf_sw_event(PERF_COUNT_SW_EMULATION_FAULTS, 1, regs, addr);
130	unaligned_fixups_notify(current, opcode, regs);
131
132	return 0;
133}
134
 
 
 
 
135static void misaligned_kernel_word_load(__u64 address, int do_sign_extend, __u64 *result)
136{
137	unsigned short x;
138	unsigned char *p, *q;
139	p = (unsigned char *) (int) address;
140	q = (unsigned char *) &x;
141	q[0] = p[0];
142	q[1] = p[1];
143
144	if (do_sign_extend) {
145		*result = (__u64)(__s64) *(short *) &x;
146	} else {
147		*result = (__u64) x;
148	}
149}
150
151static void misaligned_kernel_word_store(__u64 address, __u64 value)
152{
153	unsigned short x;
154	unsigned char *p, *q;
155	p = (unsigned char *) (int) address;
156	q = (unsigned char *) &x;
157
158	x = (__u16) value;
159	p[0] = q[0];
160	p[1] = q[1];
161}
162
163static int misaligned_load(struct pt_regs *regs,
164			   insn_size_t opcode,
165			   int displacement_not_indexed,
166			   int width_shift,
167			   int do_sign_extend)
168{
169	/* Return -1 for a fault, 0 for OK */
170	int error;
171	int destreg;
172	__u64 address;
173
174	error = generate_and_check_address(regs, opcode,
175			displacement_not_indexed, width_shift, &address);
176	if (error < 0)
177		return error;
 
 
 
178
179	destreg = (opcode >> 4) & 0x3f;
180	if (user_mode(regs)) {
181		__u64 buffer;
182
183		if (!access_ok((unsigned long) address, 1UL<<width_shift)) {
184			return -1;
185		}
186
187		if (__copy_user(&buffer, (const void *)(int)address, (1 << width_shift)) > 0) {
188			return -1; /* fault */
189		}
190		switch (width_shift) {
191		case 1:
192			if (do_sign_extend) {
193				regs->regs[destreg] = (__u64)(__s64) *(__s16 *) &buffer;
194			} else {
195				regs->regs[destreg] = (__u64) *(__u16 *) &buffer;
196			}
197			break;
198		case 2:
199			regs->regs[destreg] = (__u64)(__s64) *(__s32 *) &buffer;
200			break;
201		case 3:
202			regs->regs[destreg] = buffer;
203			break;
204		default:
205			printk("Unexpected width_shift %d in misaligned_load, PC=%08lx\n",
206				width_shift, (unsigned long) regs->pc);
207			break;
208		}
209	} else {
210		/* kernel mode - we can take short cuts since if we fault, it's a genuine bug */
211		__u64 lo, hi;
212
213		switch (width_shift) {
214		case 1:
215			misaligned_kernel_word_load(address, do_sign_extend, &regs->regs[destreg]);
216			break;
217		case 2:
218			asm ("ldlo.l %1, 0, %0" : "=r" (lo) : "r" (address));
219			asm ("ldhi.l %1, 3, %0" : "=r" (hi) : "r" (address));
220			regs->regs[destreg] = lo | hi;
221			break;
222		case 3:
223			asm ("ldlo.q %1, 0, %0" : "=r" (lo) : "r" (address));
224			asm ("ldhi.q %1, 7, %0" : "=r" (hi) : "r" (address));
225			regs->regs[destreg] = lo | hi;
226			break;
227
228		default:
229			printk("Unexpected width_shift %d in misaligned_load, PC=%08lx\n",
230				width_shift, (unsigned long) regs->pc);
231			break;
232		}
233	}
234
235	return 0;
 
236}
237
238static int misaligned_store(struct pt_regs *regs,
239			    insn_size_t opcode,
240			    int displacement_not_indexed,
241			    int width_shift)
242{
243	/* Return -1 for a fault, 0 for OK */
244	int error;
245	int srcreg;
246	__u64 address;
247
248	error = generate_and_check_address(regs, opcode,
249			displacement_not_indexed, width_shift, &address);
250	if (error < 0)
251		return error;
 
 
 
252
253	srcreg = (opcode >> 4) & 0x3f;
254	if (user_mode(regs)) {
255		__u64 buffer;
256
257		if (!access_ok((unsigned long) address, 1UL<<width_shift)) {
258			return -1;
259		}
260
261		switch (width_shift) {
262		case 1:
263			*(__u16 *) &buffer = (__u16) regs->regs[srcreg];
264			break;
265		case 2:
266			*(__u32 *) &buffer = (__u32) regs->regs[srcreg];
267			break;
268		case 3:
269			buffer = regs->regs[srcreg];
270			break;
271		default:
272			printk("Unexpected width_shift %d in misaligned_store, PC=%08lx\n",
273				width_shift, (unsigned long) regs->pc);
274			break;
275		}
276
277		if (__copy_user((void *)(int)address, &buffer, (1 << width_shift)) > 0) {
278			return -1; /* fault */
279		}
280	} else {
281		/* kernel mode - we can take short cuts since if we fault, it's a genuine bug */
282		__u64 val = regs->regs[srcreg];
283
284		switch (width_shift) {
285		case 1:
286			misaligned_kernel_word_store(address, val);
287			break;
288		case 2:
289			asm ("stlo.l %1, 0, %0" : : "r" (val), "r" (address));
290			asm ("sthi.l %1, 3, %0" : : "r" (val), "r" (address));
291			break;
292		case 3:
293			asm ("stlo.q %1, 0, %0" : : "r" (val), "r" (address));
294			asm ("sthi.q %1, 7, %0" : : "r" (val), "r" (address));
295			break;
296
297		default:
298			printk("Unexpected width_shift %d in misaligned_store, PC=%08lx\n",
299				width_shift, (unsigned long) regs->pc);
300			break;
301		}
302	}
303
304	return 0;
 
305}
306
307/* Never need to fix up misaligned FPU accesses within the kernel since that's a real
308   error. */
309static int misaligned_fpu_load(struct pt_regs *regs,
310			   insn_size_t opcode,
311			   int displacement_not_indexed,
312			   int width_shift,
313			   int do_paired_load)
314{
315	/* Return -1 for a fault, 0 for OK */
316	int error;
317	int destreg;
318	__u64 address;
319
320	error = generate_and_check_address(regs, opcode,
321			displacement_not_indexed, width_shift, &address);
322	if (error < 0)
323		return error;
 
 
 
324
325	destreg = (opcode >> 4) & 0x3f;
326	if (user_mode(regs)) {
327		__u64 buffer;
328		__u32 buflo, bufhi;
329
330		if (!access_ok((unsigned long) address, 1UL<<width_shift)) {
331			return -1;
332		}
333
334		if (__copy_user(&buffer, (const void *)(int)address, (1 << width_shift)) > 0) {
335			return -1; /* fault */
336		}
337		/* 'current' may be the current owner of the FPU state, so
338		   context switch the registers into memory so they can be
339		   indexed by register number. */
340		if (last_task_used_math == current) {
341			enable_fpu();
342			save_fpu(current);
343			disable_fpu();
344			last_task_used_math = NULL;
345			regs->sr |= SR_FD;
346		}
347
348		buflo = *(__u32*) &buffer;
349		bufhi = *(1 + (__u32*) &buffer);
350
351		switch (width_shift) {
352		case 2:
353			current->thread.xstate->hardfpu.fp_regs[destreg] = buflo;
354			break;
355		case 3:
356			if (do_paired_load) {
357				current->thread.xstate->hardfpu.fp_regs[destreg] = buflo;
358				current->thread.xstate->hardfpu.fp_regs[destreg+1] = bufhi;
359			} else {
360#if defined(CONFIG_CPU_LITTLE_ENDIAN)
361				current->thread.xstate->hardfpu.fp_regs[destreg] = bufhi;
362				current->thread.xstate->hardfpu.fp_regs[destreg+1] = buflo;
363#else
364				current->thread.xstate->hardfpu.fp_regs[destreg] = buflo;
365				current->thread.xstate->hardfpu.fp_regs[destreg+1] = bufhi;
366#endif
367			}
368			break;
369		default:
370			printk("Unexpected width_shift %d in misaligned_fpu_load, PC=%08lx\n",
371				width_shift, (unsigned long) regs->pc);
372			break;
373		}
374		return 0;
375	} else {
376		die ("Misaligned FPU load inside kernel", regs, 0);
377		return -1;
378	}
 
 
379}
380
381static int misaligned_fpu_store(struct pt_regs *regs,
382			   insn_size_t opcode,
383			   int displacement_not_indexed,
384			   int width_shift,
385			   int do_paired_load)
386{
387	/* Return -1 for a fault, 0 for OK */
388	int error;
389	int srcreg;
390	__u64 address;
391
392	error = generate_and_check_address(regs, opcode,
393			displacement_not_indexed, width_shift, &address);
394	if (error < 0)
395		return error;
 
 
 
396
397	srcreg = (opcode >> 4) & 0x3f;
398	if (user_mode(regs)) {
399		__u64 buffer;
400		/* Initialise these to NaNs. */
401		__u32 buflo=0xffffffffUL, bufhi=0xffffffffUL;
402
403		if (!access_ok((unsigned long) address, 1UL<<width_shift)) {
404			return -1;
405		}
406
407		/* 'current' may be the current owner of the FPU state, so
408		   context switch the registers into memory so they can be
409		   indexed by register number. */
410		if (last_task_used_math == current) {
411			enable_fpu();
412			save_fpu(current);
413			disable_fpu();
414			last_task_used_math = NULL;
415			regs->sr |= SR_FD;
416		}
417
418		switch (width_shift) {
419		case 2:
420			buflo = current->thread.xstate->hardfpu.fp_regs[srcreg];
421			break;
422		case 3:
423			if (do_paired_load) {
424				buflo = current->thread.xstate->hardfpu.fp_regs[srcreg];
425				bufhi = current->thread.xstate->hardfpu.fp_regs[srcreg+1];
426			} else {
427#if defined(CONFIG_CPU_LITTLE_ENDIAN)
428				bufhi = current->thread.xstate->hardfpu.fp_regs[srcreg];
429				buflo = current->thread.xstate->hardfpu.fp_regs[srcreg+1];
430#else
431				buflo = current->thread.xstate->hardfpu.fp_regs[srcreg];
432				bufhi = current->thread.xstate->hardfpu.fp_regs[srcreg+1];
433#endif
434			}
435			break;
436		default:
437			printk("Unexpected width_shift %d in misaligned_fpu_store, PC=%08lx\n",
438				width_shift, (unsigned long) regs->pc);
439			break;
440		}
441
442		*(__u32*) &buffer = buflo;
443		*(1 + (__u32*) &buffer) = bufhi;
444		if (__copy_user((void *)(int)address, &buffer, (1 << width_shift)) > 0) {
445			return -1; /* fault */
446		}
447		return 0;
448	} else {
449		die ("Misaligned FPU load inside kernel", regs, 0);
450		return -1;
451	}
452}
453
454static int misaligned_fixup(struct pt_regs *regs)
455{
456	insn_size_t opcode;
457	int error;
458	int major, minor;
459	unsigned int user_action;
460
461	user_action = unaligned_user_action();
462	if (!(user_action & UM_FIXUP))
463		return -1;
464
465	error = read_opcode(regs->pc, &opcode, user_mode(regs));
466	if (error < 0) {
467		return error;
468	}
469	major = (opcode >> 26) & 0x3f;
470	minor = (opcode >> 16) & 0xf;
471
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
472	switch (major) {
473		case (0x84>>2): /* LD.W */
474			error = misaligned_load(regs, opcode, 1, 1, 1);
475			break;
476		case (0xb0>>2): /* LD.UW */
477			error = misaligned_load(regs, opcode, 1, 1, 0);
478			break;
479		case (0x88>>2): /* LD.L */
480			error = misaligned_load(regs, opcode, 1, 2, 1);
481			break;
482		case (0x8c>>2): /* LD.Q */
483			error = misaligned_load(regs, opcode, 1, 3, 0);
484			break;
485
486		case (0xa4>>2): /* ST.W */
487			error = misaligned_store(regs, opcode, 1, 1);
488			break;
489		case (0xa8>>2): /* ST.L */
490			error = misaligned_store(regs, opcode, 1, 2);
491			break;
492		case (0xac>>2): /* ST.Q */
493			error = misaligned_store(regs, opcode, 1, 3);
494			break;
495
496		case (0x40>>2): /* indexed loads */
497			switch (minor) {
498				case 0x1: /* LDX.W */
499					error = misaligned_load(regs, opcode, 0, 1, 1);
500					break;
501				case 0x5: /* LDX.UW */
502					error = misaligned_load(regs, opcode, 0, 1, 0);
503					break;
504				case 0x2: /* LDX.L */
505					error = misaligned_load(regs, opcode, 0, 2, 1);
506					break;
507				case 0x3: /* LDX.Q */
508					error = misaligned_load(regs, opcode, 0, 3, 0);
509					break;
510				default:
511					error = -1;
512					break;
513			}
514			break;
515
516		case (0x60>>2): /* indexed stores */
517			switch (minor) {
518				case 0x1: /* STX.W */
519					error = misaligned_store(regs, opcode, 0, 1);
520					break;
521				case 0x2: /* STX.L */
522					error = misaligned_store(regs, opcode, 0, 2);
523					break;
524				case 0x3: /* STX.Q */
525					error = misaligned_store(regs, opcode, 0, 3);
526					break;
527				default:
528					error = -1;
529					break;
530			}
531			break;
532
533		case (0x94>>2): /* FLD.S */
534			error = misaligned_fpu_load(regs, opcode, 1, 2, 0);
535			break;
536		case (0x98>>2): /* FLD.P */
537			error = misaligned_fpu_load(regs, opcode, 1, 3, 1);
538			break;
539		case (0x9c>>2): /* FLD.D */
540			error = misaligned_fpu_load(regs, opcode, 1, 3, 0);
541			break;
542		case (0x1c>>2): /* floating indexed loads */
543			switch (minor) {
544			case 0x8: /* FLDX.S */
545				error = misaligned_fpu_load(regs, opcode, 0, 2, 0);
546				break;
547			case 0xd: /* FLDX.P */
548				error = misaligned_fpu_load(regs, opcode, 0, 3, 1);
549				break;
550			case 0x9: /* FLDX.D */
551				error = misaligned_fpu_load(regs, opcode, 0, 3, 0);
552				break;
553			default:
554				error = -1;
555				break;
556			}
557			break;
558		case (0xb4>>2): /* FLD.S */
559			error = misaligned_fpu_store(regs, opcode, 1, 2, 0);
560			break;
561		case (0xb8>>2): /* FLD.P */
562			error = misaligned_fpu_store(regs, opcode, 1, 3, 1);
563			break;
564		case (0xbc>>2): /* FLD.D */
565			error = misaligned_fpu_store(regs, opcode, 1, 3, 0);
566			break;
567		case (0x3c>>2): /* floating indexed stores */
568			switch (minor) {
569			case 0x8: /* FSTX.S */
570				error = misaligned_fpu_store(regs, opcode, 0, 2, 0);
571				break;
572			case 0xd: /* FSTX.P */
573				error = misaligned_fpu_store(regs, opcode, 0, 3, 1);
574				break;
575			case 0x9: /* FSTX.D */
576				error = misaligned_fpu_store(regs, opcode, 0, 3, 0);
577				break;
578			default:
579				error = -1;
580				break;
581			}
582			break;
583
584		default:
585			/* Fault */
586			error = -1;
587			break;
588	}
589
590	if (error < 0) {
591		return error;
592	} else {
593		regs->pc += 4; /* Skip the instruction that's just been emulated */
594		return 0;
595	}
596}
597
598static void do_unhandled_exception(int signr, char *str, unsigned long error,
599				   struct pt_regs *regs)
600{
601	if (user_mode(regs))
602		force_sig(signr);
603
604	die_if_no_fixup(str, regs, error);
605}
606
607#define DO_ERROR(signr, str, name) \
608asmlinkage void do_##name(unsigned long error_code, struct pt_regs *regs) \
609{ \
610	do_unhandled_exception(signr, str, error_code, regs); \
611}
612
613DO_ERROR(SIGILL,  "illegal slot instruction", illegal_slot_inst)
614DO_ERROR(SIGSEGV, "address error (exec)", address_error_exec)
615
616#if defined(CONFIG_SH64_ID2815_WORKAROUND)
617
618#define OPCODE_INVALID      0
619#define OPCODE_USER_VALID   1
620#define OPCODE_PRIV_VALID   2
621
622/* getcon/putcon - requires checking which control register is referenced. */
623#define OPCODE_CTRL_REG     3
624
625/* Table of valid opcodes for SHmedia mode.
626   Form a 10-bit value by concatenating the major/minor opcodes i.e.
627   opcode[31:26,20:16].  The 6 MSBs of this value index into the following
628   array.  The 4 LSBs select the bit-pair in the entry (bits 1:0 correspond to
629   LSBs==4'b0000 etc). */
630static unsigned long shmedia_opcode_table[64] = {
631	0x55554044,0x54445055,0x15141514,0x14541414,0x00000000,0x10001000,0x01110055,0x04050015,
632	0x00000444,0xc0000000,0x44545515,0x40405555,0x55550015,0x10005555,0x55555505,0x04050000,
633	0x00000555,0x00000404,0x00040445,0x15151414,0x00000000,0x00000000,0x00000000,0x00000000,
634	0x00000055,0x40404444,0x00000404,0xc0009495,0x00000000,0x00000000,0x00000000,0x00000000,
635	0x55555555,0x55555555,0x55555555,0x55555555,0x55555555,0x55555555,0x55555555,0x55555555,
636	0x55555555,0x55555555,0x55555555,0x55555555,0x55555555,0x55555555,0x55555555,0x55555555,
637	0x80005050,0x04005055,0x55555555,0x55555555,0x55555555,0x55555555,0x55555555,0x55555555,
638	0x81055554,0x00000404,0x55555555,0x55555555,0x00000000,0x00000000,0x00000000,0x00000000
639};
640
641/* Workaround SH5-101 cut2 silicon defect #2815 :
642   in some situations, inter-mode branches from SHcompact -> SHmedia
643   which should take ITLBMISS or EXECPROT exceptions at the target
644   falsely take RESINST at the target instead. */
645void do_reserved_inst(unsigned long error_code, struct pt_regs *regs)
646{
647	insn_size_t opcode = 0x6ff4fff0; /* guaranteed reserved opcode */
648	unsigned long pc, aligned_pc;
649	unsigned long index, shift;
650	unsigned long major, minor, combined;
651	unsigned long reserved_field;
652	int opcode_state;
653	int get_user_error;
654	int signr = SIGILL;
655	char *exception_name = "reserved_instruction";
656
657	pc = regs->pc;
658
659	/* SHcompact is not handled */
660	if (unlikely((pc & 3) == 0))
661		goto out;
662
663	/* SHmedia : check for defect.  This requires executable vmas
664	   to be readable too. */
665	aligned_pc = pc & ~3;
666	if (!access_ok(aligned_pc, sizeof(insn_size_t)))
667		get_user_error = -EFAULT;
668	else
669		get_user_error = __get_user(opcode, (insn_size_t *)aligned_pc);
670
671	if (get_user_error < 0) {
672		/*
673		 * Error trying to read opcode.  This typically means a
674		 * real fault, not a RESINST any more.  So change the
675		 * codes.
676		 */
677		exception_name = "address error (exec)";
678		signr = SIGSEGV;
679		goto out;
680	}
681
682	/* These bits are currently reserved as zero in all valid opcodes */
683	reserved_field = opcode & 0xf;
684	if (unlikely(reserved_field))
685		goto out;	/* invalid opcode */
686
687	major = (opcode >> 26) & 0x3f;
688	minor = (opcode >> 16) & 0xf;
689	combined = (major << 4) | minor;
690	index = major;
691	shift = minor << 1;
692	opcode_state = (shmedia_opcode_table[index] >> shift) & 0x3;
693	switch (opcode_state) {
694	case OPCODE_INVALID:
695		/* Trap. */
696		break;
697	case OPCODE_USER_VALID:
698		/*
699		 * Restart the instruction: the branch to the instruction
700		 * will now be from an RTE not from SHcompact so the
701		 * silicon defect won't be triggered.
702		 */
703		return;
704	case OPCODE_PRIV_VALID:
705		if (!user_mode(regs)) {
706			/*
707			 * Should only ever get here if a module has
708			 * SHcompact code inside it. If so, the same fix
709			 * up is needed.
710			 */
711			return; /* same reason */
712		}
713
714		/*
715		 * Otherwise, user mode trying to execute a privileged
716		 * instruction - fall through to trap.
717		 */
718		break;
719	case OPCODE_CTRL_REG:
720		/* If in privileged mode, return as above. */
721		if (!user_mode(regs))
722			return;
723
724		/* In user mode ... */
725		if (combined == 0x9f) { /* GETCON */
726			unsigned long regno = (opcode >> 20) & 0x3f;
727
728			if (regno >= 62)
729				return;
730
731			/* reserved/privileged control register => trap */
732		} else if (combined == 0x1bf) { /* PUTCON */
733			unsigned long regno = (opcode >> 4) & 0x3f;
734
735			if (regno >= 62)
736				return;
737
738			/* reserved/privileged control register => trap */
739		}
740
741		break;
742	default:
743		/* Fall through to trap. */
744		break;
745	}
746
747out:
748	do_unhandled_exception(signr, exception_name, error_code, regs);
749}
750
751#else /* CONFIG_SH64_ID2815_WORKAROUND */
752
753/* If the workaround isn't needed, this is just a straightforward reserved
754   instruction */
755DO_ERROR(SIGILL, "reserved instruction", reserved_inst)
756
757#endif /* CONFIG_SH64_ID2815_WORKAROUND */
758
759/* Called with interrupts disabled */
760asmlinkage void do_exception_error(unsigned long ex, struct pt_regs *regs)
761{
762	die_if_kernel("exception", regs, ex);
763}
764
765asmlinkage int do_unknown_trapa(unsigned long scId, struct pt_regs *regs)
 
 
 
 
 
 
 
 
 
766{
767	/* Syscall debug */
768	printk("System call ID error: [0x1#args:8 #syscall:16  0x%lx]\n", scId);
769
770	die_if_kernel("unknown trapa", regs, scId);
771
772	return -ENOSYS;
773}
774
775/* Implement misaligned load/store handling for kernel (and optionally for user
776   mode too).  Limitation : only SHmedia mode code is handled - there is no
777   handling at all for misaligned accesses occurring in SHcompact code yet. */
778
779asmlinkage void do_address_error_load(unsigned long error_code, struct pt_regs *regs)
780{
781	if (misaligned_fixup(regs) < 0)
782		do_unhandled_exception(SIGSEGV, "address error(load)",
783				       error_code, regs);
784}
785
786asmlinkage void do_address_error_store(unsigned long error_code, struct pt_regs *regs)
787{
788	if (misaligned_fixup(regs) < 0)
789		do_unhandled_exception(SIGSEGV, "address error(store)",
790				error_code, regs);
791}
792
793asmlinkage void do_debug_interrupt(unsigned long code, struct pt_regs *regs)
794{
795	u64 peek_real_address_q(u64 addr);
796	u64 poke_real_address_q(u64 addr, u64 val);
797	unsigned long long DM_EXP_CAUSE_PHY = 0x0c100010;
798	unsigned long long exp_cause;
799	/* It's not worth ioremapping the debug module registers for the amount
800	   of access we make to them - just go direct to their physical
801	   addresses. */
802	exp_cause = peek_real_address_q(DM_EXP_CAUSE_PHY);
803	if (exp_cause & ~4)
804		printk("DM.EXP_CAUSE had unexpected bits set (=%08lx)\n",
805			(unsigned long)(exp_cause & 0xffffffff));
 
806	show_state();
807	/* Clear all DEBUGINT causes */
808	poke_real_address_q(DM_EXP_CAUSE_PHY, 0x0);
809}
810
811void per_cpu_trap_init(void)
812{
813	/* Nothing to do for now, VBR initialization later. */
814}
v3.1
 
  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 */
 39extern 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
 45static 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) \
 49asmlinkage 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
 54static DEFINE_SPINLOCK(die_lock);
 55
 56void 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
 66static 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
 72static 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
 85DO_ERROR(13, SIGILL,  "illegal slot instruction", illegal_slot_inst, current)
 86DO_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
 93static int misaligned_fixup(struct pt_regs *regs);
 94
 95asmlinkage 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
105asmlinkage 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). */
129static 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
140void 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 */
236DO_ERROR(12, SIGILL,  "reserved instruction", reserved_inst, current)
237
238#endif /* CONFIG_SH64_ID2815_WORKAROUND */
239
240/* Called with interrupts disabled */
241asmlinkage 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
247int 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
257void 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
271void show_task(unsigned long *sp)
272{
273	show_stack(NULL, sp);
274}
275
276void 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 */
281EXPORT_SYMBOL(dump_stack);
282
283static 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
296static 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
332static 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
 
343static 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
388static int user_mode_unaligned_fixup_count = 10;
389static int user_mode_unaligned_fixup_enable = 1;
390static int kernel_mode_unaligned_fixup_count = 32;
391
392static 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
408static 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
420static 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, &regs->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
499static 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. */
574static 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
651static 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
727static 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
887static 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
911static ctl_table unaligned_root[] = {
912	{
913		.procname	= "unaligned_fixup",
914		.mode		= 0555,
915		.child		= unaligned_table
916	},
917	{}
918};
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
919
920static ctl_table sh64_root[] = {
921	{
922		.procname	= "sh64",
923		.mode		= 0555,
924		.child		= unaligned_root
925	},
926	{}
927};
928static struct ctl_table_header *sysctl_header;
929static 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
938asmlinkage 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
957void __cpuinit per_cpu_trap_init(void)
958{
959	/* Nothing to do for now, VBR initialization later. */
960}