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1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * OpenRISC traps.c
4 *
5 * Linux architectural port borrowing liberally from similar works of
6 * others. All original copyrights apply as per the original source
7 * declaration.
8 *
9 * Modifications for the OpenRISC architecture:
10 * Copyright (C) 2003 Matjaz Breskvar <phoenix@bsemi.com>
11 * Copyright (C) 2010-2011 Jonas Bonn <jonas@southpole.se>
12 *
13 * Here we handle the break vectors not used by the system call
14 * mechanism, as well as some general stack/register dumping
15 * things.
16 */
17
18#include <linux/init.h>
19#include <linux/sched.h>
20#include <linux/sched/debug.h>
21#include <linux/sched/task_stack.h>
22#include <linux/kernel.h>
23#include <linux/extable.h>
24#include <linux/kmod.h>
25#include <linux/string.h>
26#include <linux/errno.h>
27#include <linux/ptrace.h>
28#include <linux/timer.h>
29#include <linux/mm.h>
30#include <linux/kallsyms.h>
31#include <linux/uaccess.h>
32
33#include <asm/bug.h>
34#include <asm/io.h>
35#include <asm/processor.h>
36#include <asm/unwinder.h>
37#include <asm/sections.h>
38
39int lwa_flag;
40static unsigned long __user *lwa_addr;
41
42asmlinkage void unhandled_exception(struct pt_regs *regs, int ea, int vector);
43asmlinkage void do_trap(struct pt_regs *regs, unsigned long address);
44asmlinkage void do_fpe_trap(struct pt_regs *regs, unsigned long address);
45asmlinkage void do_unaligned_access(struct pt_regs *regs, unsigned long address);
46asmlinkage void do_bus_fault(struct pt_regs *regs, unsigned long address);
47asmlinkage void do_illegal_instruction(struct pt_regs *regs,
48 unsigned long address);
49
50static void print_trace(void *data, unsigned long addr, int reliable)
51{
52 const char *loglvl = data;
53
54 printk("%s[<%p>] %s%pS\n", loglvl, (void *) addr, reliable ? "" : "? ",
55 (void *) addr);
56}
57
58static void print_data(unsigned long base_addr, unsigned long word, int i)
59{
60 if (i == 0)
61 printk("(%08lx:)\t%08lx", base_addr + (i * 4), word);
62 else
63 printk(" %08lx:\t%08lx", base_addr + (i * 4), word);
64}
65
66/* displays a short stack trace */
67void show_stack(struct task_struct *task, unsigned long *esp, const char *loglvl)
68{
69 if (esp == NULL)
70 esp = (unsigned long *)&esp;
71
72 printk("%sCall trace:\n", loglvl);
73 unwind_stack((void *)loglvl, esp, print_trace);
74}
75
76void show_registers(struct pt_regs *regs)
77{
78 int i;
79 int in_kernel = 1;
80 unsigned long esp;
81
82 esp = (unsigned long)(regs->sp);
83 if (user_mode(regs))
84 in_kernel = 0;
85
86 printk("CPU #: %d\n"
87 " PC: %08lx SR: %08lx SP: %08lx FPCSR: %08lx\n",
88 smp_processor_id(), regs->pc, regs->sr, regs->sp,
89 regs->fpcsr);
90 printk("GPR00: %08lx GPR01: %08lx GPR02: %08lx GPR03: %08lx\n",
91 0L, regs->gpr[1], regs->gpr[2], regs->gpr[3]);
92 printk("GPR04: %08lx GPR05: %08lx GPR06: %08lx GPR07: %08lx\n",
93 regs->gpr[4], regs->gpr[5], regs->gpr[6], regs->gpr[7]);
94 printk("GPR08: %08lx GPR09: %08lx GPR10: %08lx GPR11: %08lx\n",
95 regs->gpr[8], regs->gpr[9], regs->gpr[10], regs->gpr[11]);
96 printk("GPR12: %08lx GPR13: %08lx GPR14: %08lx GPR15: %08lx\n",
97 regs->gpr[12], regs->gpr[13], regs->gpr[14], regs->gpr[15]);
98 printk("GPR16: %08lx GPR17: %08lx GPR18: %08lx GPR19: %08lx\n",
99 regs->gpr[16], regs->gpr[17], regs->gpr[18], regs->gpr[19]);
100 printk("GPR20: %08lx GPR21: %08lx GPR22: %08lx GPR23: %08lx\n",
101 regs->gpr[20], regs->gpr[21], regs->gpr[22], regs->gpr[23]);
102 printk("GPR24: %08lx GPR25: %08lx GPR26: %08lx GPR27: %08lx\n",
103 regs->gpr[24], regs->gpr[25], regs->gpr[26], regs->gpr[27]);
104 printk("GPR28: %08lx GPR29: %08lx GPR30: %08lx GPR31: %08lx\n",
105 regs->gpr[28], regs->gpr[29], regs->gpr[30], regs->gpr[31]);
106 printk(" RES: %08lx oGPR11: %08lx\n",
107 regs->gpr[11], regs->orig_gpr11);
108
109 printk("Process %s (pid: %d, stackpage=%08lx)\n",
110 current->comm, current->pid, (unsigned long)current);
111 /*
112 * When in-kernel, we also print out the stack and code at the
113 * time of the fault..
114 */
115 if (in_kernel) {
116
117 printk("\nStack: ");
118 show_stack(NULL, (unsigned long *)esp, KERN_EMERG);
119
120 if (esp < PAGE_OFFSET)
121 goto bad_stack;
122
123 printk("\n");
124 for (i = -8; i < 24; i += 1) {
125 unsigned long word;
126
127 if (__get_user(word, &((unsigned long *)esp)[i])) {
128bad_stack:
129 printk(" Bad Stack value.");
130 break;
131 }
132
133 print_data(esp, word, i);
134 }
135
136 printk("\nCode: ");
137 if (regs->pc < PAGE_OFFSET)
138 goto bad;
139
140 for (i = -6; i < 6; i += 1) {
141 unsigned long word;
142
143 if (__get_user(word, &((unsigned long *)regs->pc)[i])) {
144bad:
145 printk(" Bad PC value.");
146 break;
147 }
148
149 print_data(regs->pc, word, i);
150 }
151 }
152 printk("\n");
153}
154
155/* This is normally the 'Oops' routine */
156void __noreturn die(const char *str, struct pt_regs *regs, long err)
157{
158
159 console_verbose();
160 printk("\n%s#: %04lx\n", str, err & 0xffff);
161 show_registers(regs);
162#ifdef CONFIG_JUMP_UPON_UNHANDLED_EXCEPTION
163 printk("\n\nUNHANDLED_EXCEPTION: entering infinite loop\n");
164
165 /* shut down interrupts */
166 local_irq_disable();
167
168 __asm__ __volatile__("l.nop 1");
169 do {} while (1);
170#endif
171 make_task_dead(SIGSEGV);
172}
173
174asmlinkage void unhandled_exception(struct pt_regs *regs, int ea, int vector)
175{
176 printk("Unable to handle exception at EA =0x%x, vector 0x%x",
177 ea, vector);
178 die("Oops", regs, 9);
179}
180
181asmlinkage void do_fpe_trap(struct pt_regs *regs, unsigned long address)
182{
183 int code = FPE_FLTUNK;
184 unsigned long fpcsr = regs->fpcsr;
185
186 if (fpcsr & SPR_FPCSR_IVF)
187 code = FPE_FLTINV;
188 else if (fpcsr & SPR_FPCSR_OVF)
189 code = FPE_FLTOVF;
190 else if (fpcsr & SPR_FPCSR_UNF)
191 code = FPE_FLTUND;
192 else if (fpcsr & SPR_FPCSR_DZF)
193 code = FPE_FLTDIV;
194 else if (fpcsr & SPR_FPCSR_IXF)
195 code = FPE_FLTRES;
196
197 /* Clear all flags */
198 regs->fpcsr &= ~SPR_FPCSR_ALLF;
199
200 force_sig_fault(SIGFPE, code, (void __user *)regs->pc);
201}
202
203asmlinkage void do_trap(struct pt_regs *regs, unsigned long address)
204{
205 force_sig_fault(SIGTRAP, TRAP_BRKPT, (void __user *)regs->pc);
206}
207
208asmlinkage void do_unaligned_access(struct pt_regs *regs, unsigned long address)
209{
210 if (user_mode(regs)) {
211 /* Send a SIGBUS */
212 force_sig_fault(SIGBUS, BUS_ADRALN, (void __user *)address);
213 } else {
214 printk("KERNEL: Unaligned Access 0x%.8lx\n", address);
215 show_registers(regs);
216 die("Die:", regs, address);
217 }
218
219}
220
221asmlinkage void do_bus_fault(struct pt_regs *regs, unsigned long address)
222{
223 if (user_mode(regs)) {
224 /* Send a SIGBUS */
225 force_sig_fault(SIGBUS, BUS_ADRERR, (void __user *)address);
226 } else { /* Kernel mode */
227 printk("KERNEL: Bus error (SIGBUS) 0x%.8lx\n", address);
228 show_registers(regs);
229 die("Die:", regs, address);
230 }
231}
232
233static inline int in_delay_slot(struct pt_regs *regs)
234{
235#ifdef CONFIG_OPENRISC_NO_SPR_SR_DSX
236 /* No delay slot flag, do the old way */
237 unsigned int op, insn;
238
239 insn = *((unsigned int *)regs->pc);
240 op = insn >> 26;
241 switch (op) {
242 case 0x00: /* l.j */
243 case 0x01: /* l.jal */
244 case 0x03: /* l.bnf */
245 case 0x04: /* l.bf */
246 case 0x11: /* l.jr */
247 case 0x12: /* l.jalr */
248 return 1;
249 default:
250 return 0;
251 }
252#else
253 return mfspr(SPR_SR) & SPR_SR_DSX;
254#endif
255}
256
257static inline void adjust_pc(struct pt_regs *regs, unsigned long address)
258{
259 int displacement;
260 unsigned int rb, op, jmp;
261
262 if (unlikely(in_delay_slot(regs))) {
263 /* In delay slot, instruction at pc is a branch, simulate it */
264 jmp = *((unsigned int *)regs->pc);
265
266 displacement = sign_extend32(((jmp) & 0x3ffffff) << 2, 27);
267 rb = (jmp & 0x0000ffff) >> 11;
268 op = jmp >> 26;
269
270 switch (op) {
271 case 0x00: /* l.j */
272 regs->pc += displacement;
273 return;
274 case 0x01: /* l.jal */
275 regs->pc += displacement;
276 regs->gpr[9] = regs->pc + 8;
277 return;
278 case 0x03: /* l.bnf */
279 if (regs->sr & SPR_SR_F)
280 regs->pc += 8;
281 else
282 regs->pc += displacement;
283 return;
284 case 0x04: /* l.bf */
285 if (regs->sr & SPR_SR_F)
286 regs->pc += displacement;
287 else
288 regs->pc += 8;
289 return;
290 case 0x11: /* l.jr */
291 regs->pc = regs->gpr[rb];
292 return;
293 case 0x12: /* l.jalr */
294 regs->pc = regs->gpr[rb];
295 regs->gpr[9] = regs->pc + 8;
296 return;
297 default:
298 break;
299 }
300 } else {
301 regs->pc += 4;
302 }
303}
304
305static inline void simulate_lwa(struct pt_regs *regs, unsigned long address,
306 unsigned int insn)
307{
308 unsigned int ra, rd;
309 unsigned long value;
310 unsigned long orig_pc;
311 long imm;
312
313 const struct exception_table_entry *entry;
314
315 orig_pc = regs->pc;
316 adjust_pc(regs, address);
317
318 ra = (insn >> 16) & 0x1f;
319 rd = (insn >> 21) & 0x1f;
320 imm = (short)insn;
321 lwa_addr = (unsigned long __user *)(regs->gpr[ra] + imm);
322
323 if ((unsigned long)lwa_addr & 0x3) {
324 do_unaligned_access(regs, address);
325 return;
326 }
327
328 if (get_user(value, lwa_addr)) {
329 if (user_mode(regs)) {
330 force_sig(SIGSEGV);
331 return;
332 }
333
334 if ((entry = search_exception_tables(orig_pc))) {
335 regs->pc = entry->fixup;
336 return;
337 }
338
339 /* kernel access in kernel space, load it directly */
340 value = *((unsigned long *)lwa_addr);
341 }
342
343 lwa_flag = 1;
344 regs->gpr[rd] = value;
345}
346
347static inline void simulate_swa(struct pt_regs *regs, unsigned long address,
348 unsigned int insn)
349{
350 unsigned long __user *vaddr;
351 unsigned long orig_pc;
352 unsigned int ra, rb;
353 long imm;
354
355 const struct exception_table_entry *entry;
356
357 orig_pc = regs->pc;
358 adjust_pc(regs, address);
359
360 ra = (insn >> 16) & 0x1f;
361 rb = (insn >> 11) & 0x1f;
362 imm = (short)(((insn & 0x2200000) >> 10) | (insn & 0x7ff));
363 vaddr = (unsigned long __user *)(regs->gpr[ra] + imm);
364
365 if (!lwa_flag || vaddr != lwa_addr) {
366 regs->sr &= ~SPR_SR_F;
367 return;
368 }
369
370 if ((unsigned long)vaddr & 0x3) {
371 do_unaligned_access(regs, address);
372 return;
373 }
374
375 if (put_user(regs->gpr[rb], vaddr)) {
376 if (user_mode(regs)) {
377 force_sig(SIGSEGV);
378 return;
379 }
380
381 if ((entry = search_exception_tables(orig_pc))) {
382 regs->pc = entry->fixup;
383 return;
384 }
385
386 /* kernel access in kernel space, store it directly */
387 *((unsigned long *)vaddr) = regs->gpr[rb];
388 }
389
390 lwa_flag = 0;
391 regs->sr |= SPR_SR_F;
392}
393
394#define INSN_LWA 0x1b
395#define INSN_SWA 0x33
396
397asmlinkage void do_illegal_instruction(struct pt_regs *regs,
398 unsigned long address)
399{
400 unsigned int op;
401 unsigned int insn = *((unsigned int *)address);
402
403 op = insn >> 26;
404
405 switch (op) {
406 case INSN_LWA:
407 simulate_lwa(regs, address, insn);
408 return;
409
410 case INSN_SWA:
411 simulate_swa(regs, address, insn);
412 return;
413
414 default:
415 break;
416 }
417
418 if (user_mode(regs)) {
419 /* Send a SIGILL */
420 force_sig_fault(SIGILL, ILL_ILLOPC, (void __user *)address);
421 } else { /* Kernel mode */
422 printk("KERNEL: Illegal instruction (SIGILL) 0x%.8lx\n",
423 address);
424 show_registers(regs);
425 die("Die:", regs, address);
426 }
427}
1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * OpenRISC traps.c
4 *
5 * Linux architectural port borrowing liberally from similar works of
6 * others. All original copyrights apply as per the original source
7 * declaration.
8 *
9 * Modifications for the OpenRISC architecture:
10 * Copyright (C) 2003 Matjaz Breskvar <phoenix@bsemi.com>
11 * Copyright (C) 2010-2011 Jonas Bonn <jonas@southpole.se>
12 *
13 * Here we handle the break vectors not used by the system call
14 * mechanism, as well as some general stack/register dumping
15 * things.
16 */
17
18#include <linux/init.h>
19#include <linux/sched.h>
20#include <linux/sched/debug.h>
21#include <linux/sched/task_stack.h>
22#include <linux/kernel.h>
23#include <linux/extable.h>
24#include <linux/kmod.h>
25#include <linux/string.h>
26#include <linux/errno.h>
27#include <linux/ptrace.h>
28#include <linux/timer.h>
29#include <linux/mm.h>
30#include <linux/kallsyms.h>
31#include <linux/uaccess.h>
32
33#include <asm/bug.h>
34#include <asm/io.h>
35#include <asm/processor.h>
36#include <asm/unwinder.h>
37#include <asm/sections.h>
38
39int lwa_flag;
40static unsigned long __user *lwa_addr;
41
42asmlinkage void unhandled_exception(struct pt_regs *regs, int ea, int vector);
43asmlinkage void do_trap(struct pt_regs *regs, unsigned long address);
44asmlinkage void do_fpe_trap(struct pt_regs *regs, unsigned long address);
45asmlinkage void do_unaligned_access(struct pt_regs *regs, unsigned long address);
46asmlinkage void do_bus_fault(struct pt_regs *regs, unsigned long address);
47asmlinkage void do_illegal_instruction(struct pt_regs *regs,
48 unsigned long address);
49
50static void print_trace(void *data, unsigned long addr, int reliable)
51{
52 const char *loglvl = data;
53
54 printk("%s[<%p>] %s%pS\n", loglvl, (void *) addr, reliable ? "" : "? ",
55 (void *) addr);
56}
57
58static void print_data(unsigned long base_addr, unsigned long word, int i)
59{
60 if (i == 0)
61 printk("(%08lx:)\t%08lx", base_addr + (i * 4), word);
62 else
63 printk(" %08lx:\t%08lx", base_addr + (i * 4), word);
64}
65
66/* displays a short stack trace */
67void show_stack(struct task_struct *task, unsigned long *esp, const char *loglvl)
68{
69 if (esp == NULL)
70 esp = (unsigned long *)&esp;
71
72 printk("%sCall trace:\n", loglvl);
73 unwind_stack((void *)loglvl, esp, print_trace);
74}
75
76void show_registers(struct pt_regs *regs)
77{
78 int i;
79 int in_kernel = 1;
80 unsigned long esp;
81
82 esp = (unsigned long)(regs->sp);
83 if (user_mode(regs))
84 in_kernel = 0;
85
86 printk("CPU #: %d\n"
87 " PC: %08lx SR: %08lx SP: %08lx FPCSR: %08lx\n",
88 smp_processor_id(), regs->pc, regs->sr, regs->sp,
89 regs->fpcsr);
90 printk("GPR00: %08lx GPR01: %08lx GPR02: %08lx GPR03: %08lx\n",
91 0L, regs->gpr[1], regs->gpr[2], regs->gpr[3]);
92 printk("GPR04: %08lx GPR05: %08lx GPR06: %08lx GPR07: %08lx\n",
93 regs->gpr[4], regs->gpr[5], regs->gpr[6], regs->gpr[7]);
94 printk("GPR08: %08lx GPR09: %08lx GPR10: %08lx GPR11: %08lx\n",
95 regs->gpr[8], regs->gpr[9], regs->gpr[10], regs->gpr[11]);
96 printk("GPR12: %08lx GPR13: %08lx GPR14: %08lx GPR15: %08lx\n",
97 regs->gpr[12], regs->gpr[13], regs->gpr[14], regs->gpr[15]);
98 printk("GPR16: %08lx GPR17: %08lx GPR18: %08lx GPR19: %08lx\n",
99 regs->gpr[16], regs->gpr[17], regs->gpr[18], regs->gpr[19]);
100 printk("GPR20: %08lx GPR21: %08lx GPR22: %08lx GPR23: %08lx\n",
101 regs->gpr[20], regs->gpr[21], regs->gpr[22], regs->gpr[23]);
102 printk("GPR24: %08lx GPR25: %08lx GPR26: %08lx GPR27: %08lx\n",
103 regs->gpr[24], regs->gpr[25], regs->gpr[26], regs->gpr[27]);
104 printk("GPR28: %08lx GPR29: %08lx GPR30: %08lx GPR31: %08lx\n",
105 regs->gpr[28], regs->gpr[29], regs->gpr[30], regs->gpr[31]);
106 printk(" RES: %08lx oGPR11: %08lx\n",
107 regs->gpr[11], regs->orig_gpr11);
108
109 printk("Process %s (pid: %d, stackpage=%08lx)\n",
110 current->comm, current->pid, (unsigned long)current);
111 /*
112 * When in-kernel, we also print out the stack and code at the
113 * time of the fault..
114 */
115 if (in_kernel) {
116
117 printk("\nStack: ");
118 show_stack(NULL, (unsigned long *)esp, KERN_EMERG);
119
120 if (esp < PAGE_OFFSET)
121 goto bad_stack;
122
123 printk("\n");
124 for (i = -8; i < 24; i += 1) {
125 unsigned long word;
126
127 if (__get_user(word, &((unsigned long *)esp)[i])) {
128bad_stack:
129 printk(" Bad Stack value.");
130 break;
131 }
132
133 print_data(esp, word, i);
134 }
135
136 printk("\nCode: ");
137 if (regs->pc < PAGE_OFFSET)
138 goto bad;
139
140 for (i = -6; i < 6; i += 1) {
141 unsigned long word;
142
143 if (__get_user(word, &((unsigned long *)regs->pc)[i])) {
144bad:
145 printk(" Bad PC value.");
146 break;
147 }
148
149 print_data(regs->pc, word, i);
150 }
151 }
152 printk("\n");
153}
154
155/* This is normally the 'Oops' routine */
156void __noreturn die(const char *str, struct pt_regs *regs, long err)
157{
158
159 console_verbose();
160 printk("\n%s#: %04lx\n", str, err & 0xffff);
161 show_registers(regs);
162#ifdef CONFIG_JUMP_UPON_UNHANDLED_EXCEPTION
163 printk("\n\nUNHANDLED_EXCEPTION: entering infinite loop\n");
164
165 /* shut down interrupts */
166 local_irq_disable();
167
168 __asm__ __volatile__("l.nop 1");
169 do {} while (1);
170#endif
171 make_task_dead(SIGSEGV);
172}
173
174asmlinkage void unhandled_exception(struct pt_regs *regs, int ea, int vector)
175{
176 printk("Unable to handle exception at EA =0x%x, vector 0x%x",
177 ea, vector);
178 die("Oops", regs, 9);
179}
180
181asmlinkage void do_fpe_trap(struct pt_regs *regs, unsigned long address)
182{
183 if (user_mode(regs)) {
184 int code = FPE_FLTUNK;
185 unsigned long fpcsr = regs->fpcsr;
186
187 if (fpcsr & SPR_FPCSR_IVF)
188 code = FPE_FLTINV;
189 else if (fpcsr & SPR_FPCSR_OVF)
190 code = FPE_FLTOVF;
191 else if (fpcsr & SPR_FPCSR_UNF)
192 code = FPE_FLTUND;
193 else if (fpcsr & SPR_FPCSR_DZF)
194 code = FPE_FLTDIV;
195 else if (fpcsr & SPR_FPCSR_IXF)
196 code = FPE_FLTRES;
197
198 /* Clear all flags */
199 regs->fpcsr &= ~SPR_FPCSR_ALLF;
200
201 force_sig_fault(SIGFPE, code, (void __user *)regs->pc);
202 } else {
203 pr_emerg("KERNEL: Illegal fpe exception 0x%.8lx\n", regs->pc);
204 die("Die:", regs, SIGFPE);
205 }
206}
207
208asmlinkage void do_trap(struct pt_regs *regs, unsigned long address)
209{
210 if (user_mode(regs)) {
211 force_sig_fault(SIGTRAP, TRAP_BRKPT, (void __user *)regs->pc);
212 } else {
213 pr_emerg("KERNEL: Illegal trap exception 0x%.8lx\n", regs->pc);
214 die("Die:", regs, SIGILL);
215 }
216}
217
218asmlinkage void do_unaligned_access(struct pt_regs *regs, unsigned long address)
219{
220 if (user_mode(regs)) {
221 /* Send a SIGBUS */
222 force_sig_fault(SIGBUS, BUS_ADRALN, (void __user *)address);
223 } else {
224 printk("KERNEL: Unaligned Access 0x%.8lx\n", address);
225 show_registers(regs);
226 die("Die:", regs, address);
227 }
228
229}
230
231asmlinkage void do_bus_fault(struct pt_regs *regs, unsigned long address)
232{
233 if (user_mode(regs)) {
234 /* Send a SIGBUS */
235 force_sig_fault(SIGBUS, BUS_ADRERR, (void __user *)address);
236 } else { /* Kernel mode */
237 printk("KERNEL: Bus error (SIGBUS) 0x%.8lx\n", address);
238 show_registers(regs);
239 die("Die:", regs, address);
240 }
241}
242
243static inline int in_delay_slot(struct pt_regs *regs)
244{
245#ifdef CONFIG_OPENRISC_NO_SPR_SR_DSX
246 /* No delay slot flag, do the old way */
247 unsigned int op, insn;
248
249 insn = *((unsigned int *)regs->pc);
250 op = insn >> 26;
251 switch (op) {
252 case 0x00: /* l.j */
253 case 0x01: /* l.jal */
254 case 0x03: /* l.bnf */
255 case 0x04: /* l.bf */
256 case 0x11: /* l.jr */
257 case 0x12: /* l.jalr */
258 return 1;
259 default:
260 return 0;
261 }
262#else
263 return mfspr(SPR_SR) & SPR_SR_DSX;
264#endif
265}
266
267static inline void adjust_pc(struct pt_regs *regs, unsigned long address)
268{
269 int displacement;
270 unsigned int rb, op, jmp;
271
272 if (unlikely(in_delay_slot(regs))) {
273 /* In delay slot, instruction at pc is a branch, simulate it */
274 jmp = *((unsigned int *)regs->pc);
275
276 displacement = sign_extend32(((jmp) & 0x3ffffff) << 2, 27);
277 rb = (jmp & 0x0000ffff) >> 11;
278 op = jmp >> 26;
279
280 switch (op) {
281 case 0x00: /* l.j */
282 regs->pc += displacement;
283 return;
284 case 0x01: /* l.jal */
285 regs->pc += displacement;
286 regs->gpr[9] = regs->pc + 8;
287 return;
288 case 0x03: /* l.bnf */
289 if (regs->sr & SPR_SR_F)
290 regs->pc += 8;
291 else
292 regs->pc += displacement;
293 return;
294 case 0x04: /* l.bf */
295 if (regs->sr & SPR_SR_F)
296 regs->pc += displacement;
297 else
298 regs->pc += 8;
299 return;
300 case 0x11: /* l.jr */
301 regs->pc = regs->gpr[rb];
302 return;
303 case 0x12: /* l.jalr */
304 regs->pc = regs->gpr[rb];
305 regs->gpr[9] = regs->pc + 8;
306 return;
307 default:
308 break;
309 }
310 } else {
311 regs->pc += 4;
312 }
313}
314
315static inline void simulate_lwa(struct pt_regs *regs, unsigned long address,
316 unsigned int insn)
317{
318 unsigned int ra, rd;
319 unsigned long value;
320 unsigned long orig_pc;
321 long imm;
322
323 const struct exception_table_entry *entry;
324
325 orig_pc = regs->pc;
326 adjust_pc(regs, address);
327
328 ra = (insn >> 16) & 0x1f;
329 rd = (insn >> 21) & 0x1f;
330 imm = (short)insn;
331 lwa_addr = (unsigned long __user *)(regs->gpr[ra] + imm);
332
333 if ((unsigned long)lwa_addr & 0x3) {
334 do_unaligned_access(regs, address);
335 return;
336 }
337
338 if (get_user(value, lwa_addr)) {
339 if (user_mode(regs)) {
340 force_sig(SIGSEGV);
341 return;
342 }
343
344 if ((entry = search_exception_tables(orig_pc))) {
345 regs->pc = entry->fixup;
346 return;
347 }
348
349 /* kernel access in kernel space, load it directly */
350 value = *((unsigned long *)lwa_addr);
351 }
352
353 lwa_flag = 1;
354 regs->gpr[rd] = value;
355}
356
357static inline void simulate_swa(struct pt_regs *regs, unsigned long address,
358 unsigned int insn)
359{
360 unsigned long __user *vaddr;
361 unsigned long orig_pc;
362 unsigned int ra, rb;
363 long imm;
364
365 const struct exception_table_entry *entry;
366
367 orig_pc = regs->pc;
368 adjust_pc(regs, address);
369
370 ra = (insn >> 16) & 0x1f;
371 rb = (insn >> 11) & 0x1f;
372 imm = (short)(((insn & 0x2200000) >> 10) | (insn & 0x7ff));
373 vaddr = (unsigned long __user *)(regs->gpr[ra] + imm);
374
375 if (!lwa_flag || vaddr != lwa_addr) {
376 regs->sr &= ~SPR_SR_F;
377 return;
378 }
379
380 if ((unsigned long)vaddr & 0x3) {
381 do_unaligned_access(regs, address);
382 return;
383 }
384
385 if (put_user(regs->gpr[rb], vaddr)) {
386 if (user_mode(regs)) {
387 force_sig(SIGSEGV);
388 return;
389 }
390
391 if ((entry = search_exception_tables(orig_pc))) {
392 regs->pc = entry->fixup;
393 return;
394 }
395
396 /* kernel access in kernel space, store it directly */
397 *((unsigned long *)vaddr) = regs->gpr[rb];
398 }
399
400 lwa_flag = 0;
401 regs->sr |= SPR_SR_F;
402}
403
404#define INSN_LWA 0x1b
405#define INSN_SWA 0x33
406
407asmlinkage void do_illegal_instruction(struct pt_regs *regs,
408 unsigned long address)
409{
410 unsigned int op;
411 unsigned int insn = *((unsigned int *)address);
412
413 op = insn >> 26;
414
415 switch (op) {
416 case INSN_LWA:
417 simulate_lwa(regs, address, insn);
418 return;
419
420 case INSN_SWA:
421 simulate_swa(regs, address, insn);
422 return;
423
424 default:
425 break;
426 }
427
428 if (user_mode(regs)) {
429 /* Send a SIGILL */
430 force_sig_fault(SIGILL, ILL_ILLOPC, (void __user *)address);
431 } else { /* Kernel mode */
432 printk("KERNEL: Illegal instruction (SIGILL) 0x%.8lx\n",
433 address);
434 show_registers(regs);
435 die("Die:", regs, address);
436 }
437}