1 /*
2 * arch/sparc/kernel/traps.c
3 *
4 * Copyright 1995, 2008 David S. Miller (davem@davemloft.net)
5 * Copyright 2000 Jakub Jelinek (jakub@redhat.com)
6 */
7
8 /*
9 * I hate traps on the sparc, grrr...
10 */
11
12 #include <linux/sched.h> /* for jiffies */
13 #include <linux/kernel.h>
14 #include <linux/signal.h>
15 #include <linux/smp.h>
16 #include <linux/kdebug.h>
17 #include <linux/export.h>
18
19 #include <asm/delay.h>
20 #include <asm/ptrace.h>
21 #include <asm/oplib.h>
22 #include <asm/page.h>
23 #include <asm/pgtable.h>
24 #include <asm/unistd.h>
25 #include <asm/traps.h>
26
27 #include "entry.h"
28 #include "kernel.h"
29
30 /* #define TRAP_DEBUG */
31
instruction_dump(unsigned long * pc)32 static void instruction_dump(unsigned long *pc)
33 {
34 int i;
35
36 if((((unsigned long) pc) & 3))
37 return;
38
39 for(i = -3; i < 6; i++)
40 printk("%c%08lx%c",i?' ':'<',pc[i],i?' ':'>');
41 printk("\n");
42 }
43
44 #define __SAVE __asm__ __volatile__("save %sp, -0x40, %sp\n\t")
45 #define __RESTORE __asm__ __volatile__("restore %g0, %g0, %g0\n\t")
46
die_if_kernel(char * str,struct pt_regs * regs)47 void die_if_kernel(char *str, struct pt_regs *regs)
48 {
49 static int die_counter;
50 int count = 0;
51
52 /* Amuse the user. */
53 printk(
54 " \\|/ ____ \\|/\n"
55 " \"@'/ ,. \\`@\"\n"
56 " /_| \\__/ |_\\\n"
57 " \\__U_/\n");
58
59 printk("%s(%d): %s [#%d]\n", current->comm, task_pid_nr(current), str, ++die_counter);
60 show_regs(regs);
61 add_taint(TAINT_DIE);
62
63 __SAVE; __SAVE; __SAVE; __SAVE;
64 __SAVE; __SAVE; __SAVE; __SAVE;
65 __RESTORE; __RESTORE; __RESTORE; __RESTORE;
66 __RESTORE; __RESTORE; __RESTORE; __RESTORE;
67
68 {
69 struct reg_window32 *rw = (struct reg_window32 *)regs->u_regs[UREG_FP];
70
71 /* Stop the back trace when we hit userland or we
72 * find some badly aligned kernel stack. Set an upper
73 * bound in case our stack is trashed and we loop.
74 */
75 while(rw &&
76 count++ < 30 &&
77 (((unsigned long) rw) >= PAGE_OFFSET) &&
78 !(((unsigned long) rw) & 0x7)) {
79 printk("Caller[%08lx]: %pS\n", rw->ins[7],
80 (void *) rw->ins[7]);
81 rw = (struct reg_window32 *)rw->ins[6];
82 }
83 }
84 printk("Instruction DUMP:");
85 instruction_dump ((unsigned long *) regs->pc);
86 if(regs->psr & PSR_PS)
87 do_exit(SIGKILL);
88 do_exit(SIGSEGV);
89 }
90
do_hw_interrupt(struct pt_regs * regs,unsigned long type)91 void do_hw_interrupt(struct pt_regs *regs, unsigned long type)
92 {
93 siginfo_t info;
94
95 if(type < 0x80) {
96 /* Sun OS's puke from bad traps, Linux survives! */
97 printk("Unimplemented Sparc TRAP, type = %02lx\n", type);
98 die_if_kernel("Whee... Hello Mr. Penguin", regs);
99 }
100
101 if(regs->psr & PSR_PS)
102 die_if_kernel("Kernel bad trap", regs);
103
104 info.si_signo = SIGILL;
105 info.si_errno = 0;
106 info.si_code = ILL_ILLTRP;
107 info.si_addr = (void __user *)regs->pc;
108 info.si_trapno = type - 0x80;
109 force_sig_info(SIGILL, &info, current);
110 }
111
do_illegal_instruction(struct pt_regs * regs,unsigned long pc,unsigned long npc,unsigned long psr)112 void do_illegal_instruction(struct pt_regs *regs, unsigned long pc, unsigned long npc,
113 unsigned long psr)
114 {
115 siginfo_t info;
116
117 if(psr & PSR_PS)
118 die_if_kernel("Kernel illegal instruction", regs);
119 #ifdef TRAP_DEBUG
120 printk("Ill instr. at pc=%08lx instruction is %08lx\n",
121 regs->pc, *(unsigned long *)regs->pc);
122 #endif
123 if (!do_user_muldiv (regs, pc))
124 return;
125
126 info.si_signo = SIGILL;
127 info.si_errno = 0;
128 info.si_code = ILL_ILLOPC;
129 info.si_addr = (void __user *)pc;
130 info.si_trapno = 0;
131 send_sig_info(SIGILL, &info, current);
132 }
133
do_priv_instruction(struct pt_regs * regs,unsigned long pc,unsigned long npc,unsigned long psr)134 void do_priv_instruction(struct pt_regs *regs, unsigned long pc, unsigned long npc,
135 unsigned long psr)
136 {
137 siginfo_t info;
138
139 if(psr & PSR_PS)
140 die_if_kernel("Penguin instruction from Penguin mode??!?!", regs);
141 info.si_signo = SIGILL;
142 info.si_errno = 0;
143 info.si_code = ILL_PRVOPC;
144 info.si_addr = (void __user *)pc;
145 info.si_trapno = 0;
146 send_sig_info(SIGILL, &info, current);
147 }
148
149 /* XXX User may want to be allowed to do this. XXX */
150
do_memaccess_unaligned(struct pt_regs * regs,unsigned long pc,unsigned long npc,unsigned long psr)151 void do_memaccess_unaligned(struct pt_regs *regs, unsigned long pc, unsigned long npc,
152 unsigned long psr)
153 {
154 siginfo_t info;
155
156 if(regs->psr & PSR_PS) {
157 printk("KERNEL MNA at pc %08lx npc %08lx called by %08lx\n", pc, npc,
158 regs->u_regs[UREG_RETPC]);
159 die_if_kernel("BOGUS", regs);
160 /* die_if_kernel("Kernel MNA access", regs); */
161 }
162 #if 0
163 show_regs (regs);
164 instruction_dump ((unsigned long *) regs->pc);
165 printk ("do_MNA!\n");
166 #endif
167 info.si_signo = SIGBUS;
168 info.si_errno = 0;
169 info.si_code = BUS_ADRALN;
170 info.si_addr = /* FIXME: Should dig out mna address */ (void *)0;
171 info.si_trapno = 0;
172 send_sig_info(SIGBUS, &info, current);
173 }
174
175 static unsigned long init_fsr = 0x0UL;
176 static unsigned long init_fregs[32] __attribute__ ((aligned (8))) =
177 { ~0UL, ~0UL, ~0UL, ~0UL, ~0UL, ~0UL, ~0UL, ~0UL,
178 ~0UL, ~0UL, ~0UL, ~0UL, ~0UL, ~0UL, ~0UL, ~0UL,
179 ~0UL, ~0UL, ~0UL, ~0UL, ~0UL, ~0UL, ~0UL, ~0UL,
180 ~0UL, ~0UL, ~0UL, ~0UL, ~0UL, ~0UL, ~0UL, ~0UL };
181
do_fpd_trap(struct pt_regs * regs,unsigned long pc,unsigned long npc,unsigned long psr)182 void do_fpd_trap(struct pt_regs *regs, unsigned long pc, unsigned long npc,
183 unsigned long psr)
184 {
185 /* Sanity check... */
186 if(psr & PSR_PS)
187 die_if_kernel("Kernel gets FloatingPenguinUnit disabled trap", regs);
188
189 put_psr(get_psr() | PSR_EF); /* Allow FPU ops. */
190 regs->psr |= PSR_EF;
191 #ifndef CONFIG_SMP
192 if(last_task_used_math == current)
193 return;
194 if(last_task_used_math) {
195 /* Other processes fpu state, save away */
196 struct task_struct *fptask = last_task_used_math;
197 fpsave(&fptask->thread.float_regs[0], &fptask->thread.fsr,
198 &fptask->thread.fpqueue[0], &fptask->thread.fpqdepth);
199 }
200 last_task_used_math = current;
201 if(used_math()) {
202 fpload(¤t->thread.float_regs[0], ¤t->thread.fsr);
203 } else {
204 /* Set initial sane state. */
205 fpload(&init_fregs[0], &init_fsr);
206 set_used_math();
207 }
208 #else
209 if(!used_math()) {
210 fpload(&init_fregs[0], &init_fsr);
211 set_used_math();
212 } else {
213 fpload(¤t->thread.float_regs[0], ¤t->thread.fsr);
214 }
215 set_thread_flag(TIF_USEDFPU);
216 #endif
217 }
218
219 static unsigned long fake_regs[32] __attribute__ ((aligned (8)));
220 static unsigned long fake_fsr;
221 static unsigned long fake_queue[32] __attribute__ ((aligned (8)));
222 static unsigned long fake_depth;
223
224 extern int do_mathemu(struct pt_regs *, struct task_struct *);
225
do_fpe_trap(struct pt_regs * regs,unsigned long pc,unsigned long npc,unsigned long psr)226 void do_fpe_trap(struct pt_regs *regs, unsigned long pc, unsigned long npc,
227 unsigned long psr)
228 {
229 static int calls;
230 siginfo_t info;
231 unsigned long fsr;
232 int ret = 0;
233 #ifndef CONFIG_SMP
234 struct task_struct *fpt = last_task_used_math;
235 #else
236 struct task_struct *fpt = current;
237 #endif
238 put_psr(get_psr() | PSR_EF);
239 /* If nobody owns the fpu right now, just clear the
240 * error into our fake static buffer and hope it don't
241 * happen again. Thank you crashme...
242 */
243 #ifndef CONFIG_SMP
244 if(!fpt) {
245 #else
246 if (!test_tsk_thread_flag(fpt, TIF_USEDFPU)) {
247 #endif
248 fpsave(&fake_regs[0], &fake_fsr, &fake_queue[0], &fake_depth);
249 regs->psr &= ~PSR_EF;
250 return;
251 }
252 fpsave(&fpt->thread.float_regs[0], &fpt->thread.fsr,
253 &fpt->thread.fpqueue[0], &fpt->thread.fpqdepth);
254 #ifdef DEBUG_FPU
255 printk("Hmm, FP exception, fsr was %016lx\n", fpt->thread.fsr);
256 #endif
257
258 switch ((fpt->thread.fsr & 0x1c000)) {
259 /* switch on the contents of the ftt [floating point trap type] field */
260 #ifdef DEBUG_FPU
261 case (1 << 14):
262 printk("IEEE_754_exception\n");
263 break;
264 #endif
265 case (2 << 14): /* unfinished_FPop (underflow & co) */
266 case (3 << 14): /* unimplemented_FPop (quad stuff, maybe sqrt) */
267 ret = do_mathemu(regs, fpt);
268 break;
269 #ifdef DEBUG_FPU
270 case (4 << 14):
271 printk("sequence_error (OS bug...)\n");
272 break;
273 case (5 << 14):
274 printk("hardware_error (uhoh!)\n");
275 break;
276 case (6 << 14):
277 printk("invalid_fp_register (user error)\n");
278 break;
279 #endif /* DEBUG_FPU */
280 }
281 /* If we successfully emulated the FPop, we pretend the trap never happened :-> */
282 if (ret) {
283 fpload(¤t->thread.float_regs[0], ¤t->thread.fsr);
284 return;
285 }
286 /* nope, better SIGFPE the offending process... */
287
288 #ifdef CONFIG_SMP
289 clear_tsk_thread_flag(fpt, TIF_USEDFPU);
290 #endif
291 if(psr & PSR_PS) {
292 /* The first fsr store/load we tried trapped,
293 * the second one will not (we hope).
294 */
295 printk("WARNING: FPU exception from kernel mode. at pc=%08lx\n",
296 regs->pc);
297 regs->pc = regs->npc;
298 regs->npc += 4;
299 calls++;
300 if(calls > 2)
301 die_if_kernel("Too many Penguin-FPU traps from kernel mode",
302 regs);
303 return;
304 }
305
306 fsr = fpt->thread.fsr;
307 info.si_signo = SIGFPE;
308 info.si_errno = 0;
309 info.si_addr = (void __user *)pc;
310 info.si_trapno = 0;
311 info.si_code = __SI_FAULT;
312 if ((fsr & 0x1c000) == (1 << 14)) {
313 if (fsr & 0x10)
314 info.si_code = FPE_FLTINV;
315 else if (fsr & 0x08)
316 info.si_code = FPE_FLTOVF;
317 else if (fsr & 0x04)
318 info.si_code = FPE_FLTUND;
319 else if (fsr & 0x02)
320 info.si_code = FPE_FLTDIV;
321 else if (fsr & 0x01)
322 info.si_code = FPE_FLTRES;
323 }
324 send_sig_info(SIGFPE, &info, fpt);
325 #ifndef CONFIG_SMP
326 last_task_used_math = NULL;
327 #endif
328 regs->psr &= ~PSR_EF;
329 if(calls > 0)
330 calls=0;
331 }
332
333 void handle_tag_overflow(struct pt_regs *regs, unsigned long pc, unsigned long npc,
334 unsigned long psr)
335 {
336 siginfo_t info;
337
338 if(psr & PSR_PS)
339 die_if_kernel("Penguin overflow trap from kernel mode", regs);
340 info.si_signo = SIGEMT;
341 info.si_errno = 0;
342 info.si_code = EMT_TAGOVF;
343 info.si_addr = (void __user *)pc;
344 info.si_trapno = 0;
345 send_sig_info(SIGEMT, &info, current);
346 }
347
348 void handle_watchpoint(struct pt_regs *regs, unsigned long pc, unsigned long npc,
349 unsigned long psr)
350 {
351 #ifdef TRAP_DEBUG
352 printk("Watchpoint detected at PC %08lx NPC %08lx PSR %08lx\n",
353 pc, npc, psr);
354 #endif
355 if(psr & PSR_PS)
356 panic("Tell me what a watchpoint trap is, and I'll then deal "
357 "with such a beast...");
358 }
359
360 void handle_reg_access(struct pt_regs *regs, unsigned long pc, unsigned long npc,
361 unsigned long psr)
362 {
363 siginfo_t info;
364
365 #ifdef TRAP_DEBUG
366 printk("Register Access Exception at PC %08lx NPC %08lx PSR %08lx\n",
367 pc, npc, psr);
368 #endif
369 info.si_signo = SIGBUS;
370 info.si_errno = 0;
371 info.si_code = BUS_OBJERR;
372 info.si_addr = (void __user *)pc;
373 info.si_trapno = 0;
374 force_sig_info(SIGBUS, &info, current);
375 }
376
377 void handle_cp_disabled(struct pt_regs *regs, unsigned long pc, unsigned long npc,
378 unsigned long psr)
379 {
380 siginfo_t info;
381
382 info.si_signo = SIGILL;
383 info.si_errno = 0;
384 info.si_code = ILL_COPROC;
385 info.si_addr = (void __user *)pc;
386 info.si_trapno = 0;
387 send_sig_info(SIGILL, &info, current);
388 }
389
390 void handle_cp_exception(struct pt_regs *regs, unsigned long pc, unsigned long npc,
391 unsigned long psr)
392 {
393 siginfo_t info;
394
395 #ifdef TRAP_DEBUG
396 printk("Co-Processor Exception at PC %08lx NPC %08lx PSR %08lx\n",
397 pc, npc, psr);
398 #endif
399 info.si_signo = SIGILL;
400 info.si_errno = 0;
401 info.si_code = ILL_COPROC;
402 info.si_addr = (void __user *)pc;
403 info.si_trapno = 0;
404 send_sig_info(SIGILL, &info, current);
405 }
406
407 void handle_hw_divzero(struct pt_regs *regs, unsigned long pc, unsigned long npc,
408 unsigned long psr)
409 {
410 siginfo_t info;
411
412 info.si_signo = SIGFPE;
413 info.si_errno = 0;
414 info.si_code = FPE_INTDIV;
415 info.si_addr = (void __user *)pc;
416 info.si_trapno = 0;
417 send_sig_info(SIGFPE, &info, current);
418 }
419
420 #ifdef CONFIG_DEBUG_BUGVERBOSE
421 void do_BUG(const char *file, int line)
422 {
423 // bust_spinlocks(1); XXX Not in our original BUG()
424 printk("kernel BUG at %s:%d!\n", file, line);
425 }
426 EXPORT_SYMBOL(do_BUG);
427 #endif
428
429 /* Since we have our mappings set up, on multiprocessors we can spin them
430 * up here so that timer interrupts work during initialization.
431 */
432
433 void trap_init(void)
434 {
435 extern void thread_info_offsets_are_bolixed_pete(void);
436
437 /* Force linker to barf if mismatched */
438 if (TI_UWINMASK != offsetof(struct thread_info, uwinmask) ||
439 TI_TASK != offsetof(struct thread_info, task) ||
440 TI_EXECDOMAIN != offsetof(struct thread_info, exec_domain) ||
441 TI_FLAGS != offsetof(struct thread_info, flags) ||
442 TI_CPU != offsetof(struct thread_info, cpu) ||
443 TI_PREEMPT != offsetof(struct thread_info, preempt_count) ||
444 TI_SOFTIRQ != offsetof(struct thread_info, softirq_count) ||
445 TI_HARDIRQ != offsetof(struct thread_info, hardirq_count) ||
446 TI_KSP != offsetof(struct thread_info, ksp) ||
447 TI_KPC != offsetof(struct thread_info, kpc) ||
448 TI_KPSR != offsetof(struct thread_info, kpsr) ||
449 TI_KWIM != offsetof(struct thread_info, kwim) ||
450 TI_REG_WINDOW != offsetof(struct thread_info, reg_window) ||
451 TI_RWIN_SPTRS != offsetof(struct thread_info, rwbuf_stkptrs) ||
452 TI_W_SAVED != offsetof(struct thread_info, w_saved))
453 thread_info_offsets_are_bolixed_pete();
454
455 /* Attach to the address space of init_task. */
456 atomic_inc(&init_mm.mm_count);
457 current->active_mm = &init_mm;
458
459 /* NOTE: Other cpus have this done as they are started
460 * up on SMP.
461 */
462 }
463