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/smp_lock.h>
17 #include <linux/kdebug.h>
18
19 #include <asm/delay.h>
20 #include <asm/system.h>
21 #include <asm/ptrace.h>
22 #include <asm/oplib.h>
23 #include <asm/page.h>
24 #include <asm/pgtable.h>
25 #include <asm/unistd.h>
26 #include <asm/traps.h>
27
28 #include "entry.h"
29 #include "kernel.h"
30
31 /* #define TRAP_DEBUG */
32
instruction_dump(unsigned long * pc)33 static void instruction_dump(unsigned long *pc)
34 {
35 int i;
36
37 if((((unsigned long) pc) & 3))
38 return;
39
40 for(i = -3; i < 6; i++)
41 printk("%c%08lx%c",i?' ':'<',pc[i],i?' ':'>');
42 printk("\n");
43 }
44
45 #define __SAVE __asm__ __volatile__("save %sp, -0x40, %sp\n\t")
46 #define __RESTORE __asm__ __volatile__("restore %g0, %g0, %g0\n\t")
47
die_if_kernel(char * str,struct pt_regs * regs)48 void die_if_kernel(char *str, struct pt_regs *regs)
49 {
50 static int die_counter;
51 int count = 0;
52
53 /* Amuse the user. */
54 printk(
55 " \\|/ ____ \\|/\n"
56 " \"@'/ ,. \\`@\"\n"
57 " /_| \\__/ |_\\\n"
58 " \\__U_/\n");
59
60 printk("%s(%d): %s [#%d]\n", current->comm, task_pid_nr(current), str, ++die_counter);
61 show_regs(regs);
62 add_taint(TAINT_DIE);
63
64 __SAVE; __SAVE; __SAVE; __SAVE;
65 __SAVE; __SAVE; __SAVE; __SAVE;
66 __RESTORE; __RESTORE; __RESTORE; __RESTORE;
67 __RESTORE; __RESTORE; __RESTORE; __RESTORE;
68
69 {
70 struct reg_window32 *rw = (struct reg_window32 *)regs->u_regs[UREG_FP];
71
72 /* Stop the back trace when we hit userland or we
73 * find some badly aligned kernel stack. Set an upper
74 * bound in case our stack is trashed and we loop.
75 */
76 while(rw &&
77 count++ < 30 &&
78 (((unsigned long) rw) >= PAGE_OFFSET) &&
79 !(((unsigned long) rw) & 0x7)) {
80 printk("Caller[%08lx]: %pS\n", rw->ins[7],
81 (void *) rw->ins[7]);
82 rw = (struct reg_window32 *)rw->ins[6];
83 }
84 }
85 printk("Instruction DUMP:");
86 instruction_dump ((unsigned long *) regs->pc);
87 if(regs->psr & PSR_PS)
88 do_exit(SIGKILL);
89 do_exit(SIGSEGV);
90 }
91
do_hw_interrupt(struct pt_regs * regs,unsigned long type)92 void do_hw_interrupt(struct pt_regs *regs, unsigned long type)
93 {
94 siginfo_t info;
95
96 if(type < 0x80) {
97 /* Sun OS's puke from bad traps, Linux survives! */
98 printk("Unimplemented Sparc TRAP, type = %02lx\n", type);
99 die_if_kernel("Whee... Hello Mr. Penguin", regs);
100 }
101
102 if(regs->psr & PSR_PS)
103 die_if_kernel("Kernel bad trap", regs);
104
105 info.si_signo = SIGILL;
106 info.si_errno = 0;
107 info.si_code = ILL_ILLTRP;
108 info.si_addr = (void __user *)regs->pc;
109 info.si_trapno = type - 0x80;
110 force_sig_info(SIGILL, &info, current);
111 }
112
do_illegal_instruction(struct pt_regs * regs,unsigned long pc,unsigned long npc,unsigned long psr)113 void do_illegal_instruction(struct pt_regs *regs, unsigned long pc, unsigned long npc,
114 unsigned long psr)
115 {
116 siginfo_t info;
117
118 if(psr & PSR_PS)
119 die_if_kernel("Kernel illegal instruction", regs);
120 #ifdef TRAP_DEBUG
121 printk("Ill instr. at pc=%08lx instruction is %08lx\n",
122 regs->pc, *(unsigned long *)regs->pc);
123 #endif
124 if (!do_user_muldiv (regs, pc))
125 return;
126
127 info.si_signo = SIGILL;
128 info.si_errno = 0;
129 info.si_code = ILL_ILLOPC;
130 info.si_addr = (void __user *)pc;
131 info.si_trapno = 0;
132 send_sig_info(SIGILL, &info, current);
133 }
134
do_priv_instruction(struct pt_regs * regs,unsigned long pc,unsigned long npc,unsigned long psr)135 void do_priv_instruction(struct pt_regs *regs, unsigned long pc, unsigned long npc,
136 unsigned long psr)
137 {
138 siginfo_t info;
139
140 if(psr & PSR_PS)
141 die_if_kernel("Penguin instruction from Penguin mode??!?!", regs);
142 info.si_signo = SIGILL;
143 info.si_errno = 0;
144 info.si_code = ILL_PRVOPC;
145 info.si_addr = (void __user *)pc;
146 info.si_trapno = 0;
147 send_sig_info(SIGILL, &info, current);
148 }
149
150 /* XXX User may want to be allowed to do this. XXX */
151
do_memaccess_unaligned(struct pt_regs * regs,unsigned long pc,unsigned long npc,unsigned long psr)152 void do_memaccess_unaligned(struct pt_regs *regs, unsigned long pc, unsigned long npc,
153 unsigned long psr)
154 {
155 siginfo_t info;
156
157 if(regs->psr & PSR_PS) {
158 printk("KERNEL MNA at pc %08lx npc %08lx called by %08lx\n", pc, npc,
159 regs->u_regs[UREG_RETPC]);
160 die_if_kernel("BOGUS", regs);
161 /* die_if_kernel("Kernel MNA access", regs); */
162 }
163 #if 0
164 show_regs (regs);
165 instruction_dump ((unsigned long *) regs->pc);
166 printk ("do_MNA!\n");
167 #endif
168 info.si_signo = SIGBUS;
169 info.si_errno = 0;
170 info.si_code = BUS_ADRALN;
171 info.si_addr = /* FIXME: Should dig out mna address */ (void *)0;
172 info.si_trapno = 0;
173 send_sig_info(SIGBUS, &info, current);
174 }
175
176 static unsigned long init_fsr = 0x0UL;
177 static unsigned long init_fregs[32] __attribute__ ((aligned (8))) =
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 ~0UL, ~0UL, ~0UL, ~0UL, ~0UL, ~0UL, ~0UL, ~0UL };
182
do_fpd_trap(struct pt_regs * regs,unsigned long pc,unsigned long npc,unsigned long psr)183 void do_fpd_trap(struct pt_regs *regs, unsigned long pc, unsigned long npc,
184 unsigned long psr)
185 {
186 /* Sanity check... */
187 if(psr & PSR_PS)
188 die_if_kernel("Kernel gets FloatingPenguinUnit disabled trap", regs);
189
190 put_psr(get_psr() | PSR_EF); /* Allow FPU ops. */
191 regs->psr |= PSR_EF;
192 #ifndef CONFIG_SMP
193 if(last_task_used_math == current)
194 return;
195 if(last_task_used_math) {
196 /* Other processes fpu state, save away */
197 struct task_struct *fptask = last_task_used_math;
198 fpsave(&fptask->thread.float_regs[0], &fptask->thread.fsr,
199 &fptask->thread.fpqueue[0], &fptask->thread.fpqdepth);
200 }
201 last_task_used_math = current;
202 if(used_math()) {
203 fpload(¤t->thread.float_regs[0], ¤t->thread.fsr);
204 } else {
205 /* Set initial sane state. */
206 fpload(&init_fregs[0], &init_fsr);
207 set_used_math();
208 }
209 #else
210 if(!used_math()) {
211 fpload(&init_fregs[0], &init_fsr);
212 set_used_math();
213 } else {
214 fpload(¤t->thread.float_regs[0], ¤t->thread.fsr);
215 }
216 set_thread_flag(TIF_USEDFPU);
217 #endif
218 }
219
220 static unsigned long fake_regs[32] __attribute__ ((aligned (8)));
221 static unsigned long fake_fsr;
222 static unsigned long fake_queue[32] __attribute__ ((aligned (8)));
223 static unsigned long fake_depth;
224
225 extern int do_mathemu(struct pt_regs *, struct task_struct *);
226
do_fpe_trap(struct pt_regs * regs,unsigned long pc,unsigned long npc,unsigned long psr)227 void do_fpe_trap(struct pt_regs *regs, unsigned long pc, unsigned long npc,
228 unsigned long psr)
229 {
230 static int calls;
231 siginfo_t info;
232 unsigned long fsr;
233 int ret = 0;
234 #ifndef CONFIG_SMP
235 struct task_struct *fpt = last_task_used_math;
236 #else
237 struct task_struct *fpt = current;
238 #endif
239 put_psr(get_psr() | PSR_EF);
240 /* If nobody owns the fpu right now, just clear the
241 * error into our fake static buffer and hope it don't
242 * happen again. Thank you crashme...
243 */
244 #ifndef CONFIG_SMP
245 if(!fpt) {
246 #else
247 if (!test_tsk_thread_flag(fpt, TIF_USEDFPU)) {
248 #endif
249 fpsave(&fake_regs[0], &fake_fsr, &fake_queue[0], &fake_depth);
250 regs->psr &= ~PSR_EF;
251 return;
252 }
253 fpsave(&fpt->thread.float_regs[0], &fpt->thread.fsr,
254 &fpt->thread.fpqueue[0], &fpt->thread.fpqdepth);
255 #ifdef DEBUG_FPU
256 printk("Hmm, FP exception, fsr was %016lx\n", fpt->thread.fsr);
257 #endif
258
259 switch ((fpt->thread.fsr & 0x1c000)) {
260 /* switch on the contents of the ftt [floating point trap type] field */
261 #ifdef DEBUG_FPU
262 case (1 << 14):
263 printk("IEEE_754_exception\n");
264 break;
265 #endif
266 case (2 << 14): /* unfinished_FPop (underflow & co) */
267 case (3 << 14): /* unimplemented_FPop (quad stuff, maybe sqrt) */
268 ret = do_mathemu(regs, fpt);
269 break;
270 #ifdef DEBUG_FPU
271 case (4 << 14):
272 printk("sequence_error (OS bug...)\n");
273 break;
274 case (5 << 14):
275 printk("hardware_error (uhoh!)\n");
276 break;
277 case (6 << 14):
278 printk("invalid_fp_register (user error)\n");
279 break;
280 #endif /* DEBUG_FPU */
281 }
282 /* If we successfully emulated the FPop, we pretend the trap never happened :-> */
283 if (ret) {
284 fpload(¤t->thread.float_regs[0], ¤t->thread.fsr);
285 return;
286 }
287 /* nope, better SIGFPE the offending process... */
288
289 #ifdef CONFIG_SMP
290 clear_tsk_thread_flag(fpt, TIF_USEDFPU);
291 #endif
292 if(psr & PSR_PS) {
293 /* The first fsr store/load we tried trapped,
294 * the second one will not (we hope).
295 */
296 printk("WARNING: FPU exception from kernel mode. at pc=%08lx\n",
297 regs->pc);
298 regs->pc = regs->npc;
299 regs->npc += 4;
300 calls++;
301 if(calls > 2)
302 die_if_kernel("Too many Penguin-FPU traps from kernel mode",
303 regs);
304 return;
305 }
306
307 fsr = fpt->thread.fsr;
308 info.si_signo = SIGFPE;
309 info.si_errno = 0;
310 info.si_addr = (void __user *)pc;
311 info.si_trapno = 0;
312 info.si_code = __SI_FAULT;
313 if ((fsr & 0x1c000) == (1 << 14)) {
314 if (fsr & 0x10)
315 info.si_code = FPE_FLTINV;
316 else if (fsr & 0x08)
317 info.si_code = FPE_FLTOVF;
318 else if (fsr & 0x04)
319 info.si_code = FPE_FLTUND;
320 else if (fsr & 0x02)
321 info.si_code = FPE_FLTDIV;
322 else if (fsr & 0x01)
323 info.si_code = FPE_FLTRES;
324 }
325 send_sig_info(SIGFPE, &info, fpt);
326 #ifndef CONFIG_SMP
327 last_task_used_math = NULL;
328 #endif
329 regs->psr &= ~PSR_EF;
330 if(calls > 0)
331 calls=0;
332 }
333
334 void handle_tag_overflow(struct pt_regs *regs, unsigned long pc, unsigned long npc,
335 unsigned long psr)
336 {
337 siginfo_t info;
338
339 if(psr & PSR_PS)
340 die_if_kernel("Penguin overflow trap from kernel mode", regs);
341 info.si_signo = SIGEMT;
342 info.si_errno = 0;
343 info.si_code = EMT_TAGOVF;
344 info.si_addr = (void __user *)pc;
345 info.si_trapno = 0;
346 send_sig_info(SIGEMT, &info, current);
347 }
348
349 void handle_watchpoint(struct pt_regs *regs, unsigned long pc, unsigned long npc,
350 unsigned long psr)
351 {
352 #ifdef TRAP_DEBUG
353 printk("Watchpoint detected at PC %08lx NPC %08lx PSR %08lx\n",
354 pc, npc, psr);
355 #endif
356 if(psr & PSR_PS)
357 panic("Tell me what a watchpoint trap is, and I'll then deal "
358 "with such a beast...");
359 }
360
361 void handle_reg_access(struct pt_regs *regs, unsigned long pc, unsigned long npc,
362 unsigned long psr)
363 {
364 siginfo_t info;
365
366 #ifdef TRAP_DEBUG
367 printk("Register Access Exception at PC %08lx NPC %08lx PSR %08lx\n",
368 pc, npc, psr);
369 #endif
370 info.si_signo = SIGBUS;
371 info.si_errno = 0;
372 info.si_code = BUS_OBJERR;
373 info.si_addr = (void __user *)pc;
374 info.si_trapno = 0;
375 force_sig_info(SIGBUS, &info, current);
376 }
377
378 void handle_cp_disabled(struct pt_regs *regs, unsigned long pc, unsigned long npc,
379 unsigned long psr)
380 {
381 siginfo_t info;
382
383 info.si_signo = SIGILL;
384 info.si_errno = 0;
385 info.si_code = ILL_COPROC;
386 info.si_addr = (void __user *)pc;
387 info.si_trapno = 0;
388 send_sig_info(SIGILL, &info, current);
389 }
390
391 void handle_cp_exception(struct pt_regs *regs, unsigned long pc, unsigned long npc,
392 unsigned long psr)
393 {
394 siginfo_t info;
395
396 #ifdef TRAP_DEBUG
397 printk("Co-Processor Exception at PC %08lx NPC %08lx PSR %08lx\n",
398 pc, npc, psr);
399 #endif
400 info.si_signo = SIGILL;
401 info.si_errno = 0;
402 info.si_code = ILL_COPROC;
403 info.si_addr = (void __user *)pc;
404 info.si_trapno = 0;
405 send_sig_info(SIGILL, &info, current);
406 }
407
408 void handle_hw_divzero(struct pt_regs *regs, unsigned long pc, unsigned long npc,
409 unsigned long psr)
410 {
411 siginfo_t info;
412
413 info.si_signo = SIGFPE;
414 info.si_errno = 0;
415 info.si_code = FPE_INTDIV;
416 info.si_addr = (void __user *)pc;
417 info.si_trapno = 0;
418 send_sig_info(SIGFPE, &info, current);
419 }
420
421 #ifdef CONFIG_DEBUG_BUGVERBOSE
422 void do_BUG(const char *file, int line)
423 {
424 // bust_spinlocks(1); XXX Not in our original BUG()
425 printk("kernel BUG at %s:%d!\n", file, line);
426 }
427 EXPORT_SYMBOL(do_BUG);
428 #endif
429
430 /* Since we have our mappings set up, on multiprocessors we can spin them
431 * up here so that timer interrupts work during initialization.
432 */
433
434 void trap_init(void)
435 {
436 extern void thread_info_offsets_are_bolixed_pete(void);
437
438 /* Force linker to barf if mismatched */
439 if (TI_UWINMASK != offsetof(struct thread_info, uwinmask) ||
440 TI_TASK != offsetof(struct thread_info, task) ||
441 TI_EXECDOMAIN != offsetof(struct thread_info, exec_domain) ||
442 TI_FLAGS != offsetof(struct thread_info, flags) ||
443 TI_CPU != offsetof(struct thread_info, cpu) ||
444 TI_PREEMPT != offsetof(struct thread_info, preempt_count) ||
445 TI_SOFTIRQ != offsetof(struct thread_info, softirq_count) ||
446 TI_HARDIRQ != offsetof(struct thread_info, hardirq_count) ||
447 TI_KSP != offsetof(struct thread_info, ksp) ||
448 TI_KPC != offsetof(struct thread_info, kpc) ||
449 TI_KPSR != offsetof(struct thread_info, kpsr) ||
450 TI_KWIM != offsetof(struct thread_info, kwim) ||
451 TI_REG_WINDOW != offsetof(struct thread_info, reg_window) ||
452 TI_RWIN_SPTRS != offsetof(struct thread_info, rwbuf_stkptrs) ||
453 TI_W_SAVED != offsetof(struct thread_info, w_saved))
454 thread_info_offsets_are_bolixed_pete();
455
456 /* Attach to the address space of init_task. */
457 atomic_inc(&init_mm.mm_count);
458 current->active_mm = &init_mm;
459
460 /* NOTE: Other cpus have this done as they are started
461 * up on SMP.
462 */
463 }
464