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 18 #include <asm/delay.h> 19 #include <asm/system.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 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 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 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 } 111 112 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 } 133 134 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 */ 150 151 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 }; 181 182 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 *); 225 226 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