arch/sparc/kernel/traps.c

   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 /* #define TRAP_DEBUG */
  29
  30 struct trap_trace_entry {
  31         unsigned long pc;
  32         unsigned long type;
  33 };
  34
  35 void syscall_trace_entry(struct pt_regs *regs)
  36 {
  37         printk("%s[%d]: ", current->comm, task_pid_nr(current));
  38         printk("scall<%d> (could be %d)\n", (int) regs->u_regs[UREG_G1],
  39                (int) regs->u_regs[UREG_I0]);
  40 }
  41
  42 void syscall_trace_exit(struct pt_regs *regs)
  43 {
  44 }
  45
  46 void sun4d_nmi(struct pt_regs *regs)
  47 {
  48         printk("Aieee: sun4d NMI received!\n");
  49         printk("you lose buddy boy...\n");
  50         show_regs(regs);
  51         prom_halt();
  52 }
  53
  54 static void instruction_dump(unsigned long *pc)
  55 {
  56         int i;
  57
  58         if((((unsigned long) pc) & 3))
  59                 return;
  60
  61         for(i = -3; i < 6; i++)
  62                 printk("%c%08lx%c",i?' ':'<',pc[i],i?' ':'>');
  63         printk("\n");
  64 }
  65
  66 #define __SAVE __asm__ __volatile__("save %sp, -0x40, %sp\n\t")
  67 #define __RESTORE __asm__ __volatile__("restore %g0, %g0, %g0\n\t")
  68
  69 void die_if_kernel(char *str, struct pt_regs *regs)
  70 {
  71         static int die_counter;
  72         int count = 0;
  73
  74         /* Amuse the user. */
  75         printk(
  76 "              \\|/ ____ \\|/\n"
  77 "              \"@'/ ,. \\`@\"\n"
  78 "              /_| \\__/ |_\\\n"
  79 "                 \\__U_/\n");
  80
  81         printk("%s(%d): %s [#%d]\n", current->comm, task_pid_nr(current), str, ++die_counter);
  82         show_regs(regs);
  83         add_taint(TAINT_DIE);
  84
  85         __SAVE; __SAVE; __SAVE; __SAVE;
  86         __SAVE; __SAVE; __SAVE; __SAVE;
  87         __RESTORE; __RESTORE; __RESTORE; __RESTORE;
  88         __RESTORE; __RESTORE; __RESTORE; __RESTORE;
  89
  90         {
  91                 struct reg_window *rw = (struct reg_window *)regs->u_regs[UREG_FP];
  92
  93                 /* Stop the back trace when we hit userland or we
  94                  * find some badly aligned kernel stack. Set an upper
  95                  * bound in case our stack is trashed and we loop.
  96                  */
  97                 while(rw                                        &&
  98                       count++ < 30                              &&
  99                       (((unsigned long) rw) >= PAGE_OFFSET)     &&
 100                       !(((unsigned long) rw) & 0x7)) {
 101                         printk("Caller[%08lx]: %pS\n", rw->ins[7],
 102                                (void *) rw->ins[7]);
 103                         rw = (struct reg_window *)rw->ins[6];
 104                 }
 105         }
 106         printk("Instruction DUMP:");
 107         instruction_dump ((unsigned long *) regs->pc);
 108         if(regs->psr & PSR_PS)
 109                 do_exit(SIGKILL);
 110         do_exit(SIGSEGV);
 111 }
 112
 113 void do_hw_interrupt(struct pt_regs *regs, unsigned long type)
 114 {
 115         siginfo_t info;
 116
 117         if(type < 0x80) {
 118                 /* Sun OS's puke from bad traps, Linux survives! */
 119                 printk("Unimplemented Sparc TRAP, type = %02lx\n", type);
 120                 die_if_kernel("Whee... Hello Mr. Penguin", regs);
 121         }
 122
 123         if(regs->psr & PSR_PS)
 124                 die_if_kernel("Kernel bad trap", regs);
 125
 126         info.si_signo = SIGILL;
 127         info.si_errno = 0;
 128         info.si_code = ILL_ILLTRP;
 129         info.si_addr = (void __user *)regs->pc;
 130         info.si_trapno = type - 0x80;
 131         force_sig_info(SIGILL, &info, current);
 132 }
 133
 134 void do_illegal_instruction(struct pt_regs *regs, unsigned long pc, unsigned long npc,
 135                             unsigned long psr)
 136 {
 137         extern int do_user_muldiv (struct pt_regs *, unsigned long);
 138         siginfo_t info;
 139
 140         if(psr & PSR_PS)
 141                 die_if_kernel("Kernel illegal instruction", regs);
 142 #ifdef TRAP_DEBUG
 143         printk("Ill instr. at pc=%08lx instruction is %08lx\n",
 144                regs->pc, *(unsigned long *)regs->pc);
 145 #endif
 146         if (!do_user_muldiv (regs, pc))
 147                 return;
 148
 149         info.si_signo = SIGILL;
 150         info.si_errno = 0;
 151         info.si_code = ILL_ILLOPC;
 152         info.si_addr = (void __user *)pc;
 153         info.si_trapno = 0;
 154         send_sig_info(SIGILL, &info, current);
 155 }
 156
 157 void do_priv_instruction(struct pt_regs *regs, unsigned long pc, unsigned long npc,
 158                          unsigned long psr)
 159 {
 160         siginfo_t info;
 161
 162         if(psr & PSR_PS)
 163                 die_if_kernel("Penguin instruction from Penguin mode??!?!", regs);
 164         info.si_signo = SIGILL;
 165         info.si_errno = 0;
 166         info.si_code = ILL_PRVOPC;
 167         info.si_addr = (void __user *)pc;
 168         info.si_trapno = 0;
 169         send_sig_info(SIGILL, &info, current);
 170 }
 171
 172 /* XXX User may want to be allowed to do this. XXX */
 173
 174 void do_memaccess_unaligned(struct pt_regs *regs, unsigned long pc, unsigned long npc,
 175                             unsigned long psr)
 176 {
 177         siginfo_t info;
 178
 179         if(regs->psr & PSR_PS) {
 180                 printk("KERNEL MNA at pc %08lx npc %08lx called by %08lx\n", pc, npc,
 181                        regs->u_regs[UREG_RETPC]);
 182                 die_if_kernel("BOGUS", regs);
 183                 /* die_if_kernel("Kernel MNA access", regs); */
 184         }
 185 #if 0
 186         show_regs (regs);
 187         instruction_dump ((unsigned long *) regs->pc);
 188         printk ("do_MNA!\n");
 189 #endif
 190         info.si_signo = SIGBUS;
 191         info.si_errno = 0;
 192         info.si_code = BUS_ADRALN;
 193         info.si_addr = /* FIXME: Should dig out mna address */ (void *)0;
 194         info.si_trapno = 0;
 195         send_sig_info(SIGBUS, &info, current);
 196 }
 197
 198 extern void fpsave(unsigned long *fpregs, unsigned long *fsr,
 199                    void *fpqueue, unsigned long *fpqdepth);
 200 extern void fpload(unsigned long *fpregs, unsigned long *fsr);
 201
 202 static unsigned long init_fsr = 0x0UL;
 203 static unsigned long init_fregs[32] __attribute__ ((aligned (8))) =
 204                 { ~0UL, ~0UL, ~0UL, ~0UL, ~0UL, ~0UL, ~0UL, ~0UL,
 205                   ~0UL, ~0UL, ~0UL, ~0UL, ~0UL, ~0UL, ~0UL, ~0UL,
 206                   ~0UL, ~0UL, ~0UL, ~0UL, ~0UL, ~0UL, ~0UL, ~0UL,
 207                   ~0UL, ~0UL, ~0UL, ~0UL, ~0UL, ~0UL, ~0UL, ~0UL };
 208
 209 void do_fpd_trap(struct pt_regs *regs, unsigned long pc, unsigned long npc,
 210                  unsigned long psr)
 211 {
 212         /* Sanity check... */
 213         if(psr & PSR_PS)
 214                 die_if_kernel("Kernel gets FloatingPenguinUnit disabled trap", regs);
 215
 216         put_psr(get_psr() | PSR_EF);    /* Allow FPU ops. */
 217         regs->psr |= PSR_EF;
 218 #ifndef CONFIG_SMP
 219         if(last_task_used_math == current)
 220                 return;
 221         if(last_task_used_math) {
 222                 /* Other processes fpu state, save away */
 223                 struct task_struct *fptask = last_task_used_math;
 224                 fpsave(&fptask->thread.float_regs[0], &fptask->thread.fsr,
 225                        &fptask->thread.fpqueue[0], &fptask->thread.fpqdepth);
 226         }
 227         last_task_used_math = current;
 228         if(used_math()) {
 229                 fpload(&current->thread.float_regs[0], &current->thread.fsr);
 230         } else {
 231                 /* Set initial sane state. */
 232                 fpload(&init_fregs[0], &init_fsr);
 233                 set_used_math();
 234         }
 235 #else
 236         if(!used_math()) {
 237                 fpload(&init_fregs[0], &init_fsr);
 238                 set_used_math();
 239         } else {
 240                 fpload(&current->thread.float_regs[0], &current->thread.fsr);
 241         }
 242         set_thread_flag(TIF_USEDFPU);
 243 #endif
 244 }
 245
 246 static unsigned long fake_regs[32] __attribute__ ((aligned (8)));
 247 static unsigned long fake_fsr;
 248 static unsigned long fake_queue[32] __attribute__ ((aligned (8)));
 249 static unsigned long fake_depth;
 250
 251 extern int do_mathemu(struct pt_regs *, struct task_struct *);
 252
 253 void do_fpe_trap(struct pt_regs *regs, unsigned long pc, unsigned long npc,
 254                  unsigned long psr)
 255 {
 256         static int calls;
 257         siginfo_t info;
 258         unsigned long fsr;
 259         int ret = 0;
 260 #ifndef CONFIG_SMP
 261         struct task_struct *fpt = last_task_used_math;
 262 #else
 263         struct task_struct *fpt = current;
 264 #endif
 265         put_psr(get_psr() | PSR_EF);
 266         /* If nobody owns the fpu right now, just clear the
 267          * error into our fake static buffer and hope it don't
 268          * happen again.  Thank you crashme...
 269          */
 270 #ifndef CONFIG_SMP
 271         if(!fpt) {
 272 #else
 273         if (!test_tsk_thread_flag(fpt, TIF_USEDFPU)) {
 274 #endif
 275                 fpsave(&fake_regs[0], &fake_fsr, &fake_queue[0], &fake_depth);
 276                 regs->psr &= ~PSR_EF;
 277                 return;
 278         }
 279         fpsave(&fpt->thread.float_regs[0], &fpt->thread.fsr,
 280                &fpt->thread.fpqueue[0], &fpt->thread.fpqdepth);
 281 #ifdef DEBUG_FPU
 282         printk("Hmm, FP exception, fsr was %016lx\n", fpt->thread.fsr);
 283 #endif
 284
 285         switch ((fpt->thread.fsr & 0x1c000)) {
 286         /* switch on the contents of the ftt [floating point trap type] field */
 287 #ifdef DEBUG_FPU
 288         case (1 << 14):
 289                 printk("IEEE_754_exception\n");
 290                 break;
 291 #endif
 292         case (2 << 14):  /* unfinished_FPop (underflow & co) */
 293         case (3 << 14):  /* unimplemented_FPop (quad stuff, maybe sqrt) */
 294                 ret = do_mathemu(regs, fpt);
 295                 break;
 296 #ifdef DEBUG_FPU
 297         case (4 << 14):
 298                 printk("sequence_error (OS bug...)\n");
 299                 break;
 300         case (5 << 14):
 301                 printk("hardware_error (uhoh!)\n");
 302                 break;
 303         case (6 << 14):
 304                 printk("invalid_fp_register (user error)\n");
 305                 break;
 306 #endif /* DEBUG_FPU */
 307         }
 308         /* If we successfully emulated the FPop, we pretend the trap never happened :-> */
 309         if (ret) {
 310                 fpload(&current->thread.float_regs[0], &current->thread.fsr);
 311                 return;
 312         }
 313         /* nope, better SIGFPE the offending process... */
 314
 315 #ifdef CONFIG_SMP
 316         clear_tsk_thread_flag(fpt, TIF_USEDFPU);
 317 #endif
 318         if(psr & PSR_PS) {
 319                 /* The first fsr store/load we tried trapped,
 320                  * the second one will not (we hope).
 321                  */
 322                 printk("WARNING: FPU exception from kernel mode. at pc=%08lx\n",
 323                        regs->pc);
 324                 regs->pc = regs->npc;
 325                 regs->npc += 4;
 326                 calls++;
 327                 if(calls > 2)
 328                         die_if_kernel("Too many Penguin-FPU traps from kernel mode",
 329                                       regs);
 330                 return;
 331         }
 332
 333         fsr = fpt->thread.fsr;
 334         info.si_signo = SIGFPE;
 335         info.si_errno = 0;
 336         info.si_addr = (void __user *)pc;
 337         info.si_trapno = 0;
 338         info.si_code = __SI_FAULT;
 339         if ((fsr & 0x1c000) == (1 << 14)) {
 340                 if (fsr & 0x10)
 341                         info.si_code = FPE_FLTINV;
 342                 else if (fsr & 0x08)
 343                         info.si_code = FPE_FLTOVF;
 344                 else if (fsr & 0x04)
 345                         info.si_code = FPE_FLTUND;
 346                 else if (fsr & 0x02)
 347                         info.si_code = FPE_FLTDIV;
 348                 else if (fsr & 0x01)
 349                         info.si_code = FPE_FLTRES;
 350         }
 351         send_sig_info(SIGFPE, &info, fpt);
 352 #ifndef CONFIG_SMP
 353         last_task_used_math = NULL;
 354 #endif
 355         regs->psr &= ~PSR_EF;
 356         if(calls > 0)
 357                 calls=0;
 358 }
 359
 360 void handle_tag_overflow(struct pt_regs *regs, unsigned long pc, unsigned long npc,
 361                          unsigned long psr)
 362 {
 363         siginfo_t info;
 364
 365         if(psr & PSR_PS)
 366                 die_if_kernel("Penguin overflow trap from kernel mode", regs);
 367         info.si_signo = SIGEMT;
 368         info.si_errno = 0;
 369         info.si_code = EMT_TAGOVF;
 370         info.si_addr = (void __user *)pc;
 371         info.si_trapno = 0;
 372         send_sig_info(SIGEMT, &info, current);
 373 }
 374
 375 void handle_watchpoint(struct pt_regs *regs, unsigned long pc, unsigned long npc,
 376                        unsigned long psr)
 377 {
 378 #ifdef TRAP_DEBUG
 379         printk("Watchpoint detected at PC %08lx NPC %08lx PSR %08lx\n",
 380                pc, npc, psr);
 381 #endif
 382         if(psr & PSR_PS)
 383                 panic("Tell me what a watchpoint trap is, and I'll then deal "
 384                       "with such a beast...");
 385 }
 386
 387 void handle_reg_access(struct pt_regs *regs, unsigned long pc, unsigned long npc,
 388                        unsigned long psr)
 389 {
 390         siginfo_t info;
 391
 392 #ifdef TRAP_DEBUG
 393         printk("Register Access Exception at PC %08lx NPC %08lx PSR %08lx\n",
 394                pc, npc, psr);
 395 #endif
 396         info.si_signo = SIGBUS;
 397         info.si_errno = 0;
 398         info.si_code = BUS_OBJERR;
 399         info.si_addr = (void __user *)pc;
 400         info.si_trapno = 0;
 401         force_sig_info(SIGBUS, &info, current);
 402 }
 403
 404 void handle_cp_disabled(struct pt_regs *regs, unsigned long pc, unsigned long npc,
 405                         unsigned long psr)
 406 {
 407         siginfo_t info;
 408
 409         info.si_signo = SIGILL;
 410         info.si_errno = 0;
 411         info.si_code = ILL_COPROC;
 412         info.si_addr = (void __user *)pc;
 413         info.si_trapno = 0;
 414         send_sig_info(SIGILL, &info, current);
 415 }
 416
 417 void handle_cp_exception(struct pt_regs *regs, unsigned long pc, unsigned long npc,
 418                          unsigned long psr)
 419 {
 420         siginfo_t info;
 421
 422 #ifdef TRAP_DEBUG
 423         printk("Co-Processor Exception at PC %08lx NPC %08lx PSR %08lx\n",
 424                pc, npc, psr);
 425 #endif
 426         info.si_signo = SIGILL;
 427         info.si_errno = 0;
 428         info.si_code = ILL_COPROC;
 429         info.si_addr = (void __user *)pc;
 430         info.si_trapno = 0;
 431         send_sig_info(SIGILL, &info, current);
 432 }
 433
 434 void handle_hw_divzero(struct pt_regs *regs, unsigned long pc, unsigned long npc,
 435                        unsigned long psr)
 436 {
 437         siginfo_t info;
 438
 439         info.si_signo = SIGFPE;
 440         info.si_errno = 0;
 441         info.si_code = FPE_INTDIV;
 442         info.si_addr = (void __user *)pc;
 443         info.si_trapno = 0;
 444         send_sig_info(SIGFPE, &info, current);
 445 }
 446
 447 #ifdef CONFIG_DEBUG_BUGVERBOSE
 448 void do_BUG(const char *file, int line)
 449 {
 450         // bust_spinlocks(1);   XXX Not in our original BUG()
 451         printk("kernel BUG at %s:%d!\n", file, line);
 452 }
 453 #endif
 454
 455 /* Since we have our mappings set up, on multiprocessors we can spin them
 456  * up here so that timer interrupts work during initialization.
 457  */
 458
 459 extern void sparc_cpu_startup(void);
 460
 461 void trap_init(void)
 462 {
 463         extern void thread_info_offsets_are_bolixed_pete(void);
 464
 465         /* Force linker to barf if mismatched */
 466         if (TI_UWINMASK    != offsetof(struct thread_info, uwinmask) ||
 467             TI_TASK        != offsetof(struct thread_info, task) ||
 468             TI_EXECDOMAIN  != offsetof(struct thread_info, exec_domain) ||
 469             TI_FLAGS       != offsetof(struct thread_info, flags) ||
 470             TI_CPU         != offsetof(struct thread_info, cpu) ||
 471             TI_PREEMPT     != offsetof(struct thread_info, preempt_count) ||
 472             TI_SOFTIRQ     != offsetof(struct thread_info, softirq_count) ||
 473             TI_HARDIRQ     != offsetof(struct thread_info, hardirq_count) ||
 474             TI_KSP         != offsetof(struct thread_info, ksp) ||
 475             TI_KPC         != offsetof(struct thread_info, kpc) ||
 476             TI_KPSR        != offsetof(struct thread_info, kpsr) ||
 477             TI_KWIM        != offsetof(struct thread_info, kwim) ||
 478             TI_REG_WINDOW  != offsetof(struct thread_info, reg_window) ||
 479             TI_RWIN_SPTRS  != offsetof(struct thread_info, rwbuf_stkptrs) ||
 480             TI_W_SAVED     != offsetof(struct thread_info, w_saved))
 481                 thread_info_offsets_are_bolixed_pete();
 482
 483         /* Attach to the address space of init_task. */
 484         atomic_inc(&init_mm.mm_count);
 485         current->active_mm = &init_mm;
 486
 487         /* NOTE: Other cpus have this done as they are started
 488          *       up on SMP.
 489          */
 490 }