arch/sparc/kernel/traps.c

   1 /* $Id: traps.c,v 1.64 2000/09/03 15:00:49 anton Exp $
   2  * arch/sparc/kernel/traps.c
   3  *
   4  * Copyright 1995 David S. Miller (davem@caip.rutgers.edu)
   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/kallsyms.h>
  15 #include <linux/signal.h>
  16 #include <linux/smp.h>
  17 #include <linux/smp_lock.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/kdebug.h>
  26 #include <asm/unistd.h>
  27 #include <asm/traps.h>
  28
  29 /* #define TRAP_DEBUG */
  30
  31 struct trap_trace_entry {
  32         unsigned long pc;
  33         unsigned long type;
  34 };
  35
  36 int trap_curbuf = 0;
  37 struct trap_trace_entry trapbuf[1024];
  38
  39 void syscall_trace_entry(struct pt_regs *regs)
  40 {
  41         printk("%s[%d]: ", current->comm, current->pid);
  42         printk("scall<%d> (could be %d)\n", (int) regs->u_regs[UREG_G1],
  43                (int) regs->u_regs[UREG_I0]);
  44 }
  45
  46 void syscall_trace_exit(struct pt_regs *regs)
  47 {
  48 }
  49
  50 void sun4m_nmi(struct pt_regs *regs)
  51 {
  52         unsigned long afsr, afar;
  53
  54         printk("Aieee: sun4m NMI received!\n");
  55         /* XXX HyperSparc hack XXX */
  56         __asm__ __volatile__("mov 0x500, %%g1\n\t"
  57                              "lda [%%g1] 0x4, %0\n\t"
  58                              "mov 0x600, %%g1\n\t"
  59                              "lda [%%g1] 0x4, %1\n\t" :
  60                              "=r" (afsr), "=r" (afar));
  61         printk("afsr=%08lx afar=%08lx\n", afsr, afar);
  62         printk("you lose buddy boy...\n");
  63         show_regs(regs);
  64         prom_halt();
  65 }
  66
  67 void sun4d_nmi(struct pt_regs *regs)
  68 {
  69         printk("Aieee: sun4d NMI received!\n");
  70         printk("you lose buddy boy...\n");
  71         show_regs(regs);
  72         prom_halt();
  73 }
  74
  75 void instruction_dump (unsigned long *pc)
  76 {
  77         int i;
  78
  79         if((((unsigned long) pc) & 3))
  80                 return;
  81
  82         for(i = -3; i < 6; i++)
  83                 printk("%c%08lx%c",i?' ':'<',pc[i],i?' ':'>');
  84         printk("\n");
  85 }
  86
  87 #define __SAVE __asm__ __volatile__("save %sp, -0x40, %sp\n\t")
  88 #define __RESTORE __asm__ __volatile__("restore %g0, %g0, %g0\n\t")
  89
  90 void die_if_kernel(char *str, struct pt_regs *regs)
  91 {
  92         static int die_counter;
  93         int count = 0;
  94
  95         /* Amuse the user. */
  96         printk(
  97 "              \\|/ ____ \\|/\n"
  98 "              \"@'/ ,. \\`@\"\n"
  99 "              /_| \\__/ |_\\\n"
 100 "                 \\__U_/\n");
 101
 102         printk("%s(%d): %s [#%d]\n", current->comm, current->pid, str, ++die_counter);
 103         show_regs(regs);
 104
 105         __SAVE; __SAVE; __SAVE; __SAVE;
 106         __SAVE; __SAVE; __SAVE; __SAVE;
 107         __RESTORE; __RESTORE; __RESTORE; __RESTORE;
 108         __RESTORE; __RESTORE; __RESTORE; __RESTORE;
 109
 110         {
 111                 struct reg_window *rw = (struct reg_window *)regs->u_regs[UREG_FP];
 112
 113                 /* Stop the back trace when we hit userland or we
 114                  * find some badly aligned kernel stack. Set an upper
 115                  * bound in case our stack is trashed and we loop.
 116                  */
 117                 while(rw                                        &&
 118                       count++ < 30                              &&
 119                       (((unsigned long) rw) >= PAGE_OFFSET)     &&
 120                       !(((unsigned long) rw) & 0x7)) {
 121                         printk("Caller[%08lx]", rw->ins[7]);
 122                         print_symbol(": %s\n", rw->ins[7]);
 123                         rw = (struct reg_window *)rw->ins[6];
 124                 }
 125         }
 126         printk("Instruction DUMP:");
 127         instruction_dump ((unsigned long *) regs->pc);
 128         if(regs->psr & PSR_PS)
 129                 do_exit(SIGKILL);
 130         do_exit(SIGSEGV);
 131 }
 132
 133 void do_hw_interrupt(struct pt_regs *regs, unsigned long type)
 134 {
 135         siginfo_t info;
 136
 137         if(type < 0x80) {
 138                 /* Sun OS's puke from bad traps, Linux survives! */
 139                 printk("Unimplemented Sparc TRAP, type = %02lx\n", type);
 140                 die_if_kernel("Whee... Hello Mr. Penguin", regs);
 141         }
 142
 143         if(regs->psr & PSR_PS)
 144                 die_if_kernel("Kernel bad trap", regs);
 145
 146         info.si_signo = SIGILL;
 147         info.si_errno = 0;
 148         info.si_code = ILL_ILLTRP;
 149         info.si_addr = (void __user *)regs->pc;
 150         info.si_trapno = type - 0x80;
 151         force_sig_info(SIGILL, &info, current);
 152 }
 153
 154 void do_illegal_instruction(struct pt_regs *regs, unsigned long pc, unsigned long npc,
 155                             unsigned long psr)
 156 {
 157         extern int do_user_muldiv (struct pt_regs *, unsigned long);
 158         siginfo_t info;
 159
 160         if(psr & PSR_PS)
 161                 die_if_kernel("Kernel illegal instruction", regs);
 162 #ifdef TRAP_DEBUG
 163         printk("Ill instr. at pc=%08lx instruction is %08lx\n",
 164                regs->pc, *(unsigned long *)regs->pc);
 165 #endif
 166         if (!do_user_muldiv (regs, pc))
 167                 return;
 168
 169         info.si_signo = SIGILL;
 170         info.si_errno = 0;
 171         info.si_code = ILL_ILLOPC;
 172         info.si_addr = (void __user *)pc;
 173         info.si_trapno = 0;
 174         send_sig_info(SIGILL, &info, current);
 175 }
 176
 177 void do_priv_instruction(struct pt_regs *regs, unsigned long pc, unsigned long npc,
 178                          unsigned long psr)
 179 {
 180         siginfo_t info;
 181
 182         if(psr & PSR_PS)
 183                 die_if_kernel("Penguin instruction from Penguin mode??!?!", regs);
 184         info.si_signo = SIGILL;
 185         info.si_errno = 0;
 186         info.si_code = ILL_PRVOPC;
 187         info.si_addr = (void __user *)pc;
 188         info.si_trapno = 0;
 189         send_sig_info(SIGILL, &info, current);
 190 }
 191
 192 /* XXX User may want to be allowed to do this. XXX */
 193
 194 void do_memaccess_unaligned(struct pt_regs *regs, unsigned long pc, unsigned long npc,
 195                             unsigned long psr)
 196 {
 197         siginfo_t info;
 198
 199         if(regs->psr & PSR_PS) {
 200                 printk("KERNEL MNA at pc %08lx npc %08lx called by %08lx\n", pc, npc,
 201                        regs->u_regs[UREG_RETPC]);
 202                 die_if_kernel("BOGUS", regs);
 203                 /* die_if_kernel("Kernel MNA access", regs); */
 204         }
 205 #if 0
 206         show_regs (regs);
 207         instruction_dump ((unsigned long *) regs->pc);
 208         printk ("do_MNA!\n");
 209 #endif
 210         info.si_signo = SIGBUS;
 211         info.si_errno = 0;
 212         info.si_code = BUS_ADRALN;
 213         info.si_addr = /* FIXME: Should dig out mna address */ (void *)0;
 214         info.si_trapno = 0;
 215         send_sig_info(SIGBUS, &info, current);
 216 }
 217
 218 extern void fpsave(unsigned long *fpregs, unsigned long *fsr,
 219                    void *fpqueue, unsigned long *fpqdepth);
 220 extern void fpload(unsigned long *fpregs, unsigned long *fsr);
 221
 222 static unsigned long init_fsr = 0x0UL;
 223 static unsigned long init_fregs[32] __attribute__ ((aligned (8))) =
 224                 { ~0UL, ~0UL, ~0UL, ~0UL, ~0UL, ~0UL, ~0UL, ~0UL,
 225                   ~0UL, ~0UL, ~0UL, ~0UL, ~0UL, ~0UL, ~0UL, ~0UL,
 226                   ~0UL, ~0UL, ~0UL, ~0UL, ~0UL, ~0UL, ~0UL, ~0UL,
 227                   ~0UL, ~0UL, ~0UL, ~0UL, ~0UL, ~0UL, ~0UL, ~0UL };
 228
 229 void do_fpd_trap(struct pt_regs *regs, unsigned long pc, unsigned long npc,
 230                  unsigned long psr)
 231 {
 232         /* Sanity check... */
 233         if(psr & PSR_PS)
 234                 die_if_kernel("Kernel gets FloatingPenguinUnit disabled trap", regs);
 235
 236         put_psr(get_psr() | PSR_EF);    /* Allow FPU ops. */
 237         regs->psr |= PSR_EF;
 238 #ifndef CONFIG_SMP
 239         if(last_task_used_math == current)
 240                 return;
 241         if(last_task_used_math) {
 242                 /* Other processes fpu state, save away */
 243                 struct task_struct *fptask = last_task_used_math;
 244                 fpsave(&fptask->thread.float_regs[0], &fptask->thread.fsr,
 245                        &fptask->thread.fpqueue[0], &fptask->thread.fpqdepth);
 246         }
 247         last_task_used_math = current;
 248         if(used_math()) {
 249                 fpload(&current->thread.float_regs[0], &current->thread.fsr);
 250         } else {
 251                 /* Set initial sane state. */
 252                 fpload(&init_fregs[0], &init_fsr);
 253                 set_used_math();
 254         }
 255 #else
 256         if(!used_math()) {
 257                 fpload(&init_fregs[0], &init_fsr);
 258                 set_used_math();
 259         } else {
 260                 fpload(&current->thread.float_regs[0], &current->thread.fsr);
 261         }
 262         current_thread_info()->flags |= _TIF_USEDFPU;
 263 #endif
 264 }
 265
 266 static unsigned long fake_regs[32] __attribute__ ((aligned (8)));
 267 static unsigned long fake_fsr;
 268 static unsigned long fake_queue[32] __attribute__ ((aligned (8)));
 269 static unsigned long fake_depth;
 270
 271 extern int do_mathemu(struct pt_regs *, struct task_struct *);
 272
 273 void do_fpe_trap(struct pt_regs *regs, unsigned long pc, unsigned long npc,
 274                  unsigned long psr)
 275 {
 276         static int calls;
 277         siginfo_t info;
 278         unsigned long fsr;
 279         int ret = 0;
 280 #ifndef CONFIG_SMP
 281         struct task_struct *fpt = last_task_used_math;
 282 #else
 283         struct task_struct *fpt = current;
 284 #endif
 285         put_psr(get_psr() | PSR_EF);
 286         /* If nobody owns the fpu right now, just clear the
 287          * error into our fake static buffer and hope it don't
 288          * happen again.  Thank you crashme...
 289          */
 290 #ifndef CONFIG_SMP
 291         if(!fpt) {
 292 #else
 293         if(!(task_thread_info(fpt)->flags & _TIF_USEDFPU)) {
 294 #endif
 295                 fpsave(&fake_regs[0], &fake_fsr, &fake_queue[0], &fake_depth);
 296                 regs->psr &= ~PSR_EF;
 297                 return;
 298         }
 299         fpsave(&fpt->thread.float_regs[0], &fpt->thread.fsr,
 300                &fpt->thread.fpqueue[0], &fpt->thread.fpqdepth);
 301 #ifdef DEBUG_FPU
 302         printk("Hmm, FP exception, fsr was %016lx\n", fpt->thread.fsr);
 303 #endif
 304
 305         switch ((fpt->thread.fsr & 0x1c000)) {
 306         /* switch on the contents of the ftt [floating point trap type] field */
 307 #ifdef DEBUG_FPU
 308         case (1 << 14):
 309                 printk("IEEE_754_exception\n");
 310                 break;
 311 #endif
 312         case (2 << 14):  /* unfinished_FPop (underflow & co) */
 313         case (3 << 14):  /* unimplemented_FPop (quad stuff, maybe sqrt) */
 314                 ret = do_mathemu(regs, fpt);
 315                 break;
 316 #ifdef DEBUG_FPU
 317         case (4 << 14):
 318                 printk("sequence_error (OS bug...)\n");
 319                 break;
 320         case (5 << 14):
 321                 printk("hardware_error (uhoh!)\n");
 322                 break;
 323         case (6 << 14):
 324                 printk("invalid_fp_register (user error)\n");
 325                 break;
 326 #endif /* DEBUG_FPU */
 327         }
 328         /* If we successfully emulated the FPop, we pretend the trap never happened :-> */
 329         if (ret) {
 330                 fpload(&current->thread.float_regs[0], &current->thread.fsr);
 331                 return;
 332         }
 333         /* nope, better SIGFPE the offending process... */
 334
 335 #ifdef CONFIG_SMP
 336         task_thread_info(fpt)->flags &= ~_TIF_USEDFPU;
 337 #endif
 338         if(psr & PSR_PS) {
 339                 /* The first fsr store/load we tried trapped,
 340                  * the second one will not (we hope).
 341                  */
 342                 printk("WARNING: FPU exception from kernel mode. at pc=%08lx\n",
 343                        regs->pc);
 344                 regs->pc = regs->npc;
 345                 regs->npc += 4;
 346                 calls++;
 347                 if(calls > 2)
 348                         die_if_kernel("Too many Penguin-FPU traps from kernel mode",
 349                                       regs);
 350                 return;
 351         }
 352
 353         fsr = fpt->thread.fsr;
 354         info.si_signo = SIGFPE;
 355         info.si_errno = 0;
 356         info.si_addr = (void __user *)pc;
 357         info.si_trapno = 0;
 358         info.si_code = __SI_FAULT;
 359         if ((fsr & 0x1c000) == (1 << 14)) {
 360                 if (fsr & 0x10)
 361                         info.si_code = FPE_FLTINV;
 362                 else if (fsr & 0x08)
 363                         info.si_code = FPE_FLTOVF;
 364                 else if (fsr & 0x04)
 365                         info.si_code = FPE_FLTUND;
 366                 else if (fsr & 0x02)
 367                         info.si_code = FPE_FLTDIV;
 368                 else if (fsr & 0x01)
 369                         info.si_code = FPE_FLTRES;
 370         }
 371         send_sig_info(SIGFPE, &info, fpt);
 372 #ifndef CONFIG_SMP
 373         last_task_used_math = NULL;
 374 #endif
 375         regs->psr &= ~PSR_EF;
 376         if(calls > 0)
 377                 calls=0;
 378 }
 379
 380 void handle_tag_overflow(struct pt_regs *regs, unsigned long pc, unsigned long npc,
 381                          unsigned long psr)
 382 {
 383         siginfo_t info;
 384
 385         if(psr & PSR_PS)
 386                 die_if_kernel("Penguin overflow trap from kernel mode", regs);
 387         info.si_signo = SIGEMT;
 388         info.si_errno = 0;
 389         info.si_code = EMT_TAGOVF;
 390         info.si_addr = (void __user *)pc;
 391         info.si_trapno = 0;
 392         send_sig_info(SIGEMT, &info, current);
 393 }
 394
 395 void handle_watchpoint(struct pt_regs *regs, unsigned long pc, unsigned long npc,
 396                        unsigned long psr)
 397 {
 398 #ifdef TRAP_DEBUG
 399         printk("Watchpoint detected at PC %08lx NPC %08lx PSR %08lx\n",
 400                pc, npc, psr);
 401 #endif
 402         if(psr & PSR_PS)
 403                 panic("Tell me what a watchpoint trap is, and I'll then deal "
 404                       "with such a beast...");
 405 }
 406
 407 void handle_reg_access(struct pt_regs *regs, unsigned long pc, unsigned long npc,
 408                        unsigned long psr)
 409 {
 410         siginfo_t info;
 411
 412 #ifdef TRAP_DEBUG
 413         printk("Register Access Exception at PC %08lx NPC %08lx PSR %08lx\n",
 414                pc, npc, psr);
 415 #endif
 416         info.si_signo = SIGBUS;
 417         info.si_errno = 0;
 418         info.si_code = BUS_OBJERR;
 419         info.si_addr = (void __user *)pc;
 420         info.si_trapno = 0;
 421         force_sig_info(SIGBUS, &info, current);
 422 }
 423
 424 void handle_cp_disabled(struct pt_regs *regs, unsigned long pc, unsigned long npc,
 425                         unsigned long psr)
 426 {
 427         siginfo_t info;
 428
 429         info.si_signo = SIGILL;
 430         info.si_errno = 0;
 431         info.si_code = ILL_COPROC;
 432         info.si_addr = (void __user *)pc;
 433         info.si_trapno = 0;
 434         send_sig_info(SIGILL, &info, current);
 435 }
 436
 437 void handle_cp_exception(struct pt_regs *regs, unsigned long pc, unsigned long npc,
 438                          unsigned long psr)
 439 {
 440         siginfo_t info;
 441
 442 #ifdef TRAP_DEBUG
 443         printk("Co-Processor Exception at PC %08lx NPC %08lx PSR %08lx\n",
 444                pc, npc, psr);
 445 #endif
 446         info.si_signo = SIGILL;
 447         info.si_errno = 0;
 448         info.si_code = ILL_COPROC;
 449         info.si_addr = (void __user *)pc;
 450         info.si_trapno = 0;
 451         send_sig_info(SIGILL, &info, current);
 452 }
 453
 454 void handle_hw_divzero(struct pt_regs *regs, unsigned long pc, unsigned long npc,
 455                        unsigned long psr)
 456 {
 457         siginfo_t info;
 458
 459         info.si_signo = SIGFPE;
 460         info.si_errno = 0;
 461         info.si_code = FPE_INTDIV;
 462         info.si_addr = (void __user *)pc;
 463         info.si_trapno = 0;
 464         send_sig_info(SIGFPE, &info, current);
 465 }
 466
 467 #ifdef CONFIG_DEBUG_BUGVERBOSE
 468 void do_BUG(const char *file, int line)
 469 {
 470         // bust_spinlocks(1);   XXX Not in our original BUG()
 471         printk("kernel BUG at %s:%d!\n", file, line);
 472 }
 473 #endif
 474
 475 /* Since we have our mappings set up, on multiprocessors we can spin them
 476  * up here so that timer interrupts work during initialization.
 477  */
 478
 479 extern void sparc_cpu_startup(void);
 480
 481 int linux_smp_still_initting;
 482 unsigned int thiscpus_tbr;
 483 int thiscpus_mid;
 484
 485 void trap_init(void)
 486 {
 487         extern void thread_info_offsets_are_bolixed_pete(void);
 488
 489         /* Force linker to barf if mismatched */
 490         if (TI_UWINMASK    != offsetof(struct thread_info, uwinmask) ||
 491             TI_TASK        != offsetof(struct thread_info, task) ||
 492             TI_EXECDOMAIN  != offsetof(struct thread_info, exec_domain) ||
 493             TI_FLAGS       != offsetof(struct thread_info, flags) ||
 494             TI_CPU         != offsetof(struct thread_info, cpu) ||
 495             TI_PREEMPT     != offsetof(struct thread_info, preempt_count) ||
 496             TI_SOFTIRQ     != offsetof(struct thread_info, softirq_count) ||
 497             TI_HARDIRQ     != offsetof(struct thread_info, hardirq_count) ||
 498             TI_KSP         != offsetof(struct thread_info, ksp) ||
 499             TI_KPC         != offsetof(struct thread_info, kpc) ||
 500             TI_KPSR        != offsetof(struct thread_info, kpsr) ||
 501             TI_KWIM        != offsetof(struct thread_info, kwim) ||
 502             TI_REG_WINDOW  != offsetof(struct thread_info, reg_window) ||
 503             TI_RWIN_SPTRS  != offsetof(struct thread_info, rwbuf_stkptrs) ||
 504             TI_W_SAVED     != offsetof(struct thread_info, w_saved))
 505                 thread_info_offsets_are_bolixed_pete();
 506
 507         /* Attach to the address space of init_task. */
 508         atomic_inc(&init_mm.mm_count);
 509         current->active_mm = &init_mm;
 510
 511         /* NOTE: Other cpus have this done as they are started
 512          *       up on SMP.
 513          */
 514 }