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/config.h>
  13 #include <linux/sched.h>  /* for jiffies */
  14 #include <linux/kernel.h>
  15 #include <linux/kallsyms.h>
  16 #include <linux/signal.h>
  17 #include <linux/smp.h>
  18 #include <linux/smp_lock.h>
  19
  20 #include <asm/delay.h>
  21 #include <asm/system.h>
  22 #include <asm/ptrace.h>
  23 #include <asm/oplib.h>
  24 #include <asm/page.h>
  25 #include <asm/pgtable.h>
  26 #include <asm/kdebug.h>
  27 #include <asm/unistd.h>
  28 #include <asm/traps.h>
  29
  30 /* #define TRAP_DEBUG */
  31
  32 struct trap_trace_entry {
  33         unsigned long pc;
  34         unsigned long type;
  35 };
  36
  37 int trap_curbuf = 0;
  38 struct trap_trace_entry trapbuf[1024];
  39
  40 void syscall_trace_entry(struct pt_regs *regs)
  41 {
  42         printk("%s[%d]: ", current->comm, current->pid);
  43         printk("scall<%d> (could be %d)\n", (int) regs->u_regs[UREG_G1],
  44                (int) regs->u_regs[UREG_I0]);
  45 }
  46
  47 void syscall_trace_exit(struct pt_regs *regs)
  48 {
  49 }
  50
  51 void sun4m_nmi(struct pt_regs *regs)
  52 {
  53         unsigned long afsr, afar;
  54
  55         printk("Aieee: sun4m NMI received!\n");
  56         /* XXX HyperSparc hack XXX */
  57         __asm__ __volatile__("mov 0x500, %%g1\n\t"
  58                              "lda [%%g1] 0x4, %0\n\t"
  59                              "mov 0x600, %%g1\n\t"
  60                              "lda [%%g1] 0x4, %1\n\t" :
  61                              "=r" (afsr), "=r" (afar));
  62         printk("afsr=%08lx afar=%08lx\n", afsr, afar);
  63         printk("you lose buddy boy...\n");
  64         show_regs(regs);
  65         prom_halt();
  66 }
  67
  68 void sun4d_nmi(struct pt_regs *regs)
  69 {
  70         printk("Aieee: sun4d NMI received!\n");
  71         printk("you lose buddy boy...\n");
  72         show_regs(regs);
  73         prom_halt();
  74 }
  75
  76 void instruction_dump (unsigned long *pc)
  77 {
  78         int i;
  79
  80         if((((unsigned long) pc) & 3))
  81                 return;
  82
  83         for(i = -3; i < 6; i++)
  84                 printk("%c%08lx%c",i?' ':'<',pc[i],i?' ':'>');
  85         printk("\n");
  86 }
  87
  88 #define __SAVE __asm__ __volatile__("save %sp, -0x40, %sp\n\t")
  89 #define __RESTORE __asm__ __volatile__("restore %g0, %g0, %g0\n\t")
  90
  91 void die_if_kernel(char *str, struct pt_regs *regs)
  92 {
  93         static int die_counter;
  94         int count = 0;
  95
  96         /* Amuse the user. */
  97         printk(
  98 "              \\|/ ____ \\|/\n"
  99 "              \"@'/ ,. \\`@\"\n"
 100 "              /_| \\__/ |_\\\n"
 101 "                 \\__U_/\n");
 102
 103         printk("%s(%d): %s [#%d]\n", current->comm, current->pid, str, ++die_counter);
 104         show_regs(regs);
 105
 106         __SAVE; __SAVE; __SAVE; __SAVE;
 107         __SAVE; __SAVE; __SAVE; __SAVE;
 108         __RESTORE; __RESTORE; __RESTORE; __RESTORE;
 109         __RESTORE; __RESTORE; __RESTORE; __RESTORE;
 110
 111         {
 112                 struct reg_window *rw = (struct reg_window *)regs->u_regs[UREG_FP];
 113
 114                 /* Stop the back trace when we hit userland or we
 115                  * find some badly aligned kernel stack. Set an upper
 116                  * bound in case our stack is trashed and we loop.
 117                  */
 118                 while(rw                                        &&
 119                       count++ < 30                              &&
 120                       (((unsigned long) rw) >= PAGE_OFFSET)     &&
 121                       !(((unsigned long) rw) & 0x7)) {
 122                         printk("Caller[%08lx]", rw->ins[7]);
 123                         print_symbol(": %s\n", rw->ins[7]);
 124                         rw = (struct reg_window *)rw->ins[6];
 125                 }
 126         }
 127         printk("Instruction DUMP:");
 128         instruction_dump ((unsigned long *) regs->pc);
 129         if(regs->psr & PSR_PS)
 130                 do_exit(SIGKILL);
 131         do_exit(SIGSEGV);
 132 }
 133
 134 void do_hw_interrupt(struct pt_regs *regs, unsigned long type)
 135 {
 136         siginfo_t info;
 137
 138         if(type < 0x80) {
 139                 /* Sun OS's puke from bad traps, Linux survives! */
 140                 printk("Unimplemented Sparc TRAP, type = %02lx\n", type);
 141                 die_if_kernel("Whee... Hello Mr. Penguin", regs);
 142         }
 143
 144         if(regs->psr & PSR_PS)
 145                 die_if_kernel("Kernel bad trap", regs);
 146
 147         info.si_signo = SIGILL;
 148         info.si_errno = 0;
 149         info.si_code = ILL_ILLTRP;
 150         info.si_addr = (void __user *)regs->pc;
 151         info.si_trapno = type - 0x80;
 152         force_sig_info(SIGILL, &info, current);
 153 }
 154
 155 void do_illegal_instruction(struct pt_regs *regs, unsigned long pc, unsigned long npc,
 156                             unsigned long psr)
 157 {
 158         extern int do_user_muldiv (struct pt_regs *, unsigned long);
 159         siginfo_t info;
 160
 161         if(psr & PSR_PS)
 162                 die_if_kernel("Kernel illegal instruction", regs);
 163 #ifdef TRAP_DEBUG
 164         printk("Ill instr. at pc=%08lx instruction is %08lx\n",
 165                regs->pc, *(unsigned long *)regs->pc);
 166 #endif
 167         if (!do_user_muldiv (regs, pc))
 168                 return;
 169
 170         info.si_signo = SIGILL;
 171         info.si_errno = 0;
 172         info.si_code = ILL_ILLOPC;
 173         info.si_addr = (void __user *)pc;
 174         info.si_trapno = 0;
 175         send_sig_info(SIGILL, &info, current);
 176 }
 177
 178 void do_priv_instruction(struct pt_regs *regs, unsigned long pc, unsigned long npc,
 179                          unsigned long psr)
 180 {
 181         siginfo_t info;
 182
 183         if(psr & PSR_PS)
 184                 die_if_kernel("Penguin instruction from Penguin mode??!?!", regs);
 185         info.si_signo = SIGILL;
 186         info.si_errno = 0;
 187         info.si_code = ILL_PRVOPC;
 188         info.si_addr = (void __user *)pc;
 189         info.si_trapno = 0;
 190         send_sig_info(SIGILL, &info, current);
 191 }
 192
 193 /* XXX User may want to be allowed to do this. XXX */
 194
 195 void do_memaccess_unaligned(struct pt_regs *regs, unsigned long pc, unsigned long npc,
 196                             unsigned long psr)
 197 {
 198         siginfo_t info;
 199
 200         if(regs->psr & PSR_PS) {
 201                 printk("KERNEL MNA at pc %08lx npc %08lx called by %08lx\n", pc, npc,
 202                        regs->u_regs[UREG_RETPC]);
 203                 die_if_kernel("BOGUS", regs);
 204                 /* die_if_kernel("Kernel MNA access", regs); */
 205         }
 206 #if 0
 207         show_regs (regs);
 208         instruction_dump ((unsigned long *) regs->pc);
 209         printk ("do_MNA!\n");
 210 #endif
 211         info.si_signo = SIGBUS;
 212         info.si_errno = 0;
 213         info.si_code = BUS_ADRALN;
 214         info.si_addr = /* FIXME: Should dig out mna address */ (void *)0;
 215         info.si_trapno = 0;
 216         send_sig_info(SIGBUS, &info, current);
 217 }
 218
 219 extern void fpsave(unsigned long *fpregs, unsigned long *fsr,
 220                    void *fpqueue, unsigned long *fpqdepth);
 221 extern void fpload(unsigned long *fpregs, unsigned long *fsr);
 222
 223 static unsigned long init_fsr = 0x0UL;
 224 static unsigned long init_fregs[32] __attribute__ ((aligned (8))) =
 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                   ~0UL, ~0UL, ~0UL, ~0UL, ~0UL, ~0UL, ~0UL, ~0UL };
 229
 230 void do_fpd_trap(struct pt_regs *regs, unsigned long pc, unsigned long npc,
 231                  unsigned long psr)
 232 {
 233         /* Sanity check... */
 234         if(psr & PSR_PS)
 235                 die_if_kernel("Kernel gets FloatingPenguinUnit disabled trap", regs);
 236
 237         put_psr(get_psr() | PSR_EF);    /* Allow FPU ops. */
 238         regs->psr |= PSR_EF;
 239 #ifndef CONFIG_SMP
 240         if(last_task_used_math == current)
 241                 return;
 242         if(last_task_used_math) {
 243                 /* Other processes fpu state, save away */
 244                 struct task_struct *fptask = last_task_used_math;
 245                 fpsave(&fptask->thread.float_regs[0], &fptask->thread.fsr,
 246                        &fptask->thread.fpqueue[0], &fptask->thread.fpqdepth);
 247         }
 248         last_task_used_math = current;
 249         if(current->used_math) {
 250                 fpload(&current->thread.float_regs[0], &current->thread.fsr);
 251         } else {
 252                 /* Set initial sane state. */
 253                 fpload(&init_fregs[0], &init_fsr);
 254                 current->used_math = 1;
 255         }
 256 #else
 257         if(!current->used_math) {
 258                 fpload(&init_fregs[0], &init_fsr);
 259                 current->used_math = 1;
 260         } else {
 261                 fpload(&current->thread.float_regs[0], &current->thread.fsr);
 262         }
 263         current_thread_info()->flags |= _TIF_USEDFPU;
 264 #endif
 265 }
 266
 267 static unsigned long fake_regs[32] __attribute__ ((aligned (8)));
 268 static unsigned long fake_fsr;
 269 static unsigned long fake_queue[32] __attribute__ ((aligned (8)));
 270 static unsigned long fake_depth;
 271
 272 extern int do_mathemu(struct pt_regs *, struct task_struct *);
 273
 274 void do_fpe_trap(struct pt_regs *regs, unsigned long pc, unsigned long npc,
 275                  unsigned long psr)
 276 {
 277         static int calls;
 278         siginfo_t info;
 279         unsigned long fsr;
 280         int ret = 0;
 281 #ifndef CONFIG_SMP
 282         struct task_struct *fpt = last_task_used_math;
 283 #else
 284         struct task_struct *fpt = current;
 285 #endif
 286         put_psr(get_psr() | PSR_EF);
 287         /* If nobody owns the fpu right now, just clear the
 288          * error into our fake static buffer and hope it don't
 289          * happen again.  Thank you crashme...
 290          */
 291 #ifndef CONFIG_SMP
 292         if(!fpt) {
 293 #else
 294         if(!(fpt->thread_info->flags & _TIF_USEDFPU)) {
 295 #endif
 296                 fpsave(&fake_regs[0], &fake_fsr, &fake_queue[0], &fake_depth);
 297                 regs->psr &= ~PSR_EF;
 298                 return;
 299         }
 300         fpsave(&fpt->thread.float_regs[0], &fpt->thread.fsr,
 301                &fpt->thread.fpqueue[0], &fpt->thread.fpqdepth);
 302 #ifdef DEBUG_FPU
 303         printk("Hmm, FP exception, fsr was %016lx\n", fpt->thread.fsr);
 304 #endif
 305
 306         switch ((fpt->thread.fsr & 0x1c000)) {
 307         /* switch on the contents of the ftt [floating point trap type] field */
 308 #ifdef DEBUG_FPU
 309         case (1 << 14):
 310                 printk("IEEE_754_exception\n");
 311                 break;
 312 #endif
 313         case (2 << 14):  /* unfinished_FPop (underflow & co) */
 314         case (3 << 14):  /* unimplemented_FPop (quad stuff, maybe sqrt) */
 315                 ret = do_mathemu(regs, fpt);
 316                 break;
 317 #ifdef DEBUG_FPU
 318         case (4 << 14):
 319                 printk("sequence_error (OS bug...)\n");
 320                 break;
 321         case (5 << 14):
 322                 printk("hardware_error (uhoh!)\n");
 323                 break;
 324         case (6 << 14):
 325                 printk("invalid_fp_register (user error)\n");
 326                 break;
 327 #endif /* DEBUG_FPU */
 328         }
 329         /* If we successfully emulated the FPop, we pretend the trap never happened :-> */
 330         if (ret) {
 331                 fpload(&current->thread.float_regs[0], &current->thread.fsr);
 332                 return;
 333         }
 334         /* nope, better SIGFPE the offending process... */
 335
 336 #ifdef CONFIG_SMP
 337         fpt->thread_info->flags &= ~_TIF_USEDFPU;
 338 #endif
 339         if(psr & PSR_PS) {
 340                 /* The first fsr store/load we tried trapped,
 341                  * the second one will not (we hope).
 342                  */
 343                 printk("WARNING: FPU exception from kernel mode. at pc=%08lx\n",
 344                        regs->pc);
 345                 regs->pc = regs->npc;
 346                 regs->npc += 4;
 347                 calls++;
 348                 if(calls > 2)
 349                         die_if_kernel("Too many Penguin-FPU traps from kernel mode",
 350                                       regs);
 351                 return;
 352         }
 353
 354         fsr = fpt->thread.fsr;
 355         info.si_signo = SIGFPE;
 356         info.si_errno = 0;
 357         info.si_addr = (void __user *)pc;
 358         info.si_trapno = 0;
 359         info.si_code = __SI_FAULT;
 360         if ((fsr & 0x1c000) == (1 << 14)) {
 361                 if (fsr & 0x10)
 362                         info.si_code = FPE_FLTINV;
 363                 else if (fsr & 0x08)
 364                         info.si_code = FPE_FLTOVF;
 365                 else if (fsr & 0x04)
 366                         info.si_code = FPE_FLTUND;
 367                 else if (fsr & 0x02)
 368                         info.si_code = FPE_FLTDIV;
 369                 else if (fsr & 0x01)
 370                         info.si_code = FPE_FLTRES;
 371         }
 372         send_sig_info(SIGFPE, &info, fpt);
 373 #ifndef CONFIG_SMP
 374         last_task_used_math = NULL;
 375 #endif
 376         regs->psr &= ~PSR_EF;
 377         if(calls > 0)
 378                 calls=0;
 379 }
 380
 381 void handle_tag_overflow(struct pt_regs *regs, unsigned long pc, unsigned long npc,
 382                          unsigned long psr)
 383 {
 384         siginfo_t info;
 385
 386         if(psr & PSR_PS)
 387                 die_if_kernel("Penguin overflow trap from kernel mode", regs);
 388         info.si_signo = SIGEMT;
 389         info.si_errno = 0;
 390         info.si_code = EMT_TAGOVF;
 391         info.si_addr = (void __user *)pc;
 392         info.si_trapno = 0;
 393         send_sig_info(SIGEMT, &info, current);
 394 }
 395
 396 void handle_watchpoint(struct pt_regs *regs, unsigned long pc, unsigned long npc,
 397                        unsigned long psr)
 398 {
 399 #ifdef TRAP_DEBUG
 400         printk("Watchpoint detected at PC %08lx NPC %08lx PSR %08lx\n",
 401                pc, npc, psr);
 402 #endif
 403         if(psr & PSR_PS)
 404                 panic("Tell me what a watchpoint trap is, and I'll then deal "
 405                       "with such a beast...");
 406 }
 407
 408 void handle_reg_access(struct pt_regs *regs, unsigned long pc, unsigned long npc,
 409                        unsigned long psr)
 410 {
 411         siginfo_t info;
 412
 413 #ifdef TRAP_DEBUG
 414         printk("Register Access Exception at PC %08lx NPC %08lx PSR %08lx\n",
 415                pc, npc, psr);
 416 #endif
 417         info.si_signo = SIGBUS;
 418         info.si_errno = 0;
 419         info.si_code = BUS_OBJERR;
 420         info.si_addr = (void __user *)pc;
 421         info.si_trapno = 0;
 422         force_sig_info(SIGBUS, &info, current);
 423 }
 424
 425 void handle_cp_disabled(struct pt_regs *regs, unsigned long pc, unsigned long npc,
 426                         unsigned long psr)
 427 {
 428         siginfo_t info;
 429
 430         info.si_signo = SIGILL;
 431         info.si_errno = 0;
 432         info.si_code = ILL_COPROC;
 433         info.si_addr = (void __user *)pc;
 434         info.si_trapno = 0;
 435         send_sig_info(SIGILL, &info, current);
 436 }
 437
 438 void handle_cp_exception(struct pt_regs *regs, unsigned long pc, unsigned long npc,
 439                          unsigned long psr)
 440 {
 441         siginfo_t info;
 442
 443 #ifdef TRAP_DEBUG
 444         printk("Co-Processor Exception at PC %08lx NPC %08lx PSR %08lx\n",
 445                pc, npc, psr);
 446 #endif
 447         info.si_signo = SIGILL;
 448         info.si_errno = 0;
 449         info.si_code = ILL_COPROC;
 450         info.si_addr = (void __user *)pc;
 451         info.si_trapno = 0;
 452         send_sig_info(SIGILL, &info, current);
 453 }
 454
 455 void handle_hw_divzero(struct pt_regs *regs, unsigned long pc, unsigned long npc,
 456                        unsigned long psr)
 457 {
 458         siginfo_t info;
 459
 460         info.si_signo = SIGFPE;
 461         info.si_errno = 0;
 462         info.si_code = FPE_INTDIV;
 463         info.si_addr = (void __user *)pc;
 464         info.si_trapno = 0;
 465         send_sig_info(SIGFPE, &info, current);
 466 }
 467
 468 #ifdef CONFIG_DEBUG_BUGVERBOSE
 469 void do_BUG(const char *file, int line)
 470 {
 471         // bust_spinlocks(1);   XXX Not in our original BUG()
 472         printk("kernel BUG at %s:%d!\n", file, line);
 473 }
 474 #endif
 475
 476 /* Since we have our mappings set up, on multiprocessors we can spin them
 477  * up here so that timer interrupts work during initialization.
 478  */
 479
 480 extern void sparc_cpu_startup(void);
 481
 482 int linux_smp_still_initting;
 483 unsigned int thiscpus_tbr;
 484 int thiscpus_mid;
 485
 486 void trap_init(void)
 487 {
 488         extern void thread_info_offsets_are_bolixed_pete(void);
 489
 490         /* Force linker to barf if mismatched */
 491         if (TI_UWINMASK    != offsetof(struct thread_info, uwinmask) ||
 492             TI_TASK        != offsetof(struct thread_info, task) ||
 493             TI_EXECDOMAIN  != offsetof(struct thread_info, exec_domain) ||
 494             TI_FLAGS       != offsetof(struct thread_info, flags) ||
 495             TI_CPU         != offsetof(struct thread_info, cpu) ||
 496             TI_PREEMPT     != offsetof(struct thread_info, preempt_count) ||
 497             TI_SOFTIRQ     != offsetof(struct thread_info, softirq_count) ||
 498             TI_HARDIRQ     != offsetof(struct thread_info, hardirq_count) ||
 499             TI_KSP         != offsetof(struct thread_info, ksp) ||
 500             TI_KPC         != offsetof(struct thread_info, kpc) ||
 501             TI_KPSR        != offsetof(struct thread_info, kpsr) ||
 502             TI_KWIM        != offsetof(struct thread_info, kwim) ||
 503             TI_REG_WINDOW  != offsetof(struct thread_info, reg_window) ||
 504             TI_RWIN_SPTRS  != offsetof(struct thread_info, rwbuf_stkptrs) ||
 505             TI_W_SAVED     != offsetof(struct thread_info, w_saved))
 506                 thread_info_offsets_are_bolixed_pete();
 507
 508         /* Attach to the address space of init_task. */
 509         atomic_inc(&init_mm.mm_count);
 510         current->active_mm = &init_mm;
 511
 512         /* NOTE: Other cpus have this done as they are started
 513          *       up on SMP.
 514          */
 515 }