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