arch/sparc/kernel/traps_32.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/kdebug.h>
  17 #include <linux/export.h>
  18
  19 #include <asm/delay.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, LOCKDEP_NOW_UNRELIABLE);
  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
 124         info.si_signo = SIGILL;
 125         info.si_errno = 0;
 126         info.si_code = ILL_ILLOPC;
 127         info.si_addr = (void __user *)pc;
 128         info.si_trapno = 0;
 129         send_sig_info(SIGILL, &info, current);
 130 }
 131
 132 void do_priv_instruction(struct pt_regs *regs, unsigned long pc, unsigned long npc,
 133                          unsigned long psr)
 134 {
 135         siginfo_t info;
 136
 137         if(psr & PSR_PS)
 138                 die_if_kernel("Penguin instruction from Penguin mode??!?!", regs);
 139         info.si_signo = SIGILL;
 140         info.si_errno = 0;
 141         info.si_code = ILL_PRVOPC;
 142         info.si_addr = (void __user *)pc;
 143         info.si_trapno = 0;
 144         send_sig_info(SIGILL, &info, current);
 145 }
 146
 147 /* XXX User may want to be allowed to do this. XXX */
 148
 149 void do_memaccess_unaligned(struct pt_regs *regs, unsigned long pc, unsigned long npc,
 150                             unsigned long psr)
 151 {
 152         siginfo_t info;
 153
 154         if(regs->psr & PSR_PS) {
 155                 printk("KERNEL MNA at pc %08lx npc %08lx called by %08lx\n", pc, npc,
 156                        regs->u_regs[UREG_RETPC]);
 157                 die_if_kernel("BOGUS", regs);
 158                 /* die_if_kernel("Kernel MNA access", regs); */
 159         }
 160 #if 0
 161         show_regs (regs);
 162         instruction_dump ((unsigned long *) regs->pc);
 163         printk ("do_MNA!\n");
 164 #endif
 165         info.si_signo = SIGBUS;
 166         info.si_errno = 0;
 167         info.si_code = BUS_ADRALN;
 168         info.si_addr = /* FIXME: Should dig out mna address */ (void *)0;
 169         info.si_trapno = 0;
 170         send_sig_info(SIGBUS, &info, current);
 171 }
 172
 173 static unsigned long init_fsr = 0x0UL;
 174 static unsigned long init_fregs[32] __attribute__ ((aligned (8))) =
 175                 { ~0UL, ~0UL, ~0UL, ~0UL, ~0UL, ~0UL, ~0UL, ~0UL,
 176                   ~0UL, ~0UL, ~0UL, ~0UL, ~0UL, ~0UL, ~0UL, ~0UL,
 177                   ~0UL, ~0UL, ~0UL, ~0UL, ~0UL, ~0UL, ~0UL, ~0UL,
 178                   ~0UL, ~0UL, ~0UL, ~0UL, ~0UL, ~0UL, ~0UL, ~0UL };
 179
 180 void do_fpd_trap(struct pt_regs *regs, unsigned long pc, unsigned long npc,
 181                  unsigned long psr)
 182 {
 183         /* Sanity check... */
 184         if(psr & PSR_PS)
 185                 die_if_kernel("Kernel gets FloatingPenguinUnit disabled trap", regs);
 186
 187         put_psr(get_psr() | PSR_EF);    /* Allow FPU ops. */
 188         regs->psr |= PSR_EF;
 189 #ifndef CONFIG_SMP
 190         if(last_task_used_math == current)
 191                 return;
 192         if(last_task_used_math) {
 193                 /* Other processes fpu state, save away */
 194                 struct task_struct *fptask = last_task_used_math;
 195                 fpsave(&fptask->thread.float_regs[0], &fptask->thread.fsr,
 196                        &fptask->thread.fpqueue[0], &fptask->thread.fpqdepth);
 197         }
 198         last_task_used_math = current;
 199         if(used_math()) {
 200                 fpload(&current->thread.float_regs[0], &current->thread.fsr);
 201         } else {
 202                 /* Set initial sane state. */
 203                 fpload(&init_fregs[0], &init_fsr);
 204                 set_used_math();
 205         }
 206 #else
 207         if(!used_math()) {
 208                 fpload(&init_fregs[0], &init_fsr);
 209                 set_used_math();
 210         } else {
 211                 fpload(&current->thread.float_regs[0], &current->thread.fsr);
 212         }
 213         set_thread_flag(TIF_USEDFPU);
 214 #endif
 215 }
 216
 217 static unsigned long fake_regs[32] __attribute__ ((aligned (8)));
 218 static unsigned long fake_fsr;
 219 static unsigned long fake_queue[32] __attribute__ ((aligned (8)));
 220 static unsigned long fake_depth;
 221
 222 extern int do_mathemu(struct pt_regs *, struct task_struct *);
 223
 224 void do_fpe_trap(struct pt_regs *regs, unsigned long pc, unsigned long npc,
 225                  unsigned long psr)
 226 {
 227         static int calls;
 228         siginfo_t info;
 229         unsigned long fsr;
 230         int ret = 0;
 231 #ifndef CONFIG_SMP
 232         struct task_struct *fpt = last_task_used_math;
 233 #else
 234         struct task_struct *fpt = current;
 235 #endif
 236         put_psr(get_psr() | PSR_EF);
 237         /* If nobody owns the fpu right now, just clear the
 238          * error into our fake static buffer and hope it don't
 239          * happen again.  Thank you crashme...
 240          */
 241 #ifndef CONFIG_SMP
 242         if(!fpt) {
 243 #else
 244         if (!test_tsk_thread_flag(fpt, TIF_USEDFPU)) {
 245 #endif
 246                 fpsave(&fake_regs[0], &fake_fsr, &fake_queue[0], &fake_depth);
 247                 regs->psr &= ~PSR_EF;
 248                 return;
 249         }
 250         fpsave(&fpt->thread.float_regs[0], &fpt->thread.fsr,
 251                &fpt->thread.fpqueue[0], &fpt->thread.fpqdepth);
 252 #ifdef DEBUG_FPU
 253         printk("Hmm, FP exception, fsr was %016lx\n", fpt->thread.fsr);
 254 #endif
 255
 256         switch ((fpt->thread.fsr & 0x1c000)) {
 257         /* switch on the contents of the ftt [floating point trap type] field */
 258 #ifdef DEBUG_FPU
 259         case (1 << 14):
 260                 printk("IEEE_754_exception\n");
 261                 break;
 262 #endif
 263         case (2 << 14):  /* unfinished_FPop (underflow & co) */
 264         case (3 << 14):  /* unimplemented_FPop (quad stuff, maybe sqrt) */
 265                 ret = do_mathemu(regs, fpt);
 266                 break;
 267 #ifdef DEBUG_FPU
 268         case (4 << 14):
 269                 printk("sequence_error (OS bug...)\n");
 270                 break;
 271         case (5 << 14):
 272                 printk("hardware_error (uhoh!)\n");
 273                 break;
 274         case (6 << 14):
 275                 printk("invalid_fp_register (user error)\n");
 276                 break;
 277 #endif /* DEBUG_FPU */
 278         }
 279         /* If we successfully emulated the FPop, we pretend the trap never happened :-> */
 280         if (ret) {
 281                 fpload(&current->thread.float_regs[0], &current->thread.fsr);
 282                 return;
 283         }
 284         /* nope, better SIGFPE the offending process... */
 285
 286 #ifdef CONFIG_SMP
 287         clear_tsk_thread_flag(fpt, TIF_USEDFPU);
 288 #endif
 289         if(psr & PSR_PS) {
 290                 /* The first fsr store/load we tried trapped,
 291                  * the second one will not (we hope).
 292                  */
 293                 printk("WARNING: FPU exception from kernel mode. at pc=%08lx\n",
 294                        regs->pc);
 295                 regs->pc = regs->npc;
 296                 regs->npc += 4;
 297                 calls++;
 298                 if(calls > 2)
 299                         die_if_kernel("Too many Penguin-FPU traps from kernel mode",
 300                                       regs);
 301                 return;
 302         }
 303
 304         fsr = fpt->thread.fsr;
 305         info.si_signo = SIGFPE;
 306         info.si_errno = 0;
 307         info.si_addr = (void __user *)pc;
 308         info.si_trapno = 0;
 309         info.si_code = __SI_FAULT;
 310         if ((fsr & 0x1c000) == (1 << 14)) {
 311                 if (fsr & 0x10)
 312                         info.si_code = FPE_FLTINV;
 313                 else if (fsr & 0x08)
 314                         info.si_code = FPE_FLTOVF;
 315                 else if (fsr & 0x04)
 316                         info.si_code = FPE_FLTUND;
 317                 else if (fsr & 0x02)
 318                         info.si_code = FPE_FLTDIV;
 319                 else if (fsr & 0x01)
 320                         info.si_code = FPE_FLTRES;
 321         }
 322         send_sig_info(SIGFPE, &info, fpt);
 323 #ifndef CONFIG_SMP
 324         last_task_used_math = NULL;
 325 #endif
 326         regs->psr &= ~PSR_EF;
 327         if(calls > 0)
 328                 calls=0;
 329 }
 330
 331 void handle_tag_overflow(struct pt_regs *regs, unsigned long pc, unsigned long npc,
 332                          unsigned long psr)
 333 {
 334         siginfo_t info;
 335
 336         if(psr & PSR_PS)
 337                 die_if_kernel("Penguin overflow trap from kernel mode", regs);
 338         info.si_signo = SIGEMT;
 339         info.si_errno = 0;
 340         info.si_code = EMT_TAGOVF;
 341         info.si_addr = (void __user *)pc;
 342         info.si_trapno = 0;
 343         send_sig_info(SIGEMT, &info, current);
 344 }
 345
 346 void handle_watchpoint(struct pt_regs *regs, unsigned long pc, unsigned long npc,
 347                        unsigned long psr)
 348 {
 349 #ifdef TRAP_DEBUG
 350         printk("Watchpoint detected at PC %08lx NPC %08lx PSR %08lx\n",
 351                pc, npc, psr);
 352 #endif
 353         if(psr & PSR_PS)
 354                 panic("Tell me what a watchpoint trap is, and I'll then deal "
 355                       "with such a beast...");
 356 }
 357
 358 void handle_reg_access(struct pt_regs *regs, unsigned long pc, unsigned long npc,
 359                        unsigned long psr)
 360 {
 361         siginfo_t info;
 362
 363 #ifdef TRAP_DEBUG
 364         printk("Register Access Exception at PC %08lx NPC %08lx PSR %08lx\n",
 365                pc, npc, psr);
 366 #endif
 367         info.si_signo = SIGBUS;
 368         info.si_errno = 0;
 369         info.si_code = BUS_OBJERR;
 370         info.si_addr = (void __user *)pc;
 371         info.si_trapno = 0;
 372         force_sig_info(SIGBUS, &info, current);
 373 }
 374
 375 void handle_cp_disabled(struct pt_regs *regs, unsigned long pc, unsigned long npc,
 376                         unsigned long psr)
 377 {
 378         siginfo_t info;
 379
 380         info.si_signo = SIGILL;
 381         info.si_errno = 0;
 382         info.si_code = ILL_COPROC;
 383         info.si_addr = (void __user *)pc;
 384         info.si_trapno = 0;
 385         send_sig_info(SIGILL, &info, current);
 386 }
 387
 388 void handle_cp_exception(struct pt_regs *regs, unsigned long pc, unsigned long npc,
 389                          unsigned long psr)
 390 {
 391         siginfo_t info;
 392
 393 #ifdef TRAP_DEBUG
 394         printk("Co-Processor Exception at PC %08lx NPC %08lx PSR %08lx\n",
 395                pc, npc, psr);
 396 #endif
 397         info.si_signo = SIGILL;
 398         info.si_errno = 0;
 399         info.si_code = ILL_COPROC;
 400         info.si_addr = (void __user *)pc;
 401         info.si_trapno = 0;
 402         send_sig_info(SIGILL, &info, current);
 403 }
 404
 405 void handle_hw_divzero(struct pt_regs *regs, unsigned long pc, unsigned long npc,
 406                        unsigned long psr)
 407 {
 408         siginfo_t info;
 409
 410         info.si_signo = SIGFPE;
 411         info.si_errno = 0;
 412         info.si_code = FPE_INTDIV;
 413         info.si_addr = (void __user *)pc;
 414         info.si_trapno = 0;
 415         send_sig_info(SIGFPE, &info, current);
 416 }
 417
 418 #ifdef CONFIG_DEBUG_BUGVERBOSE
 419 void do_BUG(const char *file, int line)
 420 {
 421         // bust_spinlocks(1);   XXX Not in our original BUG()
 422         printk("kernel BUG at %s:%d!\n", file, line);
 423 }
 424 EXPORT_SYMBOL(do_BUG);
 425 #endif
 426
 427 /* Since we have our mappings set up, on multiprocessors we can spin them
 428  * up here so that timer interrupts work during initialization.
 429  */
 430
 431 void trap_init(void)
 432 {
 433         extern void thread_info_offsets_are_bolixed_pete(void);
 434
 435         /* Force linker to barf if mismatched */
 436         if (TI_UWINMASK    != offsetof(struct thread_info, uwinmask) ||
 437             TI_TASK        != offsetof(struct thread_info, task) ||
 438             TI_EXECDOMAIN  != offsetof(struct thread_info, exec_domain) ||
 439             TI_FLAGS       != offsetof(struct thread_info, flags) ||
 440             TI_CPU         != offsetof(struct thread_info, cpu) ||
 441             TI_PREEMPT     != offsetof(struct thread_info, preempt_count) ||
 442             TI_SOFTIRQ     != offsetof(struct thread_info, softirq_count) ||
 443             TI_HARDIRQ     != offsetof(struct thread_info, hardirq_count) ||
 444             TI_KSP         != offsetof(struct thread_info, ksp) ||
 445             TI_KPC         != offsetof(struct thread_info, kpc) ||
 446             TI_KPSR        != offsetof(struct thread_info, kpsr) ||
 447             TI_KWIM        != offsetof(struct thread_info, kwim) ||
 448             TI_REG_WINDOW  != offsetof(struct thread_info, reg_window) ||
 449             TI_RWIN_SPTRS  != offsetof(struct thread_info, rwbuf_stkptrs) ||
 450             TI_W_SAVED     != offsetof(struct thread_info, w_saved))
 451                 thread_info_offsets_are_bolixed_pete();
 452
 453         /* Attach to the address space of init_task. */
 454         atomic_inc(&init_mm.mm_count);
 455         current->active_mm = &init_mm;
 456
 457         /* NOTE: Other cpus have this done as they are started
 458          *       up on SMP.
 459          */
 460 }