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 __noreturn 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 void do_fpe_trap(struct pt_regs *regs, unsigned long pc, unsigned long npc,
 223                  unsigned long psr)
 224 {
 225         static int calls;
 226         siginfo_t info;
 227         unsigned long fsr;
 228         int ret = 0;
 229 #ifndef CONFIG_SMP
 230         struct task_struct *fpt = last_task_used_math;
 231 #else
 232         struct task_struct *fpt = current;
 233 #endif
 234         put_psr(get_psr() | PSR_EF);
 235         /* If nobody owns the fpu right now, just clear the
 236          * error into our fake static buffer and hope it don't
 237          * happen again.  Thank you crashme...
 238          */
 239 #ifndef CONFIG_SMP
 240         if(!fpt) {
 241 #else
 242         if (!test_tsk_thread_flag(fpt, TIF_USEDFPU)) {
 243 #endif
 244                 fpsave(&fake_regs[0], &fake_fsr, &fake_queue[0], &fake_depth);
 245                 regs->psr &= ~PSR_EF;
 246                 return;
 247         }
 248         fpsave(&fpt->thread.float_regs[0], &fpt->thread.fsr,
 249                &fpt->thread.fpqueue[0], &fpt->thread.fpqdepth);
 250 #ifdef DEBUG_FPU
 251         printk("Hmm, FP exception, fsr was %016lx\n", fpt->thread.fsr);
 252 #endif
 253
 254         switch ((fpt->thread.fsr & 0x1c000)) {
 255         /* switch on the contents of the ftt [floating point trap type] field */
 256 #ifdef DEBUG_FPU
 257         case (1 << 14):
 258                 printk("IEEE_754_exception\n");
 259                 break;
 260 #endif
 261         case (2 << 14):  /* unfinished_FPop (underflow & co) */
 262         case (3 << 14):  /* unimplemented_FPop (quad stuff, maybe sqrt) */
 263                 ret = do_mathemu(regs, fpt);
 264                 break;
 265 #ifdef DEBUG_FPU
 266         case (4 << 14):
 267                 printk("sequence_error (OS bug...)\n");
 268                 break;
 269         case (5 << 14):
 270                 printk("hardware_error (uhoh!)\n");
 271                 break;
 272         case (6 << 14):
 273                 printk("invalid_fp_register (user error)\n");
 274                 break;
 275 #endif /* DEBUG_FPU */
 276         }
 277         /* If we successfully emulated the FPop, we pretend the trap never happened :-> */
 278         if (ret) {
 279                 fpload(&current->thread.float_regs[0], &current->thread.fsr);
 280                 return;
 281         }
 282         /* nope, better SIGFPE the offending process... */
 283
 284 #ifdef CONFIG_SMP
 285         clear_tsk_thread_flag(fpt, TIF_USEDFPU);
 286 #endif
 287         if(psr & PSR_PS) {
 288                 /* The first fsr store/load we tried trapped,
 289                  * the second one will not (we hope).
 290                  */
 291                 printk("WARNING: FPU exception from kernel mode. at pc=%08lx\n",
 292                        regs->pc);
 293                 regs->pc = regs->npc;
 294                 regs->npc += 4;
 295                 calls++;
 296                 if(calls > 2)
 297                         die_if_kernel("Too many Penguin-FPU traps from kernel mode",
 298                                       regs);
 299                 return;
 300         }
 301
 302         fsr = fpt->thread.fsr;
 303         info.si_signo = SIGFPE;
 304         info.si_errno = 0;
 305         info.si_addr = (void __user *)pc;
 306         info.si_trapno = 0;
 307         info.si_code = __SI_FAULT;
 308         if ((fsr & 0x1c000) == (1 << 14)) {
 309                 if (fsr & 0x10)
 310                         info.si_code = FPE_FLTINV;
 311                 else if (fsr & 0x08)
 312                         info.si_code = FPE_FLTOVF;
 313                 else if (fsr & 0x04)
 314                         info.si_code = FPE_FLTUND;
 315                 else if (fsr & 0x02)
 316                         info.si_code = FPE_FLTDIV;
 317                 else if (fsr & 0x01)
 318                         info.si_code = FPE_FLTRES;
 319         }
 320         send_sig_info(SIGFPE, &info, fpt);
 321 #ifndef CONFIG_SMP
 322         last_task_used_math = NULL;
 323 #endif
 324         regs->psr &= ~PSR_EF;
 325         if(calls > 0)
 326                 calls=0;
 327 }
 328
 329 void handle_tag_overflow(struct pt_regs *regs, unsigned long pc, unsigned long npc,
 330                          unsigned long psr)
 331 {
 332         siginfo_t info;
 333
 334         if(psr & PSR_PS)
 335                 die_if_kernel("Penguin overflow trap from kernel mode", regs);
 336         info.si_signo = SIGEMT;
 337         info.si_errno = 0;
 338         info.si_code = EMT_TAGOVF;
 339         info.si_addr = (void __user *)pc;
 340         info.si_trapno = 0;
 341         send_sig_info(SIGEMT, &info, current);
 342 }
 343
 344 void handle_watchpoint(struct pt_regs *regs, unsigned long pc, unsigned long npc,
 345                        unsigned long psr)
 346 {
 347 #ifdef TRAP_DEBUG
 348         printk("Watchpoint detected at PC %08lx NPC %08lx PSR %08lx\n",
 349                pc, npc, psr);
 350 #endif
 351         if(psr & PSR_PS)
 352                 panic("Tell me what a watchpoint trap is, and I'll then deal "
 353                       "with such a beast...");
 354 }
 355
 356 void handle_reg_access(struct pt_regs *regs, unsigned long pc, unsigned long npc,
 357                        unsigned long psr)
 358 {
 359         siginfo_t info;
 360
 361 #ifdef TRAP_DEBUG
 362         printk("Register Access Exception at PC %08lx NPC %08lx PSR %08lx\n",
 363                pc, npc, psr);
 364 #endif
 365         info.si_signo = SIGBUS;
 366         info.si_errno = 0;
 367         info.si_code = BUS_OBJERR;
 368         info.si_addr = (void __user *)pc;
 369         info.si_trapno = 0;
 370         force_sig_info(SIGBUS, &info, current);
 371 }
 372
 373 void handle_cp_disabled(struct pt_regs *regs, unsigned long pc, unsigned long npc,
 374                         unsigned long psr)
 375 {
 376         siginfo_t info;
 377
 378         info.si_signo = SIGILL;
 379         info.si_errno = 0;
 380         info.si_code = ILL_COPROC;
 381         info.si_addr = (void __user *)pc;
 382         info.si_trapno = 0;
 383         send_sig_info(SIGILL, &info, current);
 384 }
 385
 386 void handle_cp_exception(struct pt_regs *regs, unsigned long pc, unsigned long npc,
 387                          unsigned long psr)
 388 {
 389         siginfo_t info;
 390
 391 #ifdef TRAP_DEBUG
 392         printk("Co-Processor Exception at PC %08lx NPC %08lx PSR %08lx\n",
 393                pc, npc, psr);
 394 #endif
 395         info.si_signo = SIGILL;
 396         info.si_errno = 0;
 397         info.si_code = ILL_COPROC;
 398         info.si_addr = (void __user *)pc;
 399         info.si_trapno = 0;
 400         send_sig_info(SIGILL, &info, current);
 401 }
 402
 403 void handle_hw_divzero(struct pt_regs *regs, unsigned long pc, unsigned long npc,
 404                        unsigned long psr)
 405 {
 406         siginfo_t info;
 407
 408         info.si_signo = SIGFPE;
 409         info.si_errno = 0;
 410         info.si_code = FPE_INTDIV;
 411         info.si_addr = (void __user *)pc;
 412         info.si_trapno = 0;
 413         send_sig_info(SIGFPE, &info, current);
 414 }
 415
 416 #ifdef CONFIG_DEBUG_BUGVERBOSE
 417 void do_BUG(const char *file, int line)
 418 {
 419         // bust_spinlocks(1);   XXX Not in our original BUG()
 420         printk("kernel BUG at %s:%d!\n", file, line);
 421 }
 422 EXPORT_SYMBOL(do_BUG);
 423 #endif
 424
 425 /* Since we have our mappings set up, on multiprocessors we can spin them
 426  * up here so that timer interrupts work during initialization.
 427  */
 428
 429 void trap_init(void)
 430 {
 431         extern void thread_info_offsets_are_bolixed_pete(void);
 432
 433         /* Force linker to barf if mismatched */
 434         if (TI_UWINMASK    != offsetof(struct thread_info, uwinmask) ||
 435             TI_TASK        != offsetof(struct thread_info, task) ||
 436             TI_FLAGS       != offsetof(struct thread_info, flags) ||
 437             TI_CPU         != offsetof(struct thread_info, cpu) ||
 438             TI_PREEMPT     != offsetof(struct thread_info, preempt_count) ||
 439             TI_SOFTIRQ     != offsetof(struct thread_info, softirq_count) ||
 440             TI_HARDIRQ     != offsetof(struct thread_info, hardirq_count) ||
 441             TI_KSP         != offsetof(struct thread_info, ksp) ||
 442             TI_KPC         != offsetof(struct thread_info, kpc) ||
 443             TI_KPSR        != offsetof(struct thread_info, kpsr) ||
 444             TI_KWIM        != offsetof(struct thread_info, kwim) ||
 445             TI_REG_WINDOW  != offsetof(struct thread_info, reg_window) ||
 446             TI_RWIN_SPTRS  != offsetof(struct thread_info, rwbuf_stkptrs) ||
 447             TI_W_SAVED     != offsetof(struct thread_info, w_saved))
 448                 thread_info_offsets_are_bolixed_pete();
 449
 450         /* Attach to the address space of init_task. */
 451         mmgrab(&init_mm);
 452         current->active_mm = &init_mm;
 453
 454         /* NOTE: Other cpus have this done as they are started
 455          *       up on SMP.
 456          */
 457 }