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/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 #include "entry.h"
  29 #include "kernel.h"
  30
  31 /* #define TRAP_DEBUG */
  32
  33 static void instruction_dump(unsigned long *pc)
  34 {
  35         int i;
  36
  37         if((((unsigned long) pc) & 3))
  38                 return;
  39
  40         for(i = -3; i < 6; i++)
  41                 printk("%c%08lx%c",i?' ':'<',pc[i],i?' ':'>');
  42         printk("\n");
  43 }
  44
  45 #define __SAVE __asm__ __volatile__("save %sp, -0x40, %sp\n\t")
  46 #define __RESTORE __asm__ __volatile__("restore %g0, %g0, %g0\n\t")
  47
  48 void die_if_kernel(char *str, struct pt_regs *regs)
  49 {
  50         static int die_counter;
  51         int count = 0;
  52
  53         /* Amuse the user. */
  54         printk(
  55 "              \\|/ ____ \\|/\n"
  56 "              \"@'/ ,. \\`@\"\n"
  57 "              /_| \\__/ |_\\\n"
  58 "                 \\__U_/\n");
  59
  60         printk("%s(%d): %s [#%d]\n", current->comm, task_pid_nr(current), str, ++die_counter);
  61         show_regs(regs);
  62         add_taint(TAINT_DIE);
  63
  64         __SAVE; __SAVE; __SAVE; __SAVE;
  65         __SAVE; __SAVE; __SAVE; __SAVE;
  66         __RESTORE; __RESTORE; __RESTORE; __RESTORE;
  67         __RESTORE; __RESTORE; __RESTORE; __RESTORE;
  68
  69         {
  70                 struct reg_window32 *rw = (struct reg_window32 *)regs->u_regs[UREG_FP];
  71
  72                 /* Stop the back trace when we hit userland or we
  73                  * find some badly aligned kernel stack. Set an upper
  74                  * bound in case our stack is trashed and we loop.
  75                  */
  76                 while(rw                                        &&
  77                       count++ < 30                              &&
  78                       (((unsigned long) rw) >= PAGE_OFFSET)     &&
  79                       !(((unsigned long) rw) & 0x7)) {
  80                         printk("Caller[%08lx]: %pS\n", rw->ins[7],
  81                                (void *) rw->ins[7]);
  82                         rw = (struct reg_window32 *)rw->ins[6];
  83                 }
  84         }
  85         printk("Instruction DUMP:");
  86         instruction_dump ((unsigned long *) regs->pc);
  87         if(regs->psr & PSR_PS)
  88                 do_exit(SIGKILL);
  89         do_exit(SIGSEGV);
  90 }
  91
  92 void do_hw_interrupt(struct pt_regs *regs, unsigned long type)
  93 {
  94         siginfo_t info;
  95
  96         if(type < 0x80) {
  97                 /* Sun OS's puke from bad traps, Linux survives! */
  98                 printk("Unimplemented Sparc TRAP, type = %02lx\n", type);
  99                 die_if_kernel("Whee... Hello Mr. Penguin", regs);
 100         }
 101
 102         if(regs->psr & PSR_PS)
 103                 die_if_kernel("Kernel bad trap", regs);
 104
 105         info.si_signo = SIGILL;
 106         info.si_errno = 0;
 107         info.si_code = ILL_ILLTRP;
 108         info.si_addr = (void __user *)regs->pc;
 109         info.si_trapno = type - 0x80;
 110         force_sig_info(SIGILL, &info, current);
 111 }
 112
 113 void do_illegal_instruction(struct pt_regs *regs, unsigned long pc, unsigned long npc,
 114                             unsigned long psr)
 115 {
 116         siginfo_t info;
 117
 118         if(psr & PSR_PS)
 119                 die_if_kernel("Kernel illegal instruction", regs);
 120 #ifdef TRAP_DEBUG
 121         printk("Ill instr. at pc=%08lx instruction is %08lx\n",
 122                regs->pc, *(unsigned long *)regs->pc);
 123 #endif
 124         if (!do_user_muldiv (regs, pc))
 125                 return;
 126
 127         info.si_signo = SIGILL;
 128         info.si_errno = 0;
 129         info.si_code = ILL_ILLOPC;
 130         info.si_addr = (void __user *)pc;
 131         info.si_trapno = 0;
 132         send_sig_info(SIGILL, &info, current);
 133 }
 134
 135 void do_priv_instruction(struct pt_regs *regs, unsigned long pc, unsigned long npc,
 136                          unsigned long psr)
 137 {
 138         siginfo_t info;
 139
 140         if(psr & PSR_PS)
 141                 die_if_kernel("Penguin instruction from Penguin mode??!?!", regs);
 142         info.si_signo = SIGILL;
 143         info.si_errno = 0;
 144         info.si_code = ILL_PRVOPC;
 145         info.si_addr = (void __user *)pc;
 146         info.si_trapno = 0;
 147         send_sig_info(SIGILL, &info, current);
 148 }
 149
 150 /* XXX User may want to be allowed to do this. XXX */
 151
 152 void do_memaccess_unaligned(struct pt_regs *regs, unsigned long pc, unsigned long npc,
 153                             unsigned long psr)
 154 {
 155         siginfo_t info;
 156
 157         if(regs->psr & PSR_PS) {
 158                 printk("KERNEL MNA at pc %08lx npc %08lx called by %08lx\n", pc, npc,
 159                        regs->u_regs[UREG_RETPC]);
 160                 die_if_kernel("BOGUS", regs);
 161                 /* die_if_kernel("Kernel MNA access", regs); */
 162         }
 163 #if 0
 164         show_regs (regs);
 165         instruction_dump ((unsigned long *) regs->pc);
 166         printk ("do_MNA!\n");
 167 #endif
 168         info.si_signo = SIGBUS;
 169         info.si_errno = 0;
 170         info.si_code = BUS_ADRALN;
 171         info.si_addr = /* FIXME: Should dig out mna address */ (void *)0;
 172         info.si_trapno = 0;
 173         send_sig_info(SIGBUS, &info, current);
 174 }
 175
 176 static unsigned long init_fsr = 0x0UL;
 177 static unsigned long init_fregs[32] __attribute__ ((aligned (8))) =
 178                 { ~0UL, ~0UL, ~0UL, ~0UL, ~0UL, ~0UL, ~0UL, ~0UL,
 179                   ~0UL, ~0UL, ~0UL, ~0UL, ~0UL, ~0UL, ~0UL, ~0UL,
 180                   ~0UL, ~0UL, ~0UL, ~0UL, ~0UL, ~0UL, ~0UL, ~0UL,
 181                   ~0UL, ~0UL, ~0UL, ~0UL, ~0UL, ~0UL, ~0UL, ~0UL };
 182
 183 void do_fpd_trap(struct pt_regs *regs, unsigned long pc, unsigned long npc,
 184                  unsigned long psr)
 185 {
 186         /* Sanity check... */
 187         if(psr & PSR_PS)
 188                 die_if_kernel("Kernel gets FloatingPenguinUnit disabled trap", regs);
 189
 190         put_psr(get_psr() | PSR_EF);    /* Allow FPU ops. */
 191         regs->psr |= PSR_EF;
 192 #ifndef CONFIG_SMP
 193         if(last_task_used_math == current)
 194                 return;
 195         if(last_task_used_math) {
 196                 /* Other processes fpu state, save away */
 197                 struct task_struct *fptask = last_task_used_math;
 198                 fpsave(&fptask->thread.float_regs[0], &fptask->thread.fsr,
 199                        &fptask->thread.fpqueue[0], &fptask->thread.fpqdepth);
 200         }
 201         last_task_used_math = current;
 202         if(used_math()) {
 203                 fpload(&current->thread.float_regs[0], &current->thread.fsr);
 204         } else {
 205                 /* Set initial sane state. */
 206                 fpload(&init_fregs[0], &init_fsr);
 207                 set_used_math();
 208         }
 209 #else
 210         if(!used_math()) {
 211                 fpload(&init_fregs[0], &init_fsr);
 212                 set_used_math();
 213         } else {
 214                 fpload(&current->thread.float_regs[0], &current->thread.fsr);
 215         }
 216         set_thread_flag(TIF_USEDFPU);
 217 #endif
 218 }
 219
 220 static unsigned long fake_regs[32] __attribute__ ((aligned (8)));
 221 static unsigned long fake_fsr;
 222 static unsigned long fake_queue[32] __attribute__ ((aligned (8)));
 223 static unsigned long fake_depth;
 224
 225 extern int do_mathemu(struct pt_regs *, struct task_struct *);
 226
 227 void do_fpe_trap(struct pt_regs *regs, unsigned long pc, unsigned long npc,
 228                  unsigned long psr)
 229 {
 230         static int calls;
 231         siginfo_t info;
 232         unsigned long fsr;
 233         int ret = 0;
 234 #ifndef CONFIG_SMP
 235         struct task_struct *fpt = last_task_used_math;
 236 #else
 237         struct task_struct *fpt = current;
 238 #endif
 239         put_psr(get_psr() | PSR_EF);
 240         /* If nobody owns the fpu right now, just clear the
 241          * error into our fake static buffer and hope it don't
 242          * happen again.  Thank you crashme...
 243          */
 244 #ifndef CONFIG_SMP
 245         if(!fpt) {
 246 #else
 247         if (!test_tsk_thread_flag(fpt, TIF_USEDFPU)) {
 248 #endif
 249                 fpsave(&fake_regs[0], &fake_fsr, &fake_queue[0], &fake_depth);
 250                 regs->psr &= ~PSR_EF;
 251                 return;
 252         }
 253         fpsave(&fpt->thread.float_regs[0], &fpt->thread.fsr,
 254                &fpt->thread.fpqueue[0], &fpt->thread.fpqdepth);
 255 #ifdef DEBUG_FPU
 256         printk("Hmm, FP exception, fsr was %016lx\n", fpt->thread.fsr);
 257 #endif
 258
 259         switch ((fpt->thread.fsr & 0x1c000)) {
 260         /* switch on the contents of the ftt [floating point trap type] field */
 261 #ifdef DEBUG_FPU
 262         case (1 << 14):
 263                 printk("IEEE_754_exception\n");
 264                 break;
 265 #endif
 266         case (2 << 14):  /* unfinished_FPop (underflow & co) */
 267         case (3 << 14):  /* unimplemented_FPop (quad stuff, maybe sqrt) */
 268                 ret = do_mathemu(regs, fpt);
 269                 break;
 270 #ifdef DEBUG_FPU
 271         case (4 << 14):
 272                 printk("sequence_error (OS bug...)\n");
 273                 break;
 274         case (5 << 14):
 275                 printk("hardware_error (uhoh!)\n");
 276                 break;
 277         case (6 << 14):
 278                 printk("invalid_fp_register (user error)\n");
 279                 break;
 280 #endif /* DEBUG_FPU */
 281         }
 282         /* If we successfully emulated the FPop, we pretend the trap never happened :-> */
 283         if (ret) {
 284                 fpload(&current->thread.float_regs[0], &current->thread.fsr);
 285                 return;
 286         }
 287         /* nope, better SIGFPE the offending process... */
 288
 289 #ifdef CONFIG_SMP
 290         clear_tsk_thread_flag(fpt, TIF_USEDFPU);
 291 #endif
 292         if(psr & PSR_PS) {
 293                 /* The first fsr store/load we tried trapped,
 294                  * the second one will not (we hope).
 295                  */
 296                 printk("WARNING: FPU exception from kernel mode. at pc=%08lx\n",
 297                        regs->pc);
 298                 regs->pc = regs->npc;
 299                 regs->npc += 4;
 300                 calls++;
 301                 if(calls > 2)
 302                         die_if_kernel("Too many Penguin-FPU traps from kernel mode",
 303                                       regs);
 304                 return;
 305         }
 306
 307         fsr = fpt->thread.fsr;
 308         info.si_signo = SIGFPE;
 309         info.si_errno = 0;
 310         info.si_addr = (void __user *)pc;
 311         info.si_trapno = 0;
 312         info.si_code = __SI_FAULT;
 313         if ((fsr & 0x1c000) == (1 << 14)) {
 314                 if (fsr & 0x10)
 315                         info.si_code = FPE_FLTINV;
 316                 else if (fsr & 0x08)
 317                         info.si_code = FPE_FLTOVF;
 318                 else if (fsr & 0x04)
 319                         info.si_code = FPE_FLTUND;
 320                 else if (fsr & 0x02)
 321                         info.si_code = FPE_FLTDIV;
 322                 else if (fsr & 0x01)
 323                         info.si_code = FPE_FLTRES;
 324         }
 325         send_sig_info(SIGFPE, &info, fpt);
 326 #ifndef CONFIG_SMP
 327         last_task_used_math = NULL;
 328 #endif
 329         regs->psr &= ~PSR_EF;
 330         if(calls > 0)
 331                 calls=0;
 332 }
 333
 334 void handle_tag_overflow(struct pt_regs *regs, unsigned long pc, unsigned long npc,
 335                          unsigned long psr)
 336 {
 337         siginfo_t info;
 338
 339         if(psr & PSR_PS)
 340                 die_if_kernel("Penguin overflow trap from kernel mode", regs);
 341         info.si_signo = SIGEMT;
 342         info.si_errno = 0;
 343         info.si_code = EMT_TAGOVF;
 344         info.si_addr = (void __user *)pc;
 345         info.si_trapno = 0;
 346         send_sig_info(SIGEMT, &info, current);
 347 }
 348
 349 void handle_watchpoint(struct pt_regs *regs, unsigned long pc, unsigned long npc,
 350                        unsigned long psr)
 351 {
 352 #ifdef TRAP_DEBUG
 353         printk("Watchpoint detected at PC %08lx NPC %08lx PSR %08lx\n",
 354                pc, npc, psr);
 355 #endif
 356         if(psr & PSR_PS)
 357                 panic("Tell me what a watchpoint trap is, and I'll then deal "
 358                       "with such a beast...");
 359 }
 360
 361 void handle_reg_access(struct pt_regs *regs, unsigned long pc, unsigned long npc,
 362                        unsigned long psr)
 363 {
 364         siginfo_t info;
 365
 366 #ifdef TRAP_DEBUG
 367         printk("Register Access Exception at PC %08lx NPC %08lx PSR %08lx\n",
 368                pc, npc, psr);
 369 #endif
 370         info.si_signo = SIGBUS;
 371         info.si_errno = 0;
 372         info.si_code = BUS_OBJERR;
 373         info.si_addr = (void __user *)pc;
 374         info.si_trapno = 0;
 375         force_sig_info(SIGBUS, &info, current);
 376 }
 377
 378 void handle_cp_disabled(struct pt_regs *regs, unsigned long pc, unsigned long npc,
 379                         unsigned long psr)
 380 {
 381         siginfo_t info;
 382
 383         info.si_signo = SIGILL;
 384         info.si_errno = 0;
 385         info.si_code = ILL_COPROC;
 386         info.si_addr = (void __user *)pc;
 387         info.si_trapno = 0;
 388         send_sig_info(SIGILL, &info, current);
 389 }
 390
 391 void handle_cp_exception(struct pt_regs *regs, unsigned long pc, unsigned long npc,
 392                          unsigned long psr)
 393 {
 394         siginfo_t info;
 395
 396 #ifdef TRAP_DEBUG
 397         printk("Co-Processor Exception at PC %08lx NPC %08lx PSR %08lx\n",
 398                pc, npc, psr);
 399 #endif
 400         info.si_signo = SIGILL;
 401         info.si_errno = 0;
 402         info.si_code = ILL_COPROC;
 403         info.si_addr = (void __user *)pc;
 404         info.si_trapno = 0;
 405         send_sig_info(SIGILL, &info, current);
 406 }
 407
 408 void handle_hw_divzero(struct pt_regs *regs, unsigned long pc, unsigned long npc,
 409                        unsigned long psr)
 410 {
 411         siginfo_t info;
 412
 413         info.si_signo = SIGFPE;
 414         info.si_errno = 0;
 415         info.si_code = FPE_INTDIV;
 416         info.si_addr = (void __user *)pc;
 417         info.si_trapno = 0;
 418         send_sig_info(SIGFPE, &info, current);
 419 }
 420
 421 #ifdef CONFIG_DEBUG_BUGVERBOSE
 422 void do_BUG(const char *file, int line)
 423 {
 424         // bust_spinlocks(1);   XXX Not in our original BUG()
 425         printk("kernel BUG at %s:%d!\n", file, line);
 426 }
 427 EXPORT_SYMBOL(do_BUG);
 428 #endif
 429
 430 /* Since we have our mappings set up, on multiprocessors we can spin them
 431  * up here so that timer interrupts work during initialization.
 432  */
 433
 434 void trap_init(void)
 435 {
 436         extern void thread_info_offsets_are_bolixed_pete(void);
 437
 438         /* Force linker to barf if mismatched */
 439         if (TI_UWINMASK    != offsetof(struct thread_info, uwinmask) ||
 440             TI_TASK        != offsetof(struct thread_info, task) ||
 441             TI_EXECDOMAIN  != offsetof(struct thread_info, exec_domain) ||
 442             TI_FLAGS       != offsetof(struct thread_info, flags) ||
 443             TI_CPU         != offsetof(struct thread_info, cpu) ||
 444             TI_PREEMPT     != offsetof(struct thread_info, preempt_count) ||
 445             TI_SOFTIRQ     != offsetof(struct thread_info, softirq_count) ||
 446             TI_HARDIRQ     != offsetof(struct thread_info, hardirq_count) ||
 447             TI_KSP         != offsetof(struct thread_info, ksp) ||
 448             TI_KPC         != offsetof(struct thread_info, kpc) ||
 449             TI_KPSR        != offsetof(struct thread_info, kpsr) ||
 450             TI_KWIM        != offsetof(struct thread_info, kwim) ||
 451             TI_REG_WINDOW  != offsetof(struct thread_info, reg_window) ||
 452             TI_RWIN_SPTRS  != offsetof(struct thread_info, rwbuf_stkptrs) ||
 453             TI_W_SAVED     != offsetof(struct thread_info, w_saved))
 454                 thread_info_offsets_are_bolixed_pete();
 455
 456         /* Attach to the address space of init_task. */
 457         atomic_inc(&init_mm.mm_count);
 458         current->active_mm = &init_mm;
 459
 460         /* NOTE: Other cpus have this done as they are started
 461          *       up on SMP.
 462          */
 463 }