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
  18 #include <asm/delay.h>
  19 #include <asm/system.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);
  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         if (!do_user_muldiv (regs, pc))
 124                 return;
 125
 126         info.si_signo = SIGILL;
 127         info.si_errno = 0;
 128         info.si_code = ILL_ILLOPC;
 129         info.si_addr = (void __user *)pc;
 130         info.si_trapno = 0;
 131         send_sig_info(SIGILL, &info, current);
 132 }
 133
 134 void do_priv_instruction(struct pt_regs *regs, unsigned long pc, unsigned long npc,
 135                          unsigned long psr)
 136 {
 137         siginfo_t info;
 138
 139         if(psr & PSR_PS)
 140                 die_if_kernel("Penguin instruction from Penguin mode??!?!", regs);
 141         info.si_signo = SIGILL;
 142         info.si_errno = 0;
 143         info.si_code = ILL_PRVOPC;
 144         info.si_addr = (void __user *)pc;
 145         info.si_trapno = 0;
 146         send_sig_info(SIGILL, &info, current);
 147 }
 148
 149 /* XXX User may want to be allowed to do this. XXX */
 150
 151 void do_memaccess_unaligned(struct pt_regs *regs, unsigned long pc, unsigned long npc,
 152                             unsigned long psr)
 153 {
 154         siginfo_t info;
 155
 156         if(regs->psr & PSR_PS) {
 157                 printk("KERNEL MNA at pc %08lx npc %08lx called by %08lx\n", pc, npc,
 158                        regs->u_regs[UREG_RETPC]);
 159                 die_if_kernel("BOGUS", regs);
 160                 /* die_if_kernel("Kernel MNA access", regs); */
 161         }
 162 #if 0
 163         show_regs (regs);
 164         instruction_dump ((unsigned long *) regs->pc);
 165         printk ("do_MNA!\n");
 166 #endif
 167         info.si_signo = SIGBUS;
 168         info.si_errno = 0;
 169         info.si_code = BUS_ADRALN;
 170         info.si_addr = /* FIXME: Should dig out mna address */ (void *)0;
 171         info.si_trapno = 0;
 172         send_sig_info(SIGBUS, &info, current);
 173 }
 174
 175 static unsigned long init_fsr = 0x0UL;
 176 static unsigned long init_fregs[32] __attribute__ ((aligned (8))) =
 177                 { ~0UL, ~0UL, ~0UL, ~0UL, ~0UL, ~0UL, ~0UL, ~0UL,
 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
 182 void do_fpd_trap(struct pt_regs *regs, unsigned long pc, unsigned long npc,
 183                  unsigned long psr)
 184 {
 185         /* Sanity check... */
 186         if(psr & PSR_PS)
 187                 die_if_kernel("Kernel gets FloatingPenguinUnit disabled trap", regs);
 188
 189         put_psr(get_psr() | PSR_EF);    /* Allow FPU ops. */
 190         regs->psr |= PSR_EF;
 191 #ifndef CONFIG_SMP
 192         if(last_task_used_math == current)
 193                 return;
 194         if(last_task_used_math) {
 195                 /* Other processes fpu state, save away */
 196                 struct task_struct *fptask = last_task_used_math;
 197                 fpsave(&fptask->thread.float_regs[0], &fptask->thread.fsr,
 198                        &fptask->thread.fpqueue[0], &fptask->thread.fpqdepth);
 199         }
 200         last_task_used_math = current;
 201         if(used_math()) {
 202                 fpload(&current->thread.float_regs[0], &current->thread.fsr);
 203         } else {
 204                 /* Set initial sane state. */
 205                 fpload(&init_fregs[0], &init_fsr);
 206                 set_used_math();
 207         }
 208 #else
 209         if(!used_math()) {
 210                 fpload(&init_fregs[0], &init_fsr);
 211                 set_used_math();
 212         } else {
 213                 fpload(&current->thread.float_regs[0], &current->thread.fsr);
 214         }
 215         set_thread_flag(TIF_USEDFPU);
 216 #endif
 217 }
 218
 219 static unsigned long fake_regs[32] __attribute__ ((aligned (8)));
 220 static unsigned long fake_fsr;
 221 static unsigned long fake_queue[32] __attribute__ ((aligned (8)));
 222 static unsigned long fake_depth;
 223
 224 extern int do_mathemu(struct pt_regs *, struct task_struct *);
 225
 226 void do_fpe_trap(struct pt_regs *regs, unsigned long pc, unsigned long npc,
 227                  unsigned long psr)
 228 {
 229         static int calls;
 230         siginfo_t info;
 231         unsigned long fsr;
 232         int ret = 0;
 233 #ifndef CONFIG_SMP
 234         struct task_struct *fpt = last_task_used_math;
 235 #else
 236         struct task_struct *fpt = current;
 237 #endif
 238         put_psr(get_psr() | PSR_EF);
 239         /* If nobody owns the fpu right now, just clear the
 240          * error into our fake static buffer and hope it don't
 241          * happen again.  Thank you crashme...
 242          */
 243 #ifndef CONFIG_SMP
 244         if(!fpt) {
 245 #else
 246         if (!test_tsk_thread_flag(fpt, TIF_USEDFPU)) {
 247 #endif
 248                 fpsave(&fake_regs[0], &fake_fsr, &fake_queue[0], &fake_depth);
 249                 regs->psr &= ~PSR_EF;
 250                 return;
 251         }
 252         fpsave(&fpt->thread.float_regs[0], &fpt->thread.fsr,
 253                &fpt->thread.fpqueue[0], &fpt->thread.fpqdepth);
 254 #ifdef DEBUG_FPU
 255         printk("Hmm, FP exception, fsr was %016lx\n", fpt->thread.fsr);
 256 #endif
 257
 258         switch ((fpt->thread.fsr & 0x1c000)) {
 259         /* switch on the contents of the ftt [floating point trap type] field */
 260 #ifdef DEBUG_FPU
 261         case (1 << 14):
 262                 printk("IEEE_754_exception\n");
 263                 break;
 264 #endif
 265         case (2 << 14):  /* unfinished_FPop (underflow & co) */
 266         case (3 << 14):  /* unimplemented_FPop (quad stuff, maybe sqrt) */
 267                 ret = do_mathemu(regs, fpt);
 268                 break;
 269 #ifdef DEBUG_FPU
 270         case (4 << 14):
 271                 printk("sequence_error (OS bug...)\n");
 272                 break;
 273         case (5 << 14):
 274                 printk("hardware_error (uhoh!)\n");
 275                 break;
 276         case (6 << 14):
 277                 printk("invalid_fp_register (user error)\n");
 278                 break;
 279 #endif /* DEBUG_FPU */
 280         }
 281         /* If we successfully emulated the FPop, we pretend the trap never happened :-> */
 282         if (ret) {
 283                 fpload(&current->thread.float_regs[0], &current->thread.fsr);
 284                 return;
 285         }
 286         /* nope, better SIGFPE the offending process... */
 287
 288 #ifdef CONFIG_SMP
 289         clear_tsk_thread_flag(fpt, TIF_USEDFPU);
 290 #endif
 291         if(psr & PSR_PS) {
 292                 /* The first fsr store/load we tried trapped,
 293                  * the second one will not (we hope).
 294                  */
 295                 printk("WARNING: FPU exception from kernel mode. at pc=%08lx\n",
 296                        regs->pc);
 297                 regs->pc = regs->npc;
 298                 regs->npc += 4;
 299                 calls++;
 300                 if(calls > 2)
 301                         die_if_kernel("Too many Penguin-FPU traps from kernel mode",
 302                                       regs);
 303                 return;
 304         }
 305
 306         fsr = fpt->thread.fsr;
 307         info.si_signo = SIGFPE;
 308         info.si_errno = 0;
 309         info.si_addr = (void __user *)pc;
 310         info.si_trapno = 0;
 311         info.si_code = __SI_FAULT;
 312         if ((fsr & 0x1c000) == (1 << 14)) {
 313                 if (fsr & 0x10)
 314                         info.si_code = FPE_FLTINV;
 315                 else if (fsr & 0x08)
 316                         info.si_code = FPE_FLTOVF;
 317                 else if (fsr & 0x04)
 318                         info.si_code = FPE_FLTUND;
 319                 else if (fsr & 0x02)
 320                         info.si_code = FPE_FLTDIV;
 321                 else if (fsr & 0x01)
 322                         info.si_code = FPE_FLTRES;
 323         }
 324         send_sig_info(SIGFPE, &info, fpt);
 325 #ifndef CONFIG_SMP
 326         last_task_used_math = NULL;
 327 #endif
 328         regs->psr &= ~PSR_EF;
 329         if(calls > 0)
 330                 calls=0;
 331 }
 332
 333 void handle_tag_overflow(struct pt_regs *regs, unsigned long pc, unsigned long npc,
 334                          unsigned long psr)
 335 {
 336         siginfo_t info;
 337
 338         if(psr & PSR_PS)
 339                 die_if_kernel("Penguin overflow trap from kernel mode", regs);
 340         info.si_signo = SIGEMT;
 341         info.si_errno = 0;
 342         info.si_code = EMT_TAGOVF;
 343         info.si_addr = (void __user *)pc;
 344         info.si_trapno = 0;
 345         send_sig_info(SIGEMT, &info, current);
 346 }
 347
 348 void handle_watchpoint(struct pt_regs *regs, unsigned long pc, unsigned long npc,
 349                        unsigned long psr)
 350 {
 351 #ifdef TRAP_DEBUG
 352         printk("Watchpoint detected at PC %08lx NPC %08lx PSR %08lx\n",
 353                pc, npc, psr);
 354 #endif
 355         if(psr & PSR_PS)
 356                 panic("Tell me what a watchpoint trap is, and I'll then deal "
 357                       "with such a beast...");
 358 }
 359
 360 void handle_reg_access(struct pt_regs *regs, unsigned long pc, unsigned long npc,
 361                        unsigned long psr)
 362 {
 363         siginfo_t info;
 364
 365 #ifdef TRAP_DEBUG
 366         printk("Register Access Exception at PC %08lx NPC %08lx PSR %08lx\n",
 367                pc, npc, psr);
 368 #endif
 369         info.si_signo = SIGBUS;
 370         info.si_errno = 0;
 371         info.si_code = BUS_OBJERR;
 372         info.si_addr = (void __user *)pc;
 373         info.si_trapno = 0;
 374         force_sig_info(SIGBUS, &info, current);
 375 }
 376
 377 void handle_cp_disabled(struct pt_regs *regs, unsigned long pc, unsigned long npc,
 378                         unsigned long psr)
 379 {
 380         siginfo_t info;
 381
 382         info.si_signo = SIGILL;
 383         info.si_errno = 0;
 384         info.si_code = ILL_COPROC;
 385         info.si_addr = (void __user *)pc;
 386         info.si_trapno = 0;
 387         send_sig_info(SIGILL, &info, current);
 388 }
 389
 390 void handle_cp_exception(struct pt_regs *regs, unsigned long pc, unsigned long npc,
 391                          unsigned long psr)
 392 {
 393         siginfo_t info;
 394
 395 #ifdef TRAP_DEBUG
 396         printk("Co-Processor Exception at PC %08lx NPC %08lx PSR %08lx\n",
 397                pc, npc, psr);
 398 #endif
 399         info.si_signo = SIGILL;
 400         info.si_errno = 0;
 401         info.si_code = ILL_COPROC;
 402         info.si_addr = (void __user *)pc;
 403         info.si_trapno = 0;
 404         send_sig_info(SIGILL, &info, current);
 405 }
 406
 407 void handle_hw_divzero(struct pt_regs *regs, unsigned long pc, unsigned long npc,
 408                        unsigned long psr)
 409 {
 410         siginfo_t info;
 411
 412         info.si_signo = SIGFPE;
 413         info.si_errno = 0;
 414         info.si_code = FPE_INTDIV;
 415         info.si_addr = (void __user *)pc;
 416         info.si_trapno = 0;
 417         send_sig_info(SIGFPE, &info, current);
 418 }
 419
 420 #ifdef CONFIG_DEBUG_BUGVERBOSE
 421 void do_BUG(const char *file, int line)
 422 {
 423         // bust_spinlocks(1);   XXX Not in our original BUG()
 424         printk("kernel BUG at %s:%d!\n", file, line);
 425 }
 426 EXPORT_SYMBOL(do_BUG);
 427 #endif
 428
 429 /* Since we have our mappings set up, on multiprocessors we can spin them
 430  * up here so that timer interrupts work during initialization.
 431  */
 432
 433 void trap_init(void)
 434 {
 435         extern void thread_info_offsets_are_bolixed_pete(void);
 436
 437         /* Force linker to barf if mismatched */
 438         if (TI_UWINMASK    != offsetof(struct thread_info, uwinmask) ||
 439             TI_TASK        != offsetof(struct thread_info, task) ||
 440             TI_EXECDOMAIN  != offsetof(struct thread_info, exec_domain) ||
 441             TI_FLAGS       != offsetof(struct thread_info, flags) ||
 442             TI_CPU         != offsetof(struct thread_info, cpu) ||
 443             TI_PREEMPT     != offsetof(struct thread_info, preempt_count) ||
 444             TI_SOFTIRQ     != offsetof(struct thread_info, softirq_count) ||
 445             TI_HARDIRQ     != offsetof(struct thread_info, hardirq_count) ||
 446             TI_KSP         != offsetof(struct thread_info, ksp) ||
 447             TI_KPC         != offsetof(struct thread_info, kpc) ||
 448             TI_KPSR        != offsetof(struct thread_info, kpsr) ||
 449             TI_KWIM        != offsetof(struct thread_info, kwim) ||
 450             TI_REG_WINDOW  != offsetof(struct thread_info, reg_window) ||
 451             TI_RWIN_SPTRS  != offsetof(struct thread_info, rwbuf_stkptrs) ||
 452             TI_W_SAVED     != offsetof(struct thread_info, w_saved))
 453                 thread_info_offsets_are_bolixed_pete();
 454
 455         /* Attach to the address space of init_task. */
 456         atomic_inc(&init_mm.mm_count);
 457         current->active_mm = &init_mm;
 458
 459         /* NOTE: Other cpus have this done as they are started
 460          *       up on SMP.
 461          */
 462 }