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