arch/sparc/kernel/traps_32.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * arch/sparc/kernel/traps.c
   4  *
   5  * Copyright 1995, 2008 David S. Miller (davem@davemloft.net)
   6  * Copyright 2000 Jakub Jelinek (jakub@redhat.com)
   7  */
   8
   9 /*
  10  * I hate traps on the sparc, grrr...
  11  */
  12
  13 #include <linux/sched/mm.h>
  14 #include <linux/sched/debug.h>
  15 #include <linux/mm_types.h>
  16 #include <linux/kernel.h>
  17 #include <linux/signal.h>
  18 #include <linux/smp.h>
  19 #include <linux/kdebug.h>
  20 #include <linux/export.h>
  21
  22 #include <asm/delay.h>
  23 #include <asm/ptrace.h>
  24 #include <asm/oplib.h>
  25 #include <asm/page.h>
  26 #include <asm/pgtable.h>
  27 #include <asm/unistd.h>
  28 #include <asm/traps.h>
  29
  30 #include "entry.h"
  31 #include "kernel.h"
  32
  33 /* #define TRAP_DEBUG */
  34
  35 static void instruction_dump(unsigned long *pc)
  36 {
  37         int i;
  38
  39         if((((unsigned long) pc) & 3))
  40                 return;
  41
  42         for(i = -3; i < 6; i++)
  43                 printk("%c%08lx%c",i?' ':'<',pc[i],i?' ':'>');
  44         printk("\n");
  45 }
  46
  47 #define __SAVE __asm__ __volatile__("save %sp, -0x40, %sp\n\t")
  48 #define __RESTORE __asm__ __volatile__("restore %g0, %g0, %g0\n\t")
  49
  50 void __noreturn die_if_kernel(char *str, struct pt_regs *regs)
  51 {
  52         static int die_counter;
  53         int count = 0;
  54
  55         /* Amuse the user. */
  56         printk(
  57 "              \\|/ ____ \\|/\n"
  58 "              \"@'/ ,. \\`@\"\n"
  59 "              /_| \\__/ |_\\\n"
  60 "                 \\__U_/\n");
  61
  62         printk("%s(%d): %s [#%d]\n", current->comm, task_pid_nr(current), str, ++die_counter);
  63         show_regs(regs);
  64         add_taint(TAINT_DIE, LOCKDEP_NOW_UNRELIABLE);
  65
  66         __SAVE; __SAVE; __SAVE; __SAVE;
  67         __SAVE; __SAVE; __SAVE; __SAVE;
  68         __RESTORE; __RESTORE; __RESTORE; __RESTORE;
  69         __RESTORE; __RESTORE; __RESTORE; __RESTORE;
  70
  71         {
  72                 struct reg_window32 *rw = (struct reg_window32 *)regs->u_regs[UREG_FP];
  73
  74                 /* Stop the back trace when we hit userland or we
  75                  * find some badly aligned kernel stack. Set an upper
  76                  * bound in case our stack is trashed and we loop.
  77                  */
  78                 while(rw                                        &&
  79                       count++ < 30                              &&
  80                       (((unsigned long) rw) >= PAGE_OFFSET)     &&
  81                       !(((unsigned long) rw) & 0x7)) {
  82                         printk("Caller[%08lx]: %pS\n", rw->ins[7],
  83                                (void *) rw->ins[7]);
  84                         rw = (struct reg_window32 *)rw->ins[6];
  85                 }
  86         }
  87         printk("Instruction DUMP:");
  88         instruction_dump ((unsigned long *) regs->pc);
  89         if(regs->psr & PSR_PS)
  90                 do_exit(SIGKILL);
  91         do_exit(SIGSEGV);
  92 }
  93
  94 void do_hw_interrupt(struct pt_regs *regs, unsigned long type)
  95 {
  96         siginfo_t info;
  97
  98         if(type < 0x80) {
  99                 /* Sun OS's puke from bad traps, Linux survives! */
 100                 printk("Unimplemented Sparc TRAP, type = %02lx\n", type);
 101                 die_if_kernel("Whee... Hello Mr. Penguin", regs);
 102         }
 103
 104         if(regs->psr & PSR_PS)
 105                 die_if_kernel("Kernel bad trap", regs);
 106
 107         info.si_signo = SIGILL;
 108         info.si_errno = 0;
 109         info.si_code = ILL_ILLTRP;
 110         info.si_addr = (void __user *)regs->pc;
 111         info.si_trapno = type - 0x80;
 112         force_sig_info(SIGILL, &info, current);
 113 }
 114
 115 void do_illegal_instruction(struct pt_regs *regs, unsigned long pc, unsigned long npc,
 116                             unsigned long psr)
 117 {
 118         siginfo_t info;
 119
 120         if(psr & PSR_PS)
 121                 die_if_kernel("Kernel illegal instruction", regs);
 122 #ifdef TRAP_DEBUG
 123         printk("Ill instr. at pc=%08lx instruction is %08lx\n",
 124                regs->pc, *(unsigned long *)regs->pc);
 125 #endif
 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 void do_fpe_trap(struct pt_regs *regs, unsigned long pc, unsigned long npc,
 226                  unsigned long psr)
 227 {
 228         static int calls;
 229         siginfo_t info;
 230         unsigned long fsr;
 231         int ret = 0;
 232 #ifndef CONFIG_SMP
 233         struct task_struct *fpt = last_task_used_math;
 234 #else
 235         struct task_struct *fpt = current;
 236 #endif
 237         put_psr(get_psr() | PSR_EF);
 238         /* If nobody owns the fpu right now, just clear the
 239          * error into our fake static buffer and hope it don't
 240          * happen again.  Thank you crashme...
 241          */
 242 #ifndef CONFIG_SMP
 243         if(!fpt) {
 244 #else
 245         if (!test_tsk_thread_flag(fpt, TIF_USEDFPU)) {
 246 #endif
 247                 fpsave(&fake_regs[0], &fake_fsr, &fake_queue[0], &fake_depth);
 248                 regs->psr &= ~PSR_EF;
 249                 return;
 250         }
 251         fpsave(&fpt->thread.float_regs[0], &fpt->thread.fsr,
 252                &fpt->thread.fpqueue[0], &fpt->thread.fpqdepth);
 253 #ifdef DEBUG_FPU
 254         printk("Hmm, FP exception, fsr was %016lx\n", fpt->thread.fsr);
 255 #endif
 256
 257         switch ((fpt->thread.fsr & 0x1c000)) {
 258         /* switch on the contents of the ftt [floating point trap type] field */
 259 #ifdef DEBUG_FPU
 260         case (1 << 14):
 261                 printk("IEEE_754_exception\n");
 262                 break;
 263 #endif
 264         case (2 << 14):  /* unfinished_FPop (underflow & co) */
 265         case (3 << 14):  /* unimplemented_FPop (quad stuff, maybe sqrt) */
 266                 ret = do_mathemu(regs, fpt);
 267                 break;
 268 #ifdef DEBUG_FPU
 269         case (4 << 14):
 270                 printk("sequence_error (OS bug...)\n");
 271                 break;
 272         case (5 << 14):
 273                 printk("hardware_error (uhoh!)\n");
 274                 break;
 275         case (6 << 14):
 276                 printk("invalid_fp_register (user error)\n");
 277                 break;
 278 #endif /* DEBUG_FPU */
 279         }
 280         /* If we successfully emulated the FPop, we pretend the trap never happened :-> */
 281         if (ret) {
 282                 fpload(&current->thread.float_regs[0], &current->thread.fsr);
 283                 return;
 284         }
 285         /* nope, better SIGFPE the offending process... */
 286
 287 #ifdef CONFIG_SMP
 288         clear_tsk_thread_flag(fpt, TIF_USEDFPU);
 289 #endif
 290         if(psr & PSR_PS) {
 291                 /* The first fsr store/load we tried trapped,
 292                  * the second one will not (we hope).
 293                  */
 294                 printk("WARNING: FPU exception from kernel mode. at pc=%08lx\n",
 295                        regs->pc);
 296                 regs->pc = regs->npc;
 297                 regs->npc += 4;
 298                 calls++;
 299                 if(calls > 2)
 300                         die_if_kernel("Too many Penguin-FPU traps from kernel mode",
 301                                       regs);
 302                 return;
 303         }
 304
 305         fsr = fpt->thread.fsr;
 306         info.si_signo = SIGFPE;
 307         info.si_errno = 0;
 308         info.si_addr = (void __user *)pc;
 309         info.si_trapno = 0;
 310         info.si_code = FPE_FIXME;
 311         if ((fsr & 0x1c000) == (1 << 14)) {
 312                 if (fsr & 0x10)
 313                         info.si_code = FPE_FLTINV;
 314                 else if (fsr & 0x08)
 315                         info.si_code = FPE_FLTOVF;
 316                 else if (fsr & 0x04)
 317                         info.si_code = FPE_FLTUND;
 318                 else if (fsr & 0x02)
 319                         info.si_code = FPE_FLTDIV;
 320                 else if (fsr & 0x01)
 321                         info.si_code = FPE_FLTRES;
 322         }
 323         send_sig_info(SIGFPE, &info, fpt);
 324 #ifndef CONFIG_SMP
 325         last_task_used_math = NULL;
 326 #endif
 327         regs->psr &= ~PSR_EF;
 328         if(calls > 0)
 329                 calls=0;
 330 }
 331
 332 void handle_tag_overflow(struct pt_regs *regs, unsigned long pc, unsigned long npc,
 333                          unsigned long psr)
 334 {
 335         siginfo_t info;
 336
 337         if(psr & PSR_PS)
 338                 die_if_kernel("Penguin overflow trap from kernel mode", regs);
 339         info.si_signo = SIGEMT;
 340         info.si_errno = 0;
 341         info.si_code = EMT_TAGOVF;
 342         info.si_addr = (void __user *)pc;
 343         info.si_trapno = 0;
 344         send_sig_info(SIGEMT, &info, current);
 345 }
 346
 347 void handle_watchpoint(struct pt_regs *regs, unsigned long pc, unsigned long npc,
 348                        unsigned long psr)
 349 {
 350 #ifdef TRAP_DEBUG
 351         printk("Watchpoint detected at PC %08lx NPC %08lx PSR %08lx\n",
 352                pc, npc, psr);
 353 #endif
 354         if(psr & PSR_PS)
 355                 panic("Tell me what a watchpoint trap is, and I'll then deal "
 356                       "with such a beast...");
 357 }
 358
 359 void handle_reg_access(struct pt_regs *regs, unsigned long pc, unsigned long npc,
 360                        unsigned long psr)
 361 {
 362         siginfo_t info;
 363
 364 #ifdef TRAP_DEBUG
 365         printk("Register Access Exception at PC %08lx NPC %08lx PSR %08lx\n",
 366                pc, npc, psr);
 367 #endif
 368         info.si_signo = SIGBUS;
 369         info.si_errno = 0;
 370         info.si_code = BUS_OBJERR;
 371         info.si_addr = (void __user *)pc;
 372         info.si_trapno = 0;
 373         force_sig_info(SIGBUS, &info, current);
 374 }
 375
 376 void handle_cp_disabled(struct pt_regs *regs, unsigned long pc, unsigned long npc,
 377                         unsigned long psr)
 378 {
 379         siginfo_t info;
 380
 381         info.si_signo = SIGILL;
 382         info.si_errno = 0;
 383         info.si_code = ILL_COPROC;
 384         info.si_addr = (void __user *)pc;
 385         info.si_trapno = 0;
 386         send_sig_info(SIGILL, &info, current);
 387 }
 388
 389 void handle_cp_exception(struct pt_regs *regs, unsigned long pc, unsigned long npc,
 390                          unsigned long psr)
 391 {
 392         siginfo_t info;
 393
 394 #ifdef TRAP_DEBUG
 395         printk("Co-Processor Exception at PC %08lx NPC %08lx PSR %08lx\n",
 396                pc, npc, psr);
 397 #endif
 398         info.si_signo = SIGILL;
 399         info.si_errno = 0;
 400         info.si_code = ILL_COPROC;
 401         info.si_addr = (void __user *)pc;
 402         info.si_trapno = 0;
 403         send_sig_info(SIGILL, &info, current);
 404 }
 405
 406 void handle_hw_divzero(struct pt_regs *regs, unsigned long pc, unsigned long npc,
 407                        unsigned long psr)
 408 {
 409         siginfo_t info;
 410
 411         info.si_signo = SIGFPE;
 412         info.si_errno = 0;
 413         info.si_code = FPE_INTDIV;
 414         info.si_addr = (void __user *)pc;
 415         info.si_trapno = 0;
 416         send_sig_info(SIGFPE, &info, current);
 417 }
 418
 419 #ifdef CONFIG_DEBUG_BUGVERBOSE
 420 void do_BUG(const char *file, int line)
 421 {
 422         // bust_spinlocks(1);   XXX Not in our original BUG()
 423         printk("kernel BUG at %s:%d!\n", file, line);
 424 }
 425 EXPORT_SYMBOL(do_BUG);
 426 #endif
 427
 428 /* Since we have our mappings set up, on multiprocessors we can spin them
 429  * up here so that timer interrupts work during initialization.
 430  */
 431
 432 void trap_init(void)
 433 {
 434         extern void thread_info_offsets_are_bolixed_pete(void);
 435
 436         /* Force linker to barf if mismatched */
 437         if (TI_UWINMASK    != offsetof(struct thread_info, uwinmask) ||
 438             TI_TASK        != offsetof(struct thread_info, task) ||
 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         mmgrab(&init_mm);
 455         current->active_mm = &init_mm;
 456
 457         /* NOTE: Other cpus have this done as they are started
 458          *       up on SMP.
 459          */
 460 }