arch/s390/kernel/traps.c

   1 /*
   2  *  arch/s390/kernel/traps.c
   3  *
   4  *  S390 version
   5  *    Copyright (C) 1999,2000 IBM Deutschland Entwicklung GmbH, IBM Corporation
   6  *    Author(s): Martin Schwidefsky (schwidefsky@de.ibm.com),
   7  *               Denis Joseph Barrow (djbarrow@de.ibm.com,barrow_dj@yahoo.com),
   8  *
   9  *  Derived from "arch/i386/kernel/traps.c"
  10  *    Copyright (C) 1991, 1992 Linus Torvalds
  11  */
  12
  13 /*
  14  * 'Traps.c' handles hardware traps and faults after we have saved some
  15  * state in 'asm.s'.
  16  */
  17 #include <linux/config.h>
  18 #include <linux/sched.h>
  19 #include <linux/kernel.h>
  20 #include <linux/string.h>
  21 #include <linux/errno.h>
  22 #include <linux/ptrace.h>
  23 #include <linux/timer.h>
  24 #include <linux/mm.h>
  25 #include <linux/smp.h>
  26 #include <linux/smp_lock.h>
  27 #include <linux/init.h>
  28 #include <linux/delay.h>
  29
  30 #include <asm/system.h>
  31 #include <asm/uaccess.h>
  32 #include <asm/io.h>
  33 #include <asm/atomic.h>
  34 #include <asm/mathemu.h>
  35 #if CONFIG_REMOTE_DEBUG
  36 #include <asm/gdb-stub.h>
  37 #endif
  38
  39 /* Called from entry.S only */
  40 extern void handle_per_exception(struct pt_regs *regs);
  41
  42 typedef void pgm_check_handler_t(struct pt_regs *, long);
  43 pgm_check_handler_t *pgm_check_table[128];
  44
  45 extern pgm_check_handler_t default_trap_handler;
  46 extern pgm_check_handler_t do_page_fault;
  47
  48 asmlinkage int system_call(void);
  49
  50 #define DO_ERROR(trapnr, signr, str, name, tsk) \
  51 asmlinkage void name(struct pt_regs * regs, long error_code) \
  52 { \
  53         tsk->thread.error_code = error_code; \
  54         tsk->thread.trap_no = trapnr; \
  55         die_if_no_fixup(str,regs,error_code); \
  56         force_sig(signr, tsk); \
  57 }
  58
  59 /* TODO: define these as 'pgm_check_handler_t xxx;'
  60 asmlinkage void divide_error(void);
  61 asmlinkage void debug(void);
  62 asmlinkage void nmi(void);
  63 asmlinkage void int3(void);
  64 asmlinkage void overflow(void);
  65 asmlinkage void bounds(void);
  66 asmlinkage void invalid_op(void);
  67 asmlinkage void device_not_available(void);
  68 asmlinkage void double_fault(void);
  69 asmlinkage void coprocessor_segment_overrun(void);
  70 asmlinkage void invalid_TSS(void);
  71 asmlinkage void segment_not_present(void);
  72 asmlinkage void stack_segment(void);
  73 asmlinkage void general_protection(void);
  74 asmlinkage void coprocessor_error(void);
  75 asmlinkage void reserved(void);
  76 asmlinkage void alignment_check(void);
  77 asmlinkage void spurious_interrupt_bug(void);
  78 */
  79
  80 int kstack_depth_to_print = 24;
  81
  82 /*
  83  * These constants are for searching for possible module text
  84  * segments.  VMALLOC_OFFSET comes from mm/vmalloc.c; MODULE_RANGE is
  85  * a guess of how much space is likely to be vmalloced.
  86  */
  87 #define VMALLOC_OFFSET (8*1024*1024)
  88 #define MODULE_RANGE (8*1024*1024)
  89
  90 void show_crashed_task_info(void)
  91 {
  92         printk("CPU:    %d\n",smp_processor_id());
  93         printk("Process %s (pid: %d, stackpage=%08X)\n",
  94                 current->comm, current->pid, 4096+(addr_t)current);
  95         show_regs(current,NULL,NULL);
  96 }
  97 #if 0
  98 static void show_registers(struct pt_regs *regs)
  99 {
 100         printk("CPU:    %d\nPSW:    %08lx %08lx\n",
 101                 smp_processor_id(), (unsigned long) regs->psw.mask,
 102                 (unsigned long) regs->psw.addr);
 103         printk("GPRS:\n");
 104
 105         printk("%08lx  %08lx  %08lx  %08lx\n",
 106                 regs->gprs[0], regs->gprs[1],
 107                 regs->gprs[2], regs->gprs[3]);
 108         printk("%08lx  %08lx  %08lx  %08lx\n",
 109                 regs->gprs[4], regs->gprs[5],
 110                 regs->gprs[6], regs->gprs[7]);
 111         printk("%08lx  %08lx  %08lx  %08lx\n",
 112                 regs->gprs[8], regs->gprs[9],
 113                 regs->gprs[10], regs->gprs[11]);
 114         printk("%08lx  %08lx  %08lx  %08lx\n",
 115                 regs->gprs[12], regs->gprs[13],
 116                 regs->gprs[14], regs->gprs[15]);
 117         printk("Process %s (pid: %d, stackpage=%08lx)\nStack: ",
 118                 current->comm, current->pid, 4096+(unsigned long)current);
 119 /*
 120         stack = (unsigned long *) esp;
 121         for(i=0; i < kstack_depth_to_print; i++) {
 122                 if (((long) stack & 4095) == 0)
 123                         break;
 124                 if (i && ((i % 8) == 0))
 125                         printk("\n       ");
 126                 printk("%08lx ", get_seg_long(ss,stack++));
 127         }
 128         printk("\nCall Trace: ");
 129         stack = (unsigned long *) esp;
 130         i = 1;
 131         module_start = PAGE_OFFSET + (max_mapnr << PAGE_SHIFT);
 132         module_start = ((module_start + VMALLOC_OFFSET) & ~(VMALLOC_OFFSET-1));
 133         module_end = module_start + MODULE_RANGE;
 134         while (((long) stack & 4095) != 0) {
 135                 addr = get_seg_long(ss, stack++); */
 136                 /*
 137                  * If the address is either in the text segment of the
 138                  * kernel, or in the region which contains vmalloc'ed
 139                  * memory, it *may* be the address of a calling
 140                  * routine; if so, print it so that someone tracing
 141                  * down the cause of the crash will be able to figure
 142                  * out the call path that was taken.
 143                  */
 144 /*                if (((addr >= (unsigned long) &_stext) &&
 145                      (addr <= (unsigned long) &_etext)) ||
 146                     ((addr >= module_start) && (addr <= module_end))) {
 147                         if (i && ((i % 8) == 0))
 148                                 printk("\n       ");
 149                         printk("[<%08lx>] ", addr);
 150                         i++;
 151                 }
 152         }
 153         printk("\nCode: ");
 154         for(i=0;i<20;i++)
 155                 printk("%02x ",0xff & get_seg_byte(regs->xcs & 0xffff,(i+(char *)regs->eip)));
 156         printk("\n");
 157 */
 158 }
 159 #endif
 160
 161
 162 spinlock_t die_lock;
 163
 164 void die(const char * str, struct pt_regs * regs, long err)
 165 {
 166         console_verbose();
 167         spin_lock_irq(&die_lock);
 168         printk("%s: %04lx\n", str, err & 0xffff);
 169         show_crashed_task_info();
 170         spin_unlock_irq(&die_lock);
 171         do_exit(SIGSEGV);
 172 }
 173
 174 int check_for_fixup(struct pt_regs * regs)
 175 {
 176         if (!(regs->psw.mask & PSW_PROBLEM_STATE)) {
 177                 unsigned long fixup;
 178                 fixup = search_exception_table(regs->psw.addr);
 179                 if (fixup) {
 180                         regs->psw.addr = fixup;
 181                         return 1;
 182                 }
 183         }
 184         return 0;
 185 }
 186
 187 int do_debugger_trap(struct pt_regs *regs,int signal)
 188 {
 189         if(regs->psw.mask&PSW_PROBLEM_STATE)
 190         {
 191                 if(current->flags & PF_PTRACED)
 192                         force_sig(signal,current);
 193                 else
 194                         return 1;
 195         }
 196         else
 197         {
 198 #if CONFIG_REMOTE_DEBUG
 199                 if(gdb_stub_initialised)
 200                 {
 201                         gdb_stub_handle_exception((gdb_pt_regs *)regs,signal);
 202                         return 0;
 203                 }
 204 #endif
 205                 return 1;
 206         }
 207         return 0;
 208 }
 209
 210 static void die_if_no_fixup(const char * str, struct pt_regs * regs, long err)
 211 {
 212         if (!(regs->psw.mask & PSW_PROBLEM_STATE)) {
 213                 unsigned long fixup;
 214                 fixup = search_exception_table(regs->psw.addr);
 215                 if (fixup) {
 216                         regs->psw.addr = fixup;
 217                         return;
 218                 }
 219                 die(str, regs, err);
 220         }
 221 }
 222
 223 asmlinkage void default_trap_handler(struct pt_regs * regs, long error_code)
 224 {
 225         current->thread.error_code = error_code;
 226         current->thread.trap_no = error_code;
 227         die_if_no_fixup("Unknown program exception",regs,error_code);
 228         force_sig(SIGSEGV, current);
 229 }
 230
 231 DO_ERROR(2, SIGILL, "privileged operation", privileged_op, current)
 232 DO_ERROR(3, SIGILL, "execute exception", execute_exception, current)
 233 DO_ERROR(5, SIGSEGV, "addressing exception", addressing_exception, current)
 234 DO_ERROR(9, SIGFPE, "fixpoint divide exception", divide_exception, current)
 235 DO_ERROR(0x12, SIGILL, "translation exception", translation_exception, current)
 236 DO_ERROR(0x13, SIGILL, "special operand exception", special_op_exception, current)
 237 DO_ERROR(0x15, SIGILL, "operand exception", operand_exception, current)
 238
 239 /* need to define
 240 DO_ERROR( 6, SIGILL,  "invalid operand", invalid_op, current)
 241 DO_ERROR( 8, SIGSEGV, "double fault", double_fault, current)
 242 DO_ERROR( 9, SIGFPE,  "coprocessor segment overrun", coprocessor_segment_overrun, last_task_used_math)
 243 DO_ERROR(10, SIGSEGV, "invalid TSS", invalid_TSS, current)
 244 DO_ERROR(11, SIGBUS,  "segment not present", segment_not_present, current)
 245 DO_ERROR(12, SIGBUS,  "stack segment", stack_segment, current)
 246 DO_ERROR(17, SIGSEGV, "alignment check", alignment_check, current)
 247 DO_ERROR(18, SIGSEGV, "reserved", reserved, current)
 248 DO_ERROR(19, SIGSEGV, "cache flush denied", cache_flush_denied, current)
 249 */
 250
 251 #ifdef CONFIG_IEEEFPU_EMULATION
 252
 253 asmlinkage void illegal_op(struct pt_regs * regs, long error_code)
 254 {
 255         __u8 opcode[6];
 256         __u16 *location;
 257         int do_sig = 0;
 258         int problem_state=(regs->psw.mask & PSW_PROBLEM_STATE);
 259
 260         lock_kernel();
 261         location = (__u16 *)(regs->psw.addr-S390_lowcore.pgm_ilc);
 262         if(problem_state)
 263                 get_user(*((__u16 *) opcode), location);
 264         else
 265                 *((__u16 *)opcode)=*((__u16 *)location);
 266         if(*((__u16 *)opcode)==S390_BREAKPOINT_U16)
 267         {
 268                 if(do_debugger_trap(regs,SIGTRAP))
 269                         do_sig=1;
 270         }
 271         else if (problem_state )
 272         {
 273                 if (opcode[0] == 0xb3) {
 274                         get_user(*((__u16 *) (opcode+2)), location+1);
 275                         do_sig = math_emu_b3(opcode, regs);
 276                 } else if (opcode[0] == 0xed) {
 277                         get_user(*((__u32 *) (opcode+2)),
 278                                  (__u32 *)(location+1));
 279                         do_sig = math_emu_ed(opcode, regs);
 280                 } else if (*((__u16 *) opcode) == 0xb299) {
 281                         get_user(*((__u16 *) (opcode+2)), location+1);
 282                         do_sig = math_emu_srnm(opcode, regs);
 283                 } else if (*((__u16 *) opcode) == 0xb29c) {
 284                         get_user(*((__u16 *) (opcode+2)), location+1);
 285                         do_sig = math_emu_stfpc(opcode, regs);
 286                 } else if (*((__u16 *) opcode) == 0xb29d) {
 287                         get_user(*((__u16 *) (opcode+2)), location+1);
 288                         do_sig = math_emu_lfpc(opcode, regs);
 289                 } else
 290                         do_sig = 1;
 291         } else
 292                 do_sig = 1;
 293         if (do_sig) {
 294                 current->thread.error_code = error_code;
 295                 current->thread.trap_no = 1;
 296                 force_sig(SIGILL, current);
 297                 die_if_no_fixup("illegal operation", regs, error_code);
 298         }
 299         unlock_kernel();
 300 }
 301
 302 asmlinkage void specification_exception(struct pt_regs * regs, long error_code)
 303 {
 304         __u8 opcode[6];
 305         __u16 *location;
 306         int do_sig = 0;
 307
 308         lock_kernel();
 309         if (regs->psw.mask & 0x00010000L) {
 310                 location = (__u16 *)(regs->psw.addr-S390_lowcore.pgm_ilc);
 311                 get_user(*((__u16 *) opcode), location);
 312                 switch (opcode[0]) {
 313                 case 0x28: /* LDR Rx,Ry   */
 314                         math_emu_ldr(opcode);
 315                         break;
 316                 case 0x38: /* LER Rx,Ry   */
 317                         math_emu_ler(opcode);
 318                         break;
 319                 case 0x60: /* STD R,D(X,B) */
 320                         get_user(*((__u16 *) (opcode+2)), location+1);
 321                         math_emu_std(opcode, regs);
 322                         break;
 323                 case 0x68: /* LD R,D(X,B) */
 324                         get_user(*((__u16 *) (opcode+2)), location+1);
 325                         math_emu_ld(opcode, regs);
 326                         break;
 327                 case 0x70: /* STE R,D(X,B) */
 328                         get_user(*((__u16 *) (opcode+2)), location+1);
 329                         math_emu_ste(opcode, regs);
 330                         break;
 331                 case 0x78: /* LE R,D(X,B) */
 332                         get_user(*((__u16 *) (opcode+2)), location+1);
 333                         math_emu_le(opcode, regs);
 334                         break;
 335                 default:
 336                         do_sig = 1;
 337                         break;
 338                 }
 339         } else
 340                 do_sig = 1;
 341         if (do_sig) {
 342                 current->thread.error_code = error_code;
 343                 current->thread.trap_no = 1;
 344                 force_sig(SIGILL, current);
 345                 die_if_no_fixup("illegal operation", regs, error_code);
 346         }
 347         unlock_kernel();
 348 }
 349
 350 asmlinkage void data_exception(struct pt_regs * regs, long error_code)
 351 {
 352         __u8 opcode[6];
 353         __u16 *location;
 354         int do_sig = 0;
 355
 356         lock_kernel();
 357         if (regs->psw.mask & 0x00010000L) {
 358                 location = (__u16 *)(regs->psw.addr-S390_lowcore.pgm_ilc);
 359                 get_user(*((__u16 *) opcode), location);
 360                 switch (opcode[0]) {
 361                 case 0x28: /* LDR Rx,Ry   */
 362                         math_emu_ldr(opcode);
 363                         break;
 364                 case 0x38: /* LER Rx,Ry   */
 365                         math_emu_ler(opcode);
 366                         break;
 367                 case 0x60: /* STD R,D(X,B) */
 368                         get_user(*((__u16 *) (opcode+2)), location+1);
 369                         math_emu_std(opcode, regs);
 370                         break;
 371                 case 0x68: /* LD R,D(X,B) */
 372                         get_user(*((__u16 *) (opcode+2)), location+1);
 373                         math_emu_ld(opcode, regs);
 374                         break;
 375                 case 0x70: /* STE R,D(X,B) */
 376                         get_user(*((__u16 *) (opcode+2)), location+1);
 377                         math_emu_ste(opcode, regs);
 378                         break;
 379                 case 0x78: /* LE R,D(X,B) */
 380                         get_user(*((__u16 *) (opcode+2)), location+1);
 381                         math_emu_le(opcode, regs);
 382                         break;
 383                 case 0xb3:
 384                         get_user(*((__u16 *) (opcode+2)), location+1);
 385                         do_sig = math_emu_b3(opcode, regs);
 386                         break;
 387                 case 0xed:
 388                         get_user(*((__u32 *) (opcode+2)),
 389                                  (__u32 *)(location+1));
 390                         do_sig = math_emu_ed(opcode, regs);
 391                         break;
 392                 case 0xb2:
 393                         if (opcode[1] == 0x99) {
 394                                 get_user(*((__u16 *) (opcode+2)), location+1);
 395                                 do_sig = math_emu_srnm(opcode, regs);
 396                         } else if (opcode[1] == 0x9c) {
 397                                 get_user(*((__u16 *) (opcode+2)), location+1);
 398                                 do_sig = math_emu_stfpc(opcode, regs);
 399                         } else if (opcode[1] == 0x9d) {
 400                                 get_user(*((__u16 *) (opcode+2)), location+1);
 401                                 do_sig = math_emu_lfpc(opcode, regs);
 402                         } else
 403                                 do_sig = 1;
 404                         break;
 405                 default:
 406                         do_sig = 1;
 407                         break;
 408                 }
 409         } else
 410                 do_sig = 1;
 411         if (do_sig) {
 412                 current->thread.error_code = error_code;
 413                 current->thread.trap_no = 1;
 414                 force_sig(SIGILL, current);
 415                 die_if_no_fixup("illegal operation", regs, error_code);
 416         }
 417         unlock_kernel();
 418 }
 419
 420 #else
 421 DO_ERROR(1, SIGILL, "illegal operation", illegal_op, current)
 422 DO_ERROR(6, SIGILL, "specification exception", specification_exception, current)
 423 DO_ERROR(7, SIGILL, "data exception", data_exception, current)
 424 #endif /* CONFIG_IEEEFPU_EMULATION */
 425
 426
 427 /* init is done in lowcore.S and head.S */
 428
 429 void __init trap_init(void)
 430 {
 431         int i;
 432
 433         for (i = 0; i < 128; i++)
 434           pgm_check_table[i] = &default_trap_handler;
 435         pgm_check_table[1] = &illegal_op;
 436         pgm_check_table[2] = &privileged_op;
 437         pgm_check_table[3] = &execute_exception;
 438         pgm_check_table[5] = &addressing_exception;
 439         pgm_check_table[6] = &specification_exception;
 440         pgm_check_table[7] = &data_exception;
 441         pgm_check_table[9] = &divide_exception;
 442         pgm_check_table[0x12] = &translation_exception;
 443         pgm_check_table[0x13] = &special_op_exception;
 444         pgm_check_table[0x15] = &operand_exception;
 445         pgm_check_table[4] = &do_page_fault;
 446         pgm_check_table[0x10] = &do_page_fault;
 447         pgm_check_table[0x11] = &do_page_fault;
 448         pgm_check_table[0x1C] = &privileged_op;
 449 }
 450
 451
 452 void handle_per_exception(struct pt_regs *regs)
 453 {
 454         if(regs->psw.mask&PSW_PROBLEM_STATE)
 455         {
 456                 per_struct *per_info=&current->thread.per_info;
 457                 per_info->lowcore.words.perc_atmid=S390_lowcore.per_perc_atmid;
 458                 per_info->lowcore.words.address=S390_lowcore.per_address;
 459                 per_info->lowcore.words.access_id=S390_lowcore.per_access_id;
 460         }
 461         if(do_debugger_trap(regs,SIGTRAP))
 462         {
 463                 /* I've seen this possibly a task structure being reused ? */
 464                 printk("Spurious per exception detected\n");
 465                 printk("switching off per tracing for this task.\n");
 466                 show_crashed_task_info();
 467                 /* Hopefully switching off per tracing will help us survive */
 468                 regs->psw.mask &= ~PSW_PER_MASK;
 469         }
 470 }
 471