mono/mini/exceptions-sparc.c

   1 /*
   2  * exceptions-sparc.c: exception support for sparc
   3  *
   4  * Authors:
   5  *   Mark Crichton (crichton@gimp.org)
   6  *   Dietmar Maurer (dietmar@ximian.com)
   7  *
   8  * (C) 2003 Ximian, Inc.
   9  */
  10
  11 #include <config.h>
  12 #include <glib.h>
  13 #include <signal.h>
  14 #include <string.h>
  15 #include <sys/ucontext.h>
  16
  17 #include <mono/arch/sparc/sparc-codegen.h>
  18 #include <mono/metadata/appdomain.h>
  19 #include <mono/metadata/tabledefs.h>
  20 #include <mono/metadata/threads.h>
  21 #include <mono/metadata/debug-helpers.h>
  22 #include <mono/metadata/exception.h>
  23 #include <mono/metadata/mono-debug.h>
  24 #include <mono/metadata/gc-internal.h>
  25 #include <mono/metadata/tokentype.h>
  26
  27 #include "mini.h"
  28 #include "mini-sparc.h"
  29
  30 #ifndef REG_SP
  31 #define REG_SP REG_O6
  32 #endif
  33
  34 #define MONO_SPARC_WINDOW_ADDR(sp) ((gpointer*)(((guint8*)(sp)) + MONO_SPARC_STACK_BIAS))
  35
  36 /*
  37  * mono_arch_get_restore_context:
  38  *
  39  * Returns a pointer to a method which restores a previously saved sigcontext.
  40  */
  41 gpointer
  42 mono_arch_get_restore_context (void)
  43 {
  44         static guint32 *start;
  45         static int inited = 0;
  46         guint32 *code;
  47
  48         if (inited)
  49                 return start;
  50
  51         code = start = mono_global_codeman_reserve (32 * sizeof (guint32));
  52
  53         sparc_ldi_imm (code, sparc_o0, G_STRUCT_OFFSET (MonoContext, ip), sparc_i7);
  54         sparc_ldi_imm (code, sparc_o0, G_STRUCT_OFFSET (MonoContext, sp), sparc_i6);
  55
  56         sparc_jmpl_imm (code, sparc_i7, 0, sparc_g0);
  57         /* FIXME: This does not return to the correct window */
  58         sparc_restore_imm (code, sparc_g0, 0, sparc_g0);
  59
  60         g_assert ((code - start) < 32);
  61
  62         mono_arch_flush_icache ((guint8*)start, (guint8*)code - (guint8*)start);
  63
  64         inited = 1;
  65
  66         return start;
  67 }
  68
  69 /*
  70  * mono_arch_get_call_filter:
  71  *
  72  * Returns a pointer to a method which calls an exception filter. We
  73  * also use this function to call finally handlers (we pass NULL as
  74  * @exc object in this case).
  75  *
  76  * call_filter (MonoContext *ctx, gpointer ip)
  77  */
  78 gpointer
  79 mono_arch_get_call_filter (void)
  80 {
  81         static guint32 *start;
  82         static int inited = 0;
  83         guint32 *code;
  84         int i;
  85
  86         if (inited)
  87                 return start;
  88
  89         code = start = mono_global_codeman_reserve (64 * sizeof (guint32));
  90
  91         /*
  92          * There are two frames here:
  93          * - the first frame is used by call_filter
  94          * - the second frame is used to run the filter code
  95          */
  96
  97         /* Create first frame */
  98         sparc_save_imm (code, sparc_sp, -256, sparc_sp);
  99
 100         sparc_mov_reg_reg (code, sparc_i1, sparc_o0);
 101         sparc_ldi_imm (code, sparc_i0, G_STRUCT_OFFSET (MonoContext, sp), sparc_o1);
 102
 103         /* Create second frame */
 104         sparc_save_imm (code, sparc_sp, -256, sparc_sp);
 105
 106         sparc_mov_reg_reg (code, sparc_i0, sparc_o0);
 107         sparc_mov_reg_reg (code, sparc_i1, sparc_o1);
 108
 109         /*
 110          * We need to change %fp to point to the stack frame of the method
 111          * containing the filter. But changing %fp also changes the %sp of
 112          * the parent frame (the first frame), so if the OS saves the first frame,
 113          * it saves it to the stack frame of the method, which is not good.
 114          * So flush all register windows to memory before changing %fp.
 115          */
 116         sparc_flushw (code);
 117
 118         sparc_mov_reg_reg (code, sparc_fp, sparc_o7);
 119
 120         /*
 121          * Modify the second frame so it is identical to the one used in the
 122          * method containing the filter.
 123          */
 124         for (i = 0; i < 16; ++i)
 125                 sparc_ldi_imm (code, sparc_o1, MONO_SPARC_STACK_BIAS + i * sizeof (gpointer), sparc_l0 + i);
 126
 127         /* Save %fp to a location reserved in mono_arch_allocate_vars */
 128         sparc_sti_imm (code, sparc_o7, sparc_fp, MONO_SPARC_STACK_BIAS - sizeof (gpointer));
 129
 130         /* Call the filter code, after this returns, %o0 will hold the result */
 131         sparc_call_imm (code, sparc_o0, 0);
 132         sparc_nop (code);
 133
 134         /* Restore original %fp */
 135         sparc_ldi_imm (code, sparc_fp, MONO_SPARC_STACK_BIAS - sizeof (gpointer), sparc_fp);
 136
 137         sparc_mov_reg_reg (code, sparc_o0, sparc_i0);
 138
 139         /* Return to first frame */
 140         sparc_restore (code, sparc_g0, sparc_g0, sparc_g0);
 141
 142         /* FIXME: Save locals to the stack */
 143
 144         /* Return to caller */
 145         sparc_ret (code);
 146         /* Return result in delay slot */
 147         sparc_restore (code, sparc_o0, sparc_g0, sparc_o0);
 148
 149         g_assert ((code - start) < 64);
 150
 151         mono_arch_flush_icache ((guint8*)start, (guint8*)code - (guint8*)start);
 152
 153         inited = 1;
 154
 155         return start;
 156 }
 157
 158 static void
 159 throw_exception (MonoObject *exc, gpointer sp, gpointer ip, gboolean rethrow)
 160 {
 161         MonoContext ctx;
 162         static void (*restore_context) (MonoContext *);
 163         gpointer *window;
 164
 165         if (!restore_context)
 166                 restore_context = mono_arch_get_restore_context ();
 167
 168         window = MONO_SPARC_WINDOW_ADDR (sp);
 169         ctx.sp = (gpointer*)sp;
 170         ctx.ip = ip;
 171         ctx.fp = (gpointer*)(MONO_SPARC_WINDOW_ADDR (sp) [sparc_i6 - 16]);
 172
 173         if (mono_object_isinst (exc, mono_defaults.exception_class)) {
 174                 MonoException *mono_ex = (MonoException*)exc;
 175                 if (!rethrow)
 176                         mono_ex->stack_trace = NULL;
 177         }
 178         mono_handle_exception (&ctx, exc, ip, FALSE);
 179         restore_context (&ctx);
 180
 181         g_assert_not_reached ();
 182 }
 183
 184 static gpointer
 185 get_throw_exception (gboolean rethrow)
 186 {
 187         guint32 *start, *code;
 188
 189         code = start = mono_global_codeman_reserve (16 * sizeof (guint32));
 190
 191         sparc_save_imm (code, sparc_sp, -512, sparc_sp);
 192
 193         sparc_flushw (code);
 194         sparc_mov_reg_reg (code, sparc_i0, sparc_o0);
 195         sparc_mov_reg_reg (code, sparc_fp, sparc_o1);
 196         sparc_mov_reg_reg (code, sparc_i7, sparc_o2);
 197         sparc_set (code, rethrow, sparc_o3);
 198         sparc_set (code, throw_exception, sparc_o7);
 199         sparc_jmpl (code, sparc_o7, sparc_g0, sparc_callsite);
 200         sparc_nop (code);
 201
 202         g_assert ((code - start) <= 16);
 203
 204         mono_arch_flush_icache ((guint8*)start, (guint8*)code - (guint8*)start);
 205
 206         return start;
 207 }
 208
 209 /**
 210  * mono_arch_get_throw_exception:
 211  *
 212  * Returns a function pointer which can be used to raise exceptions.
 213  * The returned function has the following
 214  * signature: void (*func) (MonoException *exc);
 215  */
 216 gpointer
 217 mono_arch_get_throw_exception (void)
 218 {
 219         static guint32* start;
 220         static int inited = 0;
 221
 222         if (inited)
 223                 return start;
 224
 225         inited = 1;
 226
 227         start = get_throw_exception (FALSE);
 228
 229         return start;
 230 }
 231
 232 gpointer
 233 mono_arch_get_rethrow_exception (void)
 234 {
 235         static guint32* start;
 236         static int inited = 0;
 237
 238         if (inited)
 239                 return start;
 240
 241         inited = 1;
 242
 243         start = get_throw_exception (TRUE);
 244
 245         return start;
 246 }
 247
 248 /**
 249  * mono_arch_get_throw_corlib_exception:
 250  *
 251  * Returns a function pointer which can be used to raise
 252  * corlib exceptions. The returned function has the following
 253  * signature: void (*func) (guint32 ex_token, guint32 offset);
 254  * Here, offset is the offset which needs to be substracted from the caller IP
 255  * to get the IP of the throw. Passing the offset has the advantage that it
 256  * needs no relocations in the caller.
 257  */
 258 gpointer
 259 mono_arch_get_throw_corlib_exception (void)
 260 {
 261         static guint32 *start;
 262         static int inited = 0;
 263         guint32 *code;
 264         int reg;
 265
 266         if (inited)
 267                 return start;
 268
 269         inited = 1;
 270         code = start = mono_global_codeman_reserve (64 * sizeof (guint32));
 271
 272 #ifdef SPARCV9
 273         reg = sparc_g4;
 274 #else
 275         reg = sparc_g1;
 276 #endif
 277
 278         sparc_mov_reg_reg (code, sparc_o7, sparc_o2);
 279         sparc_save_imm (code, sparc_sp, -160, sparc_sp);
 280
 281         sparc_set (code, MONO_TOKEN_TYPE_DEF, sparc_o7);
 282         sparc_add (code, FALSE, sparc_i0, sparc_o7, sparc_o1);
 283         sparc_set (code, mono_defaults.exception_class->image, sparc_o0);
 284         sparc_set (code, mono_exception_from_token, sparc_o7);
 285         sparc_jmpl (code, sparc_o7, sparc_g0, sparc_callsite);
 286         sparc_nop (code);
 287
 288         /* Return to the caller, so exception handling does not see this frame */
 289         sparc_restore (code, sparc_o0, sparc_g0, sparc_o0);
 290
 291         /* Compute throw ip */
 292         sparc_sll_imm (code, sparc_o1, 2, sparc_o1);
 293         sparc_sub (code, 0, sparc_o2, sparc_o1, sparc_o7);
 294
 295         sparc_set (code, mono_arch_get_throw_exception (), reg);
 296         /* Use a jmp instead of a call so o7 is preserved */
 297         sparc_jmpl_imm (code, reg, 0, sparc_g0);
 298         sparc_nop (code);
 299
 300         g_assert ((code - start) < 32);
 301
 302         mono_arch_flush_icache ((guint8*)start, (guint8*)code - (guint8*)start);
 303
 304         return start;
 305 }
 306
 307 /* mono_arch_find_jit_info:
 308  *
 309  * This function is used to gather information from @ctx. It return the
 310  * MonoJitInfo of the corresponding function, unwinds one stack frame and
 311  * stores the resulting context into @new_ctx. It also stores a string
 312  * describing the stack location into @trace (if not NULL), and modifies
 313  * the @lmf if necessary. @native_offset return the IP offset from the
 314  * start of the function or -1 if that info is not available.
 315  */
 316 MonoJitInfo *
 317 mono_arch_find_jit_info (MonoDomain *domain, MonoJitTlsData *jit_tls, MonoJitInfo *res, MonoJitInfo *prev_ji, MonoContext *ctx,
 318                          MonoContext *new_ctx, MonoLMF **lmf, gboolean *managed)
 319 {
 320         MonoJitInfo *ji;
 321         gpointer ip = MONO_CONTEXT_GET_IP (ctx);
 322         gpointer *window;
 323
 324         /* Avoid costly table lookup during stack overflow */
 325         if (prev_ji && (ip > prev_ji->code_start && ((guint8*)ip < ((guint8*)prev_ji->code_start) + prev_ji->code_size)))
 326                 ji = prev_ji;
 327         else
 328                 ji = mini_jit_info_table_find (domain, ip, NULL);
 329
 330         if (managed)
 331                 *managed = FALSE;
 332
 333         if (ji != NULL) {
 334                 *new_ctx = *ctx;
 335
 336                 if (managed)
 337                         if (!ji->method->wrapper_type)
 338                                 *managed = TRUE;
 339
 340                 if (*lmf && (MONO_CONTEXT_GET_BP (ctx) >= (gpointer)(*lmf)->ebp)) {
 341                         /* remove any unused lmf */
 342                         *lmf = (*lmf)->previous_lmf;
 343                 }
 344
 345                 /* Restore ip and sp from the saved register window */
 346                 window = MONO_SPARC_WINDOW_ADDR (ctx->sp);
 347                 new_ctx->ip = window [sparc_i7 - 16];
 348                 new_ctx->sp = (gpointer*)(window [sparc_i6 - 16]);
 349                 new_ctx->fp = (gpointer*)(MONO_SPARC_WINDOW_ADDR (new_ctx->sp) [sparc_i6 - 16]);
 350
 351                 return ji;
 352         }
 353         else {
 354                 if (!(*lmf))
 355                         return NULL;
 356
 357                 *new_ctx = *ctx;
 358
 359                 if (!(*lmf)->method)
 360                         return (gpointer)-1;
 361
 362                 if ((ji = mini_jit_info_table_find (domain, (gpointer)(*lmf)->ip, NULL))) {
 363                 } else {
 364                         memset (res, 0, MONO_SIZEOF_JIT_INFO);
 365                         res->method = (*lmf)->method;
 366                 }
 367
 368                 new_ctx->ip = (*lmf)->ip;
 369                 new_ctx->sp = (*lmf)->sp;
 370                 new_ctx->fp = (*lmf)->ebp;
 371
 372                 *lmf = (*lmf)->previous_lmf;
 373
 374                 return ji ? ji : res;
 375         }
 376 }
 377
 378 gboolean
 379 mono_arch_has_unwind_info (gconstpointer addr)
 380 {
 381         return FALSE;
 382 }
 383
 384 #ifdef __linux__
 385
 386 gboolean
 387 mono_arch_handle_exception (void *sigctx, gpointer obj, gboolean test_only)
 388 {
 389        MonoContext mctx;
 390        struct sigcontext *sc = sigctx;
 391        gpointer *window;
 392
 393 #ifdef SPARCV9
 394        mctx.ip = (gpointer) sc->sigc_regs.tpc;
 395        mctx.sp = (gpointer) sc->sigc_regs.u_regs[14];
 396 #else
 397        mctx.ip = (gpointer) sc->si_regs.pc;
 398        mctx.sp = (gpointer) sc->si_regs.u_regs[14];
 399 #endif
 400
 401        window = (gpointer*)(((guint8*)mctx.sp) + MONO_SPARC_STACK_BIAS);
 402        mctx.fp = window [sparc_fp - 16];
 403
 404        mono_handle_exception (&mctx, obj, mctx.ip, test_only);
 405
 406 #ifdef SPARCV9
 407        sc->sigc_regs.tpc = (unsigned long) mctx.ip;
 408        sc->sigc_regs.tnpc = (unsigned long) (mctx.ip + 4);
 409        sc->sigc_regs.u_regs[14] = (unsigned long) mctx.sp;
 410 #else
 411        sc->si_regs.pc = (unsigned long) mctx.ip;
 412        sc->si_regs.npc = (unsigned long) (mctx.ip + 4);
 413        sc->si_regs.u_regs[14] = (unsigned long) mctx.sp;
 414 #endif
 415
 416        window = (gpointer*)(((guint8*)mctx.sp) + MONO_SPARC_STACK_BIAS);
 417        window [sparc_fp - 16] = mctx.fp;
 418
 419        return TRUE;
 420 }
 421
 422 gpointer
 423 mono_arch_ip_from_context (void *sigctx)
 424 {
 425        struct sigcontext *sc = sigctx;
 426        gpointer *ret;
 427
 428 #ifdef SPARCV9
 429        ret = (gpointer) sc->sigc_regs.tpc;
 430 #else
 431        ret = (gpointer) sc->si_regs.pc;
 432 #endif
 433
 434        return ret;
 435 }
 436
 437 #else /* !__linux__ */
 438
 439 gboolean
 440 mono_arch_handle_exception (void *sigctx, gpointer obj, gboolean test_only)
 441 {
 442         MonoContext mctx;
 443         ucontext_t *ctx = (ucontext_t*)sigctx;
 444         gpointer *window;
 445
 446         /*
 447          * Access to the machine state using the ucontext_t parameter is somewhat
 448          * under documented under solaris. The code below seems to work under
 449          * Solaris 9.
 450          */
 451         g_assert (!ctx->uc_mcontext.gwins);
 452
 453         mctx.ip = ctx->uc_mcontext.gregs [REG_PC];
 454         mctx.sp = ctx->uc_mcontext.gregs [REG_SP];
 455         window = (gpointer*)(((guint8*)mctx.sp) + MONO_SPARC_STACK_BIAS);
 456         mctx.fp = window [sparc_fp - 16];
 457
 458         mono_handle_exception (&mctx, obj, mctx.ip, test_only);
 459
 460         /* We can't use restore_context to return from a signal handler */
 461         ctx->uc_mcontext.gregs [REG_PC] = mctx.ip;
 462         ctx->uc_mcontext.gregs [REG_nPC] = mctx.ip + 4;
 463         ctx->uc_mcontext.gregs [REG_SP] = mctx.sp;
 464         window = (gpointer*)(((guint8*)mctx.sp) + MONO_SPARC_STACK_BIAS);
 465         window [sparc_fp - 16] = mctx.fp;
 466
 467         return TRUE;
 468 }
 469
 470 gpointer
 471 mono_arch_ip_from_context (void *sigctx)
 472 {
 473         ucontext_t *ctx = (ucontext_t*)sigctx;
 474         return (gpointer)ctx->uc_mcontext.gregs [REG_PC];
 475 }
 476
 477 #endif