2 * exceptions-ia64.c: exception support for IA64
5 * Zoltan Varga (vargaz@gmail.com)
7 * (C) 2001 Ximian, Inc.
11 * We implement exception handling with the help of the libuwind library:
13 * http://www.hpl.hp.com/research/linux/libunwind/
15 * Under IA64 all functions are assumed to have unwind info, we do not need to save
16 * the machine state in the LMF. But we have to generate unwind info for all
17 * dynamically generated code.
24 #include <sys/ucontext.h>
26 #include <mono/arch/ia64/ia64-codegen.h>
27 #include <mono/metadata/appdomain.h>
28 #include <mono/metadata/tabledefs.h>
29 #include <mono/metadata/threads.h>
30 #include <mono/metadata/debug-helpers.h>
31 #include <mono/metadata/exception.h>
32 #include <mono/metadata/gc-internal.h>
33 #include <mono/metadata/mono-debug.h>
36 #include "mini-ia64.h"
38 #define ALIGN_TO(val,align) (((val) + ((align) - 1)) & ~((align) - 1))
40 #define NOT_IMPLEMENTED g_assert_not_reached ()
42 #define GP_SCRATCH_REG 31
43 #define GP_SCRATCH_REG2 30
46 print_ctx (MonoContext *ctx)
49 unw_word_t off, ip, sp;
53 unw_get_proc_name (&ctx->cursor, name, 256, &off);
54 unw_get_proc_info(&ctx->cursor, &pi);
55 res = unw_get_reg (&ctx->cursor, UNW_IA64_IP, &ip);
57 res = unw_get_reg (&ctx->cursor, UNW_IA64_SP, &sp);
60 printf ("%s:%lx [%lx-%lx] SP: %lx\n", name, ip - pi.start_ip, pi.start_ip, pi.end_ip, sp);
64 ia64_create_ftnptr (gpointer ptr)
66 gpointer *desc = mono_global_codeman_reserve (2 * sizeof (gpointer));
74 restore_context (MonoContext *ctx)
79 res = unw_get_reg (&ctx->cursor, UNW_IA64_IP, &ip);
82 /* Set this to 0 to tell OP_START_HANDLER that it doesn't have to set the frame pointer */
83 res = unw_set_reg (&ctx->cursor, UNW_IA64_GR + 15, 0);
86 unw_resume (&ctx->cursor);
90 * mono_arch_get_restore_context:
92 * Returns a pointer to a method which restores a previously saved sigcontext.
95 mono_arch_get_restore_context (void)
97 return restore_context;
101 get_real_call_filter (void)
103 static gpointer filter;
105 gboolean inited = FALSE;
106 Ia64CodegenState code;
107 int in0, local0, out0, nout;
109 unw_dyn_region_info_t *r_pro, *r_body, *r_epilog;
114 start = mono_global_codeman_reserve (1024);
116 /* int call_filter (guint64 fp, guint64 ip) */
119 * We have to create a register+stack frame similar to the frame which contains
122 * - setting up a register stack frame
123 * These cannot be set up in this function, because the fp register is a stacked
124 * register which is different in each method. Also, the register stack frame is
125 * different in each method. So we pass the FP value in a a non-stacked
126 * register and the code generated by the OP_START_HANDLER opcode will copy it
127 * to the appropriate register after setting up the register stack frame.
128 * The stacked registers are not need to be set since variables used in
129 * handler registers are never allocated to registers.
137 ia64_codegen_init (code, start);
139 ia64_codegen_set_one_ins_per_bundle (code, TRUE);
141 ia64_unw_save_reg (code, UNW_IA64_AR_PFS, UNW_IA64_GR + local0 + 0);
142 ia64_alloc (code, local0 + 0, local0 - in0, out0 - local0, nout, 0);
143 ia64_unw_save_reg (code, UNW_IA64_RP, UNW_IA64_GR + local0 + 1);
144 ia64_mov_from_br (code, local0 + 1, IA64_B0);
146 ia64_begin_bundle (code);
148 r_pro = mono_ia64_create_unwind_region (&code);
151 ia64_mov (code, IA64_R15, in0 + 0);
153 ia64_mov_to_br (code, IA64_B6, in0 + 1);
156 ia64_mov_from_ip (code, GP_SCRATCH_REG);
157 ia64_adds_imm (code, GP_SCRATCH_REG, 3 * 16, GP_SCRATCH_REG);
159 /* Call the filter */
160 ia64_br_call_reg (code, IA64_B0, IA64_B6);
162 /* R8 contains the result of the filter */
163 /* R9 contains the saved apr_pfs value */
165 /* FIXME: Add unwind info for this */
167 /* The filter returns using br_cond_reg, so have to do another return */
168 ia64_mov_to_ar_i (code, IA64_PFS, IA64_R9);
169 ia64_mov_from_ip (code, GP_SCRATCH_REG);
170 ia64_adds_imm (code, GP_SCRATCH_REG, 4 * 16, GP_SCRATCH_REG);
171 ia64_mov_to_br (code, IA64_B0, GP_SCRATCH_REG);
172 ia64_br_ret_reg (code, IA64_B0);
174 ia64_begin_bundle (code);
176 r_body = mono_ia64_create_unwind_region (&code);
177 r_pro->next = r_body;
179 ia64_mov_to_ar_i (code, IA64_PFS, local0 + 0);
180 ia64_mov_ret_to_br (code, IA64_B0, local0 + 1);
181 ia64_br_ret_reg (code, IA64_B0);
183 ia64_begin_bundle (code);
185 r_epilog = mono_ia64_create_unwind_region (&code);
186 r_body->next = r_epilog;
188 ia64_codegen_set_one_ins_per_bundle (code, FALSE);
190 ia64_codegen_close (code);
192 g_assert ((code.buf - start) <= 256);
194 mono_arch_flush_icache (start, code.buf - start);
196 di = g_malloc0 (sizeof (unw_dyn_info_t));
197 di->start_ip = (unw_word_t) start;
198 di->end_ip = (unw_word_t) code.buf;
200 di->format = UNW_INFO_FORMAT_DYNAMIC;
201 di->u.pi.name_ptr = (unw_word_t)"throw_trampoline";
202 di->u.pi.regions = r_body;
204 _U_dyn_register (di);
206 filter = ia64_create_ftnptr (start);
214 call_filter (MonoContext *ctx, gpointer ip)
216 int (*filter) (MonoContext *, gpointer);
217 gpointer fp = MONO_CONTEXT_GET_BP (ctx);
219 filter = get_real_call_filter ();
221 return filter (fp, ip);
225 * mono_arch_get_call_filter:
227 * Returns a pointer to a method which calls an exception filter. We
228 * also use this function to call finally handlers (we pass NULL as
229 * @exc object in this case).
232 mono_arch_get_call_filter (void)
234 /* Initialize the real filter non-lazily */
235 get_real_call_filter ();
241 throw_exception (MonoObject *exc, guint64 rethrow)
243 unw_context_t unw_ctx;
249 if (mono_object_isinst (exc, mono_defaults.exception_class)) {
250 MonoException *mono_ex = (MonoException*)exc;
252 mono_ex->stack_trace = NULL;
255 res = unw_getcontext (&unw_ctx);
257 res = unw_init_local (&ctx.cursor, &unw_ctx);
261 * Unwind until the first managed frame. This is needed since
262 * mono_handle_exception expects the variables in the original context to
263 * correspond to the method returned by mono_find_jit_info.
266 res = unw_get_reg (&ctx.cursor, UNW_IA64_IP, &ip);
269 res = unw_get_reg (&ctx.cursor, UNW_IA64_SP, &sp);
272 ji = mono_jit_info_table_find (mono_domain_get (), (gpointer)ip);
274 //printf ("UN: %s %lx %lx\n", ji ? ji->method->name : "", ip, sp);
279 res = unw_step (&ctx.cursor);
283 * This means an unhandled exception during the compilation of a
284 * topmost method like Main
291 mono_handle_exception (&ctx, exc, (gpointer)(ip), FALSE);
292 restore_context (&ctx);
294 g_assert_not_reached ();
298 get_throw_trampoline (gboolean rethrow)
301 Ia64CodegenState code;
302 gpointer ptr = throw_exception;
303 int i, in0, local0, out0;
305 unw_dyn_region_info_t *r_pro;
307 start = mono_global_codeman_reserve (256);
313 ia64_codegen_init (code, start);
314 ia64_alloc (code, local0 + 0, local0 - in0, out0 - local0, 3, 0);
315 ia64_mov_from_br (code, local0 + 1, IA64_B0);
317 /* FIXME: This depends on the current instruction emitter */
319 r_pro = g_malloc0 (_U_dyn_region_info_size (2));
321 r_pro->insn_count = 6;
323 _U_dyn_op_save_reg (&r_pro->op[i++], _U_QP_TRUE, /* when=*/ 2,
324 /* reg=*/ UNW_IA64_AR_PFS, /* dst=*/ UNW_IA64_GR + local0 + 0);
325 _U_dyn_op_save_reg (&r_pro->op[i++], _U_QP_TRUE, /* when=*/ 5,
326 /* reg=*/ UNW_IA64_RP, /* dst=*/ UNW_IA64_GR + local0 + 1);
327 g_assert ((unsigned) i <= r_pro->op_count);
330 ia64_mov (code, out0 + 0, in0 + 0);
331 ia64_adds_imm (code, out0 + 1, rethrow, IA64_R0);
333 /* Call throw_exception */
334 ia64_movl (code, GP_SCRATCH_REG, ptr);
335 ia64_ld8_inc_imm (code, GP_SCRATCH_REG2, GP_SCRATCH_REG, 8);
336 ia64_mov_to_br (code, IA64_B6, GP_SCRATCH_REG2);
337 ia64_ld8 (code, IA64_GP, GP_SCRATCH_REG);
338 ia64_br_call_reg (code, IA64_B0, IA64_B6);
341 ia64_break_i (code, 1000);
342 ia64_codegen_close (code);
344 g_assert ((code.buf - start) <= 256);
346 mono_arch_flush_icache (start, code.buf - start);
348 di = g_malloc0 (sizeof (unw_dyn_info_t));
349 di->start_ip = (unw_word_t) start;
350 di->end_ip = (unw_word_t) code.buf;
352 di->format = UNW_INFO_FORMAT_DYNAMIC;
353 di->u.pi.name_ptr = (unw_word_t)"throw_trampoline";
354 di->u.pi.regions = r_pro;
356 _U_dyn_register (di);
358 return ia64_create_ftnptr (start);
362 * mono_arch_get_throw_exception:
364 * Returns a function pointer which can be used to raise
365 * exceptions. The returned function has the following
366 * signature: void (*func) (MonoException *exc);
370 mono_arch_get_throw_exception (void)
372 static guint8* start;
373 static gboolean inited = FALSE;
378 start = get_throw_trampoline (FALSE);
386 mono_arch_get_rethrow_exception (void)
388 static guint8* start;
389 static gboolean inited = FALSE;
394 start = get_throw_trampoline (TRUE);
402 mono_arch_get_throw_exception_by_name (void)
405 Ia64CodegenState code;
407 start = mono_global_codeman_reserve (64);
409 /* Not used on ia64 */
410 ia64_codegen_init (code, start);
411 ia64_break_i (code, 1001);
412 ia64_codegen_close (code);
414 g_assert ((code.buf - start) <= 256);
416 mono_arch_flush_icache (start, code.buf - start);
422 * mono_arch_get_throw_corlib_exception:
424 * Returns a function pointer which can be used to raise
425 * corlib exceptions. The returned function has the following
426 * signature: void (*func) (guint32 ex_token, guint32 offset);
427 * Here, offset is the offset which needs to be substracted from the caller IP
428 * to get the IP of the throw. Passing the offset has the advantage that it
429 * needs no relocations in the caller.
432 mono_arch_get_throw_corlib_exception (void)
434 static guint8* start;
435 static gboolean inited = FALSE;
437 int i, in0, local0, out0, nout;
438 Ia64CodegenState code;
440 unw_dyn_region_info_t *r_pro;
445 start = mono_global_codeman_reserve (1024);
452 ia64_codegen_init (code, start);
453 ia64_alloc (code, local0 + 0, local0 - in0, out0 - local0, nout, 0);
454 ia64_mov_from_br (code, local0 + 1, IA64_RP);
456 r_pro = g_malloc0 (_U_dyn_region_info_size (2));
458 r_pro->insn_count = 6;
460 _U_dyn_op_save_reg (&r_pro->op[i++], _U_QP_TRUE, /* when=*/ 2,
461 /* reg=*/ UNW_IA64_AR_PFS, /* dst=*/ UNW_IA64_GR + local0 + 0);
462 _U_dyn_op_save_reg (&r_pro->op[i++], _U_QP_TRUE, /* when=*/ 5,
463 /* reg=*/ UNW_IA64_RP, /* dst=*/ UNW_IA64_GR + local0 + 1);
464 g_assert ((unsigned) i <= r_pro->op_count);
466 /* Call exception_from_token */
467 ia64_movl (code, out0 + 0, mono_defaults.exception_class->image);
468 ia64_mov (code, out0 + 1, in0 + 0);
469 ptr = mono_exception_from_token;
470 ia64_movl (code, GP_SCRATCH_REG, ptr);
471 ia64_ld8_inc_imm (code, GP_SCRATCH_REG2, GP_SCRATCH_REG, 8);
472 ia64_mov_to_br (code, IA64_B6, GP_SCRATCH_REG2);
473 ia64_ld8 (code, IA64_GP, GP_SCRATCH_REG);
474 ia64_br_call_reg (code, IA64_B0, IA64_B6);
475 ia64_mov (code, local0 + 3, IA64_R8);
477 /* Compute throw ip */
478 ia64_mov (code, local0 + 2, local0 + 1);
479 ia64_sub (code, local0 + 2, local0 + 2, in0 + 1);
481 /* Trick the unwind library into using throw_ip as the IP in the caller frame */
482 ia64_mov (code, local0 + 1, local0 + 2);
485 ia64_mov (code, out0 + 0, local0 + 3);
486 ia64_mov (code, out0 + 1, IA64_R0);
488 /* Call throw_exception */
489 ptr = throw_exception;
490 ia64_movl (code, GP_SCRATCH_REG, ptr);
491 ia64_ld8_inc_imm (code, GP_SCRATCH_REG2, GP_SCRATCH_REG, 8);
492 ia64_mov_to_br (code, IA64_B6, GP_SCRATCH_REG2);
493 ia64_ld8 (code, IA64_GP, GP_SCRATCH_REG);
494 ia64_br_call_reg (code, IA64_B0, IA64_B6);
496 ia64_break_i (code, 1002);
497 ia64_codegen_close (code);
499 g_assert ((code.buf - start) <= 1024);
501 di = g_malloc0 (sizeof (unw_dyn_info_t));
502 di->start_ip = (unw_word_t) start;
503 di->end_ip = (unw_word_t) code.buf;
505 di->format = UNW_INFO_FORMAT_DYNAMIC;
506 di->u.pi.name_ptr = (unw_word_t)"throw_corlib_exception_trampoline";
507 di->u.pi.regions = r_pro;
509 _U_dyn_register (di);
511 mono_arch_flush_icache (start, code.buf - start);
513 return ia64_create_ftnptr (start);
516 /* mono_arch_find_jit_info:
518 * This function is used to gather information from @ctx. It return the
519 * MonoJitInfo of the corresponding function, unwinds one stack frame and
520 * stores the resulting context into @new_ctx. It also stores a string
521 * describing the stack location into @trace (if not NULL), and modifies
522 * the @lmf if necessary. @native_offset return the IP offset from the
523 * start of the function or -1 if that info is not available.
526 mono_arch_find_jit_info (MonoDomain *domain, MonoJitTlsData *jit_tls, MonoJitInfo *res, MonoJitInfo *prev_ji, MonoContext *ctx,
527 MonoContext *new_ctx, char **trace, MonoLMF **lmf, int *native_offset,
537 err = unw_get_reg (&new_ctx->cursor, UNW_IA64_IP, &ip);
540 /* Avoid costly table lookup during stack overflow */
541 if (prev_ji && ((guint8*)ip > (guint8*)prev_ji->code_start && ((guint8*)ip < ((guint8*)prev_ji->code_start) + prev_ji->code_size)))
544 ji = mono_jit_info_table_find (domain, (gpointer)ip);
554 unw_get_proc_name (&new_ctx->cursor, name, 256, &off);
555 printf ("F: %s\n", name);
561 if (!ji->method->wrapper_type)
567 /* This is an unmanaged frame, so just unwind through it */
568 /* FIXME: This returns -3 for the __clone2 frame in libc */
569 err = unw_step (&new_ctx->cursor);
578 //print_ctx (new_ctx);
580 err = unw_step (&new_ctx->cursor);
583 //print_ctx (new_ctx);
588 return (gpointer)(gssize)-1;
592 * mono_arch_handle_exception:
594 * @ctx: saved processor state
595 * @obj: the exception object
598 mono_arch_handle_exception (void *sigctx, gpointer obj, gboolean test_only)
600 /* libunwind takes care of this */
601 unw_context_t unw_ctx;
607 res = unw_getcontext (&unw_ctx);
609 res = unw_init_local (&ctx.cursor, &unw_ctx);
613 * Unwind until the first managed frame. This skips the signal handler frames
617 res = unw_get_reg (&ctx.cursor, UNW_IA64_IP, &ip);
620 ji = mono_jit_info_table_find (mono_domain_get (), (gpointer)ip);
625 res = unw_step (&ctx.cursor);
629 mono_handle_exception (&ctx, obj, (gpointer)ip, test_only);
631 restore_context (&ctx);
633 g_assert_not_reached ();
637 mono_arch_ip_from_context (void *sigctx)
639 /* On IA64, these two are equal */
640 unw_context_t *ctx = (unw_context_t*)sigctx;
645 res = unw_init_local (&cursor, ctx);
647 res = unw_get_reg (&cursor, UNW_IA64_IP, &w);