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 ia64_create_ftnptr (gpointer ptr)
48 gpointer *desc = mono_global_codeman_reserve (2 * sizeof (gpointer));
56 restore_context (MonoContext *ctx)
60 /* Set this to 0 to tell OP_START_HANDLER that it doesn't have to set the frame pointer */
61 res = unw_set_reg (&ctx->cursor, UNW_IA64_GR + 15, 0);
64 unw_resume (&ctx->cursor);
68 * mono_arch_get_restore_context:
70 * Returns a pointer to a method which restores a previously saved sigcontext.
73 mono_arch_get_restore_context (void)
75 return restore_context;
79 get_real_call_filter (void)
82 static gboolean inited = FALSE;
83 Ia64CodegenState code;
84 int i, in0, local0, out0, nout;
86 unw_dyn_region_info_t *r_pro;
91 start = mono_global_codeman_reserve (1024);
93 /* int call_filter (guint64 fp, guint64 ip) */
96 * We have to create a register+stack frame similar to the frame which contains
99 * - setting up a register stack frame
100 * These cannot be set up in this function, because the fp register is a stacked
101 * register which is different in each method. Also, the register stack frame is
102 * different in each method. So we pass the FP value in a a non-stacked
103 * register and the code generated by the OP_START_HANDLER opcode will copy it
104 * to the appropriate register after setting up the register stack frame.
105 * The stacked registers are not need to be set since variables used in
106 * handler registers are never allocated to registers.
114 ia64_codegen_init (code, start);
116 ia64_codegen_set_one_ins_per_bundle (code, TRUE);
118 ia64_alloc (code, local0 + 0, local0 - in0, out0 - local0, nout, 0);
119 ia64_mov_from_br (code, local0 + 1, IA64_B0);
121 r_pro = g_malloc0 (_U_dyn_region_info_size (2));
123 r_pro->insn_count = 6;
125 _U_dyn_op_save_reg (&r_pro->op[i++], _U_QP_TRUE, /* when=*/ 2,
126 /* reg=*/ UNW_IA64_AR_PFS, /* dst=*/ UNW_IA64_GR + local0 + 0);
127 _U_dyn_op_save_reg (&r_pro->op[i++], _U_QP_TRUE, /* when=*/ 5,
128 /* reg=*/ UNW_IA64_RP, /* dst=*/ UNW_IA64_GR + local0 + 1);
129 g_assert ((unsigned) i <= r_pro->op_count);
132 ia64_mov (code, IA64_R15, in0 + 0);
134 ia64_mov_to_br (code, IA64_B6, in0 + 1);
137 ia64_mov_from_ip (code, GP_SCRATCH_REG);
138 ia64_adds_imm (code, GP_SCRATCH_REG, 3 * 16, GP_SCRATCH_REG);
140 /* Call the filter */
141 ia64_br_call_reg (code, IA64_B0, IA64_B6);
143 /* R8 contains the result of the filter */
144 /* R9 contains the saved apr_pfs value */
146 /* The filter returns using br_cond_reg, so have to do another return */
147 ia64_mov_to_ar_i (code, IA64_PFS, IA64_R9);
148 ia64_mov_from_ip (code, GP_SCRATCH_REG);
149 ia64_adds_imm (code, GP_SCRATCH_REG, 4 * 16, GP_SCRATCH_REG);
150 ia64_mov_to_br (code, IA64_B0, GP_SCRATCH_REG);
151 ia64_br_ret_reg (code, IA64_B0);
153 ia64_mov_to_ar_i (code, IA64_PFS, local0 + 0);
154 ia64_mov_ret_to_br (code, IA64_B0, local0 + 1);
155 ia64_br_ret_reg (code, IA64_B0);
157 ia64_codegen_set_one_ins_per_bundle (code, FALSE);
159 ia64_codegen_close (code);
161 g_assert ((code.buf - start) <= 256);
163 mono_arch_flush_icache (start, code.buf - start);
165 di = g_malloc0 (sizeof (unw_dyn_info_t));
166 di->start_ip = (unw_word_t) start;
167 di->end_ip = (unw_word_t) code.buf;
169 di->format = UNW_INFO_FORMAT_DYNAMIC;
170 di->u.pi.name_ptr = (unw_word_t)"throw_trampoline";
171 di->u.pi.regions = r_pro;
173 _U_dyn_register (di);
175 return ia64_create_ftnptr (start);
179 call_filter (MonoContext *ctx, gpointer ip)
181 static int (*filter) (MonoContext *, gpointer) = NULL;
182 gpointer fp = MONO_CONTEXT_GET_BP (ctx);
184 /* FIXME: thread safety */
186 filter = get_real_call_filter ();
188 return filter (fp, ip);
192 * mono_arch_get_call_filter:
194 * Returns a pointer to a method which calls an exception filter. We
195 * also use this function to call finally handlers (we pass NULL as
196 * @exc object in this case).
199 mono_arch_get_call_filter (void)
205 throw_exception (MonoObject *exc, guint64 rethrow)
207 unw_context_t unw_ctx;
213 if (mono_object_isinst (exc, mono_defaults.exception_class)) {
214 MonoException *mono_ex = (MonoException*)exc;
216 mono_ex->stack_trace = NULL;
219 res = unw_getcontext (&unw_ctx);
221 res = unw_init_local (&ctx.cursor, &unw_ctx);
225 * Unwind until the first managed frame. This is needed since
226 * mono_handle_exception expects the variables in the original context to
227 * correspond to the method returned by mono_find_jit_info.
230 res = unw_get_reg (&ctx.cursor, UNW_IA64_IP, &ip);
233 ji = mono_jit_info_table_find (mono_domain_get (), (gpointer)ip);
238 res = unw_step (&ctx.cursor);
242 * This means an unhandled exception during the compilation of a
243 * topmost method like Main
250 mono_handle_exception (&ctx, exc, (gpointer)(ip), FALSE);
251 restore_context (&ctx);
253 g_assert_not_reached ();
257 get_throw_trampoline (gboolean rethrow)
260 Ia64CodegenState code;
261 gpointer ptr = throw_exception;
262 int i, in0, local0, out0;
264 unw_dyn_region_info_t *r_pro;
266 start = mono_global_codeman_reserve (256);
272 ia64_codegen_init (code, start);
273 ia64_alloc (code, local0 + 0, local0 - in0, out0 - local0, 3, 0);
274 ia64_mov_from_br (code, local0 + 1, IA64_B0);
276 /* FIXME: This depends on the current instruction emitter */
278 r_pro = g_malloc0 (_U_dyn_region_info_size (2));
280 r_pro->insn_count = 6;
282 _U_dyn_op_save_reg (&r_pro->op[i++], _U_QP_TRUE, /* when=*/ 2,
283 /* reg=*/ UNW_IA64_AR_PFS, /* dst=*/ UNW_IA64_GR + local0 + 0);
284 _U_dyn_op_save_reg (&r_pro->op[i++], _U_QP_TRUE, /* when=*/ 5,
285 /* reg=*/ UNW_IA64_RP, /* dst=*/ UNW_IA64_GR + local0 + 1);
286 g_assert ((unsigned) i <= r_pro->op_count);
289 ia64_mov (code, out0 + 0, in0 + 0);
290 ia64_adds_imm (code, out0 + 1, rethrow, IA64_R0);
292 /* Call throw_exception */
293 ia64_movl (code, GP_SCRATCH_REG, ptr);
294 ia64_ld8_inc_imm (code, GP_SCRATCH_REG2, GP_SCRATCH_REG, 8);
295 ia64_mov_to_br (code, IA64_B6, GP_SCRATCH_REG2);
296 ia64_ld8 (code, IA64_GP, GP_SCRATCH_REG);
297 ia64_br_call_reg (code, IA64_B0, IA64_B6);
300 ia64_break_i (code, 1000);
301 ia64_codegen_close (code);
303 g_assert ((code.buf - start) <= 256);
305 mono_arch_flush_icache (start, code.buf - start);
307 di = g_malloc0 (sizeof (unw_dyn_info_t));
308 di->start_ip = (unw_word_t) start;
309 di->end_ip = (unw_word_t) code.buf;
311 di->format = UNW_INFO_FORMAT_DYNAMIC;
312 di->u.pi.name_ptr = (unw_word_t)"throw_trampoline";
313 di->u.pi.regions = r_pro;
315 _U_dyn_register (di);
317 return ia64_create_ftnptr (start);
321 * mono_arch_get_throw_exception:
323 * Returns a function pointer which can be used to raise
324 * exceptions. The returned function has the following
325 * signature: void (*func) (MonoException *exc);
329 mono_arch_get_throw_exception (void)
331 static guint8* start;
332 static gboolean inited = FALSE;
337 start = get_throw_trampoline (FALSE);
345 mono_arch_get_rethrow_exception (void)
347 static guint8* start;
348 static gboolean inited = FALSE;
353 start = get_throw_trampoline (TRUE);
361 mono_arch_get_throw_exception_by_name (void)
364 Ia64CodegenState code;
366 start = mono_global_codeman_reserve (64);
368 /* Not used on ia64 */
369 ia64_codegen_init (code, start);
370 ia64_break_i (code, 1001);
371 ia64_codegen_close (code);
373 g_assert ((code.buf - start) <= 256);
375 mono_arch_flush_icache (start, code.buf - start);
381 * mono_arch_get_throw_corlib_exception:
383 * Returns a function pointer which can be used to raise
384 * corlib exceptions. The returned function has the following
385 * signature: void (*func) (guint32 ex_token, guint32 offset);
386 * Here, offset is the offset which needs to be substracted from the caller IP
387 * to get the IP of the throw. Passing the offset has the advantage that it
388 * needs no relocations in the caller.
391 mono_arch_get_throw_corlib_exception (void)
393 static guint8* start;
394 static gboolean inited = FALSE;
396 int i, in0, local0, out0, nout;
397 Ia64CodegenState code;
399 unw_dyn_region_info_t *r_pro;
404 start = mono_global_codeman_reserve (1024);
411 ia64_codegen_init (code, start);
412 ia64_alloc (code, local0 + 0, local0 - in0, out0 - local0, nout, 0);
413 ia64_mov_from_br (code, local0 + 1, IA64_RP);
415 r_pro = g_malloc0 (_U_dyn_region_info_size (2));
417 r_pro->insn_count = 6;
419 _U_dyn_op_save_reg (&r_pro->op[i++], _U_QP_TRUE, /* when=*/ 2,
420 /* reg=*/ UNW_IA64_AR_PFS, /* dst=*/ UNW_IA64_GR + local0 + 0);
421 _U_dyn_op_save_reg (&r_pro->op[i++], _U_QP_TRUE, /* when=*/ 5,
422 /* reg=*/ UNW_IA64_RP, /* dst=*/ UNW_IA64_GR + local0 + 1);
423 g_assert ((unsigned) i <= r_pro->op_count);
425 /* Call exception_from_token */
426 ia64_movl (code, out0 + 0, mono_defaults.exception_class->image);
427 ia64_mov (code, out0 + 1, in0 + 0);
428 ptr = mono_exception_from_token;
429 ia64_movl (code, GP_SCRATCH_REG, ptr);
430 ia64_ld8_inc_imm (code, GP_SCRATCH_REG2, GP_SCRATCH_REG, 8);
431 ia64_mov_to_br (code, IA64_B6, GP_SCRATCH_REG2);
432 ia64_ld8 (code, IA64_GP, GP_SCRATCH_REG);
433 ia64_br_call_reg (code, IA64_B0, IA64_B6);
434 ia64_mov (code, local0 + 3, IA64_R8);
436 /* Compute throw ip */
437 ia64_mov (code, local0 + 2, local0 + 1);
438 ia64_sub (code, local0 + 2, local0 + 2, in0 + 1);
440 /* Trick the unwind library into using throw_ip as the IP in the caller frame */
441 ia64_mov (code, local0 + 1, local0 + 2);
444 ia64_mov (code, out0 + 0, local0 + 3);
445 ia64_mov (code, out0 + 1, IA64_R0);
447 /* Call throw_exception */
448 ptr = throw_exception;
449 ia64_movl (code, GP_SCRATCH_REG, ptr);
450 ia64_ld8_inc_imm (code, GP_SCRATCH_REG2, GP_SCRATCH_REG, 8);
451 ia64_mov_to_br (code, IA64_B6, GP_SCRATCH_REG2);
452 ia64_ld8 (code, IA64_GP, GP_SCRATCH_REG);
453 ia64_br_call_reg (code, IA64_B0, IA64_B6);
455 ia64_break_i (code, 1002);
456 ia64_codegen_close (code);
458 g_assert ((code.buf - start) <= 1024);
460 di = g_malloc0 (sizeof (unw_dyn_info_t));
461 di->start_ip = (unw_word_t) start;
462 di->end_ip = (unw_word_t) code.buf;
464 di->format = UNW_INFO_FORMAT_DYNAMIC;
465 di->u.pi.name_ptr = (unw_word_t)"throw_corlib_exception_trampoline";
466 di->u.pi.regions = r_pro;
468 _U_dyn_register (di);
470 mono_arch_flush_icache (start, code.buf - start);
472 return ia64_create_ftnptr (start);
475 /* mono_arch_find_jit_info:
477 * This function is used to gather information from @ctx. It return the
478 * MonoJitInfo of the corresponding function, unwinds one stack frame and
479 * stores the resulting context into @new_ctx. It also stores a string
480 * describing the stack location into @trace (if not NULL), and modifies
481 * the @lmf if necessary. @native_offset return the IP offset from the
482 * start of the function or -1 if that info is not available.
485 mono_arch_find_jit_info (MonoDomain *domain, MonoJitTlsData *jit_tls, MonoJitInfo *res, MonoJitInfo *prev_ji, MonoContext *ctx,
486 MonoContext *new_ctx, char **trace, MonoLMF **lmf, int *native_offset,
496 err = unw_get_reg (&new_ctx->cursor, UNW_IA64_IP, &ip);
499 /* Avoid costly table lookup during stack overflow */
500 if (prev_ji && ((guint8*)ip > (guint8*)prev_ji->code_start && ((guint8*)ip < ((guint8*)prev_ji->code_start) + prev_ji->code_size)))
503 ji = mono_jit_info_table_find (domain, (gpointer)ip);
513 unw_get_proc_name (&new_ctx->cursor, name, 256, &off);
514 printf ("F: %s\n", name);
520 if (!ji->method->wrapper_type)
526 /* This is an unmanaged frame, so just unwind through it */
527 /* FIXME: This returns -3 for the __clone2 frame in libc */
528 err = unw_step (&new_ctx->cursor);
537 err = unw_step (&new_ctx->cursor);
543 return (gpointer)(gssize)-1;
547 * mono_arch_handle_exception:
549 * @ctx: saved processor state
550 * @obj: the exception object
553 mono_arch_handle_exception (void *sigctx, gpointer obj, gboolean test_only)
555 /* libunwind takes care of this */
556 unw_context_t unw_ctx;
562 res = unw_getcontext (&unw_ctx);
564 res = unw_init_local (&ctx.cursor, &unw_ctx);
568 * Unwind until the first managed frame. This skips the signal handler frames
572 res = unw_get_reg (&ctx.cursor, UNW_IA64_IP, &ip);
575 ji = mono_jit_info_table_find (mono_domain_get (), (gpointer)ip);
580 res = unw_step (&ctx.cursor);
584 mono_handle_exception (&ctx, obj, (gpointer)ip, test_only);
586 restore_context (&ctx);
588 g_assert_not_reached ();
592 mono_arch_ip_from_context (void *sigctx)
594 /* On IA64, these two are equal */
595 unw_context_t *ctx = (unw_context_t*)sigctx;
600 res = unw_init_local (&cursor, ctx);
602 res = unw_get_reg (&cursor, UNW_IA64_IP, &w);