2 * unwind.c: Stack Unwinding Interface
5 * Zoltan Varga (vargaz@gmail.com)
7 * (C) 2008 Novell, Inc.
11 #include "mini-unwind.h"
13 #include <mono/utils/mono-counters.h>
14 #include <mono/utils/freebsd-dwarf.h>
15 #include <mono/utils/hazard-pointer.h>
16 #include <mono/metadata/threads-types.h>
17 #include <mono/metadata/mono-endian.h>
31 guint8 info [MONO_ZERO_LEN_ARRAY];
34 #define ALIGN_TO(val,align) ((((size_t)val) + ((align) - 1)) & ~((align) - 1))
36 static mono_mutex_t unwind_mutex;
38 static MonoUnwindInfo **cached_info;
39 static int cached_info_next, cached_info_size;
40 static GSList *cached_info_list;
42 static int unwind_info_size;
44 #define unwind_lock() mono_os_mutex_lock (&unwind_mutex)
45 #define unwind_unlock() mono_os_mutex_unlock (&unwind_mutex)
48 static int map_hw_reg_to_dwarf_reg [] = { 0, 2, 1, 3, 7, 6, 4, 5, 8, 9, 10, 11, 12, 13, 14, 15, 16 };
49 #define NUM_DWARF_REGS AMD64_NREG
50 #define DWARF_DATA_ALIGN (-8)
51 #define DWARF_PC_REG (mono_hw_reg_to_dwarf_reg (AMD64_RIP))
52 #elif defined(TARGET_ARM)
53 // http://infocenter.arm.com/help/topic/com.arm.doc.ihi0040a/IHI0040A_aadwarf.pdf
54 /* Assign d8..d15 to hregs 16..24 (dwarf regs 264..271) */
55 static int map_hw_reg_to_dwarf_reg [] = { 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 264, 265, 266, 267, 268, 269, 270, 271 };
56 #define NUM_DWARF_REGS 272
57 #define DWARF_DATA_ALIGN (-4)
58 #define DWARF_PC_REG (mono_hw_reg_to_dwarf_reg (ARMREG_LR))
59 #define IS_DOUBLE_REG(dwarf_reg) (((dwarf_reg) >= 264) && ((dwarf_reg) <= 271))
60 #elif defined(TARGET_ARM64)
61 #define NUM_DWARF_REGS 96
62 #define DWARF_DATA_ALIGN (-8)
64 #define DWARF_PC_REG 30
65 static int map_hw_reg_to_dwarf_reg [] = {
66 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15,
67 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31,
69 72, 73, 74, 75, 76, 77, 78, 79,
71 #elif defined (TARGET_X86)
73 * ebp and esp are swapped:
74 * http://lists.cs.uiuc.edu/pipermail/lldb-dev/2014-January/003101.html
76 static int map_hw_reg_to_dwarf_reg [] = { 0, 1, 2, 3, 5, 4, 6, 7, 8 };
78 #define NUM_DWARF_REGS (X86_NREG + 1)
79 #define DWARF_DATA_ALIGN (-4)
80 #define DWARF_PC_REG (mono_hw_reg_to_dwarf_reg (X86_NREG))
81 #elif defined (TARGET_POWERPC)
82 // http://refspecs.linuxfoundation.org/ELF/ppc64/PPC-elf64abi-1.9.html
83 static int map_hw_reg_to_dwarf_reg [] = { 0, 1, 2, 3, 4, 5, 6, 7, 8,
84 9, 10, 11, 12, 13, 14, 15, 16,
85 17, 18, 19, 20, 21, 22, 23, 24,
86 25, 26, 27, 28, 29, 30, 31 };
87 #define NUM_DWARF_REGS 110
88 #define DWARF_DATA_ALIGN (-(gint32)sizeof (mgreg_t))
89 #define DWARF_PC_REG 108
90 #elif defined (TARGET_S390X)
91 static int map_hw_reg_to_dwarf_reg [] = { 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15 };
92 #define NUM_DWARF_REGS 16
93 #define DWARF_DATA_ALIGN (-8)
94 #define DWARF_PC_REG (mono_hw_reg_to_dwarf_reg (14))
95 #elif defined (TARGET_MIPS)
97 static int map_hw_reg_to_dwarf_reg [32] = {
98 0, 1, 2, 3, 4, 5, 6, 7,
99 8, 9, 10, 11, 12, 13, 14, 15,
100 16, 17, 18, 19, 20, 21, 22, 23,
101 24, 25, 26, 27, 28, 29, 30, 31
103 #define NUM_DWARF_REGS 32
104 #define DWARF_DATA_ALIGN (-(gint32)sizeof (mgreg_t))
105 #define DWARF_PC_REG (mono_hw_reg_to_dwarf_reg (mips_ra))
107 static int map_hw_reg_to_dwarf_reg [16];
108 #define NUM_DWARF_REGS 16
109 #define DWARF_DATA_ALIGN 0
110 #define DWARF_PC_REG -1
113 #define NUM_HW_REGS (sizeof (map_hw_reg_to_dwarf_reg) / sizeof (int))
115 #ifndef IS_DOUBLE_REG
116 #define IS_DOUBLE_REG(dwarf_reg) (dwarf_reg ? 0 : 0)
119 static gboolean dwarf_reg_to_hw_reg_inited;
121 static int map_dwarf_reg_to_hw_reg [NUM_DWARF_REGS];
124 * mono_hw_reg_to_dwarf_reg:
126 * Map the hardware register number REG to the register number used by DWARF.
129 mono_hw_reg_to_dwarf_reg (int reg)
131 #ifdef TARGET_POWERPC
135 g_assert (reg < NUM_HW_REGS);
138 if (NUM_HW_REGS == 0) {
139 g_assert_not_reached ();
142 return map_hw_reg_to_dwarf_reg [reg];
151 g_assert (NUM_HW_REGS > 0);
152 for (i = 0; i < NUM_HW_REGS; ++i) {
153 map_dwarf_reg_to_hw_reg [mono_hw_reg_to_dwarf_reg (i)] = i;
156 #ifdef TARGET_POWERPC
157 map_dwarf_reg_to_hw_reg [DWARF_PC_REG] = ppc_lr;
160 mono_memory_barrier ();
161 dwarf_reg_to_hw_reg_inited = TRUE;
165 mono_dwarf_reg_to_hw_reg (int reg)
167 if (!dwarf_reg_to_hw_reg_inited)
170 return map_dwarf_reg_to_hw_reg [reg];
173 static G_GNUC_UNUSED void
174 encode_uleb128 (guint32 value, guint8 *buf, guint8 **endbuf)
179 guint8 b = value & 0x7f;
181 if (value != 0) /* more bytes to come */
189 static G_GNUC_UNUSED void
190 encode_sleb128 (gint32 value, guint8 *buf, guint8 **endbuf)
193 gboolean negative = (value < 0);
201 /* the following is unnecessary if the
202 * implementation of >>= uses an arithmetic rather
203 * than logical shift for a signed left operand
207 value |= - (1 <<(size - 7));
208 /* sign bit of byte is second high order bit (0x40) */
209 if ((value == 0 && !(byte & 0x40)) ||
210 (value == -1 && (byte & 0x40)))
220 static inline guint32
221 decode_uleb128 (guint8 *buf, guint8 **endbuf)
231 res = res | (((int)(b & 0x7f)) << shift);
243 decode_sleb128 (guint8 *buf, guint8 **endbuf)
253 res = res | (((int)(b & 0x7f)) << shift);
256 if (shift < 32 && (b & 0x40))
257 res |= - (1 << shift);
268 mono_print_unwind_info (guint8 *unwind_info, int unwind_info_len)
271 int pos, reg, offset, cfa_reg, cfa_offset;
275 while (p < unwind_info + unwind_info_len) {
279 case DW_CFA_advance_loc:
286 offset = decode_uleb128 (p, &p) * DWARF_DATA_ALIGN;
287 if (reg == DWARF_PC_REG)
288 printf ("CFA: [%x] offset: %s at cfa-0x%x\n", pos, "pc", -offset);
290 printf ("CFA: [%x] offset: %s at cfa-0x%x\n", pos, mono_arch_regname (mono_dwarf_reg_to_hw_reg (reg)), -offset);
297 cfa_reg = decode_uleb128 (p, &p);
298 cfa_offset = decode_uleb128 (p, &p);
299 printf ("CFA: [%x] def_cfa: %s+0x%x\n", pos, mono_arch_regname (mono_dwarf_reg_to_hw_reg (cfa_reg)), cfa_offset);
301 case DW_CFA_def_cfa_offset:
302 cfa_offset = decode_uleb128 (p, &p);
303 printf ("CFA: [%x] def_cfa_offset: 0x%x\n", pos, cfa_offset);
305 case DW_CFA_def_cfa_register:
306 cfa_reg = decode_uleb128 (p, &p);
307 printf ("CFA: [%x] def_cfa_reg: %s\n", pos, mono_arch_regname (mono_dwarf_reg_to_hw_reg (cfa_reg)));
309 case DW_CFA_offset_extended_sf:
310 reg = decode_uleb128 (p, &p);
311 offset = decode_sleb128 (p, &p) * DWARF_DATA_ALIGN;
312 printf ("CFA: [%x] offset_extended_sf: %s at cfa-0x%x\n", pos, mono_arch_regname (mono_dwarf_reg_to_hw_reg (reg)), -offset);
314 case DW_CFA_same_value:
315 reg = decode_uleb128 (p, &p);
316 printf ("CFA: [%x] same_value: %s\n", pos, mono_arch_regname (mono_dwarf_reg_to_hw_reg (reg)));
318 case DW_CFA_advance_loc4:
322 case DW_CFA_remember_state:
323 printf ("CFA: [%x] remember_state\n", pos);
325 case DW_CFA_restore_state:
326 printf ("CFA: [%x] restore_state\n", pos);
328 case DW_CFA_mono_advance_loc:
329 printf ("CFA: [%x] mono_advance_loc\n", pos);
332 g_assert_not_reached ();
337 g_assert_not_reached ();
343 * mono_unwind_ops_encode_full:
345 * Encode the unwind ops in UNWIND_OPS into the compact DWARF encoding.
346 * Return a pointer to malloc'ed memory.
347 * If ENABLE_EXTENSIONS is FALSE, avoid encoding the mono extension
348 * opcode (DW_CFA_mono_advance_loc).
351 mono_unwind_ops_encode_full (GSList *unwind_ops, guint32 *out_len, gboolean enable_extensions)
363 for (; l; l = l->next) {
366 op = (MonoUnwindOp *)l->data;
368 /* Convert the register from the hw encoding to the dwarf encoding */
369 reg = mono_hw_reg_to_dwarf_reg (op->reg);
371 if (op->op == DW_CFA_mono_advance_loc) {
372 /* This advances loc to its location */
376 /* Emit an advance_loc if neccesary */
377 while (op->when > loc) {
378 if (op->when - loc > 65536) {
379 *p ++ = DW_CFA_advance_loc4;
380 guint32 v = (guint32)(op->when - loc);
382 g_assert (read32 (p) == (guint32)(op->when - loc));
385 } else if (op->when - loc > 256) {
386 *p ++ = DW_CFA_advance_loc2;
387 guint16 v = (guint16)(op->when - loc);
389 g_assert (read16 (p) == (guint32)(op->when - loc));
392 } else if (op->when - loc >= 32) {
393 *p ++ = DW_CFA_advance_loc1;
394 *(guint8*)p = (guint8)(op->when - loc);
397 } else if (op->when - loc < 32) {
398 *p ++ = DW_CFA_advance_loc | (op->when - loc);
401 *p ++ = DW_CFA_advance_loc | (30);
409 encode_uleb128 (reg, p, &p);
410 encode_uleb128 (op->val, p, &p);
412 case DW_CFA_def_cfa_offset:
414 encode_uleb128 (op->val, p, &p);
416 case DW_CFA_def_cfa_register:
418 encode_uleb128 (reg, p, &p);
420 case DW_CFA_same_value:
422 encode_uleb128 (reg, p, &p);
426 *p ++ = DW_CFA_offset_extended_sf;
427 encode_uleb128 (reg, p, &p);
428 encode_sleb128 (op->val / DWARF_DATA_ALIGN, p, &p);
430 *p ++ = DW_CFA_offset | reg;
431 encode_uleb128 (op->val / DWARF_DATA_ALIGN, p, &p);
434 case DW_CFA_remember_state:
435 case DW_CFA_restore_state:
438 case DW_CFA_mono_advance_loc:
439 if (!enable_extensions)
441 /* Only one location is supported */
442 g_assert (op->val == 0);
446 g_assert_not_reached ();
451 g_assert (p - buf < 4096);
453 res = (guint8 *)g_malloc (p - buf);
454 memcpy (res, buf, p - buf);
459 mono_unwind_ops_encode (GSList *unwind_ops, guint32 *out_len)
461 return mono_unwind_ops_encode_full (unwind_ops, out_len, TRUE);
465 #define UNW_DEBUG(stmt) do { stmt; } while (0)
467 #define UNW_DEBUG(stmt) do { } while (0)
470 static G_GNUC_UNUSED void
471 print_dwarf_state (int cfa_reg, int cfa_offset, int ip, int nregs, Loc *locations, guint8 *reg_saved)
475 printf ("\t%x: cfa=r%d+%d ", ip, cfa_reg, cfa_offset);
477 for (i = 0; i < nregs; ++i)
478 if (reg_saved [i] && locations [i].loc_type == LOC_OFFSET)
479 printf ("r%d@%d(cfa) ", i, locations [i].offset);
484 Loc locations [NUM_HW_REGS];
485 guint8 reg_saved [NUM_HW_REGS];
486 int cfa_reg, cfa_offset;
490 * Given the state of the current frame as stored in REGS, execute the unwind
491 * operations in unwind_info until the location counter reaches POS. The result is
492 * stored back into REGS. OUT_CFA will receive the value of the CFA.
493 * If SAVE_LOCATIONS is non-NULL, it should point to an array of size SAVE_LOCATIONS_LEN.
494 * On return, the nth entry will point to the address of the stack slot where register
495 * N was saved, or NULL, if it was not saved by this frame.
496 * MARK_LOCATIONS should contain the locations marked by mono_emit_unwind_op_mark_loc (), if any.
497 * This function is signal safe.
500 mono_unwind_frame (guint8 *unwind_info, guint32 unwind_info_len,
501 guint8 *start_ip, guint8 *end_ip, guint8 *ip, guint8 **mark_locations,
502 mono_unwind_reg_t *regs, int nregs,
503 mgreg_t **save_locations, int save_locations_len,
506 Loc locations [NUM_HW_REGS];
507 guint8 reg_saved [NUM_HW_REGS];
508 int pos, reg, hwreg, cfa_reg = -1, cfa_offset = 0, offset;
511 UnwindState state_stack [1];
514 memset (reg_saved, 0, sizeof (reg_saved));
515 state_stack [0].cfa_reg = -1;
516 state_stack [0].cfa_offset = 0;
523 while (pos <= ip - start_ip && p < unwind_info + unwind_info_len) {
527 case DW_CFA_advance_loc:
528 UNW_DEBUG (print_dwarf_state (cfa_reg, cfa_offset, pos, nregs, locations));
533 hwreg = mono_dwarf_reg_to_hw_reg (*p & 0x3f);
535 reg_saved [hwreg] = TRUE;
536 locations [hwreg].loc_type = LOC_OFFSET;
537 locations [hwreg].offset = decode_uleb128 (p, &p) * DWARF_DATA_ALIGN;
544 cfa_reg = decode_uleb128 (p, &p);
545 cfa_offset = decode_uleb128 (p, &p);
547 case DW_CFA_def_cfa_offset:
548 cfa_offset = decode_uleb128 (p, &p);
550 case DW_CFA_def_cfa_register:
551 cfa_reg = decode_uleb128 (p, &p);
553 case DW_CFA_offset_extended_sf:
554 reg = decode_uleb128 (p, &p);
555 hwreg = mono_dwarf_reg_to_hw_reg (reg);
556 offset = decode_sleb128 (p, &p);
557 g_assert (reg < NUM_DWARF_REGS);
558 reg_saved [hwreg] = TRUE;
559 locations [hwreg].loc_type = LOC_OFFSET;
560 locations [hwreg].offset = offset * DWARF_DATA_ALIGN;
562 case DW_CFA_offset_extended:
563 reg = decode_uleb128 (p, &p);
564 hwreg = mono_dwarf_reg_to_hw_reg (reg);
565 offset = decode_uleb128 (p, &p);
566 g_assert (reg < NUM_DWARF_REGS);
567 reg_saved [hwreg] = TRUE;
568 locations [hwreg].loc_type = LOC_OFFSET;
569 locations [hwreg].offset = offset * DWARF_DATA_ALIGN;
571 case DW_CFA_same_value:
572 hwreg = mono_dwarf_reg_to_hw_reg (decode_uleb128 (p, &p));
573 locations [hwreg].loc_type = LOC_SAME;
575 case DW_CFA_advance_loc1:
579 case DW_CFA_advance_loc2:
583 case DW_CFA_advance_loc4:
587 case DW_CFA_remember_state:
588 g_assert (state_stack_pos == 0);
589 memcpy (&state_stack [0].locations, &locations, sizeof (locations));
590 memcpy (&state_stack [0].reg_saved, ®_saved, sizeof (reg_saved));
591 state_stack [0].cfa_reg = cfa_reg;
592 state_stack [0].cfa_offset = cfa_offset;
595 case DW_CFA_restore_state:
596 g_assert (state_stack_pos == 1);
598 memcpy (&locations, &state_stack [0].locations, sizeof (locations));
599 memcpy (®_saved, &state_stack [0].reg_saved, sizeof (reg_saved));
600 cfa_reg = state_stack [0].cfa_reg;
601 cfa_offset = state_stack [0].cfa_offset;
603 case DW_CFA_mono_advance_loc:
604 g_assert (mark_locations [0]);
605 pos = mark_locations [0] - start_ip;
608 g_assert_not_reached ();
613 g_assert_not_reached ();
618 memset (save_locations, 0, save_locations_len * sizeof (mgreg_t*));
620 g_assert (cfa_reg != -1);
621 cfa_val = (guint8*)regs [mono_dwarf_reg_to_hw_reg (cfa_reg)] + cfa_offset;
622 for (hwreg = 0; hwreg < NUM_HW_REGS; ++hwreg) {
623 if (reg_saved [hwreg] && locations [hwreg].loc_type == LOC_OFFSET) {
624 int dwarfreg = mono_hw_reg_to_dwarf_reg (hwreg);
625 g_assert (hwreg < nregs);
626 if (IS_DOUBLE_REG (dwarfreg))
627 regs [hwreg] = *(guint64*)(cfa_val + locations [hwreg].offset);
629 regs [hwreg] = *(mgreg_t*)(cfa_val + locations [hwreg].offset);
630 if (save_locations && hwreg < save_locations_len)
631 save_locations [hwreg] = (mgreg_t*)(cfa_val + locations [hwreg].offset);
639 mono_unwind_init (void)
641 mono_os_mutex_init_recursive (&unwind_mutex);
643 mono_counters_register ("Unwind info size", MONO_COUNTER_JIT | MONO_COUNTER_INT, &unwind_info_size);
647 mono_unwind_cleanup (void)
651 mono_os_mutex_destroy (&unwind_mutex);
656 for (i = 0; i < cached_info_next; ++i) {
657 MonoUnwindInfo *cached = cached_info [i];
661 g_free (cached_info);
663 for (GSList *cursor = cached_info_list; cursor != NULL; cursor = cursor->next)
664 g_free (cursor->data);
666 g_slist_free (cached_info_list);
670 * mono_cache_unwind_info
672 * Save UNWIND_INFO in the unwind info cache and return an id which can be passed
673 * to mono_get_cached_unwind_info to get a cached copy of the info.
674 * A copy is made of the unwind info.
675 * This function is useful for two reasons:
676 * - many methods have the same unwind info
677 * - MonoJitInfo->unwind_info is an int so it can't store the pointer to the unwind info
680 mono_cache_unwind_info (guint8 *unwind_info, guint32 unwind_info_len)
683 MonoUnwindInfo *info;
687 if (cached_info == NULL) {
688 cached_info_size = 16;
689 cached_info = g_new0 (MonoUnwindInfo*, cached_info_size);
692 for (i = 0; i < cached_info_next; ++i) {
693 MonoUnwindInfo *cached = cached_info [i];
695 if (cached->len == unwind_info_len && memcmp (cached->info, unwind_info, unwind_info_len) == 0) {
701 info = (MonoUnwindInfo *)g_malloc (sizeof (MonoUnwindInfo) + unwind_info_len);
702 info->len = unwind_info_len;
703 memcpy (&info->info, unwind_info, unwind_info_len);
705 i = cached_info_next;
707 if (cached_info_next >= cached_info_size) {
708 MonoUnwindInfo **new_table;
711 * Avoid freeing the old table so mono_get_cached_unwind_info ()
712 * doesn't need locks/hazard pointers.
715 new_table = g_new0 (MonoUnwindInfo*, cached_info_size * 2);
717 memcpy (new_table, cached_info, cached_info_size * sizeof (MonoUnwindInfo*));
719 mono_memory_barrier ();
721 cached_info_list = g_slist_prepend (cached_info_list, cached_info);
723 cached_info = new_table;
725 cached_info_size *= 2;
728 cached_info [cached_info_next ++] = info;
730 unwind_info_size += sizeof (MonoUnwindInfo) + unwind_info_len;
737 * This function is signal safe.
740 mono_get_cached_unwind_info (guint32 index, guint32 *unwind_info_len)
742 MonoUnwindInfo **table;
743 MonoUnwindInfo *info;
747 * This doesn't need any locks/hazard pointers,
748 * since new tables are copies of the old ones.
752 info = table [index];
754 *unwind_info_len = info->len;
761 * mono_unwind_get_dwarf_data_align:
763 * Return the data alignment used by the encoded unwind information.
766 mono_unwind_get_dwarf_data_align (void)
768 return DWARF_DATA_ALIGN;
772 * mono_unwind_get_dwarf_pc_reg:
774 * Return the dwarf register number of the register holding the ip of the
778 mono_unwind_get_dwarf_pc_reg (void)
784 decode_cie_op (guint8 *p, guint8 **endp)
789 case DW_CFA_advance_loc:
794 decode_uleb128 (p, &p);
801 decode_uleb128 (p, &p);
802 decode_uleb128 (p, &p);
804 case DW_CFA_def_cfa_offset:
805 decode_uleb128 (p, &p);
807 case DW_CFA_def_cfa_register:
808 decode_uleb128 (p, &p);
810 case DW_CFA_advance_loc4:
813 case DW_CFA_offset_extended_sf:
814 decode_uleb128 (p, &p);
815 decode_uleb128 (p, &p);
818 g_assert_not_reached ();
823 g_assert_not_reached ();
830 read_encoded_val (guint32 encoding, guint8 *p, guint8 **endp)
834 switch (encoding & 0xf) {
835 case DW_EH_PE_sdata8:
839 case DW_EH_PE_sdata4:
844 g_assert_not_reached ();
854 * Decode the Mono specific Language Specific Data Area generated by LLVM.
857 decode_lsda (guint8 *lsda, guint8 *code, MonoJitExceptionInfo **ex_info, guint32 *ex_info_len, gpointer **type_info, int *this_reg, int *this_offset)
860 int i, ncall_sites, this_encoding;
861 guint32 mono_magic, version;
865 /* This is the modified LSDA generated by the LLVM mono branch */
866 mono_magic = decode_uleb128 (p, &p);
867 g_assert (mono_magic == 0x4d4fef4f);
868 version = decode_uleb128 (p, &p);
869 g_assert (version == 1);
872 if (this_encoding == DW_EH_PE_udata4) {
873 gint32 op, reg, offset;
875 /* 'this' location */
877 g_assert (op == DW_OP_bregx);
879 reg = decode_uleb128 (p, &p);
880 offset = decode_sleb128 (p, &p);
882 *this_reg = mono_dwarf_reg_to_hw_reg (reg);
883 *this_offset = offset;
885 g_assert (this_encoding == DW_EH_PE_omit);
890 ncall_sites = decode_uleb128 (p, &p);
891 p = (guint8*)ALIGN_TO ((mgreg_t)p, 4);
894 *ex_info = (MonoJitExceptionInfo *)g_malloc0 (ncall_sites * sizeof (MonoJitExceptionInfo));
895 *ex_info_len = ncall_sites;
898 *type_info = (gpointer *)g_malloc0 (ncall_sites * sizeof (gpointer));
900 for (i = 0; i < ncall_sites; ++i) {
901 int block_start_offset, block_size, landing_pad;
904 block_start_offset = read32 (p);
905 p += sizeof (gint32);
906 block_size = read32 (p);
907 p += sizeof (gint32);
908 landing_pad = read32 (p);
909 p += sizeof (gint32);
911 p += sizeof (gint32);
913 g_assert (landing_pad);
914 g_assert (((size_t)tinfo % 4) == 0);
915 //printf ("X: %p %d\n", landing_pad, *(int*)tinfo);
919 (*type_info) [i] = tinfo;
920 (*ex_info)[i].try_start = code + block_start_offset;
921 (*ex_info)[i].try_end = code + block_start_offset + block_size;
922 (*ex_info)[i].handler_start = code + landing_pad;
928 * mono_unwind_decode_fde:
930 * Decode a DWARF FDE entry, returning the unwind opcodes.
931 * If not NULL, EX_INFO is set to a malloc-ed array of MonoJitExceptionInfo structures,
932 * only try_start, try_end and handler_start is set.
933 * If not NULL, TYPE_INFO is set to a malloc-ed array containing the ttype table from the
937 mono_unwind_decode_fde (guint8 *fde, guint32 *out_len, guint32 *code_len, MonoJitExceptionInfo **ex_info, guint32 *ex_info_len, gpointer **type_info, int *this_reg, int *this_offset)
939 guint8 *p, *cie, *fde_current, *fde_aug = NULL, *code, *fde_cfi, *cie_cfi;
940 gint32 fde_len, cie_offset, pc_begin, pc_range, aug_len;
941 gint32 cie_len, cie_id, cie_version, code_align, data_align, return_reg;
942 gint32 i, cie_aug_len, buf_len;
945 gboolean has_fde_augmentation = FALSE;
948 * http://refspecs.freestandards.org/LSB_3.0.0/LSB-Core-generic/LSB-Core-generic/ehframechpt.html
951 /* This is generated by JITDwarfEmitter::EmitEHFrame () */
960 // FIXME: Endianess ?
961 fde_len = *(guint32*)p;
962 g_assert (fde_len != 0xffffffff && fde_len != 0);
964 cie_offset = *(guint32*)p;
965 cie = p - cie_offset;
971 cie_len = *(guint32*)p;
973 cie_id = *(guint32*)p;
974 g_assert (cie_id == 0);
977 g_assert (cie_version == 1);
979 cie_aug_str = (char*)p;
980 p += strlen (cie_aug_str) + 1;
981 code_align = decode_uleb128 (p, &p);
982 data_align = decode_sleb128 (p, &p);
983 return_reg = decode_uleb128 (p, &p);
984 if (strstr (cie_aug_str, "z")) {
988 cie_aug_len = decode_uleb128 (p, &p);
990 has_fde_augmentation = TRUE;
993 for (i = 0; cie_aug_str [i] != '\0'; ++i) {
994 switch (cie_aug_str [i]) {
1000 read_encoded_val (p_encoding, p, &p);
1003 g_assert ((*p == (DW_EH_PE_sdata4|DW_EH_PE_pcrel)) || (*p == (DW_EH_PE_sdata8|DW_EH_PE_pcrel)));
1007 g_assert (*p == (DW_EH_PE_sdata4|DW_EH_PE_pcrel));
1011 g_assert_not_reached ();
1021 /* Continue decoding FDE */
1023 /* DW_EH_PE_sdata4|DW_EH_PE_pcrel encoding */
1024 pc_begin = *(gint32*)p;
1025 code = p + pc_begin;
1027 pc_range = *(guint32*)p;
1029 if (has_fde_augmentation) {
1030 aug_len = decode_uleb128 (p, &p);
1039 *code_len = pc_range;
1046 /* Decode FDE augmention */
1051 /* sdata|pcrel encoding */
1053 lsda_offset = read32 (fde_aug);
1054 else if (aug_len == 8)
1055 lsda_offset = *(gint64*)fde_aug;
1057 g_assert_not_reached ();
1058 if (lsda_offset != 0) {
1059 lsda = fde_aug + lsda_offset;
1061 decode_lsda (lsda, code, ex_info, ex_info_len, type_info, this_reg, this_offset);
1065 /* Make sure the FDE uses the same constants as we do */
1066 g_assert (code_align == 1);
1067 g_assert (data_align == DWARF_DATA_ALIGN);
1068 g_assert (return_reg == DWARF_PC_REG);
1070 buf_len = (cie + cie_len + 4 - cie_cfi) + (fde + fde_len + 4 - fde_cfi);
1071 buf = (guint8 *)g_malloc0 (buf_len);
1075 while (p < cie + cie_len + 4) {
1076 if (*p == DW_CFA_nop)
1079 decode_cie_op (p, &p);
1081 memcpy (buf + i, cie_cfi, p - cie_cfi);
1085 while (p < fde + fde_len + 4) {
1086 if (*p == DW_CFA_nop)
1089 decode_cie_op (p, &p);
1091 memcpy (buf + i, fde_cfi, p - fde_cfi);
1093 g_assert (i <= buf_len);
1097 return (guint8 *)g_realloc (buf, i);
1101 * mono_unwind_decode_mono_fde:
1103 * Decode an FDE entry in the LLVM emitted mono EH frame.
1104 * info->ex_info is set to a malloc-ed array of MonoJitExceptionInfo structures,
1105 * only try_start, try_end and handler_start is set.
1106 * info->type_info is set to a malloc-ed array containing the ttype table from the
1110 mono_unwind_decode_llvm_mono_fde (guint8 *fde, int fde_len, guint8 *cie, guint8 *code, MonoLLVMFDEInfo *res)
1112 guint8 *p, *fde_aug, *cie_cfi, *fde_cfi, *buf;
1113 int has_aug, aug_len, cie_cfi_len, fde_cfi_len;
1114 gint32 code_align, data_align, return_reg, pers_encoding;
1116 memset (res, 0, sizeof (*res));
1118 res->this_offset = -1;
1120 /* fde points to data emitted by LLVM in DwarfMonoException::EmitMonoEHFrame () */
1125 aug_len = read32 (p);
1137 /* The LSDA is embedded directly into the FDE */
1140 decode_lsda (lsda, code, &res->ex_info, &res->ex_info_len, &res->type_info, &res->this_reg, &res->this_offset);
1145 code_align = decode_uleb128 (p, &p);
1146 data_align = decode_sleb128 (p, &p);
1147 return_reg = decode_uleb128 (p, &p);
1150 if (pers_encoding != DW_EH_PE_omit)
1151 read_encoded_val (pers_encoding, p, &p);
1155 /* Make sure the FDE uses the same constants as we do */
1156 g_assert (code_align == 1);
1157 g_assert (data_align == DWARF_DATA_ALIGN);
1158 g_assert (return_reg == DWARF_PC_REG);
1160 /* Compute size of CIE unwind info it is DW_CFA_nop terminated */
1163 if (*p == DW_CFA_nop)
1166 decode_cie_op (p, &p);
1168 cie_cfi_len = p - cie_cfi;
1169 fde_cfi_len = (fde + fde_len - fde_cfi);
1171 buf = (guint8 *)g_malloc0 (cie_cfi_len + fde_cfi_len);
1172 memcpy (buf, cie_cfi, cie_cfi_len);
1173 memcpy (buf + cie_cfi_len, fde_cfi, fde_cfi_len);
1175 res->unw_info_len = cie_cfi_len + fde_cfi_len;
1176 res->unw_info = buf;
1180 * mono_unwind_get_cie_program:
1182 * Get the unwind bytecode for the DWARF CIE.
1185 mono_unwind_get_cie_program (void)
1187 #if defined(TARGET_AMD64) || defined(TARGET_X86) || defined(TARGET_POWERPC) || defined(TARGET_ARM)
1188 return mono_arch_get_cie_program ();