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_mutex_lock (&unwind_mutex)
45 #define unwind_unlock() mono_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_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 };
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)
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_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 };
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 };
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
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];
109 #define DWARF_DATA_ALIGN 0
110 #define DWARF_PC_REG -1
113 #ifndef IS_DOUBLE_REG
114 #define IS_DOUBLE_REG(dwarf_reg) 0
117 static gboolean dwarf_reg_to_hw_reg_inited;
119 static int map_dwarf_reg_to_hw_reg [NUM_REGS];
122 * mono_hw_reg_to_dwarf_reg:
124 * Map the hardware register number REG to the register number used by DWARF.
127 mono_hw_reg_to_dwarf_reg (int reg)
129 #ifdef TARGET_POWERPC
133 g_assert (reg < NUM_REGS);
137 g_assert_not_reached ();
140 return map_hw_reg_to_dwarf_reg [reg];
149 g_assert (NUM_REGS > 0);
150 for (i = 0; i < sizeof (map_hw_reg_to_dwarf_reg) / sizeof (int); ++i) {
151 map_dwarf_reg_to_hw_reg [mono_hw_reg_to_dwarf_reg (i)] = i;
154 #ifdef TARGET_POWERPC
155 map_dwarf_reg_to_hw_reg [DWARF_PC_REG] = ppc_lr;
158 mono_memory_barrier ();
159 dwarf_reg_to_hw_reg_inited = TRUE;
163 mono_dwarf_reg_to_hw_reg (int reg)
165 if (!dwarf_reg_to_hw_reg_inited)
168 return map_dwarf_reg_to_hw_reg [reg];
171 static G_GNUC_UNUSED void
172 encode_uleb128 (guint32 value, guint8 *buf, guint8 **endbuf)
177 guint8 b = value & 0x7f;
179 if (value != 0) /* more bytes to come */
187 static G_GNUC_UNUSED void
188 encode_sleb128 (gint32 value, guint8 *buf, guint8 **endbuf)
191 gboolean negative = (value < 0);
199 /* the following is unnecessary if the
200 * implementation of >>= uses an arithmetic rather
201 * than logical shift for a signed left operand
205 value |= - (1 <<(size - 7));
206 /* sign bit of byte is second high order bit (0x40) */
207 if ((value == 0 && !(byte & 0x40)) ||
208 (value == -1 && (byte & 0x40)))
218 static inline guint32
219 decode_uleb128 (guint8 *buf, guint8 **endbuf)
229 res = res | (((int)(b & 0x7f)) << shift);
241 decode_sleb128 (guint8 *buf, guint8 **endbuf)
251 res = res | (((int)(b & 0x7f)) << shift);
254 if (shift < 32 && (b & 0x40))
255 res |= - (1 << shift);
266 mono_print_unwind_info (guint8 *unwind_info, int unwind_info_len)
269 int pos, reg, offset, cfa_reg, cfa_offset;
273 while (p < unwind_info + unwind_info_len) {
277 case DW_CFA_advance_loc:
284 offset = decode_uleb128 (p, &p) * DWARF_DATA_ALIGN;
285 if (reg == DWARF_PC_REG)
286 printf ("CFA: [%x] offset: %s at cfa-0x%x\n", pos, "pc", -offset);
288 printf ("CFA: [%x] offset: %s at cfa-0x%x\n", pos, mono_arch_regname (mono_dwarf_reg_to_hw_reg (reg)), -offset);
295 cfa_reg = decode_uleb128 (p, &p);
296 cfa_offset = decode_uleb128 (p, &p);
297 printf ("CFA: [%x] def_cfa: %s+0x%x\n", pos, mono_arch_regname (mono_dwarf_reg_to_hw_reg (cfa_reg)), cfa_offset);
299 case DW_CFA_def_cfa_offset:
300 cfa_offset = decode_uleb128 (p, &p);
301 printf ("CFA: [%x] def_cfa_offset: 0x%x\n", pos, cfa_offset);
303 case DW_CFA_def_cfa_register:
304 cfa_reg = decode_uleb128 (p, &p);
305 printf ("CFA: [%x] def_cfa_reg: %s\n", pos, mono_arch_regname (mono_dwarf_reg_to_hw_reg (cfa_reg)));
307 case DW_CFA_offset_extended_sf:
308 reg = decode_uleb128 (p, &p);
309 offset = decode_sleb128 (p, &p) * DWARF_DATA_ALIGN;
310 printf ("CFA: [%x] offset_extended_sf: %s at cfa-0x%x\n", pos, mono_arch_regname (mono_dwarf_reg_to_hw_reg (reg)), -offset);
312 case DW_CFA_same_value:
313 reg = decode_uleb128 (p, &p);
314 printf ("CFA: [%x] same_value: %s\n", pos, mono_arch_regname (mono_dwarf_reg_to_hw_reg (reg)));
316 case DW_CFA_advance_loc4:
320 case DW_CFA_remember_state:
321 printf ("CFA: [%x] remember_state\n", pos);
323 case DW_CFA_restore_state:
324 printf ("CFA: [%x] restore_state\n", pos);
326 case DW_CFA_mono_advance_loc:
327 printf ("CFA: [%x] mono_advance_loc\n", pos);
330 g_assert_not_reached ();
335 g_assert_not_reached ();
341 * mono_unwind_ops_encode:
343 * Encode the unwind ops in UNWIND_OPS into the compact DWARF encoding.
344 * Return a pointer to malloc'ed memory.
347 mono_unwind_ops_encode (GSList *unwind_ops, guint32 *out_len)
359 for (; l; l = l->next) {
364 /* Convert the register from the hw encoding to the dwarf encoding */
365 reg = mono_hw_reg_to_dwarf_reg (op->reg);
367 if (op->op == DW_CFA_mono_advance_loc) {
368 /* This advances loc to its location */
372 /* Emit an advance_loc if neccesary */
373 while (op->when > loc) {
374 if (op->when - loc > 65536) {
375 *p ++ = DW_CFA_advance_loc4;
376 *(guint32*)p = (guint32)(op->when - loc);
377 g_assert (read32 (p) == (guint32)(op->when - loc));
380 } else if (op->when - loc > 256) {
381 *p ++ = DW_CFA_advance_loc2;
382 *(guint16*)p = (guint16)(op->when - loc);
383 g_assert (read16 (p) == (guint32)(op->when - loc));
386 } else if (op->when - loc >= 32) {
387 *p ++ = DW_CFA_advance_loc1;
388 *(guint8*)p = (guint8)(op->when - loc);
391 } else if (op->when - loc < 32) {
392 *p ++ = DW_CFA_advance_loc | (op->when - loc);
395 *p ++ = DW_CFA_advance_loc | (30);
403 encode_uleb128 (reg, p, &p);
404 encode_uleb128 (op->val, p, &p);
406 case DW_CFA_def_cfa_offset:
408 encode_uleb128 (op->val, p, &p);
410 case DW_CFA_def_cfa_register:
412 encode_uleb128 (reg, p, &p);
414 case DW_CFA_same_value:
416 encode_uleb128 (reg, p, &p);
420 *p ++ = DW_CFA_offset_extended_sf;
421 encode_uleb128 (reg, p, &p);
422 encode_sleb128 (op->val / DWARF_DATA_ALIGN, p, &p);
424 *p ++ = DW_CFA_offset | reg;
425 encode_uleb128 (op->val / DWARF_DATA_ALIGN, p, &p);
428 case DW_CFA_remember_state:
429 case DW_CFA_restore_state:
432 case DW_CFA_mono_advance_loc:
433 /* Only one location is supported */
434 g_assert (op->val == 0);
438 g_assert_not_reached ();
443 g_assert (p - buf < 4096);
445 res = g_malloc (p - buf);
446 memcpy (res, buf, p - buf);
451 #define UNW_DEBUG(stmt) do { stmt; } while (0)
453 #define UNW_DEBUG(stmt) do { } while (0)
456 static G_GNUC_UNUSED void
457 print_dwarf_state (int cfa_reg, int cfa_offset, int ip, int nregs, Loc *locations, guint8 *reg_saved)
461 printf ("\t%x: cfa=r%d+%d ", ip, cfa_reg, cfa_offset);
463 for (i = 0; i < nregs; ++i)
464 if (reg_saved [i] && locations [i].loc_type == LOC_OFFSET)
465 printf ("r%d@%d(cfa) ", i, locations [i].offset);
470 Loc locations [NUM_REGS];
471 guint8 reg_saved [NUM_REGS];
472 int cfa_reg, cfa_offset;
476 * Given the state of the current frame as stored in REGS, execute the unwind
477 * operations in unwind_info until the location counter reaches POS. The result is
478 * stored back into REGS. OUT_CFA will receive the value of the CFA.
479 * If SAVE_LOCATIONS is non-NULL, it should point to an array of size SAVE_LOCATIONS_LEN.
480 * On return, the nth entry will point to the address of the stack slot where register
481 * N was saved, or NULL, if it was not saved by this frame.
482 * MARK_LOCATIONS should contain the locations marked by mono_emit_unwind_op_mark_loc (), if any.
483 * This function is signal safe.
486 mono_unwind_frame (guint8 *unwind_info, guint32 unwind_info_len,
487 guint8 *start_ip, guint8 *end_ip, guint8 *ip, guint8 **mark_locations,
488 mono_unwind_reg_t *regs, int nregs,
489 mgreg_t **save_locations, int save_locations_len,
492 Loc locations [NUM_REGS];
493 guint8 reg_saved [NUM_REGS];
494 int i, pos, reg, cfa_reg = -1, cfa_offset = 0, offset;
497 UnwindState state_stack [1];
500 memset (reg_saved, 0, sizeof (reg_saved));
501 state_stack [0].cfa_reg = -1;
502 state_stack [0].cfa_offset = 0;
509 while (pos <= ip - start_ip && p < unwind_info + unwind_info_len) {
513 case DW_CFA_advance_loc:
514 UNW_DEBUG (print_dwarf_state (cfa_reg, cfa_offset, pos, nregs, locations));
521 reg_saved [reg] = TRUE;
522 locations [reg].loc_type = LOC_OFFSET;
523 locations [reg].offset = decode_uleb128 (p, &p) * DWARF_DATA_ALIGN;
530 cfa_reg = decode_uleb128 (p, &p);
531 cfa_offset = decode_uleb128 (p, &p);
533 case DW_CFA_def_cfa_offset:
534 cfa_offset = decode_uleb128 (p, &p);
536 case DW_CFA_def_cfa_register:
537 cfa_reg = decode_uleb128 (p, &p);
539 case DW_CFA_offset_extended_sf:
540 reg = decode_uleb128 (p, &p);
541 offset = decode_sleb128 (p, &p);
542 g_assert (reg < NUM_REGS);
543 reg_saved [reg] = TRUE;
544 locations [reg].loc_type = LOC_OFFSET;
545 locations [reg].offset = offset * DWARF_DATA_ALIGN;
547 case DW_CFA_offset_extended:
548 reg = decode_uleb128 (p, &p);
549 offset = decode_uleb128 (p, &p);
550 g_assert (reg < NUM_REGS);
551 reg_saved [reg] = TRUE;
552 locations [reg].loc_type = LOC_OFFSET;
553 locations [reg].offset = offset * DWARF_DATA_ALIGN;
555 case DW_CFA_same_value:
556 reg = decode_uleb128 (p, &p);
557 locations [reg].loc_type = LOC_SAME;
559 case DW_CFA_advance_loc1:
563 case DW_CFA_advance_loc2:
567 case DW_CFA_advance_loc4:
571 case DW_CFA_remember_state:
572 g_assert (state_stack_pos == 0);
573 memcpy (&state_stack [0].locations, &locations, sizeof (locations));
574 memcpy (&state_stack [0].reg_saved, ®_saved, sizeof (reg_saved));
575 state_stack [0].cfa_reg = cfa_reg;
576 state_stack [0].cfa_offset = cfa_offset;
579 case DW_CFA_restore_state:
580 g_assert (state_stack_pos == 1);
582 memcpy (&locations, &state_stack [0].locations, sizeof (locations));
583 memcpy (®_saved, &state_stack [0].reg_saved, sizeof (reg_saved));
584 cfa_reg = state_stack [0].cfa_reg;
585 cfa_offset = state_stack [0].cfa_offset;
587 case DW_CFA_mono_advance_loc:
588 g_assert (mark_locations [0]);
589 pos = mark_locations [0] - start_ip;
592 g_assert_not_reached ();
597 g_assert_not_reached ();
602 memset (save_locations, 0, save_locations_len * sizeof (mgreg_t*));
604 g_assert (cfa_reg != -1);
605 cfa_val = (guint8*)regs [mono_dwarf_reg_to_hw_reg (cfa_reg)] + cfa_offset;
606 for (i = 0; i < NUM_REGS; ++i) {
607 if (reg_saved [i] && locations [i].loc_type == LOC_OFFSET) {
608 int hreg = mono_dwarf_reg_to_hw_reg (i);
609 g_assert (hreg < nregs);
610 if (IS_DOUBLE_REG (i))
611 regs [hreg] = *(guint64*)(cfa_val + locations [i].offset);
613 regs [hreg] = *(mgreg_t*)(cfa_val + locations [i].offset);
614 if (save_locations && hreg < save_locations_len)
615 save_locations [hreg] = (mgreg_t*)(cfa_val + locations [i].offset);
623 mono_unwind_init (void)
625 mono_mutex_init_recursive (&unwind_mutex);
627 mono_counters_register ("Unwind info size", MONO_COUNTER_JIT | MONO_COUNTER_INT, &unwind_info_size);
631 mono_unwind_cleanup (void)
635 mono_mutex_destroy (&unwind_mutex);
640 for (i = 0; i < cached_info_next; ++i) {
641 MonoUnwindInfo *cached = cached_info [i];
646 g_free (cached_info);
650 * mono_cache_unwind_info
652 * Save UNWIND_INFO in the unwind info cache and return an id which can be passed
653 * to mono_get_cached_unwind_info to get a cached copy of the info.
654 * A copy is made of the unwind info.
655 * This function is useful for two reasons:
656 * - many methods have the same unwind info
657 * - MonoJitInfo->unwind_info is an int so it can't store the pointer to the unwind info
660 mono_cache_unwind_info (guint8 *unwind_info, guint32 unwind_info_len)
663 MonoUnwindInfo *info;
667 if (cached_info == NULL) {
668 cached_info_size = 16;
669 cached_info = g_new0 (MonoUnwindInfo*, cached_info_size);
672 for (i = 0; i < cached_info_next; ++i) {
673 MonoUnwindInfo *cached = cached_info [i];
675 if (cached->len == unwind_info_len && memcmp (cached->info, unwind_info, unwind_info_len) == 0) {
681 info = g_malloc (sizeof (MonoUnwindInfo) + unwind_info_len);
682 info->len = unwind_info_len;
683 memcpy (&info->info, unwind_info, unwind_info_len);
685 i = cached_info_next;
687 if (cached_info_next >= cached_info_size) {
688 MonoUnwindInfo **new_table;
691 * Avoid freeing the old table so mono_get_cached_unwind_info ()
692 * doesn't need locks/hazard pointers.
695 new_table = g_new0 (MonoUnwindInfo*, cached_info_size * 2);
697 memcpy (new_table, cached_info, cached_info_size * sizeof (MonoUnwindInfo*));
699 mono_memory_barrier ();
701 cached_info = new_table;
703 cached_info_list = g_slist_prepend (cached_info_list, cached_info);
705 cached_info_size *= 2;
708 cached_info [cached_info_next ++] = info;
710 unwind_info_size += sizeof (MonoUnwindInfo) + unwind_info_len;
717 * This function is signal safe.
720 mono_get_cached_unwind_info (guint32 index, guint32 *unwind_info_len)
722 MonoUnwindInfo **table;
723 MonoUnwindInfo *info;
727 * This doesn't need any locks/hazard pointers,
728 * since new tables are copies of the old ones.
732 info = table [index];
734 *unwind_info_len = info->len;
741 * mono_unwind_get_dwarf_data_align:
743 * Return the data alignment used by the encoded unwind information.
746 mono_unwind_get_dwarf_data_align (void)
748 return DWARF_DATA_ALIGN;
752 * mono_unwind_get_dwarf_pc_reg:
754 * Return the dwarf register number of the register holding the ip of the
758 mono_unwind_get_dwarf_pc_reg (void)
764 decode_cie_op (guint8 *p, guint8 **endp)
769 case DW_CFA_advance_loc:
774 decode_uleb128 (p, &p);
781 decode_uleb128 (p, &p);
782 decode_uleb128 (p, &p);
784 case DW_CFA_def_cfa_offset:
785 decode_uleb128 (p, &p);
787 case DW_CFA_def_cfa_register:
788 decode_uleb128 (p, &p);
790 case DW_CFA_advance_loc4:
793 case DW_CFA_offset_extended_sf:
794 decode_uleb128 (p, &p);
795 decode_uleb128 (p, &p);
798 g_assert_not_reached ();
803 g_assert_not_reached ();
810 read_encoded_val (guint32 encoding, guint8 *p, guint8 **endp)
814 switch (encoding & 0xf) {
815 case DW_EH_PE_sdata8:
819 case DW_EH_PE_sdata4:
824 g_assert_not_reached ();
834 * Decode the Mono specific Language Specific Data Area generated by LLVM.
837 decode_lsda (guint8 *lsda, guint8 *code, MonoJitExceptionInfo **ex_info, guint32 *ex_info_len, gpointer **type_info, int *this_reg, int *this_offset)
840 int i, ncall_sites, this_encoding;
841 guint32 mono_magic, version;
845 /* This is the modified LSDA generated by the LLVM mono branch */
846 mono_magic = decode_uleb128 (p, &p);
847 g_assert (mono_magic == 0x4d4fef4f);
848 version = decode_uleb128 (p, &p);
849 g_assert (version == 1);
852 if (this_encoding == DW_EH_PE_udata4) {
853 gint32 op, reg, offset;
855 /* 'this' location */
857 g_assert (op == DW_OP_bregx);
859 reg = decode_uleb128 (p, &p);
860 offset = decode_sleb128 (p, &p);
862 *this_reg = mono_dwarf_reg_to_hw_reg (reg);
863 *this_offset = offset;
865 g_assert (this_encoding == DW_EH_PE_omit);
870 ncall_sites = decode_uleb128 (p, &p);
871 p = (guint8*)ALIGN_TO ((mgreg_t)p, 4);
874 *ex_info = g_malloc0 (ncall_sites * sizeof (MonoJitExceptionInfo));
875 *ex_info_len = ncall_sites;
878 *type_info = g_malloc0 (ncall_sites * sizeof (gpointer));
880 for (i = 0; i < ncall_sites; ++i) {
881 int block_start_offset, block_size, landing_pad;
884 block_start_offset = read32 (p);
885 p += sizeof (gint32);
886 block_size = read32 (p);
887 p += sizeof (gint32);
888 landing_pad = read32 (p);
889 p += sizeof (gint32);
891 p += sizeof (gint32);
893 g_assert (landing_pad);
894 g_assert (((size_t)tinfo % 4) == 0);
895 //printf ("X: %p %d\n", landing_pad, *(int*)tinfo);
899 (*type_info) [i] = tinfo;
900 (*ex_info)[i].try_start = code + block_start_offset;
901 (*ex_info)[i].try_end = code + block_start_offset + block_size;
902 (*ex_info)[i].handler_start = code + landing_pad;
908 * mono_unwind_decode_fde:
910 * Decode a DWARF FDE entry, returning the unwind opcodes.
911 * If not NULL, EX_INFO is set to a malloc-ed array of MonoJitExceptionInfo structures,
912 * only try_start, try_end and handler_start is set.
913 * If not NULL, TYPE_INFO is set to a malloc-ed array containing the ttype table from the
917 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)
919 guint8 *p, *cie, *fde_current, *fde_aug = NULL, *code, *fde_cfi, *cie_cfi;
920 gint32 fde_len, cie_offset, pc_begin, pc_range, aug_len;
921 gint32 cie_len, cie_id, cie_version, code_align, data_align, return_reg;
922 gint32 i, cie_aug_len, buf_len;
925 gboolean has_fde_augmentation = FALSE;
928 * http://refspecs.freestandards.org/LSB_3.0.0/LSB-Core-generic/LSB-Core-generic/ehframechpt.html
931 /* This is generated by JITDwarfEmitter::EmitEHFrame () */
940 // FIXME: Endianess ?
941 fde_len = *(guint32*)p;
942 g_assert (fde_len != 0xffffffff && fde_len != 0);
944 cie_offset = *(guint32*)p;
945 cie = p - cie_offset;
951 cie_len = *(guint32*)p;
953 cie_id = *(guint32*)p;
954 g_assert (cie_id == 0);
957 g_assert (cie_version == 1);
959 cie_aug_str = (char*)p;
960 p += strlen (cie_aug_str) + 1;
961 code_align = decode_uleb128 (p, &p);
962 data_align = decode_sleb128 (p, &p);
963 return_reg = decode_uleb128 (p, &p);
964 if (strstr (cie_aug_str, "z")) {
968 cie_aug_len = decode_uleb128 (p, &p);
970 has_fde_augmentation = TRUE;
973 for (i = 0; cie_aug_str [i] != '\0'; ++i) {
974 switch (cie_aug_str [i]) {
980 read_encoded_val (p_encoding, p, &p);
983 g_assert ((*p == (DW_EH_PE_sdata4|DW_EH_PE_pcrel)) || (*p == (DW_EH_PE_sdata8|DW_EH_PE_pcrel)));
987 g_assert (*p == (DW_EH_PE_sdata4|DW_EH_PE_pcrel));
991 g_assert_not_reached ();
1001 /* Continue decoding FDE */
1003 /* DW_EH_PE_sdata4|DW_EH_PE_pcrel encoding */
1004 pc_begin = *(gint32*)p;
1005 code = p + pc_begin;
1007 pc_range = *(guint32*)p;
1009 if (has_fde_augmentation) {
1010 aug_len = decode_uleb128 (p, &p);
1019 *code_len = pc_range;
1026 /* Decode FDE augmention */
1031 /* sdata|pcrel encoding */
1033 lsda_offset = read32 (fde_aug);
1034 else if (aug_len == 8)
1035 lsda_offset = *(gint64*)fde_aug;
1037 g_assert_not_reached ();
1038 if (lsda_offset != 0) {
1039 lsda = fde_aug + lsda_offset;
1041 decode_lsda (lsda, code, ex_info, ex_info_len, type_info, this_reg, this_offset);
1045 /* Make sure the FDE uses the same constants as we do */
1046 g_assert (code_align == 1);
1047 g_assert (data_align == DWARF_DATA_ALIGN);
1048 g_assert (return_reg == DWARF_PC_REG);
1050 buf_len = (cie + cie_len + 4 - cie_cfi) + (fde + fde_len + 4 - fde_cfi);
1051 buf = g_malloc0 (buf_len);
1055 while (p < cie + cie_len + 4) {
1056 if (*p == DW_CFA_nop)
1059 decode_cie_op (p, &p);
1061 memcpy (buf + i, cie_cfi, p - cie_cfi);
1065 while (p < fde + fde_len + 4) {
1066 if (*p == DW_CFA_nop)
1069 decode_cie_op (p, &p);
1071 memcpy (buf + i, fde_cfi, p - fde_cfi);
1073 g_assert (i <= buf_len);
1077 return g_realloc (buf, i);
1081 * mono_unwind_decode_mono_fde:
1083 * Decode an FDE entry in the LLVM emitted mono EH frame.
1084 * info->ex_info is set to a malloc-ed array of MonoJitExceptionInfo structures,
1085 * only try_start, try_end and handler_start is set.
1086 * info->type_info is set to a malloc-ed array containing the ttype table from the
1090 mono_unwind_decode_llvm_mono_fde (guint8 *fde, int fde_len, guint8 *cie, guint8 *code, MonoLLVMFDEInfo *res)
1092 guint8 *p, *fde_aug, *cie_cfi, *fde_cfi, *buf;
1093 int has_aug, aug_len, cie_cfi_len, fde_cfi_len;
1094 gint32 code_align, data_align, return_reg, pers_encoding;
1096 memset (res, 0, sizeof (*res));
1098 res->this_offset = -1;
1100 /* fde points to data emitted by LLVM in DwarfMonoException::EmitMonoEHFrame () */
1105 aug_len = read32 (p);
1117 /* The LSDA is embedded directly into the FDE */
1120 decode_lsda (lsda, code, &res->ex_info, &res->ex_info_len, &res->type_info, &res->this_reg, &res->this_offset);
1125 code_align = decode_uleb128 (p, &p);
1126 data_align = decode_sleb128 (p, &p);
1127 return_reg = decode_uleb128 (p, &p);
1130 if (pers_encoding != DW_EH_PE_omit)
1131 read_encoded_val (pers_encoding, p, &p);
1135 /* Make sure the FDE uses the same constants as we do */
1136 g_assert (code_align == 1);
1137 g_assert (data_align == DWARF_DATA_ALIGN);
1138 g_assert (return_reg == DWARF_PC_REG);
1140 /* Compute size of CIE unwind info it is DW_CFA_nop terminated */
1143 if (*p == DW_CFA_nop)
1146 decode_cie_op (p, &p);
1148 cie_cfi_len = p - cie_cfi;
1149 fde_cfi_len = (fde + fde_len - fde_cfi);
1151 buf = g_malloc0 (cie_cfi_len + fde_cfi_len);
1152 memcpy (buf, cie_cfi, cie_cfi_len);
1153 memcpy (buf + cie_cfi_len, fde_cfi, fde_cfi_len);
1155 res->unw_info_len = cie_cfi_len + fde_cfi_len;
1156 res->unw_info = buf;
1160 * mono_unwind_get_cie_program:
1162 * Get the unwind bytecode for the DWARF CIE.
1165 mono_unwind_get_cie_program (void)
1167 #if defined(TARGET_AMD64) || defined(TARGET_X86) || defined(TARGET_POWERPC)
1168 return mono_arch_get_cie_program ();