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/metadata/threads-types.h>
16 #include <mono/metadata/mono-endian.h>
30 guint8 info [MONO_ZERO_LEN_ARRAY];
33 static CRITICAL_SECTION unwind_mutex;
35 static MonoUnwindInfo **cached_info;
36 static int cached_info_next, cached_info_size;
38 static int unwind_info_size;
40 #define unwind_lock() EnterCriticalSection (&unwind_mutex)
41 #define unwind_unlock() LeaveCriticalSection (&unwind_mutex)
44 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 };
45 #define NUM_REGS AMD64_NREG
46 #define DWARF_DATA_ALIGN (-8)
47 #define DWARF_PC_REG (mono_hw_reg_to_dwarf_reg (AMD64_RIP))
48 #elif defined(TARGET_ARM)
49 // http://infocenter.arm.com/help/topic/com.arm.doc.ihi0040a/IHI0040A_aadwarf.pdf
50 static int map_hw_reg_to_dwarf_reg [] = { 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15 };
52 #define DWARF_DATA_ALIGN (-4)
53 #define DWARF_PC_REG (mono_hw_reg_to_dwarf_reg (ARMREG_LR))
54 #elif defined (TARGET_X86)
55 static int map_hw_reg_to_dwarf_reg [] = { 0, 1, 2, 3, 4, 5, 6, 7, 8 };
57 #define NUM_REGS X86_NREG + 1
58 #define DWARF_DATA_ALIGN (-4)
59 #define DWARF_PC_REG (mono_hw_reg_to_dwarf_reg (X86_NREG))
60 #elif defined (TARGET_POWERPC)
61 // http://refspecs.linuxfoundation.org/ELF/ppc64/PPC-elf64abi-1.9.html
62 static int map_hw_reg_to_dwarf_reg [] = { 0, 1, 2, 3, 4, 5, 6, 7, 8,
63 9, 10, 11, 12, 13, 14, 15, 16,
64 17, 18, 19, 20, 21, 22, 23, 24,
65 25, 26, 27, 28, 29, 30, 31 };
67 #define DWARF_DATA_ALIGN (-(gint32)sizeof (mgreg_t))
68 #define DWARF_PC_REG 108
69 #elif defined (TARGET_S390X)
70 static int map_hw_reg_to_dwarf_reg [] = { 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15 };
72 #define DWARF_DATA_ALIGN (-8)
73 #define DWARF_PC_REG (mono_hw_reg_to_dwarf_reg (14))
75 static int map_hw_reg_to_dwarf_reg [16];
77 #define DWARF_DATA_ALIGN 0
78 #define DWARF_PC_REG -1
81 static gboolean dwarf_reg_to_hw_reg_inited;
83 static int map_dwarf_reg_to_hw_reg [NUM_REGS];
86 * mono_hw_reg_to_dwarf_reg:
88 * Map the hardware register number REG to the register number used by DWARF.
91 mono_hw_reg_to_dwarf_reg (int reg)
97 g_assert (reg < NUM_REGS);
101 g_assert_not_reached ();
104 return map_hw_reg_to_dwarf_reg [reg];
113 g_assert (NUM_REGS > 0);
114 for (i = 0; i < sizeof (map_hw_reg_to_dwarf_reg) / sizeof (int); ++i) {
115 map_dwarf_reg_to_hw_reg [mono_hw_reg_to_dwarf_reg (i)] = i;
118 #ifdef TARGET_POWERPC
119 map_dwarf_reg_to_hw_reg [DWARF_PC_REG] = ppc_lr;
122 mono_memory_barrier ();
123 dwarf_reg_to_hw_reg_inited = TRUE;
127 mono_dwarf_reg_to_hw_reg (int reg)
129 if (!dwarf_reg_to_hw_reg_inited)
132 return map_dwarf_reg_to_hw_reg [reg];
135 static G_GNUC_UNUSED void
136 encode_uleb128 (guint32 value, guint8 *buf, guint8 **endbuf)
141 guint8 b = value & 0x7f;
143 if (value != 0) /* more bytes to come */
151 static G_GNUC_UNUSED void
152 encode_sleb128 (gint32 value, guint8 *buf, guint8 **endbuf)
155 gboolean negative = (value < 0);
163 /* the following is unnecessary if the
164 * implementation of >>= uses an arithmetic rather
165 * than logical shift for a signed left operand
169 value |= - (1 <<(size - 7));
170 /* sign bit of byte is second high order bit (0x40) */
171 if ((value == 0 && !(byte & 0x40)) ||
172 (value == -1 && (byte & 0x40)))
182 static inline guint32
183 decode_uleb128 (guint8 *buf, guint8 **endbuf)
193 res = res | (((int)(b & 0x7f)) << shift);
205 decode_sleb128 (guint8 *buf, guint8 **endbuf)
215 res = res | (((int)(b & 0x7f)) << shift);
218 if (shift < 32 && (b & 0x40))
219 res |= - (1 << shift);
230 * mono_unwind_ops_encode:
232 * Encode the unwind ops in UNWIND_OPS into the compact DWARF encoding.
233 * Return a pointer to malloc'ed memory.
236 mono_unwind_ops_encode (GSList *unwind_ops, guint32 *out_len)
241 guint8 *buf, *p, *res;
243 p = buf = g_malloc0 (4096);
247 for (; l; l = l->next) {
252 /* Convert the register from the hw encoding to the dwarf encoding */
253 reg = mono_hw_reg_to_dwarf_reg (op->reg);
255 /* Emit an advance_loc if neccesary */
256 while (op->when > loc) {
257 if (op->when - loc < 32) {
258 *p ++ = DW_CFA_advance_loc | (op->when - loc);
261 *p ++ = DW_CFA_advance_loc | (30);
269 encode_uleb128 (reg, p, &p);
270 encode_uleb128 (op->val, p, &p);
272 case DW_CFA_def_cfa_offset:
274 encode_uleb128 (op->val, p, &p);
276 case DW_CFA_def_cfa_register:
278 encode_uleb128 (reg, p, &p);
282 *p ++ = DW_CFA_offset_extended_sf;
283 encode_uleb128 (reg, p, &p);
284 encode_sleb128 (op->val / DWARF_DATA_ALIGN, p, &p);
286 *p ++ = DW_CFA_offset | reg;
287 encode_uleb128 (op->val / DWARF_DATA_ALIGN, p, &p);
291 g_assert_not_reached ();
296 g_assert (p - buf < 4096);
298 res = g_malloc (p - buf);
299 memcpy (res, buf, p - buf);
305 #define UNW_DEBUG(stmt) do { stmt; } while (0)
307 #define UNW_DEBUG(stmt) do { } while (0)
310 static G_GNUC_UNUSED void
311 print_dwarf_state (int cfa_reg, int cfa_offset, int ip, int nregs, Loc *locations)
315 printf ("\t%x: cfa=r%d+%d ", ip, cfa_reg, cfa_offset);
317 for (i = 0; i < nregs; ++i)
318 if (locations [i].loc_type == LOC_OFFSET)
319 printf ("r%d@%d(cfa) ", i, locations [i].offset);
324 * Given the state of the current frame as stored in REGS, execute the unwind
325 * operations in unwind_info until the location counter reaches POS. The result is
326 * stored back into REGS. OUT_CFA will receive the value of the CFA.
327 * If SAVE_LOCATIONS is non-NULL, it should point to an array of size SAVE_LOCATIONS_LEN.
328 * On return, the nth entry will point to the address of the stack slot where register
329 * N was saved, or NULL, if it was not saved by this frame.
330 * This function is signal safe.
333 mono_unwind_frame (guint8 *unwind_info, guint32 unwind_info_len,
334 guint8 *start_ip, guint8 *end_ip, guint8 *ip, mgreg_t *regs, int nregs,
335 mgreg_t **save_locations, int save_locations_len,
338 Loc locations [NUM_REGS];
339 int i, pos, reg, cfa_reg, cfa_offset;
343 for (i = 0; i < NUM_REGS; ++i)
344 locations [i].loc_type = LOC_SAME;
350 while (pos <= ip - start_ip && p < unwind_info + unwind_info_len) {
354 case DW_CFA_advance_loc:
355 UNW_DEBUG (print_dwarf_state (cfa_reg, cfa_offset, pos, nregs, locations));
362 locations [reg].loc_type = LOC_OFFSET;
363 locations [reg].offset = decode_uleb128 (p, &p) * DWARF_DATA_ALIGN;
370 cfa_reg = decode_uleb128 (p, &p);
371 cfa_offset = decode_uleb128 (p, &p);
373 case DW_CFA_def_cfa_offset:
374 cfa_offset = decode_uleb128 (p, &p);
376 case DW_CFA_def_cfa_register:
377 cfa_reg = decode_uleb128 (p, &p);
379 case DW_CFA_offset_extended_sf:
380 reg = decode_uleb128 (p, &p);
381 locations [reg].loc_type = LOC_OFFSET;
382 locations [reg].offset = decode_sleb128 (p, &p) * DWARF_DATA_ALIGN;
384 case DW_CFA_advance_loc4:
389 g_assert_not_reached ();
394 g_assert_not_reached ();
399 memset (save_locations, 0, save_locations_len * sizeof (mgreg_t*));
401 cfa_val = (guint8*)regs [mono_dwarf_reg_to_hw_reg (cfa_reg)] + cfa_offset;
402 for (i = 0; i < NUM_REGS; ++i) {
403 if (locations [i].loc_type == LOC_OFFSET) {
404 int hreg = mono_dwarf_reg_to_hw_reg (i);
405 g_assert (hreg < nregs);
406 regs [hreg] = *(mgreg_t*)(cfa_val + locations [i].offset);
407 if (save_locations && hreg < save_locations_len)
408 save_locations [hreg] = (mgreg_t*)(cfa_val + locations [i].offset);
416 mono_unwind_init (void)
418 InitializeCriticalSection (&unwind_mutex);
420 mono_counters_register ("Unwind info size", MONO_COUNTER_JIT | MONO_COUNTER_INT, &unwind_info_size);
424 mono_unwind_cleanup (void)
428 DeleteCriticalSection (&unwind_mutex);
433 for (i = 0; i < cached_info_next; ++i) {
434 MonoUnwindInfo *cached = cached_info [i];
439 g_free (cached_info);
443 * mono_cache_unwind_info
445 * Save UNWIND_INFO in the unwind info cache and return an id which can be passed
446 * to mono_get_cached_unwind_info to get a cached copy of the info.
447 * A copy is made of the unwind info.
448 * This function is useful for two reasons:
449 * - many methods have the same unwind info
450 * - MonoJitInfo->used_regs is an int so it can't store the pointer to the unwind info
453 mono_cache_unwind_info (guint8 *unwind_info, guint32 unwind_info_len)
456 MonoUnwindInfo *info;
460 if (cached_info == NULL) {
461 cached_info_size = 16;
462 cached_info = g_new0 (MonoUnwindInfo*, cached_info_size);
465 for (i = 0; i < cached_info_next; ++i) {
466 MonoUnwindInfo *cached = cached_info [i];
468 if (cached->len == unwind_info_len && memcmp (cached->info, unwind_info, unwind_info_len) == 0) {
474 info = g_malloc (sizeof (MonoUnwindInfo) + unwind_info_len);
475 info->len = unwind_info_len;
476 memcpy (&info->info, unwind_info, unwind_info_len);
478 i = cached_info_next;
480 if (cached_info_next >= cached_info_size) {
481 MonoUnwindInfo **old_table, **new_table;
484 * Have to resize the table, while synchronizing with
485 * mono_get_cached_unwind_info () using hazard pointers.
488 old_table = cached_info;
489 new_table = g_new0 (MonoUnwindInfo*, cached_info_size * 2);
491 memcpy (new_table, cached_info, cached_info_size * sizeof (MonoUnwindInfo*));
493 mono_memory_barrier ();
495 cached_info = new_table;
497 mono_memory_barrier ();
499 mono_thread_hazardous_free_or_queue (old_table, g_free);
501 cached_info_size *= 2;
504 cached_info [cached_info_next ++] = info;
506 unwind_info_size += sizeof (MonoUnwindInfo) + unwind_info_len;
513 get_hazardous_pointer (gpointer volatile *pp, MonoThreadHazardPointers *hp, int hazard_index)
518 /* Get the pointer */
520 /* If we don't have hazard pointers just return the
524 /* Make it hazardous */
525 mono_hazard_pointer_set (hp, hazard_index, p);
526 /* Check that it's still the same. If not, try
529 mono_hazard_pointer_clear (hp, hazard_index);
539 * This function is signal safe.
542 mono_get_cached_unwind_info (guint32 index, guint32 *unwind_info_len)
544 MonoUnwindInfo **table;
545 MonoUnwindInfo *info;
547 MonoThreadHazardPointers *hp = mono_hazard_pointer_get ();
549 table = get_hazardous_pointer ((gpointer volatile*)&cached_info, hp, 0);
551 info = table [index];
553 *unwind_info_len = info->len;
556 mono_hazard_pointer_clear (hp, 0);
562 * mono_unwind_get_dwarf_data_align:
564 * Return the data alignment used by the encoded unwind information.
567 mono_unwind_get_dwarf_data_align (void)
569 return DWARF_DATA_ALIGN;
573 * mono_unwind_get_dwarf_pc_reg:
575 * Return the dwarf register number of the register holding the ip of the
579 mono_unwind_get_dwarf_pc_reg (void)
585 decode_cie_op (guint8 *p, guint8 **endp)
590 case DW_CFA_advance_loc:
595 decode_uleb128 (p, &p);
602 decode_uleb128 (p, &p);
603 decode_uleb128 (p, &p);
605 case DW_CFA_def_cfa_offset:
606 decode_uleb128 (p, &p);
608 case DW_CFA_def_cfa_register:
609 decode_uleb128 (p, &p);
611 case DW_CFA_advance_loc4:
615 g_assert_not_reached ();
620 g_assert_not_reached ();
626 /* Pointer Encoding in the .eh_frame */
628 DW_EH_PE_absptr = 0x00,
629 DW_EH_PE_omit = 0xff,
631 DW_EH_PE_udata4 = 0x03,
632 DW_EH_PE_sdata4 = 0x0b,
633 DW_EH_PE_sdata8 = 0x0c,
635 DW_EH_PE_pcrel = 0x10,
636 DW_EH_PE_textrel = 0x20,
637 DW_EH_PE_datarel = 0x30,
638 DW_EH_PE_funcrel = 0x40,
639 DW_EH_PE_aligned = 0x50,
641 DW_EH_PE_indirect = 0x80
645 read_encoded_val (guint32 encoding, guint8 *p, guint8 **endp)
649 switch (encoding & 0xf) {
650 case DW_EH_PE_sdata8:
654 case DW_EH_PE_sdata4:
659 g_assert_not_reached ();
669 * Decode the Language Specific Data Area generated by LLVM.
672 decode_lsda (guint8 *lsda, guint8 *code, MonoJitExceptionInfo **ex_info, guint32 *ex_info_len, gpointer **type_info, int *this_reg, int *this_offset)
674 gint32 ttype_offset, call_site_length;
675 gint32 ttype_encoding, call_site_encoding;
676 guint8 *ttype, *action_table, *call_site, *p;
680 * LLVM generates a c++ style LSDA, which can be decoded by looking at
681 * eh_personality.cc in gcc.
685 if (*p == DW_EH_PE_udata4) {
686 /* This is the modified LSDA generated by the LLVM mono branch */
687 guint32 mono_magic, version;
688 gint32 op, reg, offset;
691 mono_magic = decode_uleb128 (p, &p);
692 g_assert (mono_magic == 0x4d4fef4f);
693 version = decode_uleb128 (p, &p);
694 g_assert (version == 1);
696 /* 'this' location */
698 g_assert (op == DW_OP_bregx);
700 reg = decode_uleb128 (p, &p);
701 offset = decode_sleb128 (p, &p);
703 *this_reg = mono_dwarf_reg_to_hw_reg (reg);
704 *this_offset = offset;
707 g_assert (*p == DW_EH_PE_omit);
717 ttype_offset = decode_uleb128 (p, &p);
718 ttype = p + ttype_offset;
720 /* Read call-site table */
721 call_site_encoding = *p;
722 g_assert (call_site_encoding == DW_EH_PE_udata4);
724 call_site_length = decode_uleb128 (p, &p);
726 p += call_site_length;
729 /* Calculate the size of our table */
732 while (p < action_table) {
733 int block_start_offset, block_size, landing_pad, action_offset;
735 block_start_offset = read32 (p);
736 p += sizeof (gint32);
737 block_size = read32 (p);
738 p += sizeof (gint32);
739 landing_pad = read32 (p);
740 p += sizeof (gint32);
741 action_offset = decode_uleb128 (p, &p);
743 /* landing_pad == 0 means the region has no landing pad */
749 *ex_info = g_malloc0 (ncall_sites * sizeof (MonoJitExceptionInfo));
750 *ex_info_len = ncall_sites;
754 *type_info = g_malloc0 (ncall_sites * sizeof (gpointer));
758 while (p < action_table) {
759 int block_start_offset, block_size, landing_pad, action_offset, type_offset;
760 guint8 *action, *tinfo;
762 block_start_offset = read32 (p);
763 p += sizeof (gint32);
764 block_size = read32 (p);
765 p += sizeof (gint32);
766 landing_pad = read32 (p);
767 p += sizeof (gint32);
768 action_offset = decode_uleb128 (p, &p);
770 action = action_table + action_offset - 1;
772 type_offset = decode_sleb128 (action, &action);
775 //printf ("BLOCK: %p-%p %p, %d\n", code + block_start_offset, code + block_start_offset + block_size, code + landing_pad, action_offset);
777 g_assert (ttype_offset);
779 if (ttype_encoding == DW_EH_PE_absptr) {
780 guint8 *ttype_entry = (ttype - (type_offset * sizeof (gpointer)));
781 tinfo = *(gpointer*)ttype_entry;
782 } else if (ttype_encoding == (DW_EH_PE_indirect | DW_EH_PE_pcrel | DW_EH_PE_sdata4)) {
783 guint8 *ttype_entry = (ttype - (type_offset * 4));
784 gint32 offset = *(gint32*)ttype_entry;
785 guint8 *stub = ttype_entry + offset;
786 tinfo = *(gpointer*)stub;
787 } else if (ttype_encoding == (DW_EH_PE_pcrel | DW_EH_PE_sdata4)) {
788 guint8 *ttype_entry = (ttype - (type_offset * 4));
789 gint32 offset = *(gint32*)ttype_entry;
790 tinfo = ttype_entry + offset;
791 } else if (ttype_encoding == DW_EH_PE_udata4) {
792 /* Embedded directly */
793 guint8 *ttype_entry = (ttype - (type_offset * 4));
796 g_assert_not_reached ();
801 (*type_info) [i] = tinfo;
802 (*ex_info)[i].try_start = code + block_start_offset;
803 (*ex_info)[i].try_end = code + block_start_offset + block_size;
804 (*ex_info)[i].handler_start = code + landing_pad;
813 * mono_unwind_decode_fde:
815 * Decode a DWARF FDE entry, returning the unwind opcodes.
816 * If not NULL, EX_INFO is set to a malloc-ed array of MonoJitExceptionInfo structures,
817 * only try_start, try_end and handler_start is set.
818 * If not NULL, TYPE_INFO is set to a malloc-ed array containing the ttype table from the
822 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)
824 guint8 *p, *cie, *fde_current, *fde_aug = NULL, *code, *fde_cfi, *cie_cfi;
825 gint32 fde_len, cie_offset, pc_begin, pc_range, aug_len, fde_data_len;
826 gint32 cie_len, cie_id, cie_version, code_align, data_align, return_reg;
827 gint32 i, cie_aug_len, buf_len;
830 gboolean has_fde_augmentation = FALSE;
833 * http://refspecs.freestandards.org/LSB_3.0.0/LSB-Core-generic/LSB-Core-generic/ehframechpt.html
843 // FIXME: Endianess ?
844 fde_len = *(guint32*)p;
845 g_assert (fde_len != 0xffffffff && fde_len != 0);
847 cie_offset = *(guint32*)p;
848 cie = p - cie_offset;
854 cie_len = *(guint32*)p;
856 cie_id = *(guint32*)p;
857 g_assert (cie_id == 0);
860 g_assert (cie_version == 1);
862 cie_aug_str = (char*)p;
863 p += strlen (cie_aug_str) + 1;
864 code_align = decode_uleb128 (p, &p);
865 data_align = decode_sleb128 (p, &p);
866 return_reg = decode_uleb128 (p, &p);
867 if (strstr (cie_aug_str, "z")) {
871 cie_aug_len = decode_uleb128 (p, &p);
873 has_fde_augmentation = TRUE;
876 for (i = 0; cie_aug_str [i] != '\0'; ++i) {
877 switch (cie_aug_str [i]) {
883 read_encoded_val (p_encoding, p, &p);
886 g_assert ((*p == (DW_EH_PE_sdata4|DW_EH_PE_pcrel)) || (*p == (DW_EH_PE_sdata8|DW_EH_PE_pcrel)));
890 g_assert (*p == (DW_EH_PE_sdata4|DW_EH_PE_pcrel));
894 g_assert_not_reached ();
904 /* Continue decoding FDE */
906 /* DW_EH_PE_sdata4|DW_EH_PE_pcrel encoding */
907 pc_begin = *(gint32*)p;
910 pc_range = *(guint32*)p;
912 if (has_fde_augmentation) {
913 aug_len = decode_uleb128 (p, &p);
920 fde_data_len = fde + 4 + fde_len - p;
923 *code_len = pc_range;
930 /* Decode FDE augmention */
935 /* sdata|pcrel encoding */
937 lsda_offset = read32 (fde_aug);
938 else if (aug_len == 8)
939 lsda_offset = *(gint64*)fde_aug;
941 g_assert_not_reached ();
942 if (lsda_offset != 0) {
943 lsda = fde_aug + lsda_offset;
945 decode_lsda (lsda, code, ex_info, ex_info_len, type_info, this_reg, this_offset);
949 /* Make sure the FDE uses the same constants as we do */
950 g_assert (code_align == 1);
951 g_assert (data_align == DWARF_DATA_ALIGN);
952 g_assert (return_reg == DWARF_PC_REG);
954 buf_len = (cie + cie_len + 4 - cie_cfi) + (fde + fde_len + 4 - fde_cfi);
955 buf = g_malloc0 (buf_len);
959 while (p < cie + cie_len + 4) {
960 if (*p == DW_CFA_nop)
963 decode_cie_op (p, &p);
965 memcpy (buf + i, cie_cfi, p - cie_cfi);
969 while (p < fde + fde_len + 4) {
970 if (*p == DW_CFA_nop)
973 decode_cie_op (p, &p);
975 memcpy (buf + i, fde_cfi, p - fde_cfi);
977 g_assert (i <= buf_len);
981 return g_realloc (buf, i);
985 * mono_unwind_decode_mono_fde:
987 * Decode an FDE entry in the LLVM emitted mono EH frame.
988 * info->ex_info is set to a malloc-ed array of MonoJitExceptionInfo structures,
989 * only try_start, try_end and handler_start is set.
990 * info->type_info is set to a malloc-ed array containing the ttype table from the
994 mono_unwind_decode_llvm_mono_fde (guint8 *fde, int fde_len, guint8 *cie, guint8 *code, MonoLLVMFDEInfo *res)
996 guint8 *p, *fde_aug, *cie_cfi, *fde_cfi, *buf;
997 int has_aug, aug_len, cie_cfi_len, fde_cfi_len;
998 gint32 code_align, data_align, return_reg, pers_encoding;
1000 memset (res, 0, sizeof (*res));
1002 res->this_offset = -1;
1004 /* fde points to data emitted by LLVM in DwarfException::EmitMonoEHFrame () */
1009 aug_len = read32 (p);
1021 /* The LSDA is embedded directly into the FDE */
1024 decode_lsda (lsda, code, &res->ex_info, &res->ex_info_len, &res->type_info, &res->this_reg, &res->this_offset);
1029 code_align = decode_uleb128 (p, &p);
1030 data_align = decode_sleb128 (p, &p);
1031 return_reg = decode_uleb128 (p, &p);
1034 if (pers_encoding != DW_EH_PE_omit)
1035 read_encoded_val (pers_encoding, p, &p);
1039 /* Make sure the FDE uses the same constants as we do */
1040 g_assert (code_align == 1);
1041 g_assert (data_align == DWARF_DATA_ALIGN);
1042 g_assert (return_reg == DWARF_PC_REG);
1044 /* Compute size of CIE unwind info it is DW_CFA_nop terminated */
1047 if (*p == DW_CFA_nop)
1050 decode_cie_op (p, &p);
1052 cie_cfi_len = p - cie_cfi;
1053 fde_cfi_len = (fde + fde_len - fde_cfi);
1055 buf = g_malloc0 (cie_cfi_len + fde_cfi_len);
1056 memcpy (buf, cie_cfi, cie_cfi_len);
1057 memcpy (buf + cie_cfi_len, fde_cfi, fde_cfi_len);
1059 res->unw_info_len = cie_cfi_len + fde_cfi_len;
1060 res->unw_info = buf;
1064 * mono_unwind_get_cie_program:
1066 * Get the unwind bytecode for the DWARF CIE.
1069 mono_unwind_get_cie_program (void)
1071 #if defined(TARGET_AMD64) || defined(TARGET_X86) || defined(TARGET_POWERPC)
1072 return mono_arch_get_cie_program ();