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 */
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 #elif defined(TARGET_ARM64)
61 #define DWARF_DATA_ALIGN (-8)
63 #define DWARF_PC_REG 30
64 static int map_hw_reg_to_dwarf_reg [] = {
65 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15,
66 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31,
68 72, 73, 74, 75, 76, 77, 78, 79,
70 #elif defined (TARGET_X86)
72 * ebp and esp are swapped:
73 * http://lists.cs.uiuc.edu/pipermail/lldb-dev/2014-January/003101.html
75 static int map_hw_reg_to_dwarf_reg [] = { 0, 1, 2, 3, 5, 4, 6, 7, 8 };
77 #define NUM_REGS X86_NREG + 1
78 #define DWARF_DATA_ALIGN (-4)
79 #define DWARF_PC_REG (mono_hw_reg_to_dwarf_reg (X86_NREG))
80 #elif defined (TARGET_POWERPC)
81 // http://refspecs.linuxfoundation.org/ELF/ppc64/PPC-elf64abi-1.9.html
82 static int map_hw_reg_to_dwarf_reg [] = { 0, 1, 2, 3, 4, 5, 6, 7, 8,
83 9, 10, 11, 12, 13, 14, 15, 16,
84 17, 18, 19, 20, 21, 22, 23, 24,
85 25, 26, 27, 28, 29, 30, 31 };
87 #define DWARF_DATA_ALIGN (-(gint32)sizeof (mgreg_t))
88 #define DWARF_PC_REG 108
89 #elif defined (TARGET_S390X)
90 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 DWARF_DATA_ALIGN (-8)
93 #define DWARF_PC_REG (mono_hw_reg_to_dwarf_reg (14))
94 #elif defined (TARGET_MIPS)
96 static int map_hw_reg_to_dwarf_reg [32] = {
97 0, 1, 2, 3, 4, 5, 6, 7,
98 8, 9, 10, 11, 12, 13, 14, 15,
99 16, 17, 18, 19, 20, 21, 22, 23,
100 24, 25, 26, 27, 28, 29, 30, 31
103 #define DWARF_DATA_ALIGN (-(gint32)sizeof (mgreg_t))
104 #define DWARF_PC_REG (mono_hw_reg_to_dwarf_reg (mips_ra))
106 static int map_hw_reg_to_dwarf_reg [16];
108 #define DWARF_DATA_ALIGN 0
109 #define DWARF_PC_REG -1
112 static gboolean dwarf_reg_to_hw_reg_inited;
114 static int map_dwarf_reg_to_hw_reg [NUM_REGS];
117 * mono_hw_reg_to_dwarf_reg:
119 * Map the hardware register number REG to the register number used by DWARF.
122 mono_hw_reg_to_dwarf_reg (int reg)
124 #ifdef TARGET_POWERPC
128 g_assert (reg < NUM_REGS);
132 g_assert_not_reached ();
135 return map_hw_reg_to_dwarf_reg [reg];
144 g_assert (NUM_REGS > 0);
145 for (i = 0; i < sizeof (map_hw_reg_to_dwarf_reg) / sizeof (int); ++i) {
146 map_dwarf_reg_to_hw_reg [mono_hw_reg_to_dwarf_reg (i)] = i;
149 #ifdef TARGET_POWERPC
150 map_dwarf_reg_to_hw_reg [DWARF_PC_REG] = ppc_lr;
153 mono_memory_barrier ();
154 dwarf_reg_to_hw_reg_inited = TRUE;
158 mono_dwarf_reg_to_hw_reg (int reg)
160 if (!dwarf_reg_to_hw_reg_inited)
163 return map_dwarf_reg_to_hw_reg [reg];
166 static G_GNUC_UNUSED void
167 encode_uleb128 (guint32 value, guint8 *buf, guint8 **endbuf)
172 guint8 b = value & 0x7f;
174 if (value != 0) /* more bytes to come */
182 static G_GNUC_UNUSED void
183 encode_sleb128 (gint32 value, guint8 *buf, guint8 **endbuf)
186 gboolean negative = (value < 0);
194 /* the following is unnecessary if the
195 * implementation of >>= uses an arithmetic rather
196 * than logical shift for a signed left operand
200 value |= - (1 <<(size - 7));
201 /* sign bit of byte is second high order bit (0x40) */
202 if ((value == 0 && !(byte & 0x40)) ||
203 (value == -1 && (byte & 0x40)))
213 static inline guint32
214 decode_uleb128 (guint8 *buf, guint8 **endbuf)
224 res = res | (((int)(b & 0x7f)) << shift);
236 decode_sleb128 (guint8 *buf, guint8 **endbuf)
246 res = res | (((int)(b & 0x7f)) << shift);
249 if (shift < 32 && (b & 0x40))
250 res |= - (1 << shift);
261 mono_print_unwind_info (guint8 *unwind_info, int unwind_info_len)
264 int pos, reg, offset, cfa_reg, cfa_offset;
268 while (p < unwind_info + unwind_info_len) {
272 case DW_CFA_advance_loc:
279 offset = decode_uleb128 (p, &p) * DWARF_DATA_ALIGN;
280 if (reg == DWARF_PC_REG)
281 printf ("CFA: [%x] offset: %s at cfa-0x%x\n", pos, "pc", -offset);
283 printf ("CFA: [%x] offset: %s at cfa-0x%x\n", pos, mono_arch_regname (mono_dwarf_reg_to_hw_reg (reg)), -offset);
290 cfa_reg = decode_uleb128 (p, &p);
291 cfa_offset = decode_uleb128 (p, &p);
292 printf ("CFA: [%x] def_cfa: %s+0x%x\n", pos, mono_arch_regname (mono_dwarf_reg_to_hw_reg (cfa_reg)), cfa_offset);
294 case DW_CFA_def_cfa_offset:
295 cfa_offset = decode_uleb128 (p, &p);
296 printf ("CFA: [%x] def_cfa_offset: 0x%x\n", pos, cfa_offset);
298 case DW_CFA_def_cfa_register:
299 cfa_reg = decode_uleb128 (p, &p);
300 printf ("CFA: [%x] def_cfa_reg: %s\n", pos, mono_arch_regname (mono_dwarf_reg_to_hw_reg (cfa_reg)));
302 case DW_CFA_offset_extended_sf:
303 reg = decode_uleb128 (p, &p);
304 offset = decode_sleb128 (p, &p) * DWARF_DATA_ALIGN;
305 printf ("CFA: [%x] offset_extended_sf: %s at cfa-0x%x\n", pos, mono_arch_regname (mono_dwarf_reg_to_hw_reg (reg)), -offset);
307 case DW_CFA_same_value:
308 reg = decode_uleb128 (p, &p);
309 printf ("CFA: [%x] same_value: %s\n", pos, mono_arch_regname (mono_dwarf_reg_to_hw_reg (reg)));
311 case DW_CFA_advance_loc4:
315 case DW_CFA_remember_state:
316 printf ("CFA: [%x] remember_state\n", pos);
318 case DW_CFA_restore_state:
319 printf ("CFA: [%x] restore_state\n", pos);
321 case DW_CFA_mono_advance_loc:
322 printf ("CFA: [%x] mono_advance_loc\n", pos);
325 g_assert_not_reached ();
330 g_assert_not_reached ();
336 * mono_unwind_ops_encode:
338 * Encode the unwind ops in UNWIND_OPS into the compact DWARF encoding.
339 * Return a pointer to malloc'ed memory.
342 mono_unwind_ops_encode (GSList *unwind_ops, guint32 *out_len)
354 for (; l; l = l->next) {
359 /* Convert the register from the hw encoding to the dwarf encoding */
360 reg = mono_hw_reg_to_dwarf_reg (op->reg);
362 if (op->op == DW_CFA_mono_advance_loc) {
363 /* This advances loc to its location */
367 /* Emit an advance_loc if neccesary */
368 while (op->when > loc) {
369 if (op->when - loc > 65536) {
370 *p ++ = DW_CFA_advance_loc4;
371 *(guint32*)p = (guint32)(op->when - loc);
372 g_assert (read32 (p) == (guint32)(op->when - loc));
375 } else if (op->when - loc > 256) {
376 *p ++ = DW_CFA_advance_loc2;
377 *(guint16*)p = (guint16)(op->when - loc);
378 g_assert (read16 (p) == (guint32)(op->when - loc));
381 } else if (op->when - loc >= 32) {
382 *p ++ = DW_CFA_advance_loc1;
383 *(guint8*)p = (guint8)(op->when - loc);
386 } else if (op->when - loc < 32) {
387 *p ++ = DW_CFA_advance_loc | (op->when - loc);
390 *p ++ = DW_CFA_advance_loc | (30);
398 encode_uleb128 (reg, p, &p);
399 encode_uleb128 (op->val, p, &p);
401 case DW_CFA_def_cfa_offset:
403 encode_uleb128 (op->val, p, &p);
405 case DW_CFA_def_cfa_register:
407 encode_uleb128 (reg, p, &p);
409 case DW_CFA_same_value:
411 encode_uleb128 (reg, p, &p);
415 *p ++ = DW_CFA_offset_extended_sf;
416 encode_uleb128 (reg, p, &p);
417 encode_sleb128 (op->val / DWARF_DATA_ALIGN, p, &p);
419 *p ++ = DW_CFA_offset | reg;
420 encode_uleb128 (op->val / DWARF_DATA_ALIGN, p, &p);
423 case DW_CFA_remember_state:
424 case DW_CFA_restore_state:
427 case DW_CFA_mono_advance_loc:
428 /* Only one location is supported */
429 g_assert (op->val == 0);
433 g_assert_not_reached ();
438 g_assert (p - buf < 4096);
440 res = g_malloc (p - buf);
441 memcpy (res, buf, p - buf);
446 #define UNW_DEBUG(stmt) do { stmt; } while (0)
448 #define UNW_DEBUG(stmt) do { } while (0)
451 static G_GNUC_UNUSED void
452 print_dwarf_state (int cfa_reg, int cfa_offset, int ip, int nregs, Loc *locations, guint8 *reg_saved)
456 printf ("\t%x: cfa=r%d+%d ", ip, cfa_reg, cfa_offset);
458 for (i = 0; i < nregs; ++i)
459 if (reg_saved [i] && locations [i].loc_type == LOC_OFFSET)
460 printf ("r%d@%d(cfa) ", i, locations [i].offset);
465 Loc locations [NUM_REGS];
466 guint8 reg_saved [NUM_REGS];
467 int cfa_reg, cfa_offset;
471 * Given the state of the current frame as stored in REGS, execute the unwind
472 * operations in unwind_info until the location counter reaches POS. The result is
473 * stored back into REGS. OUT_CFA will receive the value of the CFA.
474 * If SAVE_LOCATIONS is non-NULL, it should point to an array of size SAVE_LOCATIONS_LEN.
475 * On return, the nth entry will point to the address of the stack slot where register
476 * N was saved, or NULL, if it was not saved by this frame.
477 * MARK_LOCATIONS should contain the locations marked by mono_emit_unwind_op_mark_loc (), if any.
478 * This function is signal safe.
481 mono_unwind_frame (guint8 *unwind_info, guint32 unwind_info_len,
482 guint8 *start_ip, guint8 *end_ip, guint8 *ip, guint8 **mark_locations,
483 mgreg_t *regs, int nregs,
484 mgreg_t **save_locations, int save_locations_len,
487 Loc locations [NUM_REGS];
488 guint8 reg_saved [NUM_REGS];
489 int i, pos, reg, cfa_reg = -1, cfa_offset = 0, offset;
492 UnwindState state_stack [1];
495 memset (reg_saved, 0, sizeof (reg_saved));
496 state_stack [0].cfa_reg = -1;
497 state_stack [0].cfa_offset = 0;
504 while (pos <= ip - start_ip && p < unwind_info + unwind_info_len) {
508 case DW_CFA_advance_loc:
509 UNW_DEBUG (print_dwarf_state (cfa_reg, cfa_offset, pos, nregs, locations));
516 reg_saved [reg] = TRUE;
517 locations [reg].loc_type = LOC_OFFSET;
518 locations [reg].offset = decode_uleb128 (p, &p) * DWARF_DATA_ALIGN;
525 cfa_reg = decode_uleb128 (p, &p);
526 cfa_offset = decode_uleb128 (p, &p);
528 case DW_CFA_def_cfa_offset:
529 cfa_offset = decode_uleb128 (p, &p);
531 case DW_CFA_def_cfa_register:
532 cfa_reg = decode_uleb128 (p, &p);
534 case DW_CFA_offset_extended_sf:
535 reg = decode_uleb128 (p, &p);
536 offset = decode_sleb128 (p, &p);
537 g_assert (reg < NUM_REGS);
538 reg_saved [reg] = TRUE;
539 locations [reg].loc_type = LOC_OFFSET;
540 locations [reg].offset = offset * DWARF_DATA_ALIGN;
542 case DW_CFA_offset_extended:
543 reg = decode_uleb128 (p, &p);
544 offset = decode_uleb128 (p, &p);
545 g_assert (reg < NUM_REGS);
546 reg_saved [reg] = TRUE;
547 locations [reg].loc_type = LOC_OFFSET;
548 locations [reg].offset = offset * DWARF_DATA_ALIGN;
550 case DW_CFA_same_value:
551 reg = decode_uleb128 (p, &p);
552 locations [reg].loc_type = LOC_SAME;
554 case DW_CFA_advance_loc1:
558 case DW_CFA_advance_loc2:
562 case DW_CFA_advance_loc4:
566 case DW_CFA_remember_state:
567 g_assert (state_stack_pos == 0);
568 memcpy (&state_stack [0].locations, &locations, sizeof (locations));
569 memcpy (&state_stack [0].reg_saved, ®_saved, sizeof (reg_saved));
570 state_stack [0].cfa_reg = cfa_reg;
571 state_stack [0].cfa_offset = cfa_offset;
574 case DW_CFA_restore_state:
575 g_assert (state_stack_pos == 1);
577 memcpy (&locations, &state_stack [0].locations, sizeof (locations));
578 memcpy (®_saved, &state_stack [0].reg_saved, sizeof (reg_saved));
579 cfa_reg = state_stack [0].cfa_reg;
580 cfa_offset = state_stack [0].cfa_offset;
582 case DW_CFA_mono_advance_loc:
583 g_assert (mark_locations [0]);
584 pos = mark_locations [0] - start_ip;
587 g_assert_not_reached ();
592 g_assert_not_reached ();
597 memset (save_locations, 0, save_locations_len * sizeof (mgreg_t*));
599 g_assert (cfa_reg != -1);
600 cfa_val = (guint8*)regs [mono_dwarf_reg_to_hw_reg (cfa_reg)] + cfa_offset;
601 for (i = 0; i < NUM_REGS; ++i) {
602 if (reg_saved [i] && locations [i].loc_type == LOC_OFFSET) {
603 int hreg = mono_dwarf_reg_to_hw_reg (i);
604 g_assert (hreg < nregs);
605 regs [hreg] = *(mgreg_t*)(cfa_val + locations [i].offset);
606 if (save_locations && hreg < save_locations_len)
607 save_locations [hreg] = (mgreg_t*)(cfa_val + locations [i].offset);
615 mono_unwind_init (void)
617 mono_mutex_init_recursive (&unwind_mutex);
619 mono_counters_register ("Unwind info size", MONO_COUNTER_JIT | MONO_COUNTER_INT, &unwind_info_size);
623 mono_unwind_cleanup (void)
627 mono_mutex_destroy (&unwind_mutex);
632 for (i = 0; i < cached_info_next; ++i) {
633 MonoUnwindInfo *cached = cached_info [i];
638 g_free (cached_info);
642 * mono_cache_unwind_info
644 * Save UNWIND_INFO in the unwind info cache and return an id which can be passed
645 * to mono_get_cached_unwind_info to get a cached copy of the info.
646 * A copy is made of the unwind info.
647 * This function is useful for two reasons:
648 * - many methods have the same unwind info
649 * - MonoJitInfo->unwind_info is an int so it can't store the pointer to the unwind info
652 mono_cache_unwind_info (guint8 *unwind_info, guint32 unwind_info_len)
655 MonoUnwindInfo *info;
659 if (cached_info == NULL) {
660 cached_info_size = 16;
661 cached_info = g_new0 (MonoUnwindInfo*, cached_info_size);
664 for (i = 0; i < cached_info_next; ++i) {
665 MonoUnwindInfo *cached = cached_info [i];
667 if (cached->len == unwind_info_len && memcmp (cached->info, unwind_info, unwind_info_len) == 0) {
673 info = g_malloc (sizeof (MonoUnwindInfo) + unwind_info_len);
674 info->len = unwind_info_len;
675 memcpy (&info->info, unwind_info, unwind_info_len);
677 i = cached_info_next;
679 if (cached_info_next >= cached_info_size) {
680 MonoUnwindInfo **new_table;
683 * Avoid freeing the old table so mono_get_cached_unwind_info ()
684 * doesn't need locks/hazard pointers.
687 new_table = g_new0 (MonoUnwindInfo*, cached_info_size * 2);
689 memcpy (new_table, cached_info, cached_info_size * sizeof (MonoUnwindInfo*));
691 mono_memory_barrier ();
693 cached_info = new_table;
695 cached_info_list = g_slist_prepend (cached_info_list, cached_info);
697 cached_info_size *= 2;
700 cached_info [cached_info_next ++] = info;
702 unwind_info_size += sizeof (MonoUnwindInfo) + unwind_info_len;
709 * This function is signal safe.
712 mono_get_cached_unwind_info (guint32 index, guint32 *unwind_info_len)
714 MonoUnwindInfo **table;
715 MonoUnwindInfo *info;
719 * This doesn't need any locks/hazard pointers,
720 * since new tables are copies of the old ones.
724 info = table [index];
726 *unwind_info_len = info->len;
733 * mono_unwind_get_dwarf_data_align:
735 * Return the data alignment used by the encoded unwind information.
738 mono_unwind_get_dwarf_data_align (void)
740 return DWARF_DATA_ALIGN;
744 * mono_unwind_get_dwarf_pc_reg:
746 * Return the dwarf register number of the register holding the ip of the
750 mono_unwind_get_dwarf_pc_reg (void)
756 decode_cie_op (guint8 *p, guint8 **endp)
761 case DW_CFA_advance_loc:
766 decode_uleb128 (p, &p);
773 decode_uleb128 (p, &p);
774 decode_uleb128 (p, &p);
776 case DW_CFA_def_cfa_offset:
777 decode_uleb128 (p, &p);
779 case DW_CFA_def_cfa_register:
780 decode_uleb128 (p, &p);
782 case DW_CFA_advance_loc4:
785 case DW_CFA_offset_extended_sf:
786 decode_uleb128 (p, &p);
787 decode_uleb128 (p, &p);
790 g_assert_not_reached ();
795 g_assert_not_reached ();
802 read_encoded_val (guint32 encoding, guint8 *p, guint8 **endp)
806 switch (encoding & 0xf) {
807 case DW_EH_PE_sdata8:
811 case DW_EH_PE_sdata4:
816 g_assert_not_reached ();
826 * Decode the Mono specific Language Specific Data Area generated by LLVM.
829 decode_lsda (guint8 *lsda, guint8 *code, MonoJitExceptionInfo **ex_info, guint32 *ex_info_len, gpointer **type_info, int *this_reg, int *this_offset)
832 int i, ncall_sites, this_encoding;
833 guint32 mono_magic, version;
837 /* This is the modified LSDA generated by the LLVM mono branch */
838 mono_magic = decode_uleb128 (p, &p);
839 g_assert (mono_magic == 0x4d4fef4f);
840 version = decode_uleb128 (p, &p);
841 g_assert (version == 1);
844 if (this_encoding == DW_EH_PE_udata4) {
845 gint32 op, reg, offset;
847 /* 'this' location */
849 g_assert (op == DW_OP_bregx);
851 reg = decode_uleb128 (p, &p);
852 offset = decode_sleb128 (p, &p);
854 *this_reg = mono_dwarf_reg_to_hw_reg (reg);
855 *this_offset = offset;
857 g_assert (this_encoding == DW_EH_PE_omit);
862 ncall_sites = decode_uleb128 (p, &p);
863 p = (guint8*)ALIGN_TO ((mgreg_t)p, 4);
866 *ex_info = g_malloc0 (ncall_sites * sizeof (MonoJitExceptionInfo));
867 *ex_info_len = ncall_sites;
870 *type_info = g_malloc0 (ncall_sites * sizeof (gpointer));
872 for (i = 0; i < ncall_sites; ++i) {
873 int block_start_offset, block_size, landing_pad;
876 block_start_offset = read32 (p);
877 p += sizeof (gint32);
878 block_size = read32 (p);
879 p += sizeof (gint32);
880 landing_pad = read32 (p);
881 p += sizeof (gint32);
883 p += sizeof (gint32);
885 g_assert (landing_pad);
886 g_assert (((size_t)tinfo % 4) == 0);
887 //printf ("X: %p %d\n", landing_pad, *(int*)tinfo);
891 (*type_info) [i] = tinfo;
892 (*ex_info)[i].try_start = code + block_start_offset;
893 (*ex_info)[i].try_end = code + block_start_offset + block_size;
894 (*ex_info)[i].handler_start = code + landing_pad;
900 * mono_unwind_decode_fde:
902 * Decode a DWARF FDE entry, returning the unwind opcodes.
903 * If not NULL, EX_INFO is set to a malloc-ed array of MonoJitExceptionInfo structures,
904 * only try_start, try_end and handler_start is set.
905 * If not NULL, TYPE_INFO is set to a malloc-ed array containing the ttype table from the
909 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)
911 guint8 *p, *cie, *fde_current, *fde_aug = NULL, *code, *fde_cfi, *cie_cfi;
912 gint32 fde_len, cie_offset, pc_begin, pc_range, aug_len;
913 gint32 cie_len, cie_id, cie_version, code_align, data_align, return_reg;
914 gint32 i, cie_aug_len, buf_len;
917 gboolean has_fde_augmentation = FALSE;
920 * http://refspecs.freestandards.org/LSB_3.0.0/LSB-Core-generic/LSB-Core-generic/ehframechpt.html
923 /* This is generated by JITDwarfEmitter::EmitEHFrame () */
932 // FIXME: Endianess ?
933 fde_len = *(guint32*)p;
934 g_assert (fde_len != 0xffffffff && fde_len != 0);
936 cie_offset = *(guint32*)p;
937 cie = p - cie_offset;
943 cie_len = *(guint32*)p;
945 cie_id = *(guint32*)p;
946 g_assert (cie_id == 0);
949 g_assert (cie_version == 1);
951 cie_aug_str = (char*)p;
952 p += strlen (cie_aug_str) + 1;
953 code_align = decode_uleb128 (p, &p);
954 data_align = decode_sleb128 (p, &p);
955 return_reg = decode_uleb128 (p, &p);
956 if (strstr (cie_aug_str, "z")) {
960 cie_aug_len = decode_uleb128 (p, &p);
962 has_fde_augmentation = TRUE;
965 for (i = 0; cie_aug_str [i] != '\0'; ++i) {
966 switch (cie_aug_str [i]) {
972 read_encoded_val (p_encoding, p, &p);
975 g_assert ((*p == (DW_EH_PE_sdata4|DW_EH_PE_pcrel)) || (*p == (DW_EH_PE_sdata8|DW_EH_PE_pcrel)));
979 g_assert (*p == (DW_EH_PE_sdata4|DW_EH_PE_pcrel));
983 g_assert_not_reached ();
993 /* Continue decoding FDE */
995 /* DW_EH_PE_sdata4|DW_EH_PE_pcrel encoding */
996 pc_begin = *(gint32*)p;
999 pc_range = *(guint32*)p;
1001 if (has_fde_augmentation) {
1002 aug_len = decode_uleb128 (p, &p);
1011 *code_len = pc_range;
1018 /* Decode FDE augmention */
1023 /* sdata|pcrel encoding */
1025 lsda_offset = read32 (fde_aug);
1026 else if (aug_len == 8)
1027 lsda_offset = *(gint64*)fde_aug;
1029 g_assert_not_reached ();
1030 if (lsda_offset != 0) {
1031 lsda = fde_aug + lsda_offset;
1033 decode_lsda (lsda, code, ex_info, ex_info_len, type_info, this_reg, this_offset);
1037 /* Make sure the FDE uses the same constants as we do */
1038 g_assert (code_align == 1);
1039 g_assert (data_align == DWARF_DATA_ALIGN);
1040 g_assert (return_reg == DWARF_PC_REG);
1042 buf_len = (cie + cie_len + 4 - cie_cfi) + (fde + fde_len + 4 - fde_cfi);
1043 buf = g_malloc0 (buf_len);
1047 while (p < cie + cie_len + 4) {
1048 if (*p == DW_CFA_nop)
1051 decode_cie_op (p, &p);
1053 memcpy (buf + i, cie_cfi, p - cie_cfi);
1057 while (p < fde + fde_len + 4) {
1058 if (*p == DW_CFA_nop)
1061 decode_cie_op (p, &p);
1063 memcpy (buf + i, fde_cfi, p - fde_cfi);
1065 g_assert (i <= buf_len);
1069 return g_realloc (buf, i);
1073 * mono_unwind_decode_mono_fde:
1075 * Decode an FDE entry in the LLVM emitted mono EH frame.
1076 * info->ex_info is set to a malloc-ed array of MonoJitExceptionInfo structures,
1077 * only try_start, try_end and handler_start is set.
1078 * info->type_info is set to a malloc-ed array containing the ttype table from the
1082 mono_unwind_decode_llvm_mono_fde (guint8 *fde, int fde_len, guint8 *cie, guint8 *code, MonoLLVMFDEInfo *res)
1084 guint8 *p, *fde_aug, *cie_cfi, *fde_cfi, *buf;
1085 int has_aug, aug_len, cie_cfi_len, fde_cfi_len;
1086 gint32 code_align, data_align, return_reg, pers_encoding;
1088 memset (res, 0, sizeof (*res));
1090 res->this_offset = -1;
1092 /* fde points to data emitted by LLVM in DwarfMonoException::EmitMonoEHFrame () */
1097 aug_len = read32 (p);
1109 /* The LSDA is embedded directly into the FDE */
1112 decode_lsda (lsda, code, &res->ex_info, &res->ex_info_len, &res->type_info, &res->this_reg, &res->this_offset);
1117 code_align = decode_uleb128 (p, &p);
1118 data_align = decode_sleb128 (p, &p);
1119 return_reg = decode_uleb128 (p, &p);
1122 if (pers_encoding != DW_EH_PE_omit)
1123 read_encoded_val (pers_encoding, p, &p);
1127 /* Make sure the FDE uses the same constants as we do */
1128 g_assert (code_align == 1);
1129 g_assert (data_align == DWARF_DATA_ALIGN);
1130 g_assert (return_reg == DWARF_PC_REG);
1132 /* Compute size of CIE unwind info it is DW_CFA_nop terminated */
1135 if (*p == DW_CFA_nop)
1138 decode_cie_op (p, &p);
1140 cie_cfi_len = p - cie_cfi;
1141 fde_cfi_len = (fde + fde_len - fde_cfi);
1143 buf = g_malloc0 (cie_cfi_len + fde_cfi_len);
1144 memcpy (buf, cie_cfi, cie_cfi_len);
1145 memcpy (buf + cie_cfi_len, fde_cfi, fde_cfi_len);
1147 res->unw_info_len = cie_cfi_len + fde_cfi_len;
1148 res->unw_info = buf;
1152 * mono_unwind_get_cie_program:
1154 * Get the unwind bytecode for the DWARF CIE.
1157 mono_unwind_get_cie_program (void)
1159 #if defined(TARGET_AMD64) || defined(TARGET_X86) || defined(TARGET_POWERPC)
1160 return mono_arch_get_cie_program ();