[Lldb-commits] [lldb] r222127 - Add a little sketch of a program that can extract unwind
Jason Molenda
jmolenda at apple.com
Mon Nov 17 03:43:38 PST 2014
Author: jmolenda
Date: Mon Nov 17 05:43:37 2014
New Revision: 222127
URL: http://llvm.org/viewvc/llvm-project?rev=222127&view=rev
Log:
Add a little sketch of a program that can extract unwind
information from the compact unwind section used on darwin
for exception handling, and dump that information..
The UNWIND_X86_64_MODE_RBP_FRAME and UNWIND_X86_64_MODE_DWARF
entries look to be handled correctly.
UNWIND_X86_64_MODE_STACK_IMMD and UNWIND_X86_64_MODE_STACK_IND
are still a work in progress.
Only x86_64 is supported right now. Given that this is an
experiment in parsing the section contents, I don't expect to
add other architectures; they are trivial variations on this
arch. There exists a real dumper included in the Xcode tools,
unwinddump.
Added:
lldb/trunk/tools/compact-unwind/
lldb/trunk/tools/compact-unwind/compact-unwind-dumper.c
Added: lldb/trunk/tools/compact-unwind/compact-unwind-dumper.c
URL: http://llvm.org/viewvc/llvm-project/lldb/trunk/tools/compact-unwind/compact-unwind-dumper.c?rev=222127&view=auto
==============================================================================
--- lldb/trunk/tools/compact-unwind/compact-unwind-dumper.c (added)
+++ lldb/trunk/tools/compact-unwind/compact-unwind-dumper.c Mon Nov 17 05:43:37 2014
@@ -0,0 +1,664 @@
+#include <stdio.h>
+#include <stdint.h>
+#include <mach-o/loader.h>
+#include <mach-o/compact_unwind_encoding.h>
+#include <mach/machine.h>
+#include <stdlib.h>
+#include <stdbool.h>
+#include <string.h>
+#include <fcntl.h>
+#include <sys/types.h>
+#include <sys/mman.h>
+#include <sys/errno.h>
+#include <sys/stat.h>
+#include <inttypes.h>
+
+
+// A quick sketch of a program which can parse the compact unwind info
+// used on Darwin systems for exception handling. The output of
+// unwinddump will be more authoritative/reliable but this program
+// can dump at least the UNWIND_X86_64_MODE_RBP_FRAME format entries
+// correctly.
+
+struct baton
+{
+ cpu_type_t cputype;
+
+ uint8_t *mach_header_start; // pointer into this program's address space
+ uint8_t *compact_unwind_start; // pointer into this program's address space
+
+ int addr_size; // 4 or 8 bytes, the size of addresses in this file
+
+ uint64_t text_segment_vmaddr;
+ uint64_t eh_section_file_address; // the file address of the __TEXT,__eh_frame section
+
+ uint8_t *lsda_array_start; // for the currently-being-processed first-level index
+ uint8_t *lsda_array_end; // the lsda_array_start for the NEXT first-level index
+
+ struct unwind_info_section_header unwind_header;
+ struct unwind_info_section_header_index_entry first_level_index_entry;
+ struct unwind_info_compressed_second_level_page_header compressed_second_level_page_header;
+ struct unwind_info_regular_second_level_page_header regular_second_level_page_header;
+};
+
+
+// step through the load commands in a thin mach-o binary,
+// find the cputype and the start of the __TEXT,__unwind_info
+// section, return a pointer to that section or NULL if not found.
+
+void
+scan_macho_load_commands (struct baton *baton)
+{
+ baton->compact_unwind_start = 0;
+
+ uint32_t *magic = (uint32_t *) baton->mach_header_start;
+
+ if (*magic != MH_MAGIC && *magic != MH_MAGIC_64)
+ {
+ printf ("Unexpected magic number 0x%x in header, exiting.", *magic);
+ exit (1);
+ }
+
+ bool is_64bit = false;
+ if (*magic == MH_MAGIC_64)
+ is_64bit = true;
+
+ uint8_t *offset = baton->mach_header_start;
+
+ struct mach_header mh;
+ memcpy (&mh, offset, sizeof (struct mach_header));
+ if (is_64bit)
+ offset += sizeof (struct mach_header_64);
+ else
+ offset += sizeof (struct mach_header);
+
+ if (is_64bit)
+ baton->addr_size = 8;
+ else
+ baton->addr_size = 4;
+
+ baton->cputype = mh.cputype;
+
+ uint32_t cur_cmd = 0;
+ while (cur_cmd < mh.ncmds && (offset - baton->mach_header_start) < mh.sizeofcmds)
+ {
+ struct load_command lc;
+ uint32_t *lc_cmd = (uint32_t *) offset;
+ uint32_t *lc_cmdsize = (uint32_t *) offset + 1;
+ uint8_t *start_of_this_load_cmd = offset;
+
+ char segment_name[17];
+ segment_name[0] = '\0';
+ uint32_t nsects = 0;
+ uint64_t segment_offset = 0;
+ uint64_t segment_vmaddr = 0;
+
+ if (*lc_cmd == LC_SEGMENT_64)
+ {
+ struct segment_command_64 seg;
+ memcpy (&seg, offset, sizeof (struct segment_command_64));
+ memcpy (&segment_name, &seg.segname, 16);
+ segment_name[16] = '\0';
+ nsects = seg.nsects;
+ segment_offset = seg.fileoff;
+ segment_vmaddr = seg.vmaddr;
+ offset += sizeof (struct segment_command_64);
+ }
+
+ if (*lc_cmd == LC_SEGMENT)
+ {
+ struct segment_command seg;
+ memcpy (&seg, offset, sizeof (struct segment_command));
+ memcpy (&segment_name, &seg.segname, 16);
+ segment_name[16] = '\0';
+ nsects = seg.nsects;
+ segment_offset = seg.fileoff;
+ segment_vmaddr = seg.vmaddr;
+ offset += sizeof (struct segment_command);
+ }
+
+ if (nsects != 0 && segment_name[0] != '\0' && strcmp (segment_name, "__TEXT") == 0)
+ {
+ baton->text_segment_vmaddr = segment_vmaddr;
+
+ uint32_t current_sect = 0;
+ while (current_sect < nsects && (offset - start_of_this_load_cmd) < *lc_cmdsize)
+ {
+ char sect_name[17];
+ memcpy (§_name, offset, 16);
+ sect_name[16] = '\0';
+ if (strcmp (sect_name, "__unwind_info") == 0)
+ {
+ if (is_64bit)
+ {
+ struct section_64 sect;
+ memcpy (§, offset, sizeof (struct section_64));
+ baton->compact_unwind_start = baton->mach_header_start + sect.offset;
+ }
+ else
+ {
+ struct section sect;
+ memcpy (§, offset, sizeof (struct section));
+ baton->compact_unwind_start = baton->mach_header_start + sect.offset;
+ }
+ }
+ if (strcmp (sect_name, "__eh_frame") == 0)
+ {
+ if (is_64bit)
+ {
+ struct section_64 sect;
+ memcpy (§, offset, sizeof (struct section_64));
+ baton->eh_section_file_address = sect.addr;
+ }
+ else
+ {
+ struct section sect;
+ memcpy (§, offset, sizeof (struct section));
+ baton->eh_section_file_address = sect.addr;
+ }
+ }
+
+ if (is_64bit)
+ {
+ offset += sizeof (struct section_64);
+ }
+ else
+ {
+ offset += sizeof (struct section);
+ }
+ }
+
+ return;
+ }
+
+ offset = start_of_this_load_cmd + *lc_cmdsize;
+ cur_cmd++;
+ }
+}
+
+void
+print_encoding_x86_64 (struct baton baton, uint32_t encoding)
+{
+ int mode = encoding & UNWIND_X86_64_MODE_MASK;
+ switch (mode)
+ {
+ case UNWIND_X86_64_MODE_RBP_FRAME:
+ {
+ printf (" - frame func: CFA is rbp+%d ", 16);
+ printf (" rip=[CFA-8] rbp=[CFA-16]");
+ uint32_t saved_registers_offset = (encoding & UNWIND_X86_64_RBP_FRAME_OFFSET) >> (__builtin_ctz (UNWIND_X86_64_RBP_FRAME_OFFSET));
+
+ uint32_t saved_registers_locations = (encoding & UNWIND_X86_64_RBP_FRAME_REGISTERS) >> (__builtin_ctz (UNWIND_X86_64_RBP_FRAME_REGISTERS));
+
+
+ saved_registers_offset += 2;
+
+ for (int i = 0; i < 5; i++)
+ {
+ switch (saved_registers_locations & 0x7)
+ {
+ case UNWIND_X86_64_REG_NONE:
+ break;
+ case UNWIND_X86_64_REG_RBX:
+ printf (" rbx=[CFA-%d]", saved_registers_offset * 8);
+ break;
+ case UNWIND_X86_64_REG_R12:
+ printf (" r12=[CFA-%d]", saved_registers_offset * 8);
+ break;
+ case UNWIND_X86_64_REG_R13:
+ printf (" r13=[CFA-%d]", saved_registers_offset * 8);
+ break;
+ case UNWIND_X86_64_REG_R14:
+ printf (" r14=[CFA-%d]", saved_registers_offset * 8);
+ break;
+ case UNWIND_X86_64_REG_R15:
+ printf (" r15=[CFA-%d]", saved_registers_offset * 8);
+ break;
+ }
+ saved_registers_offset--;
+ saved_registers_locations >>= 3;
+ }
+ }
+ break;
+
+ case UNWIND_X86_64_MODE_STACK_IND:
+ {
+ printf (" UNWIND_X86_64_MODE_STACK_IND not yet supported\n");
+ break;
+ }
+ case UNWIND_X86_64_MODE_STACK_IMMD:
+ {
+ printf (" UNWIND_X86_64_MODE_STACK_IND not yet supported\n");
+ break;
+
+ // FIXME not getting the rbp register saves out of the register permutation yet
+
+ uint32_t stack_size = (encoding & UNWIND_X86_64_FRAMELESS_STACK_SIZE) >> (__builtin_ctz (UNWIND_X86_64_FRAMELESS_STACK_SIZE));
+ uint32_t stack_adjust = (encoding & UNWIND_X86_FRAMELESS_STACK_ADJUST) >> (__builtin_ctz (UNWIND_X86_FRAMELESS_STACK_ADJUST));
+ uint32_t register_count = (encoding & UNWIND_X86_64_FRAMELESS_STACK_REG_COUNT) >> (__builtin_ctz (UNWIND_X86_64_FRAMELESS_STACK_REG_COUNT));
+ uint32_t permutation = (encoding & UNWIND_X86_FRAMELESS_STACK_REG_PERMUTATION) >> (__builtin_ctz (UNWIND_X86_FRAMELESS_STACK_REG_PERMUTATION));
+
+// printf (" frameless function: stack size %d, stack adjust %d, register count %d ", stack_size * 8, stack_adjust * 8, register_count);
+ if ((encoding & UNWIND_X86_64_MODE_MASK) == UNWIND_X86_64_MODE_STACK_IND)
+ {
+ printf (" UNWIND_X86_64_MODE_STACK_IND not handled ");
+ // stack size is too large to store in UNWIND_X86_64_FRAMELESS_STACK_SIZE; instead
+ // stack_size is an offset into the function's instruction stream to the 32-bit literal
+ // value in a "sub $xxx, %rsp" instruction.
+ return;
+ }
+
+ if (register_count == 0)
+ {
+ printf (" no registers saved");
+ }
+ else
+ {
+ int permunreg[6];
+ switch (register_count)
+ {
+ case 6:
+ permunreg[0] = permutation/120;
+ permutation -= (permunreg[0]*120);
+ permunreg[1] = permutation/24;
+ permutation -= (permunreg[1]*24);
+ permunreg[2] = permutation/6;
+ permutation -= (permunreg[2]*6);
+ permunreg[3] = permutation/2;
+ permutation -= (permunreg[3]*2);
+ permunreg[4] = permutation;
+ permunreg[5] = 0;
+ break;
+ case 5:
+ permunreg[0] = permutation/120;
+ permutation -= (permunreg[0]*120);
+ permunreg[1] = permutation/24;
+ permutation -= (permunreg[1]*24);
+ permunreg[2] = permutation/6;
+ permutation -= (permunreg[2]*6);
+ permunreg[3] = permutation/2;
+ permutation -= (permunreg[3]*2);
+ permunreg[4] = permutation;
+ break;
+ case 4:
+ permunreg[0] = permutation/60;
+ permutation -= (permunreg[0]*60);
+ permunreg[1] = permutation/12;
+ permutation -= (permunreg[1]*12);
+ permunreg[2] = permutation/3;
+ permutation -= (permunreg[2]*3);
+ permunreg[3] = permutation;
+ break;
+ case 3:
+ permunreg[0] = permutation/20;
+ permutation -= (permunreg[0]*20);
+ permunreg[1] = permutation/4;
+ permutation -= (permunreg[1]*4);
+ permunreg[2] = permutation;
+ break;
+ case 2:
+ permunreg[0] = permutation/5;
+ permutation -= (permunreg[0]*5);
+ permunreg[1] = permutation;
+ break;
+ case 1:
+ permunreg[0] = permutation;
+ break;
+ }
+
+ int registers[6];
+ bool used[7] = { false, false, false, false, false, false, false };
+ for (int i = 0; i < register_count; i++)
+ {
+ int renum = 0;
+ for (int j = 0; j < 7; j++)
+ {
+ if (used[j] == false)
+ {
+ if (renum == permunreg[i])
+ {
+ registers[i] = j;
+ used[j] = true;
+ break;
+ }
+ renum++;
+ }
+ }
+ }
+
+
+ printf ("CFA is rsp+%d ", stack_size * 8);
+
+ uint32_t saved_registers_offset = 1;
+ printf (" rip=[CFA-%d]", saved_registers_offset * 8);
+ saved_registers_offset++;
+
+ for (int i = (sizeof (registers) / sizeof (int)) - 1; i >= 0; i--)
+ {
+ switch (registers[i])
+ {
+ case UNWIND_X86_64_REG_NONE:
+ break;
+ case UNWIND_X86_64_REG_RBX:
+ printf (" rbx=[CFA-%d]", saved_registers_offset * 8);
+ break;
+ case UNWIND_X86_64_REG_R12:
+ printf (" r12=[CFA-%d]", saved_registers_offset * 8);
+ break;
+ case UNWIND_X86_64_REG_R13:
+ printf (" r13=[CFA-%d]", saved_registers_offset * 8);
+ break;
+ case UNWIND_X86_64_REG_R14:
+ printf (" r14=[CFA-%d]", saved_registers_offset * 8);
+ break;
+ case UNWIND_X86_64_REG_R15:
+ printf (" r15=[CFA-%d]", saved_registers_offset * 8);
+ break;
+ case UNWIND_X86_64_REG_RBP:
+ printf (" rbp=[CFA-%d]", saved_registers_offset * 8);
+ break;
+ }
+ saved_registers_offset++;
+ }
+
+ }
+
+ }
+ break;
+
+ case UNWIND_X86_64_MODE_DWARF:
+ {
+ uint32_t dwarf_offset = encoding & UNWIND_X86_DWARF_SECTION_OFFSET;
+ printf (" use DWARF unwind instructions: FDE at offset %d (file address 0x%" PRIx64 ")\n",
+ dwarf_offset, dwarf_offset + baton.eh_section_file_address);
+ }
+ break;
+
+ }
+}
+
+void print_encoding (struct baton baton, uint32_t encoding)
+{
+
+ if (baton.cputype == CPU_TYPE_X86_64)
+ {
+ print_encoding_x86_64 (baton, encoding);
+ }
+ else
+ {
+ printf (" -- unsupported encoding arch -- ");
+ }
+}
+
+void
+print_function_encoding (struct baton baton, uint32_t idx, uint32_t encoding, uint32_t entry_encoding_index, uint32_t entry_func_offset)
+{
+
+ char *entry_encoding_index_str = "";
+ if (entry_encoding_index != (uint32_t) -1)
+ {
+ asprintf (&entry_encoding_index_str, ", encoding #%d", entry_encoding_index);
+ }
+ else
+ {
+ asprintf (&entry_encoding_index_str, "");
+ }
+ printf (" func [%d] offset %d (file addr 0x%" PRIx64 ")%s - 0x%x",
+ idx, entry_func_offset,
+ entry_func_offset + baton.first_level_index_entry.functionOffset + baton.text_segment_vmaddr,
+ entry_encoding_index_str,
+ encoding);
+
+ print_encoding (baton, encoding);
+
+ bool has_lsda = encoding & UNWIND_HAS_LSDA;
+
+ if (has_lsda)
+ {
+ uint32_t func_offset = entry_func_offset + baton.first_level_index_entry.functionOffset;
+
+ uint32_t lsda_offset = 0;
+
+ uint32_t low = 0;
+ uint32_t high = (baton.lsda_array_end - baton.lsda_array_start) / sizeof (struct unwind_info_section_header_lsda_index_entry);
+
+ while (low < high)
+ {
+ uint32_t mid = (low + high) / 2;
+
+ uint8_t *mid_lsda_entry_addr = (baton.lsda_array_start + (mid * sizeof (struct unwind_info_section_header_lsda_index_entry)));
+ struct unwind_info_section_header_lsda_index_entry mid_lsda_entry;
+ memcpy (&mid_lsda_entry, mid_lsda_entry_addr, sizeof (struct unwind_info_section_header_lsda_index_entry));
+ if (mid_lsda_entry.functionOffset == func_offset)
+ {
+ lsda_offset = mid_lsda_entry.lsdaOffset;
+ break;
+ }
+ else if (mid_lsda_entry.functionOffset < func_offset)
+ {
+ low = mid + 1;
+ }
+ else
+ {
+ high = mid;
+ }
+ }
+
+ printf (", LSDA offset %d", lsda_offset);
+ }
+
+ uint32_t pers_idx = (encoding & UNWIND_PERSONALITY_MASK) >> (__builtin_ctz(UNWIND_PERSONALITY_MASK));
+ if (pers_idx != 0)
+ {
+ pers_idx--; // Change 1-based to 0-based index
+ uint32_t pers_delta = *((uint32_t*) (baton.compact_unwind_start + baton.unwind_header.personalityArraySectionOffset + pers_idx * 4));
+
+ uint8_t **personality_addr = (uint8_t **) (baton.mach_header_start + pers_delta);
+ void *personality = *personality_addr;
+ printf (", personality func addr @ offset %d", pers_delta);
+// printf (", personality %p", personality);
+ }
+
+ printf ("\n");
+}
+
+void
+print_second_level_index_regular (struct baton baton)
+{
+ uint8_t *page_entries = baton.compact_unwind_start + baton.first_level_index_entry.secondLevelPagesSectionOffset + baton.regular_second_level_page_header.entryPageOffset;
+ uint8_t entries_count = baton.regular_second_level_page_header.entryCount;
+
+ uint8_t *offset = page_entries;
+ uint8_t idx = 0;
+
+ for (uint32_t idx = 0; idx < entries_count; idx++, offset += 8)
+ {
+ uint32_t func_offset = *((uint32_t *) (offset));
+ uint32_t encoding = *((uint32_t *) (offset + 4));
+ print_function_encoding (baton, idx, encoding, (uint32_t) -1, func_offset);
+ }
+}
+
+void
+print_second_level_index_compressed (struct baton baton)
+{
+ uint8_t *this_index = baton.compact_unwind_start + baton.first_level_index_entry.secondLevelPagesSectionOffset;
+ uint8_t *start_of_entries = this_index + baton.compressed_second_level_page_header.entryPageOffset;
+ uint8_t *offset = start_of_entries;
+ for (uint16_t idx = 0; idx < baton.compressed_second_level_page_header.entryCount; idx++)
+ {
+ uint32_t entry = *((uint32_t*) offset);
+ offset += 4;
+ uint32_t encoding;
+
+ uint32_t entry_encoding_index = UNWIND_INFO_COMPRESSED_ENTRY_ENCODING_INDEX (entry);
+ uint32_t entry_func_offset = UNWIND_INFO_COMPRESSED_ENTRY_FUNC_OFFSET (entry);
+
+ if (entry_encoding_index < baton.unwind_header.commonEncodingsArrayCount)
+ {
+ // encoding is in common table in section header
+ encoding = *((uint32_t*) (baton.compact_unwind_start + baton.unwind_header.commonEncodingsArraySectionOffset + (entry_encoding_index * sizeof (uint32_t))));
+ }
+ else
+ {
+ // encoding is in page specific table
+ uint32_t page_encoding_index = entry_encoding_index - baton.unwind_header.commonEncodingsArrayCount;
+ encoding = *((uint32_t*) (this_index + baton.compressed_second_level_page_header.encodingsPageOffset + (page_encoding_index * sizeof (uint32_t))));
+ }
+
+
+ print_function_encoding (baton, idx, encoding, entry_encoding_index, entry_func_offset);
+ }
+}
+
+void
+print_second_level_index (struct baton baton)
+{
+ uint8_t *index_start = baton.compact_unwind_start + baton.first_level_index_entry.secondLevelPagesSectionOffset;
+
+ if ((*(uint32_t*) index_start) == UNWIND_SECOND_LEVEL_REGULAR)
+ {
+ struct unwind_info_regular_second_level_page_header header;
+ memcpy (&header, index_start, sizeof (struct unwind_info_regular_second_level_page_header));
+ printf (" UNWIND_SECOND_LEVEL_REGULAR entryPageOffset %d, entryCount %d\n", header.entryPageOffset, header.entryCount);
+ baton.regular_second_level_page_header = header;
+ print_second_level_index_regular (baton);
+ }
+
+ if ((*(uint32_t*) index_start) == UNWIND_SECOND_LEVEL_COMPRESSED)
+ {
+ struct unwind_info_compressed_second_level_page_header header;
+ memcpy (&header, index_start, sizeof (struct unwind_info_compressed_second_level_page_header));
+ printf (" UNWIND_SECOND_LEVEL_COMPRESSED entryPageOffset %d, entryCount %d, encodingsPageOffset %d, encodingsCount %d\n", header.entryPageOffset, header.entryCount, header.encodingsPageOffset, header.encodingsCount);
+ baton.compressed_second_level_page_header = header;
+ print_second_level_index_compressed (baton);
+ }
+}
+
+
+void
+print_index_sections (struct baton baton)
+{
+ uint8_t *index_section_offset = baton.compact_unwind_start + baton.unwind_header.indexSectionOffset;
+ uint32_t index_count = baton.unwind_header.indexCount;
+
+ uint32_t cur_idx = 0;
+
+ uint8_t *offset = index_section_offset;
+ while (cur_idx < index_count)
+ {
+ struct unwind_info_section_header_index_entry index_entry;
+ memcpy (&index_entry, offset, sizeof (struct unwind_info_section_header_index_entry));
+ printf ("index section #%d: functionOffset %d, secondLevelPagesSectionOffset %d, lsdaIndexArraySectionOffset %d\n", cur_idx, index_entry.functionOffset, index_entry.secondLevelPagesSectionOffset, index_entry.lsdaIndexArraySectionOffset);
+
+ // secondLevelPagesSectionOffset == 0 means this is a sentinel entry
+ if (index_entry.secondLevelPagesSectionOffset != 0)
+ {
+ struct unwind_info_section_header_index_entry next_index_entry;
+ memcpy (&next_index_entry, offset + sizeof (struct unwind_info_section_header_index_entry), sizeof (struct unwind_info_section_header_index_entry));
+
+ baton.lsda_array_start = baton.compact_unwind_start + index_entry.lsdaIndexArraySectionOffset;
+ baton.lsda_array_end = baton.compact_unwind_start + next_index_entry.lsdaIndexArraySectionOffset;
+
+ uint8_t *lsda_entry_offset = baton.lsda_array_start;
+ uint32_t lsda_count = 0;
+ while (lsda_entry_offset < baton.lsda_array_end)
+ {
+ struct unwind_info_section_header_lsda_index_entry lsda_entry;
+ memcpy (&lsda_entry, lsda_entry_offset, sizeof (struct unwind_info_section_header_lsda_index_entry));
+ printf (" LSDA [%d] functionOffset %d (%d) (file address 0x%" PRIx64 "), lsdaOffset %d (file address 0x%" PRIx64 ")\n",
+ lsda_count, lsda_entry.functionOffset,
+ lsda_entry.functionOffset - index_entry.functionOffset,
+ lsda_entry.functionOffset + baton.text_segment_vmaddr,
+ lsda_entry.lsdaOffset, lsda_entry.lsdaOffset + baton.text_segment_vmaddr);
+ lsda_count++;
+ lsda_entry_offset += sizeof (struct unwind_info_section_header_lsda_index_entry);
+ }
+
+ printf ("\n");
+
+ baton.first_level_index_entry = index_entry;
+ print_second_level_index (baton);
+ }
+
+ printf ("\n");
+
+ cur_idx++;
+ offset += sizeof (struct unwind_info_section_header_index_entry);
+ }
+}
+
+int main (int argc, char **argv)
+{
+ struct stat st;
+ char *file = argv[0];
+ if (argc > 1)
+ file = argv[1];
+ int fd = open (file, O_RDONLY);
+ if (fd == -1)
+ {
+ printf ("Failed to open '%s'\n", file);
+ exit (1);
+ }
+ fstat (fd, &st);
+ uint8_t *file_mem = (uint8_t*) mmap (0, st.st_size, PROT_READ, MAP_PRIVATE | MAP_FILE, fd, 0);
+ if (file_mem == MAP_FAILED)
+ {
+ printf ("Failed to mmap() '%s'\n", file);
+ }
+
+ FILE *f = fopen ("a.out", "r");
+
+ struct baton baton;
+ baton.mach_header_start = file_mem;
+ scan_macho_load_commands (&baton);
+
+ if (baton.compact_unwind_start == NULL)
+ {
+ printf ("could not find __TEXT,__unwind_info section\n");
+ exit (1);
+ }
+
+
+ struct unwind_info_section_header header;
+ memcpy (&header, baton.compact_unwind_start, sizeof (struct unwind_info_section_header));
+ printf ("Header:\n");
+ printf (" version %u\n", header.version);
+ printf (" commonEncodingsArraySectionOffset is %d\n", header.commonEncodingsArraySectionOffset);
+ printf (" commonEncodingsArrayCount is %d\n", header.commonEncodingsArrayCount);
+ printf (" personalityArraySectionOffset is %d\n", header.personalityArraySectionOffset);
+ printf (" personalityArrayCount is %d\n", header.personalityArrayCount);
+ printf (" indexSectionOffset is %d\n", header.indexSectionOffset);
+ printf (" indexCount is %d\n", header.indexCount);
+
+ uint8_t *common_encodings = baton.compact_unwind_start + header.commonEncodingsArraySectionOffset;
+ uint32_t encoding_idx = 0;
+ while (encoding_idx < header.commonEncodingsArrayCount)
+ {
+ uint32_t encoding = *((uint32_t*) common_encodings);
+ printf (" Common Encoding [%d]: 0x%x", encoding_idx, encoding);
+ print_encoding (baton, encoding);
+ printf ("\n");
+ common_encodings += sizeof (uint32_t);
+ encoding_idx++;
+ }
+
+ uint8_t *pers_arr = baton.compact_unwind_start + header.personalityArraySectionOffset;
+ uint32_t pers_idx = 0;
+ while (pers_idx < header.personalityArrayCount)
+ {
+ int32_t pers_delta = *((int32_t*) (baton.compact_unwind_start + header.personalityArraySectionOffset + (pers_idx * sizeof (uint32_t))));
+ printf (" Personality [%d]: offset to personality function address ptr %d (file address 0x%" PRIx64 ")\n", pers_idx, pers_delta, baton.text_segment_vmaddr + pers_delta);
+ pers_idx++;
+ pers_arr += sizeof (uint32_t);
+ }
+
+ printf ("\n");
+
+ baton.unwind_header = header;
+
+ print_index_sections (baton);
+
+
+ return 0;
+}
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