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-rw-r--r--tools/compact-unwind/compact-unwind-dumper.c1215
1 files changed, 1215 insertions, 0 deletions
diff --git a/tools/compact-unwind/compact-unwind-dumper.c b/tools/compact-unwind/compact-unwind-dumper.c
new file mode 100644
index 000000000000..fd8ea2161896
--- /dev/null
+++ b/tools/compact-unwind/compact-unwind-dumper.c
@@ -0,0 +1,1215 @@
+#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>
+#include <stdio.h>
+#include <mach-o/nlist.h>
+
+#define EXTRACT_BITS(value, mask) \
+ ( (value >> __builtin_ctz(mask)) & (((1 << __builtin_popcount(mask)))-1) )
+
+
+// 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 symbol
+{
+ uint64_t file_address;
+ const char *name;
+};
+
+int
+symbol_compare (const void *a, const void *b)
+{
+ return (int) ((struct symbol *)a)->file_address - ((struct symbol *)b)->file_address;
+}
+
+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; // __TEXT segment vmaddr
+ uint64_t text_segment_file_offset;
+
+ uint64_t text_section_vmaddr; // __TEXT,__text section vmaddr
+ uint64_t text_section_file_offset;
+
+ 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 symbol *symbols;
+ int symbols_count;
+
+ uint64_t *function_start_addresses;
+ int function_start_addresses_count;
+
+ int current_index_table_number;
+
+ 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;
+};
+
+
+uint64_t
+read_leb128 (uint8_t **offset)
+{
+ uint64_t result = 0;
+ int shift = 0;
+ while (1)
+ {
+ uint8_t byte = **offset;
+ *offset = *offset + 1;
+ result |= (byte & 0x7f) << shift;
+ if ((byte & 0x80) == 0)
+ break;
+ shift += 7;
+ }
+
+ return result;
+}
+
+// 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.
+
+static void
+scan_macho_load_commands (struct baton *baton)
+{
+ struct symtab_command symtab_cmd;
+ uint64_t linkedit_segment_vmaddr;
+ uint64_t linkedit_segment_file_offset;
+
+ 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;
+
+ uint8_t *start_of_load_commands = offset;
+
+ uint32_t cur_cmd = 0;
+ while (cur_cmd < mh.ncmds && (offset - start_of_load_commands) < 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;
+
+ if (*lc_cmd == LC_SEGMENT || *lc_cmd == LC_SEGMENT_64)
+ {
+ 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 ((seg.flags & SG_PROTECTED_VERSION_1) == SG_PROTECTED_VERSION_1)
+ {
+ printf ("Segment '%s' is encrypted.\n", segment_name);
+ }
+ }
+
+ 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 ((seg.flags & SG_PROTECTED_VERSION_1) == SG_PROTECTED_VERSION_1)
+ {
+ printf ("Segment '%s' is encrypted.\n", segment_name);
+ }
+ }
+
+ if (nsects != 0 && strcmp (segment_name, "__TEXT") == 0)
+ {
+ baton->text_segment_vmaddr = segment_vmaddr;
+ baton->text_segment_file_offset = segment_offset;
+
+ uint32_t current_sect = 0;
+ while (current_sect < nsects && (offset - start_of_this_load_cmd) < *lc_cmdsize)
+ {
+ char sect_name[17];
+ memcpy (&sect_name, offset, 16);
+ sect_name[16] = '\0';
+ if (strcmp (sect_name, "__unwind_info") == 0)
+ {
+ if (is_64bit)
+ {
+ struct section_64 sect;
+ memcpy (&sect, offset, sizeof (struct section_64));
+ baton->compact_unwind_start = baton->mach_header_start + sect.offset;
+ }
+ else
+ {
+ struct section sect;
+ memcpy (&sect, 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 (&sect, offset, sizeof (struct section_64));
+ baton->eh_section_file_address = sect.addr;
+ }
+ else
+ {
+ struct section sect;
+ memcpy (&sect, offset, sizeof (struct section));
+ baton->eh_section_file_address = sect.addr;
+ }
+ }
+ if (strcmp (sect_name, "__text") == 0)
+ {
+ if (is_64bit)
+ {
+ struct section_64 sect;
+ memcpy (&sect, offset, sizeof (struct section_64));
+ baton->text_section_vmaddr = sect.addr;
+ baton->text_section_file_offset = sect.offset;
+ }
+ else
+ {
+ struct section sect;
+ memcpy (&sect, offset, sizeof (struct section));
+ baton->text_section_vmaddr = sect.addr;
+ }
+ }
+ if (is_64bit)
+ {
+ offset += sizeof (struct section_64);
+ }
+ else
+ {
+ offset += sizeof (struct section);
+ }
+ }
+ }
+
+ if (strcmp (segment_name, "__LINKEDIT") == 0)
+ {
+ linkedit_segment_vmaddr = segment_vmaddr;
+ linkedit_segment_file_offset = segment_offset;
+ }
+ }
+
+ if (*lc_cmd == LC_SYMTAB)
+ {
+ memcpy (&symtab_cmd, offset, sizeof (struct symtab_command));
+ }
+
+ if (*lc_cmd == LC_DYSYMTAB)
+ {
+ struct dysymtab_command dysymtab_cmd;
+ memcpy (&dysymtab_cmd, offset, sizeof (struct dysymtab_command));
+
+ int nlist_size = 12;
+ if (is_64bit)
+ nlist_size = 16;
+
+ char *string_table = (char *) (baton->mach_header_start + symtab_cmd.stroff);
+ uint8_t *local_syms = baton->mach_header_start + symtab_cmd.symoff + (dysymtab_cmd.ilocalsym * nlist_size);
+ int local_syms_count = dysymtab_cmd.nlocalsym;
+ uint8_t *exported_syms = baton->mach_header_start + symtab_cmd.symoff + (dysymtab_cmd.iextdefsym * nlist_size);
+ int exported_syms_count = dysymtab_cmd.nextdefsym;
+
+ // We're only going to create records for a small number of these symbols but to
+ // simplify the memory management I'll allocate enough space to store all of them.
+ baton->symbols = (struct symbol *) malloc (sizeof (struct symbol) * (local_syms_count + exported_syms_count));
+ baton->symbols_count = 0;
+
+ for (int i = 0; i < local_syms_count; i++)
+ {
+ struct nlist_64 nlist;
+ if (is_64bit)
+ {
+ memcpy (&nlist, local_syms + (i * nlist_size), sizeof (struct nlist_64));
+ }
+ else
+ {
+ struct nlist nlist_32;
+ memcpy (&nlist_32, local_syms + (i * nlist_size), sizeof (struct nlist));
+ nlist.n_un.n_strx = nlist_32.n_un.n_strx;
+ nlist.n_type = nlist_32.n_type;
+ nlist.n_sect = nlist_32.n_sect;
+ nlist.n_desc = nlist_32.n_desc;
+ nlist.n_value = nlist_32.n_value;
+ }
+ if ((nlist.n_type & N_STAB) == 0
+ && ((nlist.n_type & N_EXT) == 1 ||
+ ((nlist.n_type & N_TYPE) == N_TYPE && nlist.n_sect != NO_SECT))
+ && nlist.n_value != 0
+ && nlist.n_value != baton->text_segment_vmaddr)
+ {
+ baton->symbols[baton->symbols_count].file_address = nlist.n_value;
+ baton->symbols[baton->symbols_count].name = string_table + nlist.n_un.n_strx;
+ baton->symbols_count++;
+ }
+ }
+
+ for (int i = 0; i < exported_syms_count; i++)
+ {
+ struct nlist_64 nlist;
+ if (is_64bit)
+ {
+ memcpy (&nlist, exported_syms + (i * nlist_size), sizeof (struct nlist_64));
+ }
+ else
+ {
+ struct nlist nlist_32;
+ memcpy (&nlist_32, exported_syms + (i * nlist_size), sizeof (struct nlist));
+ nlist.n_un.n_strx = nlist_32.n_un.n_strx;
+ nlist.n_type = nlist_32.n_type;
+ nlist.n_sect = nlist_32.n_sect;
+ nlist.n_desc = nlist_32.n_desc;
+ nlist.n_value = nlist_32.n_value;
+ }
+ if ((nlist.n_type & N_STAB) == 0
+ && ((nlist.n_type & N_EXT) == 1 ||
+ ((nlist.n_type & N_TYPE) == N_TYPE && nlist.n_sect != NO_SECT))
+ && nlist.n_value != 0
+ && nlist.n_value != baton->text_segment_vmaddr)
+ {
+ baton->symbols[baton->symbols_count].file_address = nlist.n_value;
+ baton->symbols[baton->symbols_count].name = string_table + nlist.n_un.n_strx;
+ baton->symbols_count++;
+ }
+ }
+
+ qsort (baton->symbols, baton->symbols_count, sizeof (struct symbol), symbol_compare);
+ }
+
+ if (*lc_cmd == LC_FUNCTION_STARTS)
+ {
+ struct linkedit_data_command function_starts_cmd;
+ memcpy (&function_starts_cmd, offset, sizeof (struct linkedit_data_command));
+
+ uint8_t *funcstarts_offset = baton->mach_header_start + function_starts_cmd.dataoff;
+ uint8_t *function_end = funcstarts_offset + function_starts_cmd.datasize;
+ int count = 0;
+
+ while (funcstarts_offset < function_end)
+ {
+ if (read_leb128 (&funcstarts_offset) != 0)
+ {
+ count++;
+ }
+ }
+
+ baton->function_start_addresses = (uint64_t *) malloc (sizeof (uint64_t) * count);
+ baton->function_start_addresses_count = count;
+
+ funcstarts_offset = baton->mach_header_start + function_starts_cmd.dataoff;
+ uint64_t current_pc = baton->text_segment_vmaddr;
+ int i = 0;
+ while (funcstarts_offset < function_end)
+ {
+ uint64_t func_start = read_leb128 (&funcstarts_offset);
+ if (func_start != 0)
+ {
+ current_pc += func_start;
+ baton->function_start_addresses[i++] = current_pc;
+ }
+ }
+ }
+
+ offset = start_of_this_load_cmd + *lc_cmdsize;
+ cur_cmd++;
+ }
+
+
+ // Augment the symbol table with the function starts table -- adding symbol entries
+ // for functions that were stripped.
+
+ int unnamed_functions_to_add = 0;
+ for (int i = 0; i < baton->function_start_addresses_count; i++)
+ {
+ struct symbol search_key;
+ search_key.file_address = baton->function_start_addresses[i];
+ struct symbol *sym = bsearch (&search_key, baton->symbols, baton->symbols_count, sizeof (struct symbol), symbol_compare);
+ if (sym == NULL)
+ unnamed_functions_to_add++;
+ }
+
+ baton->symbols = (struct symbol *) realloc (baton->symbols, sizeof (struct symbol) * (baton->symbols_count + unnamed_functions_to_add));
+
+ int current_unnamed_symbol = 1;
+ int number_symbols_added = 0;
+ for (int i = 0; i < baton->function_start_addresses_count; i++)
+ {
+ struct symbol search_key;
+ search_key.file_address = baton->function_start_addresses[i];
+ struct symbol *sym = bsearch (&search_key, baton->symbols, baton->symbols_count, sizeof (struct symbol), symbol_compare);
+ if (sym == NULL)
+ {
+ char *name;
+ asprintf (&name, "unnamed function #%d", current_unnamed_symbol++);
+ baton->symbols[baton->symbols_count + number_symbols_added].file_address = baton->function_start_addresses[i];
+ baton->symbols[baton->symbols_count + number_symbols_added].name = name;
+ number_symbols_added++;
+ }
+ }
+ baton->symbols_count += number_symbols_added;
+ qsort (baton->symbols, baton->symbols_count, sizeof (struct symbol), symbol_compare);
+
+
+// printf ("function start addresses\n");
+// for (int i = 0; i < baton->function_start_addresses_count; i++)
+// {
+// printf ("0x%012llx\n", baton->function_start_addresses[i]);
+// }
+
+// printf ("symbol table names & addresses\n");
+// for (int i = 0; i < baton->symbols_count; i++)
+// {
+// printf ("0x%012llx %s\n", baton->symbols[i].file_address, baton->symbols[i].name);
+// }
+
+}
+
+void
+print_encoding_x86_64 (struct baton baton, uint8_t *function_start, 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 = EXTRACT_BITS (encoding, UNWIND_X86_64_RBP_FRAME_OFFSET);
+
+ uint32_t saved_registers_locations = EXTRACT_BITS (encoding, 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:
+ case UNWIND_X86_64_MODE_STACK_IMMD:
+ {
+ uint32_t stack_size = EXTRACT_BITS (encoding, UNWIND_X86_64_FRAMELESS_STACK_SIZE);
+ uint32_t register_count = EXTRACT_BITS (encoding, UNWIND_X86_64_FRAMELESS_STACK_REG_COUNT);
+ uint32_t permutation = EXTRACT_BITS (encoding, UNWIND_X86_64_FRAMELESS_STACK_REG_PERMUTATION);
+
+ if (mode == UNWIND_X86_64_MODE_STACK_IND && function_start)
+ {
+ uint32_t stack_adjust = EXTRACT_BITS (encoding, UNWIND_X86_64_FRAMELESS_STACK_ADJUST);
+
+ // offset into the function instructions; 0 == beginning of first instruction
+ uint32_t offset_to_subl_insn = EXTRACT_BITS (encoding, UNWIND_X86_64_FRAMELESS_STACK_SIZE);
+
+ stack_size = *((uint32_t*) (function_start + offset_to_subl_insn));
+
+ stack_size += stack_adjust * 8;
+
+ printf ("large stack ");
+ }
+
+ printf ("frameless function: stack size %d, register count %d ", stack_size * 8, register_count);
+
+ if (register_count == 0)
+ {
+ printf (" no registers saved");
+ }
+ else
+ {
+
+ // We need to include (up to) 6 registers in 10 bits.
+ // That would be 18 bits if we just used 3 bits per reg to indicate
+ // the order they're saved on the stack.
+ //
+ // This is done with Lehmer code permutation, e.g. see
+ // http://stackoverflow.com/questions/1506078/fast-permutation-number-permutation-mapping-algorithms
+ int permunreg[6];
+
+ // This decodes the variable-base number in the 10 bits
+ // and gives us the Lehmer code sequence which can then
+ // be decoded.
+
+ switch (register_count)
+ {
+ case 6:
+ permunreg[0] = permutation/120; // 120 == 5!
+ permutation -= (permunreg[0]*120);
+ permunreg[1] = permutation/24; // 24 == 4!
+ permutation -= (permunreg[1]*24);
+ permunreg[2] = permutation/6; // 6 == 3!
+ permutation -= (permunreg[2]*6);
+ permunreg[3] = permutation/2; // 2 == 2!
+ permutation -= (permunreg[3]*2);
+ permunreg[4] = permutation; // 1 == 1!
+ 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;
+ }
+
+ // Decode the Lehmer code for this permutation of
+ // the registers v. http://en.wikipedia.org/wiki/Lehmer_code
+
+ 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 = 1; 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 ("DWARF unwind instructions: FDE at offset %d (file address 0x%" PRIx64 ")",
+ dwarf_offset, dwarf_offset + baton.eh_section_file_address);
+ }
+ break;
+
+ case 0:
+ {
+ printf (" no unwind information");
+ }
+ break;
+ }
+}
+
+void
+print_encoding_i386 (struct baton baton, uint8_t *function_start, uint32_t encoding)
+{
+ int mode = encoding & UNWIND_X86_MODE_MASK;
+ switch (mode)
+ {
+ case UNWIND_X86_MODE_EBP_FRAME:
+ {
+ printf ("frame func: CFA is ebp+%d ", 8);
+ printf (" eip=[CFA-4] ebp=[CFA-8]");
+ uint32_t saved_registers_offset = EXTRACT_BITS (encoding, UNWIND_X86_EBP_FRAME_OFFSET);
+
+ uint32_t saved_registers_locations = EXTRACT_BITS (encoding, UNWIND_X86_EBP_FRAME_REGISTERS);
+
+
+ saved_registers_offset += 2;
+
+ for (int i = 0; i < 5; i++)
+ {
+ switch (saved_registers_locations & 0x7)
+ {
+ case UNWIND_X86_REG_NONE:
+ break;
+ case UNWIND_X86_REG_EBX:
+ printf (" ebx=[CFA-%d]", saved_registers_offset * 4);
+ break;
+ case UNWIND_X86_REG_ECX:
+ printf (" ecx=[CFA-%d]", saved_registers_offset * 4);
+ break;
+ case UNWIND_X86_REG_EDX:
+ printf (" edx=[CFA-%d]", saved_registers_offset * 4);
+ break;
+ case UNWIND_X86_REG_EDI:
+ printf (" edi=[CFA-%d]", saved_registers_offset * 4);
+ break;
+ case UNWIND_X86_REG_ESI:
+ printf (" esi=[CFA-%d]", saved_registers_offset * 4);
+ break;
+ }
+ saved_registers_offset--;
+ saved_registers_locations >>= 3;
+ }
+ }
+ break;
+
+ case UNWIND_X86_MODE_STACK_IND:
+ case UNWIND_X86_MODE_STACK_IMMD:
+ {
+ uint32_t stack_size = EXTRACT_BITS (encoding, UNWIND_X86_FRAMELESS_STACK_SIZE);
+ uint32_t register_count = EXTRACT_BITS (encoding, UNWIND_X86_FRAMELESS_STACK_REG_COUNT);
+ uint32_t permutation = EXTRACT_BITS (encoding, UNWIND_X86_FRAMELESS_STACK_REG_PERMUTATION);
+
+ if (mode == UNWIND_X86_MODE_STACK_IND && function_start)
+ {
+ uint32_t stack_adjust = EXTRACT_BITS (encoding, UNWIND_X86_FRAMELESS_STACK_ADJUST);
+
+ // offset into the function instructions; 0 == beginning of first instruction
+ uint32_t offset_to_subl_insn = EXTRACT_BITS (encoding, UNWIND_X86_FRAMELESS_STACK_SIZE);
+
+ stack_size = *((uint32_t*) (function_start + offset_to_subl_insn));
+
+ stack_size += stack_adjust * 4;
+
+ printf ("large stack ");
+ }
+
+ printf ("frameless function: stack size %d, register count %d ", stack_size * 4, register_count);
+
+ if (register_count == 0)
+ {
+ printf (" no registers saved");
+ }
+ else
+ {
+
+ // We need to include (up to) 6 registers in 10 bits.
+ // That would be 18 bits if we just used 3 bits per reg to indicate
+ // the order they're saved on the stack.
+ //
+ // This is done with Lehmer code permutation, e.g. see
+ // http://stackoverflow.com/questions/1506078/fast-permutation-number-permutation-mapping-algorithms
+ int permunreg[6];
+
+ // This decodes the variable-base number in the 10 bits
+ // and gives us the Lehmer code sequence which can then
+ // be decoded.
+
+ switch (register_count)
+ {
+ case 6:
+ permunreg[0] = permutation/120; // 120 == 5!
+ permutation -= (permunreg[0]*120);
+ permunreg[1] = permutation/24; // 24 == 4!
+ permutation -= (permunreg[1]*24);
+ permunreg[2] = permutation/6; // 6 == 3!
+ permutation -= (permunreg[2]*6);
+ permunreg[3] = permutation/2; // 2 == 2!
+ permutation -= (permunreg[3]*2);
+ permunreg[4] = permutation; // 1 == 1!
+ 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;
+ }
+
+ // Decode the Lehmer code for this permutation of
+ // the registers v. http://en.wikipedia.org/wiki/Lehmer_code
+
+ 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 = 1; j < 7; j++)
+ {
+ if (used[j] == false)
+ {
+ if (renum == permunreg[i])
+ {
+ registers[i] = j;
+ used[j] = true;
+ break;
+ }
+ renum++;
+ }
+ }
+ }
+
+
+ printf (" CFA is esp+%d ", stack_size * 4);
+
+ uint32_t saved_registers_offset = 1;
+ printf (" eip=[CFA-%d]", saved_registers_offset * 4);
+ saved_registers_offset++;
+
+ for (int i = (sizeof (registers) / sizeof (int)) - 1; i >= 0; i--)
+ {
+ switch (registers[i])
+ {
+ case UNWIND_X86_REG_NONE:
+ break;
+ case UNWIND_X86_REG_EBX:
+ printf (" ebx=[CFA-%d]", saved_registers_offset * 4);
+ break;
+ case UNWIND_X86_REG_ECX:
+ printf (" ecx=[CFA-%d]", saved_registers_offset * 4);
+ break;
+ case UNWIND_X86_REG_EDX:
+ printf (" edx=[CFA-%d]", saved_registers_offset * 4);
+ break;
+ case UNWIND_X86_REG_EDI:
+ printf (" edi=[CFA-%d]", saved_registers_offset * 4);
+ break;
+ case UNWIND_X86_REG_ESI:
+ printf (" esi=[CFA-%d]", saved_registers_offset * 4);
+ break;
+ case UNWIND_X86_REG_EBP:
+ printf (" ebp=[CFA-%d]", saved_registers_offset * 4);
+ break;
+ }
+ saved_registers_offset++;
+ }
+
+ }
+
+ }
+ break;
+
+ case UNWIND_X86_MODE_DWARF:
+ {
+ uint32_t dwarf_offset = encoding & UNWIND_X86_DWARF_SECTION_OFFSET;
+ printf ("DWARF unwind instructions: FDE at offset %d (file address 0x%" PRIx64 ")",
+ dwarf_offset, dwarf_offset + baton.eh_section_file_address);
+ }
+ break;
+
+ case 0:
+ {
+ printf (" no unwind information");
+ }
+ break;
+ }
+}
+
+
+void print_encoding (struct baton baton, uint8_t *function_start, uint32_t encoding)
+{
+
+ if (baton.cputype == CPU_TYPE_X86_64)
+ {
+ print_encoding_x86_64 (baton, function_start, encoding);
+ }
+ else if (baton.cputype == CPU_TYPE_I386)
+ {
+ print_encoding_i386 (baton, function_start, 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, "");
+ }
+
+ uint64_t file_address = baton.first_level_index_entry.functionOffset + entry_func_offset + baton.text_segment_vmaddr;
+
+ printf (" func [%d] offset %d (file addr 0x%" PRIx64 ")%s, encoding is 0x%x",
+ idx, entry_func_offset,
+ file_address,
+ entry_encoding_index_str,
+ encoding);
+
+ struct symbol *symbol = NULL;
+ for (int i = 0; i < baton.symbols_count; i++)
+ {
+ if (i == baton.symbols_count - 1 && baton.symbols[i].file_address <= file_address)
+ {
+ symbol = &(baton.symbols[i]);
+ break;
+ }
+ else
+ {
+ if (baton.symbols[i].file_address <= file_address && baton.symbols[i + 1].file_address > file_address)
+ {
+ symbol = &(baton.symbols[i]);
+ break;
+ }
+ }
+ }
+
+ printf ("\n ");
+ if (symbol)
+ {
+ int offset = file_address - symbol->file_address;
+
+ // FIXME this is a poor heuristic - if we're greater than 16 bytes past the
+ // start of the function, this is the unwind info for a stripped function.
+ // In reality the compact unwind entry may not line up exactly with the
+ // function bounds.
+ if (offset >= 0)
+ {
+ printf ("name: %s", symbol->name);
+ if (offset > 0)
+ {
+ printf (" + %d", offset);
+ }
+ }
+ printf ("\n ");
+ }
+
+ print_encoding (baton, baton.mach_header_start + baton.first_level_index_entry.functionOffset + baton.text_section_file_offset + entry_func_offset, encoding);
+
+ bool has_lsda = encoding & UNWIND_HAS_LSDA;
+
+ if (has_lsda)
+ {
+ uint32_t func_offset = entry_func_offset + baton.first_level_index_entry.functionOffset;
+
+ int lsda_entry_number = -1;
+
+ 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_entry_number = (mid_lsda_entry_addr - baton.lsda_array_start) / sizeof (struct unwind_info_section_header_lsda_index_entry);
+ break;
+ }
+ else if (mid_lsda_entry.functionOffset < func_offset)
+ {
+ low = mid + 1;
+ }
+ else
+ {
+ high = mid;
+ }
+ }
+
+ if (lsda_entry_number != -1)
+ {
+ printf (", LSDA entry #%d", lsda_entry_number);
+ }
+ else
+ {
+ printf (", LSDA entry not found");
+ }
+ }
+
+ uint32_t pers_idx = EXTRACT_BITS (encoding, UNWIND_PERSONALITY_MASK);
+ if (pers_idx != 0)
+ {
+ pers_idx--; // Change 1-based to 0-based index
+ printf (", personality entry #%d", pers_idx);
+ }
+
+ 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;
+ uint32_t entries_count = baton.regular_second_level_page_header.entryCount;
+
+ uint8_t *offset = page_entries;
+
+ uint32_t idx = 0;
+ while (idx < entries_count)
+ {
+ uint32_t func_offset = *((uint32_t *) (offset));
+ uint32_t encoding = *((uint32_t *) (offset + 4));
+
+ // UNWIND_SECOND_LEVEL_REGULAR entries have a funcOffset which includes the
+ // functionOffset from the containing index table already. UNWIND_SECOND_LEVEL_COMPRESSED
+ // entries only have the offset from the containing index table functionOffset.
+ // So strip off the contianing index table functionOffset value here so they can
+ // be treated the same at the lower layers.
+
+ print_function_encoding (baton, idx, encoding, (uint32_t) -1, func_offset - baton.first_level_index_entry.functionOffset);
+ idx++;
+ offset += 8;
+ }
+}
+
+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 #%d entryPageOffset %d, entryCount %d\n", baton.current_index_table_number, 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 #%d entryPageOffset %d, entryCount %d, encodingsPageOffset %d, encodingsCount %d\n", baton.current_index_table_number, 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)
+ {
+ baton.current_index_table_number = cur_idx;
+ 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));
+ uint64_t function_file_address = baton.first_level_index_entry.functionOffset + lsda_entry.functionOffset + baton.text_segment_vmaddr;
+ uint64_t lsda_file_address = lsda_entry.lsdaOffset + baton.text_segment_vmaddr;
+ 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,
+ function_file_address,
+ lsda_entry.lsdaOffset, lsda_file_address);
+ 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;
+ baton.symbols = NULL;
+ baton.symbols_count = 0;
+ baton.function_start_addresses = NULL;
+ baton.function_start_addresses_count = 0;
+
+ 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, NULL, 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]: personality function ptr @ offset %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;
+}
generated by cgit v1.2.3 (git 2.25.1) at 2024-04-26 09:46:16 +0000