| 1 | #include <stdio.h> |
| 2 | #include <stdlib.h> |
| 3 | #include <string.h> |
| 4 | #include <stdarg.h> |
| 5 | #include <bfd.h> |
| 6 | #include <dis-asm.h> |
| 7 | |
| 8 | #include "host_dasm.h" |
| 9 | |
| 10 | extern char **g_argv; |
| 11 | |
| 12 | static struct disassemble_info di; |
| 13 | |
| 14 | #ifdef ARM |
| 15 | #define print_insn_func print_insn_little_arm |
| 16 | #define BFD_ARCH bfd_arch_arm |
| 17 | #define BFD_MACH bfd_mach_arm_4T |
| 18 | #else |
| 19 | #define print_insn_func print_insn_i386_intel |
| 20 | #define BFD_ARCH bfd_arch_i386 |
| 21 | #define BFD_MACH bfd_mach_i386_i386_intel_syntax |
| 22 | #endif |
| 23 | |
| 24 | /* symbols */ |
| 25 | static asymbol **symbols; |
| 26 | static long symcount; |
| 27 | |
| 28 | /* Filter out (in place) symbols that are useless for disassembly. |
| 29 | COUNT is the number of elements in SYMBOLS. |
| 30 | Return the number of useful symbols. */ |
| 31 | static long |
| 32 | remove_useless_symbols (asymbol **symbols, long count) |
| 33 | { |
| 34 | asymbol **in_ptr = symbols, **out_ptr = symbols; |
| 35 | |
| 36 | while (--count >= 0) |
| 37 | { |
| 38 | asymbol *sym = *in_ptr++; |
| 39 | |
| 40 | if (sym->name == NULL || sym->name[0] == '\0' || sym->name[0] == '$') |
| 41 | continue; |
| 42 | if (sym->flags & (BSF_DEBUGGING | BSF_SECTION_SYM)) |
| 43 | continue; |
| 44 | if (bfd_is_und_section (sym->section) |
| 45 | || bfd_is_com_section (sym->section)) |
| 46 | continue; |
| 47 | if (sym->value + sym->section->vma == 0) |
| 48 | continue; |
| 49 | /* |
| 50 | printf("sym: %08lx %04x %08x v %08x \"%s\"\n", |
| 51 | (unsigned int)sym->value, (unsigned int)sym->flags, (unsigned int)sym->udata.i, |
| 52 | (unsigned int)sym->section->vma, sym->name); |
| 53 | */ |
| 54 | *out_ptr++ = sym; |
| 55 | } |
| 56 | |
| 57 | return out_ptr - symbols; |
| 58 | } |
| 59 | |
| 60 | static void slurp_symtab(const char *filename) |
| 61 | { |
| 62 | bfd *abfd; |
| 63 | long storage; |
| 64 | |
| 65 | symcount = 0; |
| 66 | |
| 67 | abfd = bfd_openr(filename, NULL); |
| 68 | if (abfd == NULL) { |
| 69 | fprintf(stderr, "failed to open: %s\n", filename); |
| 70 | goto no_symbols; |
| 71 | } |
| 72 | |
| 73 | if (!bfd_check_format(abfd, bfd_object)) |
| 74 | goto no_symbols; |
| 75 | |
| 76 | if (!(bfd_get_file_flags(abfd) & HAS_SYMS)) |
| 77 | goto no_symbols; |
| 78 | |
| 79 | storage = bfd_get_symtab_upper_bound(abfd); |
| 80 | if (storage <= 0) |
| 81 | goto no_symbols; |
| 82 | |
| 83 | symbols = malloc(storage); |
| 84 | symcount = bfd_canonicalize_symtab(abfd, symbols); |
| 85 | if (symcount < 0) |
| 86 | goto no_symbols; |
| 87 | |
| 88 | symcount = remove_useless_symbols(symbols, symcount); |
| 89 | // bfd_close(abfd); |
| 90 | return; |
| 91 | |
| 92 | no_symbols: |
| 93 | fprintf(stderr, "no symbols in %s\n", bfd_get_filename(abfd)); |
| 94 | if (abfd != NULL) |
| 95 | bfd_close(abfd); |
| 96 | } |
| 97 | |
| 98 | |
| 99 | /* Like target_read_memory, but slightly different parameters. */ |
| 100 | static int |
| 101 | dis_asm_read_memory(bfd_vma memaddr, bfd_byte *myaddr, unsigned int len, |
| 102 | struct disassemble_info *info) |
| 103 | { |
| 104 | memcpy(myaddr, (void *)(int)memaddr, len); |
| 105 | return 0; |
| 106 | } |
| 107 | |
| 108 | static void |
| 109 | dis_asm_memory_error(int status, bfd_vma memaddr, |
| 110 | struct disassemble_info *info) |
| 111 | { |
| 112 | fprintf(stderr, "memory_error %p\n", (void *)(int)memaddr); |
| 113 | } |
| 114 | |
| 115 | static void |
| 116 | dis_asm_print_address(bfd_vma addr, struct disassemble_info *info) |
| 117 | { |
| 118 | asymbol **sptr = symbols; |
| 119 | int i; |
| 120 | |
| 121 | printf("%08x", (int)addr); |
| 122 | |
| 123 | for (i = 0; i < symcount; i++) { |
| 124 | asymbol *sym = *sptr++; |
| 125 | |
| 126 | if (addr == sym->value + sym->section->vma) { |
| 127 | printf(" <%s>", sym->name); |
| 128 | break; |
| 129 | } |
| 130 | } |
| 131 | } |
| 132 | |
| 133 | static int insn_printf(void *f, const char *format, ...) |
| 134 | { |
| 135 | va_list args; |
| 136 | size_t n; |
| 137 | |
| 138 | va_start(args, format); |
| 139 | n = vprintf(format, args); |
| 140 | va_end(args); |
| 141 | |
| 142 | return n; |
| 143 | } |
| 144 | |
| 145 | static void host_dasm_init(void) |
| 146 | { |
| 147 | slurp_symtab(g_argv[0]); |
| 148 | |
| 149 | init_disassemble_info(&di, NULL, insn_printf); |
| 150 | di.flavour = bfd_target_unknown_flavour; |
| 151 | di.memory_error_func = dis_asm_memory_error; |
| 152 | di.print_address_func = dis_asm_print_address; |
| 153 | // di.symbol_at_address_func = dis_asm_symbol_at_address; |
| 154 | di.read_memory_func = dis_asm_read_memory; |
| 155 | di.arch = BFD_ARCH; |
| 156 | di.mach = BFD_MACH; |
| 157 | di.endian = BFD_ENDIAN_LITTLE; |
| 158 | disassemble_init_for_target(&di); |
| 159 | } |
| 160 | |
| 161 | void host_dasm(void *addr, int len) |
| 162 | { |
| 163 | bfd_vma vma_end, vma = (bfd_vma)(int)addr; |
| 164 | static int init_done = 0; |
| 165 | |
| 166 | if (!init_done) { |
| 167 | host_dasm_init(); |
| 168 | init_done = 1; |
| 169 | } |
| 170 | |
| 171 | vma_end = vma + len; |
| 172 | while (vma < vma_end) { |
| 173 | printf(" %p ", (void *)(long)vma); |
| 174 | vma += print_insn_func(vma, &di); |
| 175 | printf("\n"); |
| 176 | } |
| 177 | } |
| 178 | |