679af8a3 |
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 | /* symbols */ |
15 | static asymbol **symbols; |
16 | static long symcount; |
17 | |
18 | /* Filter out (in place) symbols that are useless for disassembly. |
19 | COUNT is the number of elements in SYMBOLS. |
20 | Return the number of useful symbols. */ |
21 | static long |
22 | remove_useless_symbols (asymbol **symbols, long count) |
23 | { |
24 | asymbol **in_ptr = symbols, **out_ptr = symbols; |
25 | |
26 | while (--count >= 0) |
27 | { |
28 | asymbol *sym = *in_ptr++; |
29 | |
30 | if (sym->name == NULL || sym->name[0] == '\0') |
31 | continue; |
32 | if (sym->flags & (BSF_DEBUGGING | BSF_SECTION_SYM)) |
33 | continue; |
34 | if (bfd_is_und_section (sym->section) |
35 | || bfd_is_com_section (sym->section)) |
36 | continue; |
37 | if (sym->value + sym->section->vma == 0) |
38 | continue; |
39 | /* |
40 | printf("sym: %08lx %04x %08x v %08x \"%s\"\n", |
41 | (unsigned int)sym->value, (unsigned int)sym->flags, (unsigned int)sym->udata.i, |
42 | (unsigned int)sym->section->vma, sym->name); |
43 | */ |
44 | *out_ptr++ = sym; |
45 | } |
46 | return out_ptr - symbols; |
47 | } |
48 | |
49 | static void slurp_symtab(const char *filename) |
50 | { |
51 | bfd *abfd; |
52 | long storage; |
53 | |
54 | symcount = 0; |
55 | |
56 | abfd = bfd_openr(filename, NULL); |
57 | if (abfd == NULL) { |
58 | fprintf(stderr, "failed to open: %s\n", filename); |
59 | goto no_symbols; |
60 | } |
61 | |
62 | if (!bfd_check_format(abfd, bfd_object)) |
63 | goto no_symbols; |
64 | |
65 | if (!(bfd_get_file_flags(abfd) & HAS_SYMS)) |
66 | goto no_symbols; |
67 | |
68 | storage = bfd_get_symtab_upper_bound(abfd); |
69 | if (storage <= 0) |
70 | goto no_symbols; |
71 | |
72 | symbols = malloc(storage); |
73 | symcount = bfd_canonicalize_symtab(abfd, symbols); |
74 | if (symcount < 0) |
75 | goto no_symbols; |
76 | |
77 | symcount = remove_useless_symbols(symbols, symcount); |
78 | // bfd_close(abfd); |
79 | return; |
80 | |
81 | no_symbols: |
82 | fprintf(stderr, "no symbols in %s\n", bfd_get_filename(abfd)); |
83 | if (abfd != NULL) |
84 | bfd_close(abfd); |
85 | } |
86 | |
87 | |
88 | /* Like target_read_memory, but slightly different parameters. */ |
89 | static int |
90 | dis_asm_read_memory(bfd_vma memaddr, bfd_byte *myaddr, unsigned int len, |
91 | struct disassemble_info *info) |
92 | { |
93 | memcpy(myaddr, (void *)(int)memaddr, len); |
94 | return 0; |
95 | } |
96 | |
97 | static void |
98 | dis_asm_memory_error(int status, bfd_vma memaddr, |
99 | struct disassemble_info *info) |
100 | { |
101 | fprintf(stderr, "memory_error %p\n", (void *)(int)memaddr); |
102 | } |
103 | |
104 | static void |
105 | dis_asm_print_address(bfd_vma addr, struct disassemble_info *info) |
106 | { |
107 | asymbol **sptr = symbols; |
108 | int i; |
109 | |
110 | printf("%08x", (int)addr); |
111 | |
112 | for (i = 0; i < symcount; i++) { |
113 | asymbol *sym = *sptr++; |
114 | |
115 | if (addr == sym->value + sym->section->vma) { |
116 | printf(" <%s>", sym->name); |
117 | break; |
118 | } |
119 | } |
120 | } |
121 | |
122 | static int insn_printf(void *f, const char *format, ...) |
123 | { |
124 | va_list args; |
125 | size_t n; |
126 | |
127 | va_start(args, format); |
128 | n = vprintf(format, args); |
129 | va_end(args); |
130 | |
131 | return n; |
132 | } |
133 | |
134 | static void host_dasm_init(void) |
135 | { |
136 | slurp_symtab(g_argv[0]); |
137 | |
138 | init_disassemble_info(&di, NULL, insn_printf); |
139 | di.flavour = bfd_target_unknown_flavour; |
140 | di.memory_error_func = dis_asm_memory_error; |
141 | di.print_address_func = dis_asm_print_address; |
142 | // di.symbol_at_address_func = dis_asm_symbol_at_address; |
143 | di.read_memory_func = dis_asm_read_memory; |
144 | di.arch = bfd_arch_i386; |
145 | di.mach = bfd_mach_i386_i386_intel_syntax; |
146 | di.endian = BFD_ENDIAN_LITTLE; |
147 | disassemble_init_for_target(&di); |
148 | } |
149 | |
150 | void host_dasm(void *addr, int len) |
151 | { |
152 | bfd_vma vma_end, vma = (bfd_vma)(int)addr; |
153 | static int init_done = 0; |
154 | |
155 | if (!init_done) { |
156 | host_dasm_init(); |
157 | init_done = 1; |
158 | } |
159 | |
160 | vma_end = vma + len; |
161 | while (vma < vma_end) { |
162 | printf(" %p ", (void *)(long)vma); |
163 | vma += print_insn_i386_intel(vma, &di); |
164 | printf("\n"); |
165 | } |
166 | } |
167 | |