1 | #ifdef TARGET_DEFS_ONLY
|
---|
2 |
|
---|
3 | #define EM_TCC_TARGET EM_386
|
---|
4 |
|
---|
5 | /* relocation type for 32 bit data relocation */
|
---|
6 | #define R_DATA_32 R_386_32
|
---|
7 | #define R_DATA_PTR R_386_32
|
---|
8 | #define R_JMP_SLOT R_386_JMP_SLOT
|
---|
9 | #define R_GLOB_DAT R_386_GLOB_DAT
|
---|
10 | #define R_COPY R_386_COPY
|
---|
11 | #define R_RELATIVE R_386_RELATIVE
|
---|
12 |
|
---|
13 | #define R_NUM R_386_NUM
|
---|
14 |
|
---|
15 | #define ELF_START_ADDR 0x08048000
|
---|
16 | #define ELF_PAGE_SIZE 0x1000
|
---|
17 |
|
---|
18 | #define PCRELATIVE_DLLPLT 0
|
---|
19 | #define RELOCATE_DLLPLT 0
|
---|
20 |
|
---|
21 | #else /* !TARGET_DEFS_ONLY */
|
---|
22 |
|
---|
23 | #include "tcc.h"
|
---|
24 |
|
---|
25 | /* Returns 1 for a code relocation, 0 for a data relocation. For unknown
|
---|
26 | relocations, returns -1. */
|
---|
27 | int code_reloc (int reloc_type)
|
---|
28 | {
|
---|
29 | switch (reloc_type) {
|
---|
30 | case R_386_RELATIVE:
|
---|
31 | case R_386_16:
|
---|
32 | case R_386_32:
|
---|
33 | case R_386_GOTPC:
|
---|
34 | case R_386_GOTOFF:
|
---|
35 | case R_386_GOT32:
|
---|
36 | case R_386_GOT32X:
|
---|
37 | case R_386_GLOB_DAT:
|
---|
38 | case R_386_COPY:
|
---|
39 | return 0;
|
---|
40 |
|
---|
41 | case R_386_PC16:
|
---|
42 | case R_386_PC32:
|
---|
43 | case R_386_PLT32:
|
---|
44 | case R_386_JMP_SLOT:
|
---|
45 | return 1;
|
---|
46 | }
|
---|
47 |
|
---|
48 | tcc_error ("Unknown relocation type: %d", reloc_type);
|
---|
49 | return -1;
|
---|
50 | }
|
---|
51 |
|
---|
52 | /* Returns an enumerator to describe whether and when the relocation needs a
|
---|
53 | GOT and/or PLT entry to be created. See tcc.h for a description of the
|
---|
54 | different values. */
|
---|
55 | int gotplt_entry_type (int reloc_type)
|
---|
56 | {
|
---|
57 | switch (reloc_type) {
|
---|
58 | case R_386_RELATIVE:
|
---|
59 | case R_386_16:
|
---|
60 | case R_386_GLOB_DAT:
|
---|
61 | case R_386_JMP_SLOT:
|
---|
62 | case R_386_COPY:
|
---|
63 | return NO_GOTPLT_ENTRY;
|
---|
64 |
|
---|
65 | case R_386_32:
|
---|
66 | /* This relocations shouldn't normally need GOT or PLT
|
---|
67 | slots if it weren't for simplicity in the code generator.
|
---|
68 | See our caller for comments. */
|
---|
69 | return AUTO_GOTPLT_ENTRY;
|
---|
70 |
|
---|
71 | case R_386_PC16:
|
---|
72 | case R_386_PC32:
|
---|
73 | return AUTO_GOTPLT_ENTRY;
|
---|
74 |
|
---|
75 | case R_386_GOTPC:
|
---|
76 | case R_386_GOTOFF:
|
---|
77 | return BUILD_GOT_ONLY;
|
---|
78 |
|
---|
79 | case R_386_GOT32:
|
---|
80 | case R_386_GOT32X:
|
---|
81 | case R_386_PLT32:
|
---|
82 | return ALWAYS_GOTPLT_ENTRY;
|
---|
83 | }
|
---|
84 |
|
---|
85 | tcc_error ("Unknown relocation type: %d", reloc_type);
|
---|
86 | return -1;
|
---|
87 | }
|
---|
88 |
|
---|
89 | ST_FUNC unsigned create_plt_entry(TCCState *s1, unsigned got_offset, struct sym_attr *attr)
|
---|
90 | {
|
---|
91 | Section *plt = s1->plt;
|
---|
92 | uint8_t *p;
|
---|
93 | int modrm;
|
---|
94 | unsigned plt_offset, relofs;
|
---|
95 |
|
---|
96 | /* on i386 if we build a DLL, we add a %ebx offset */
|
---|
97 | if (s1->output_type == TCC_OUTPUT_DLL)
|
---|
98 | modrm = 0xa3;
|
---|
99 | else
|
---|
100 | modrm = 0x25;
|
---|
101 |
|
---|
102 | /* empty PLT: create PLT0 entry that pushes the library identifier
|
---|
103 | (GOT + PTR_SIZE) and jumps to ld.so resolution routine
|
---|
104 | (GOT + 2 * PTR_SIZE) */
|
---|
105 | if (plt->data_offset == 0) {
|
---|
106 | p = section_ptr_add(plt, 16);
|
---|
107 | p[0] = 0xff; /* pushl got + PTR_SIZE */
|
---|
108 | p[1] = modrm + 0x10;
|
---|
109 | write32le(p + 2, PTR_SIZE);
|
---|
110 | p[6] = 0xff; /* jmp *(got + PTR_SIZE * 2) */
|
---|
111 | p[7] = modrm;
|
---|
112 | write32le(p + 8, PTR_SIZE * 2);
|
---|
113 | }
|
---|
114 | plt_offset = plt->data_offset;
|
---|
115 |
|
---|
116 | /* The PLT slot refers to the relocation entry it needs via offset.
|
---|
117 | The reloc entry is created below, so its offset is the current
|
---|
118 | data_offset */
|
---|
119 | relofs = s1->got->reloc ? s1->got->reloc->data_offset : 0;
|
---|
120 |
|
---|
121 | /* Jump to GOT entry where ld.so initially put the address of ip + 4 */
|
---|
122 | p = section_ptr_add(plt, 16);
|
---|
123 | p[0] = 0xff; /* jmp *(got + x) */
|
---|
124 | p[1] = modrm;
|
---|
125 | write32le(p + 2, got_offset);
|
---|
126 | p[6] = 0x68; /* push $xxx */
|
---|
127 | write32le(p + 7, relofs);
|
---|
128 | p[11] = 0xe9; /* jmp plt_start */
|
---|
129 | write32le(p + 12, -(plt->data_offset));
|
---|
130 | return plt_offset;
|
---|
131 | }
|
---|
132 |
|
---|
133 | /* relocate the PLT: compute addresses and offsets in the PLT now that final
|
---|
134 | address for PLT and GOT are known (see fill_program_header) */
|
---|
135 | ST_FUNC void relocate_plt(TCCState *s1)
|
---|
136 | {
|
---|
137 | uint8_t *p, *p_end;
|
---|
138 |
|
---|
139 | if (!s1->plt)
|
---|
140 | return;
|
---|
141 |
|
---|
142 | p = s1->plt->data;
|
---|
143 | p_end = p + s1->plt->data_offset;
|
---|
144 |
|
---|
145 | if (p < p_end) {
|
---|
146 | add32le(p + 2, s1->got->sh_addr);
|
---|
147 | add32le(p + 8, s1->got->sh_addr);
|
---|
148 | p += 16;
|
---|
149 | while (p < p_end) {
|
---|
150 | add32le(p + 2, s1->got->sh_addr);
|
---|
151 | p += 16;
|
---|
152 | }
|
---|
153 | }
|
---|
154 | }
|
---|
155 |
|
---|
156 | static ElfW_Rel *qrel; /* ptr to next reloc entry reused */
|
---|
157 |
|
---|
158 | void relocate_init(Section *sr)
|
---|
159 | {
|
---|
160 | qrel = (ElfW_Rel *) sr->data;
|
---|
161 | }
|
---|
162 |
|
---|
163 | void relocate(TCCState *s1, ElfW_Rel *rel, int type, unsigned char *ptr, addr_t addr, addr_t val)
|
---|
164 | {
|
---|
165 | int sym_index, esym_index;
|
---|
166 |
|
---|
167 | sym_index = ELFW(R_SYM)(rel->r_info);
|
---|
168 |
|
---|
169 | switch (type) {
|
---|
170 | case R_386_32:
|
---|
171 | if (s1->output_type == TCC_OUTPUT_DLL) {
|
---|
172 | esym_index = s1->sym_attrs[sym_index].dyn_index;
|
---|
173 | qrel->r_offset = rel->r_offset;
|
---|
174 | if (esym_index) {
|
---|
175 | qrel->r_info = ELFW(R_INFO)(esym_index, R_386_32);
|
---|
176 | qrel++;
|
---|
177 | return;
|
---|
178 | } else {
|
---|
179 | qrel->r_info = ELFW(R_INFO)(0, R_386_RELATIVE);
|
---|
180 | qrel++;
|
---|
181 | }
|
---|
182 | }
|
---|
183 | add32le(ptr, val);
|
---|
184 | return;
|
---|
185 | case R_386_PC32:
|
---|
186 | if (s1->output_type == TCC_OUTPUT_DLL) {
|
---|
187 | /* DLL relocation */
|
---|
188 | esym_index = s1->sym_attrs[sym_index].dyn_index;
|
---|
189 | if (esym_index) {
|
---|
190 | qrel->r_offset = rel->r_offset;
|
---|
191 | qrel->r_info = ELFW(R_INFO)(esym_index, R_386_PC32);
|
---|
192 | qrel++;
|
---|
193 | return;
|
---|
194 | }
|
---|
195 | }
|
---|
196 | add32le(ptr, val - addr);
|
---|
197 | return;
|
---|
198 | case R_386_PLT32:
|
---|
199 | add32le(ptr, val - addr);
|
---|
200 | return;
|
---|
201 | case R_386_GLOB_DAT:
|
---|
202 | case R_386_JMP_SLOT:
|
---|
203 | write32le(ptr, val);
|
---|
204 | return;
|
---|
205 | case R_386_GOTPC:
|
---|
206 | add32le(ptr, s1->got->sh_addr - addr);
|
---|
207 | return;
|
---|
208 | case R_386_GOTOFF:
|
---|
209 | add32le(ptr, val - s1->got->sh_addr);
|
---|
210 | return;
|
---|
211 | case R_386_GOT32:
|
---|
212 | case R_386_GOT32X:
|
---|
213 | /* we load the got offset */
|
---|
214 | add32le(ptr, s1->sym_attrs[sym_index].got_offset);
|
---|
215 | return;
|
---|
216 | case R_386_16:
|
---|
217 | if (s1->output_format != TCC_OUTPUT_FORMAT_BINARY) {
|
---|
218 | output_file:
|
---|
219 | tcc_error("can only produce 16-bit binary files");
|
---|
220 | }
|
---|
221 | write16le(ptr, read16le(ptr) + val);
|
---|
222 | return;
|
---|
223 | case R_386_PC16:
|
---|
224 | if (s1->output_format != TCC_OUTPUT_FORMAT_BINARY)
|
---|
225 | goto output_file;
|
---|
226 | write16le(ptr, read16le(ptr) + val - addr);
|
---|
227 | return;
|
---|
228 | case R_386_RELATIVE:
|
---|
229 | #ifdef TCC_TARGET_PE
|
---|
230 | add32le(ptr, val - s1->pe_imagebase);
|
---|
231 | #endif
|
---|
232 | /* do nothing */
|
---|
233 | return;
|
---|
234 | case R_386_COPY:
|
---|
235 | /* This relocation must copy initialized data from the library
|
---|
236 | to the program .bss segment. Currently made like for ARM
|
---|
237 | (to remove noise of default case). Is this true?
|
---|
238 | */
|
---|
239 | return;
|
---|
240 | default:
|
---|
241 | fprintf(stderr,"FIXME: handle reloc type %d at %x [%p] to %x\n",
|
---|
242 | type, (unsigned)addr, ptr, (unsigned)val);
|
---|
243 | return;
|
---|
244 | }
|
---|
245 | }
|
---|
246 |
|
---|
247 | #endif /* !TARGET_DEFS_ONLY */
|
---|