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8static void BITSFUNC(go)(void *raw_addr, size_t raw_len,
9 void *stripped_addr, size_t stripped_len,
10 FILE *outfile, const char *image_name)
11{
12 int found_load = 0;
13 unsigned long load_size = -1;
14 unsigned long mapping_size;
15 ELF(Ehdr) *hdr = (ELF(Ehdr) *)raw_addr;
16 int i;
17 unsigned long j;
18 ELF(Shdr) *symtab_hdr = NULL, *strtab_hdr, *secstrings_hdr,
19 *alt_sec = NULL;
20 ELF(Dyn) *dyn = 0, *dyn_end = 0;
21 const char *secstrings;
22 INT_BITS syms[NSYMS] = {};
23
24 ELF(Phdr) *pt = (ELF(Phdr) *)(raw_addr + GET_LE(&hdr->e_phoff));
25
26 if (GET_LE(&hdr->e_type) != ET_DYN)
27 fail("input is not a shared object\n");
28
29
30 for (i = 0; i < GET_LE(&hdr->e_phnum); i++) {
31 if (GET_LE(&pt[i].p_type) == PT_LOAD) {
32 if (found_load)
33 fail("multiple PT_LOAD segs\n");
34
35 if (GET_LE(&pt[i].p_offset) != 0 ||
36 GET_LE(&pt[i].p_vaddr) != 0)
37 fail("PT_LOAD in wrong place\n");
38
39 if (GET_LE(&pt[i].p_memsz) != GET_LE(&pt[i].p_filesz))
40 fail("cannot handle memsz != filesz\n");
41
42 load_size = GET_LE(&pt[i].p_memsz);
43 found_load = 1;
44 } else if (GET_LE(&pt[i].p_type) == PT_DYNAMIC) {
45 dyn = raw_addr + GET_LE(&pt[i].p_offset);
46 dyn_end = raw_addr + GET_LE(&pt[i].p_offset) +
47 GET_LE(&pt[i].p_memsz);
48 }
49 }
50 if (!found_load)
51 fail("no PT_LOAD seg\n");
52
53 if (stripped_len < load_size)
54 fail("stripped input is too short\n");
55
56 if (!dyn)
57 fail("input has no PT_DYNAMIC section -- your toolchain is buggy\n");
58
59
60 for (i = 0; dyn + i < dyn_end &&
61 GET_LE(&dyn[i].d_tag) != DT_NULL; i++) {
62 typeof(dyn[i].d_tag) tag = GET_LE(&dyn[i].d_tag);
63 if (tag == DT_REL || tag == DT_RELSZ || tag == DT_RELA ||
64 tag == DT_RELENT || tag == DT_TEXTREL)
65 fail("vdso image contains dynamic relocations\n");
66 }
67
68
69 secstrings_hdr = raw_addr + GET_LE(&hdr->e_shoff) +
70 GET_LE(&hdr->e_shentsize)*GET_LE(&hdr->e_shstrndx);
71 secstrings = raw_addr + GET_LE(&secstrings_hdr->sh_offset);
72 for (i = 0; i < GET_LE(&hdr->e_shnum); i++) {
73 ELF(Shdr) *sh = raw_addr + GET_LE(&hdr->e_shoff) +
74 GET_LE(&hdr->e_shentsize) * i;
75 if (GET_LE(&sh->sh_type) == SHT_SYMTAB)
76 symtab_hdr = sh;
77
78 if (!strcmp(secstrings + GET_LE(&sh->sh_name),
79 ".altinstructions"))
80 alt_sec = sh;
81 }
82
83 if (!symtab_hdr)
84 fail("no symbol table\n");
85
86 strtab_hdr = raw_addr + GET_LE(&hdr->e_shoff) +
87 GET_LE(&hdr->e_shentsize) * GET_LE(&symtab_hdr->sh_link);
88
89
90 for (i = 0;
91 i < GET_LE(&symtab_hdr->sh_size) / GET_LE(&symtab_hdr->sh_entsize);
92 i++) {
93 int k;
94 ELF(Sym) *sym = raw_addr + GET_LE(&symtab_hdr->sh_offset) +
95 GET_LE(&symtab_hdr->sh_entsize) * i;
96 const char *sym_name = raw_addr +
97 GET_LE(&strtab_hdr->sh_offset) +
98 GET_LE(&sym->st_name);
99
100 for (k = 0; k < NSYMS; k++) {
101 if (!strcmp(sym_name, required_syms[k].name)) {
102 if (syms[k]) {
103 fail("duplicate symbol %s\n",
104 required_syms[k].name);
105 }
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113 syms[k] = GET_LE(&sym->st_value);
114 }
115 }
116 }
117
118
119 for (i = 0; i < sizeof(special_pages) / sizeof(special_pages[0]); i++) {
120 INT_BITS symval = syms[special_pages[i]];
121
122 if (!symval)
123 continue;
124
125 if (symval % 4096)
126 fail("%s must be a multiple of 4096\n",
127 required_syms[i].name);
128 if (symval + 4096 < syms[sym_vvar_start])
129 fail("%s underruns vvar_start\n",
130 required_syms[i].name);
131 if (symval + 4096 > 0)
132 fail("%s is on the wrong side of the vdso text\n",
133 required_syms[i].name);
134 }
135 if (syms[sym_vvar_start] % 4096)
136 fail("vvar_begin must be a multiple of 4096\n");
137
138 if (!image_name) {
139 fwrite(stripped_addr, stripped_len, 1, outfile);
140 return;
141 }
142
143 mapping_size = (stripped_len + 4095) / 4096 * 4096;
144
145 fprintf(outfile, "/* AUTOMATICALLY GENERATED -- DO NOT EDIT */\n\n");
146 fprintf(outfile, "#include <linux/linkage.h>\n");
147 fprintf(outfile, "#include <asm/page_types.h>\n");
148 fprintf(outfile, "#include <asm/vdso.h>\n");
149 fprintf(outfile, "\n");
150 fprintf(outfile,
151 "static unsigned char raw_data[%lu] __ro_after_init __aligned(PAGE_SIZE) = {",
152 mapping_size);
153 for (j = 0; j < stripped_len; j++) {
154 if (j % 10 == 0)
155 fprintf(outfile, "\n\t");
156 fprintf(outfile, "0x%02X, ",
157 (int)((unsigned char *)stripped_addr)[j]);
158 }
159 fprintf(outfile, "\n};\n\n");
160
161 fprintf(outfile, "const struct vdso_image %s = {\n", image_name);
162 fprintf(outfile, "\t.data = raw_data,\n");
163 fprintf(outfile, "\t.size = %lu,\n", mapping_size);
164 if (alt_sec) {
165 fprintf(outfile, "\t.alt = %lu,\n",
166 (unsigned long)GET_LE(&alt_sec->sh_offset));
167 fprintf(outfile, "\t.alt_len = %lu,\n",
168 (unsigned long)GET_LE(&alt_sec->sh_size));
169 }
170 for (i = 0; i < NSYMS; i++) {
171 if (required_syms[i].export && syms[i])
172 fprintf(outfile, "\t.sym_%s = %" PRIi64 ",\n",
173 required_syms[i].name, (int64_t)syms[i]);
174 }
175 fprintf(outfile, "};\n");
176}
177
