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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 unsigned long i, syms_nr;
17 ELF(Shdr) *symtab_hdr = NULL, *strtab_hdr, *secstrings_hdr,
18 *alt_sec = NULL;
19 ELF(Dyn) *dyn = 0, *dyn_end = 0;
20 const char *secstrings;
21 INT_BITS syms[NSYMS] = {};
22
23 ELF(Phdr) *pt = (ELF(Phdr) *)(raw_addr + GET_LE(&hdr->e_phoff));
24
25 if (GET_LE(&hdr->e_type) != ET_DYN)
26 fail("input is not a shared object\n");
27
28
29 for (i = 0; i < GET_LE(&hdr->e_phnum); i++) {
30 if (GET_LE(&pt[i].p_type) == PT_LOAD) {
31 if (found_load)
32 fail("multiple PT_LOAD segs\n");
33
34 if (GET_LE(&pt[i].p_offset) != 0 ||
35 GET_LE(&pt[i].p_vaddr) != 0)
36 fail("PT_LOAD in wrong place\n");
37
38 if (GET_LE(&pt[i].p_memsz) != GET_LE(&pt[i].p_filesz))
39 fail("cannot handle memsz != filesz\n");
40
41 load_size = GET_LE(&pt[i].p_memsz);
42 found_load = 1;
43 } else if (GET_LE(&pt[i].p_type) == PT_DYNAMIC) {
44 dyn = raw_addr + GET_LE(&pt[i].p_offset);
45 dyn_end = raw_addr + GET_LE(&pt[i].p_offset) +
46 GET_LE(&pt[i].p_memsz);
47 }
48 }
49 if (!found_load)
50 fail("no PT_LOAD seg\n");
51
52 if (stripped_len < load_size)
53 fail("stripped input is too short\n");
54
55 if (!dyn)
56 fail("input has no PT_DYNAMIC section -- your toolchain is buggy\n");
57
58
59 for (i = 0; dyn + i < dyn_end &&
60 GET_LE(&dyn[i].d_tag) != DT_NULL; i++) {
61 typeof(dyn[i].d_tag) tag = GET_LE(&dyn[i].d_tag);
62 if (tag == DT_REL || tag == DT_RELSZ || tag == DT_RELA ||
63 tag == DT_RELENT || tag == DT_TEXTREL)
64 fail("vdso image contains dynamic relocations\n");
65 }
66
67
68 secstrings_hdr = raw_addr + GET_LE(&hdr->e_shoff) +
69 GET_LE(&hdr->e_shentsize)*GET_LE(&hdr->e_shstrndx);
70 secstrings = raw_addr + GET_LE(&secstrings_hdr->sh_offset);
71 for (i = 0; i < GET_LE(&hdr->e_shnum); i++) {
72 ELF(Shdr) *sh = raw_addr + GET_LE(&hdr->e_shoff) +
73 GET_LE(&hdr->e_shentsize) * i;
74 if (GET_LE(&sh->sh_type) == SHT_SYMTAB)
75 symtab_hdr = sh;
76
77 if (!strcmp(secstrings + GET_LE(&sh->sh_name),
78 ".altinstructions"))
79 alt_sec = sh;
80 }
81
82 if (!symtab_hdr)
83 fail("no symbol table\n");
84
85 strtab_hdr = raw_addr + GET_LE(&hdr->e_shoff) +
86 GET_LE(&hdr->e_shentsize) * GET_LE(&symtab_hdr->sh_link);
87
88 syms_nr = GET_LE(&symtab_hdr->sh_size) / GET_LE(&symtab_hdr->sh_entsize);
89
90 for (i = 0; i < syms_nr; i++) {
91 unsigned int k;
92 ELF(Sym) *sym = raw_addr + GET_LE(&symtab_hdr->sh_offset) +
93 GET_LE(&symtab_hdr->sh_entsize) * i;
94 const char *sym_name = raw_addr +
95 GET_LE(&strtab_hdr->sh_offset) +
96 GET_LE(&sym->st_name);
97
98 for (k = 0; k < NSYMS; k++) {
99 if (!strcmp(sym_name, required_syms[k].name)) {
100 if (syms[k]) {
101 fail("duplicate symbol %s\n",
102 required_syms[k].name);
103 }
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111 syms[k] = GET_LE(&sym->st_value);
112 }
113 }
114 }
115
116
117 for (i = 0; i < sizeof(special_pages) / sizeof(special_pages[0]); i++) {
118 INT_BITS symval = syms[special_pages[i]];
119
120 if (!symval)
121 continue;
122
123 if (symval % 4096)
124 fail("%s must be a multiple of 4096\n",
125 required_syms[i].name);
126 if (symval + 4096 < syms[sym_vvar_start])
127 fail("%s underruns vvar_start\n",
128 required_syms[i].name);
129 if (symval + 4096 > 0)
130 fail("%s is on the wrong side of the vdso text\n",
131 required_syms[i].name);
132 }
133 if (syms[sym_vvar_start] % 4096)
134 fail("vvar_begin must be a multiple of 4096\n");
135
136 if (!image_name) {
137 fwrite(stripped_addr, stripped_len, 1, outfile);
138 return;
139 }
140
141 mapping_size = (stripped_len + 4095) / 4096 * 4096;
142
143 fprintf(outfile, "/* AUTOMATICALLY GENERATED -- DO NOT EDIT */\n\n");
144 fprintf(outfile, "#include <linux/linkage.h>\n");
145 fprintf(outfile, "#include <asm/page_types.h>\n");
146 fprintf(outfile, "#include <asm/vdso.h>\n");
147 fprintf(outfile, "\n");
148 fprintf(outfile,
149 "static unsigned char raw_data[%lu] __ro_after_init __aligned(PAGE_SIZE) = {",
150 mapping_size);
151 for (i = 0; i < stripped_len; i++) {
152 if (i % 10 == 0)
153 fprintf(outfile, "\n\t");
154 fprintf(outfile, "0x%02X, ",
155 (int)((unsigned char *)stripped_addr)[i]);
156 }
157 fprintf(outfile, "\n};\n\n");
158
159 fprintf(outfile, "const struct vdso_image %s = {\n", image_name);
160 fprintf(outfile, "\t.data = raw_data,\n");
161 fprintf(outfile, "\t.size = %lu,\n", mapping_size);
162 if (alt_sec) {
163 fprintf(outfile, "\t.alt = %lu,\n",
164 (unsigned long)GET_LE(&alt_sec->sh_offset));
165 fprintf(outfile, "\t.alt_len = %lu,\n",
166 (unsigned long)GET_LE(&alt_sec->sh_size));
167 }
168 for (i = 0; i < NSYMS; i++) {
169 if (required_syms[i].export && syms[i])
170 fprintf(outfile, "\t.sym_%s = %" PRIi64 ",\n",
171 required_syms[i].name, (int64_t)syms[i]);
172 }
173 fprintf(outfile, "};\n");
174}
175
