sparc: Fix VDSO build with older binutils.
[muen/linux.git] / arch / sparc / vdso / vdso2c.h
1 /*
2  * Copyright (c) 2017 Oracle and/or its affiliates. All rights reserved.
3  */
4
5 /*
6  * This file is included up to twice from vdso2c.c.  It generates code for
7  * 32-bit and 64-bit vDSOs.  We will eventually need both for 64-bit builds,
8  * since 32-bit vDSOs will then be built for 32-bit userspace.
9  */
10
11 static void BITSFUNC(go)(void *raw_addr, size_t raw_len,
12                          void *stripped_addr, size_t stripped_len,
13                          FILE *outfile, const char *name)
14 {
15         int found_load = 0;
16         unsigned long load_size = -1;  /* Work around bogus warning */
17         unsigned long mapping_size;
18         int i;
19         unsigned long j;
20         ELF(Shdr) *symtab_hdr = NULL, *strtab_hdr;
21         ELF(Ehdr) *hdr = (ELF(Ehdr) *)raw_addr;
22         ELF(Dyn) *dyn = 0, *dyn_end = 0;
23         INT_BITS syms[NSYMS] = {};
24
25         ELF(Phdr) *pt = (ELF(Phdr) *)(raw_addr + GET_BE(&hdr->e_phoff));
26
27         /* Walk the segment table. */
28         for (i = 0; i < GET_BE(&hdr->e_phnum); i++) {
29                 if (GET_BE(&pt[i].p_type) == PT_LOAD) {
30                         if (found_load)
31                                 fail("multiple PT_LOAD segs\n");
32
33                         if (GET_BE(&pt[i].p_offset) != 0 ||
34                             GET_BE(&pt[i].p_vaddr) != 0)
35                                 fail("PT_LOAD in wrong place\n");
36
37                         if (GET_BE(&pt[i].p_memsz) != GET_BE(&pt[i].p_filesz))
38                                 fail("cannot handle memsz != filesz\n");
39
40                         load_size = GET_BE(&pt[i].p_memsz);
41                         found_load = 1;
42                 } else if (GET_BE(&pt[i].p_type) == PT_DYNAMIC) {
43                         dyn = raw_addr + GET_BE(&pt[i].p_offset);
44                         dyn_end = raw_addr + GET_BE(&pt[i].p_offset) +
45                                 GET_BE(&pt[i].p_memsz);
46                 }
47         }
48         if (!found_load)
49                 fail("no PT_LOAD seg\n");
50
51         if (stripped_len < load_size)
52                 fail("stripped input is too short\n");
53
54         /* Walk the dynamic table */
55         for (i = 0; dyn + i < dyn_end &&
56                      GET_BE(&dyn[i].d_tag) != DT_NULL; i++) {
57                 typeof(dyn[i].d_tag) tag = GET_BE(&dyn[i].d_tag);
58                 typeof(dyn[i].d_un.d_val) val = GET_BE(&dyn[i].d_un.d_val);
59
60                 if ((tag == DT_RELSZ || tag == DT_RELASZ) && (val != 0))
61                         fail("vdso image contains dynamic relocations\n");
62         }
63
64         /* Walk the section table */
65         for (i = 0; i < GET_BE(&hdr->e_shnum); i++) {
66                 ELF(Shdr) *sh = raw_addr + GET_BE(&hdr->e_shoff) +
67                         GET_BE(&hdr->e_shentsize) * i;
68                 if (GET_BE(&sh->sh_type) == SHT_SYMTAB)
69                         symtab_hdr = sh;
70         }
71
72         if (!symtab_hdr)
73                 fail("no symbol table\n");
74
75         strtab_hdr = raw_addr + GET_BE(&hdr->e_shoff) +
76                 GET_BE(&hdr->e_shentsize) * GET_BE(&symtab_hdr->sh_link);
77
78         /* Walk the symbol table */
79         for (i = 0;
80              i < GET_BE(&symtab_hdr->sh_size) / GET_BE(&symtab_hdr->sh_entsize);
81              i++) {
82                 int k;
83
84                 ELF(Sym) *sym = raw_addr + GET_BE(&symtab_hdr->sh_offset) +
85                         GET_BE(&symtab_hdr->sh_entsize) * i;
86                 const char *name = raw_addr + GET_BE(&strtab_hdr->sh_offset) +
87                         GET_BE(&sym->st_name);
88
89                 for (k = 0; k < NSYMS; k++) {
90                         if (!strcmp(name, required_syms[k].name)) {
91                                 if (syms[k]) {
92                                         fail("duplicate symbol %s\n",
93                                              required_syms[k].name);
94                                 }
95
96                                 /*
97                                  * Careful: we use negative addresses, but
98                                  * st_value is unsigned, so we rely
99                                  * on syms[k] being a signed type of the
100                                  * correct width.
101                                  */
102                                 syms[k] = GET_BE(&sym->st_value);
103                         }
104                 }
105         }
106
107         /* Validate mapping addresses. */
108         if (syms[sym_vvar_start] % 8192)
109                 fail("vvar_begin must be a multiple of 8192\n");
110
111         if (!name) {
112                 fwrite(stripped_addr, stripped_len, 1, outfile);
113                 return;
114         }
115
116         mapping_size = (stripped_len + 8191) / 8192 * 8192;
117
118         fprintf(outfile, "/* AUTOMATICALLY GENERATED -- DO NOT EDIT */\n\n");
119         fprintf(outfile, "#include <linux/cache.h>\n");
120         fprintf(outfile, "#include <asm/vdso.h>\n");
121         fprintf(outfile, "\n");
122         fprintf(outfile,
123                 "static unsigned char raw_data[%lu] __ro_after_init __aligned(8192)= {",
124                 mapping_size);
125         for (j = 0; j < stripped_len; j++) {
126                 if (j % 10 == 0)
127                         fprintf(outfile, "\n\t");
128                 fprintf(outfile, "0x%02X, ",
129                         (int)((unsigned char *)stripped_addr)[j]);
130         }
131         fprintf(outfile, "\n};\n\n");
132
133         fprintf(outfile, "const struct vdso_image %s_builtin = {\n", name);
134         fprintf(outfile, "\t.data = raw_data,\n");
135         fprintf(outfile, "\t.size = %lu,\n", mapping_size);
136         for (i = 0; i < NSYMS; i++) {
137                 if (required_syms[i].export && syms[i])
138                         fprintf(outfile, "\t.sym_%s = %" PRIi64 ",\n",
139                                 required_syms[i].name, (int64_t)syms[i]);
140         }
141         fprintf(outfile, "};\n");
142 }