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- /*
- * Copyright (c) 2017 Oracle and/or its affiliates. All rights reserved.
- */
- /*
- * This file is included up to twice from vdso2c.c. It generates code for
- * 32-bit and 64-bit vDSOs. We will eventually need both for 64-bit builds,
- * since 32-bit vDSOs will then be built for 32-bit userspace.
- */
- static void BITSFUNC(go)(void *raw_addr, size_t raw_len,
- void *stripped_addr, size_t stripped_len,
- FILE *outfile, const char *name)
- {
- int found_load = 0;
- unsigned long load_size = -1; /* Work around bogus warning */
- unsigned long mapping_size;
- int i;
- unsigned long j;
- ELF(Shdr) *symtab_hdr = NULL, *strtab_hdr;
- ELF(Ehdr) *hdr = (ELF(Ehdr) *)raw_addr;
- ELF(Dyn) *dyn = 0, *dyn_end = 0;
- INT_BITS syms[NSYMS] = {};
- ELF(Phdr) *pt = (ELF(Phdr) *)(raw_addr + GET_BE(&hdr->e_phoff));
- /* Walk the segment table. */
- for (i = 0; i < GET_BE(&hdr->e_phnum); i++) {
- if (GET_BE(&pt[i].p_type) == PT_LOAD) {
- if (found_load)
- fail("multiple PT_LOAD segs\n");
- if (GET_BE(&pt[i].p_offset) != 0 ||
- GET_BE(&pt[i].p_vaddr) != 0)
- fail("PT_LOAD in wrong place\n");
- if (GET_BE(&pt[i].p_memsz) != GET_BE(&pt[i].p_filesz))
- fail("cannot handle memsz != filesz\n");
- load_size = GET_BE(&pt[i].p_memsz);
- found_load = 1;
- } else if (GET_BE(&pt[i].p_type) == PT_DYNAMIC) {
- dyn = raw_addr + GET_BE(&pt[i].p_offset);
- dyn_end = raw_addr + GET_BE(&pt[i].p_offset) +
- GET_BE(&pt[i].p_memsz);
- }
- }
- if (!found_load)
- fail("no PT_LOAD seg\n");
- if (stripped_len < load_size)
- fail("stripped input is too short\n");
- /* Walk the dynamic table */
- for (i = 0; dyn + i < dyn_end &&
- GET_BE(&dyn[i].d_tag) != DT_NULL; i++) {
- typeof(dyn[i].d_tag) tag = GET_BE(&dyn[i].d_tag);
- typeof(dyn[i].d_un.d_val) val = GET_BE(&dyn[i].d_un.d_val);
- if ((tag == DT_RELSZ || tag == DT_RELASZ) && (val != 0))
- fail("vdso image contains dynamic relocations\n");
- }
- /* Walk the section table */
- for (i = 0; i < GET_BE(&hdr->e_shnum); i++) {
- ELF(Shdr) *sh = raw_addr + GET_BE(&hdr->e_shoff) +
- GET_BE(&hdr->e_shentsize) * i;
- if (GET_BE(&sh->sh_type) == SHT_SYMTAB)
- symtab_hdr = sh;
- }
- if (!symtab_hdr)
- fail("no symbol table\n");
- strtab_hdr = raw_addr + GET_BE(&hdr->e_shoff) +
- GET_BE(&hdr->e_shentsize) * GET_BE(&symtab_hdr->sh_link);
- /* Walk the symbol table */
- for (i = 0;
- i < GET_BE(&symtab_hdr->sh_size) / GET_BE(&symtab_hdr->sh_entsize);
- i++) {
- int k;
- ELF(Sym) *sym = raw_addr + GET_BE(&symtab_hdr->sh_offset) +
- GET_BE(&symtab_hdr->sh_entsize) * i;
- const char *name = raw_addr + GET_BE(&strtab_hdr->sh_offset) +
- GET_BE(&sym->st_name);
- for (k = 0; k < NSYMS; k++) {
- if (!strcmp(name, required_syms[k].name)) {
- if (syms[k]) {
- fail("duplicate symbol %s\n",
- required_syms[k].name);
- }
- /*
- * Careful: we use negative addresses, but
- * st_value is unsigned, so we rely
- * on syms[k] being a signed type of the
- * correct width.
- */
- syms[k] = GET_BE(&sym->st_value);
- }
- }
- }
- /* Validate mapping addresses. */
- if (syms[sym_vvar_start] % 8192)
- fail("vvar_begin must be a multiple of 8192\n");
- if (!name) {
- fwrite(stripped_addr, stripped_len, 1, outfile);
- return;
- }
- mapping_size = (stripped_len + 8191) / 8192 * 8192;
- fprintf(outfile, "/* AUTOMATICALLY GENERATED -- DO NOT EDIT */\n\n");
- fprintf(outfile, "#include <linux/cache.h>\n");
- fprintf(outfile, "#include <asm/vdso.h>\n");
- fprintf(outfile, "\n");
- fprintf(outfile,
- "static unsigned char raw_data[%lu] __ro_after_init __aligned(8192)= {",
- mapping_size);
- for (j = 0; j < stripped_len; j++) {
- if (j % 10 == 0)
- fprintf(outfile, "\n\t");
- fprintf(outfile, "0x%02X, ",
- (int)((unsigned char *)stripped_addr)[j]);
- }
- fprintf(outfile, "\n};\n\n");
- fprintf(outfile, "const struct vdso_image %s_builtin = {\n", name);
- fprintf(outfile, "\t.data = raw_data,\n");
- fprintf(outfile, "\t.size = %lu,\n", mapping_size);
- for (i = 0; i < NSYMS; i++) {
- if (required_syms[i].export && syms[i])
- fprintf(outfile, "\t.sym_%s = %" PRIi64 ",\n",
- required_syms[i].name, (int64_t)syms[i]);
- }
- fprintf(outfile, "};\n");
- }
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