diff options
Diffstat (limited to 'arch/x86/vdso/vdso2c.h')
| -rw-r--r-- | arch/x86/vdso/vdso2c.h | 163 |
1 files changed, 163 insertions, 0 deletions
diff --git a/arch/x86/vdso/vdso2c.h b/arch/x86/vdso/vdso2c.h new file mode 100644 index 000000000000..d1e99e1892c4 --- /dev/null +++ b/arch/x86/vdso/vdso2c.h @@ -0,0 +1,163 @@ +/* + * This file is included twice from vdso2c.c. It generates code for 32-bit + * and 64-bit vDSOs. We need both for 64-bit builds, since 32-bit vDSOs + * are built for 32-bit userspace. + */ + +static void GOFUNC(void *addr, size_t len, FILE *outfile, const char *name) +{ + int found_load = 0; + unsigned long load_size = -1; /* Work around bogus warning */ + unsigned long data_size; + Elf_Ehdr *hdr = (Elf_Ehdr *)addr; + int i; + unsigned long j; + Elf_Shdr *symtab_hdr = NULL, *strtab_hdr, *secstrings_hdr, + *alt_sec = NULL; + Elf_Dyn *dyn = 0, *dyn_end = 0; + const char *secstrings; + uint64_t syms[NSYMS] = {}; + + Elf_Phdr *pt = (Elf_Phdr *)(addr + GET_LE(hdr->e_phoff)); + + /* Walk the segment table. */ + for (i = 0; i < GET_LE(hdr->e_phnum); i++) { + if (GET_LE(pt[i].p_type) == PT_LOAD) { + if (found_load) + fail("multiple PT_LOAD segs\n"); + + if (GET_LE(pt[i].p_offset) != 0 || + GET_LE(pt[i].p_vaddr) != 0) + fail("PT_LOAD in wrong place\n"); + + if (GET_LE(pt[i].p_memsz) != GET_LE(pt[i].p_filesz)) + fail("cannot handle memsz != filesz\n"); + + load_size = GET_LE(pt[i].p_memsz); + found_load = 1; + } else if (GET_LE(pt[i].p_type) == PT_DYNAMIC) { + dyn = addr + GET_LE(pt[i].p_offset); + dyn_end = addr + GET_LE(pt[i].p_offset) + + GET_LE(pt[i].p_memsz); + } + } + if (!found_load) + fail("no PT_LOAD seg\n"); + data_size = (load_size + 4095) / 4096 * 4096; + + /* Walk the dynamic table */ + for (i = 0; dyn + i < dyn_end && + GET_LE(dyn[i].d_tag) != DT_NULL; i++) { + typeof(dyn[i].d_tag) tag = GET_LE(dyn[i].d_tag); + if (tag == DT_REL || tag == DT_RELSZ || + tag == DT_RELENT || tag == DT_TEXTREL) + fail("vdso image contains dynamic relocations\n"); + } + + /* Walk the section table */ + secstrings_hdr = addr + GET_LE(hdr->e_shoff) + + GET_LE(hdr->e_shentsize)*GET_LE(hdr->e_shstrndx); + secstrings = addr + GET_LE(secstrings_hdr->sh_offset); + for (i = 0; i < GET_LE(hdr->e_shnum); i++) { + Elf_Shdr *sh = addr + GET_LE(hdr->e_shoff) + + GET_LE(hdr->e_shentsize) * i; + if (GET_LE(sh->sh_type) == SHT_SYMTAB) + symtab_hdr = sh; + + if (!strcmp(secstrings + GET_LE(sh->sh_name), + ".altinstructions")) + alt_sec = sh; + } + + if (!symtab_hdr) + fail("no symbol table\n"); + + strtab_hdr = addr + GET_LE(hdr->e_shoff) + + GET_LE(hdr->e_shentsize) * GET_LE(symtab_hdr->sh_link); + + /* Walk the symbol table */ + for (i = 0; + i < GET_LE(symtab_hdr->sh_size) / GET_LE(symtab_hdr->sh_entsize); + i++) { + int k; + Elf_Sym *sym = addr + GET_LE(symtab_hdr->sh_offset) + + GET_LE(symtab_hdr->sh_entsize) * i; + const char *name = addr + GET_LE(strtab_hdr->sh_offset) + + GET_LE(sym->st_name); + for (k = 0; k < NSYMS; k++) { + if (!strcmp(name, required_syms[k])) { + if (syms[k]) { + fail("duplicate symbol %s\n", + required_syms[k]); + } + syms[k] = GET_LE(sym->st_value); + } + } + } + + /* Validate mapping addresses. */ + for (i = 0; i < sizeof(special_pages) / sizeof(special_pages[0]); i++) { + if (!syms[i]) + continue; /* The mapping isn't used; ignore it. */ + + if (syms[i] % 4096) + fail("%s must be a multiple of 4096\n", + required_syms[i]); + if (syms[i] < data_size) + fail("%s must be after the text mapping\n", + required_syms[i]); + if (syms[sym_end_mapping] < syms[i] + 4096) + fail("%s overruns end_mapping\n", required_syms[i]); + } + if (syms[sym_end_mapping] % 4096) + fail("end_mapping must be a multiple of 4096\n"); + + /* Remove sections. */ + hdr->e_shoff = 0; + hdr->e_shentsize = 0; + hdr->e_shnum = 0; + hdr->e_shstrndx = htole16(SHN_UNDEF); + + if (!name) { + fwrite(addr, load_size, 1, outfile); + return; + } + + fprintf(outfile, "/* AUTOMATICALLY GENERATED -- DO NOT EDIT */\n\n"); + fprintf(outfile, "#include <linux/linkage.h>\n"); + fprintf(outfile, "#include <asm/page_types.h>\n"); + fprintf(outfile, "#include <asm/vdso.h>\n"); + fprintf(outfile, "\n"); + fprintf(outfile, + "static unsigned char raw_data[%lu] __page_aligned_data = {", + data_size); + for (j = 0; j < load_size; j++) { + if (j % 10 == 0) + fprintf(outfile, "\n\t"); + fprintf(outfile, "0x%02X, ", (int)((unsigned char *)addr)[j]); + } + fprintf(outfile, "\n};\n\n"); + + fprintf(outfile, "static struct page *pages[%lu];\n\n", + data_size / 4096); + + fprintf(outfile, "const struct vdso_image %s = {\n", name); + fprintf(outfile, "\t.data = raw_data,\n"); + fprintf(outfile, "\t.size = %lu,\n", data_size); + fprintf(outfile, "\t.text_mapping = {\n"); + fprintf(outfile, "\t\t.name = \"[vdso]\",\n"); + fprintf(outfile, "\t\t.pages = pages,\n"); + fprintf(outfile, "\t},\n"); + if (alt_sec) { + fprintf(outfile, "\t.alt = %lu,\n", + (unsigned long)GET_LE(alt_sec->sh_offset)); + fprintf(outfile, "\t.alt_len = %lu,\n", + (unsigned long)GET_LE(alt_sec->sh_size)); + } + for (i = 0; i < NSYMS; i++) { + if (syms[i]) + fprintf(outfile, "\t.sym_%s = 0x%" PRIx64 ",\n", + required_syms[i], syms[i]); + } + fprintf(outfile, "};\n"); +} |