aboutsummaryrefslogtreecommitdiff
path: root/arch/x86/boot/compressed/relocs.c
diff options
context:
space:
mode:
Diffstat (limited to 'arch/x86/boot/compressed/relocs.c')
-rw-r--r--arch/x86/boot/compressed/relocs.c682
1 files changed, 0 insertions, 682 deletions
diff --git a/arch/x86/boot/compressed/relocs.c b/arch/x86/boot/compressed/relocs.c
deleted file mode 100644
index 89bbf4e4d05..00000000000
--- a/arch/x86/boot/compressed/relocs.c
+++ /dev/null
@@ -1,682 +0,0 @@
-#include <stdio.h>
-#include <stdarg.h>
-#include <stdlib.h>
-#include <stdint.h>
-#include <string.h>
-#include <errno.h>
-#include <unistd.h>
-#include <elf.h>
-#include <byteswap.h>
-#define USE_BSD
-#include <endian.h>
-#include <regex.h>
-
-static void die(char *fmt, ...);
-
-#define ARRAY_SIZE(x) (sizeof(x) / sizeof((x)[0]))
-static Elf32_Ehdr ehdr;
-static unsigned long reloc_count, reloc_idx;
-static unsigned long *relocs;
-
-struct section {
- Elf32_Shdr shdr;
- struct section *link;
- Elf32_Sym *symtab;
- Elf32_Rel *reltab;
- char *strtab;
-};
-static struct section *secs;
-
-/*
- * Following symbols have been audited. There values are constant and do
- * not change if bzImage is loaded at a different physical address than
- * the address for which it has been compiled. Don't warn user about
- * absolute relocations present w.r.t these symbols.
- */
-static const char abs_sym_regex[] =
- "^(xen_irq_disable_direct_reloc$|"
- "xen_save_fl_direct_reloc$|"
- "VDSO|"
- "__crc_)";
-static regex_t abs_sym_regex_c;
-static int is_abs_reloc(const char *sym_name)
-{
- return !regexec(&abs_sym_regex_c, sym_name, 0, NULL, 0);
-}
-
-/*
- * These symbols are known to be relative, even if the linker marks them
- * as absolute (typically defined outside any section in the linker script.)
- */
-static const char rel_sym_regex[] =
- "^_end$";
-static regex_t rel_sym_regex_c;
-static int is_rel_reloc(const char *sym_name)
-{
- return !regexec(&rel_sym_regex_c, sym_name, 0, NULL, 0);
-}
-
-static void regex_init(void)
-{
- char errbuf[128];
- int err;
-
- err = regcomp(&abs_sym_regex_c, abs_sym_regex,
- REG_EXTENDED|REG_NOSUB);
- if (err) {
- regerror(err, &abs_sym_regex_c, errbuf, sizeof errbuf);
- die("%s", errbuf);
- }
-
- err = regcomp(&rel_sym_regex_c, rel_sym_regex,
- REG_EXTENDED|REG_NOSUB);
- if (err) {
- regerror(err, &rel_sym_regex_c, errbuf, sizeof errbuf);
- die("%s", errbuf);
- }
-}
-
-static void die(char *fmt, ...)
-{
- va_list ap;
- va_start(ap, fmt);
- vfprintf(stderr, fmt, ap);
- va_end(ap);
- exit(1);
-}
-
-static const char *sym_type(unsigned type)
-{
- static const char *type_name[] = {
-#define SYM_TYPE(X) [X] = #X
- SYM_TYPE(STT_NOTYPE),
- SYM_TYPE(STT_OBJECT),
- SYM_TYPE(STT_FUNC),
- SYM_TYPE(STT_SECTION),
- SYM_TYPE(STT_FILE),
- SYM_TYPE(STT_COMMON),
- SYM_TYPE(STT_TLS),
-#undef SYM_TYPE
- };
- const char *name = "unknown sym type name";
- if (type < ARRAY_SIZE(type_name)) {
- name = type_name[type];
- }
- return name;
-}
-
-static const char *sym_bind(unsigned bind)
-{
- static const char *bind_name[] = {
-#define SYM_BIND(X) [X] = #X
- SYM_BIND(STB_LOCAL),
- SYM_BIND(STB_GLOBAL),
- SYM_BIND(STB_WEAK),
-#undef SYM_BIND
- };
- const char *name = "unknown sym bind name";
- if (bind < ARRAY_SIZE(bind_name)) {
- name = bind_name[bind];
- }
- return name;
-}
-
-static const char *sym_visibility(unsigned visibility)
-{
- static const char *visibility_name[] = {
-#define SYM_VISIBILITY(X) [X] = #X
- SYM_VISIBILITY(STV_DEFAULT),
- SYM_VISIBILITY(STV_INTERNAL),
- SYM_VISIBILITY(STV_HIDDEN),
- SYM_VISIBILITY(STV_PROTECTED),
-#undef SYM_VISIBILITY
- };
- const char *name = "unknown sym visibility name";
- if (visibility < ARRAY_SIZE(visibility_name)) {
- name = visibility_name[visibility];
- }
- return name;
-}
-
-static const char *rel_type(unsigned type)
-{
- static const char *type_name[] = {
-#define REL_TYPE(X) [X] = #X
- REL_TYPE(R_386_NONE),
- REL_TYPE(R_386_32),
- REL_TYPE(R_386_PC32),
- REL_TYPE(R_386_GOT32),
- REL_TYPE(R_386_PLT32),
- REL_TYPE(R_386_COPY),
- REL_TYPE(R_386_GLOB_DAT),
- REL_TYPE(R_386_JMP_SLOT),
- REL_TYPE(R_386_RELATIVE),
- REL_TYPE(R_386_GOTOFF),
- REL_TYPE(R_386_GOTPC),
-#undef REL_TYPE
- };
- const char *name = "unknown type rel type name";
- if (type < ARRAY_SIZE(type_name) && type_name[type]) {
- name = type_name[type];
- }
- return name;
-}
-
-static const char *sec_name(unsigned shndx)
-{
- const char *sec_strtab;
- const char *name;
- sec_strtab = secs[ehdr.e_shstrndx].strtab;
- name = "<noname>";
- if (shndx < ehdr.e_shnum) {
- name = sec_strtab + secs[shndx].shdr.sh_name;
- }
- else if (shndx == SHN_ABS) {
- name = "ABSOLUTE";
- }
- else if (shndx == SHN_COMMON) {
- name = "COMMON";
- }
- return name;
-}
-
-static const char *sym_name(const char *sym_strtab, Elf32_Sym *sym)
-{
- const char *name;
- name = "<noname>";
- if (sym->st_name) {
- name = sym_strtab + sym->st_name;
- }
- else {
- name = sec_name(secs[sym->st_shndx].shdr.sh_name);
- }
- return name;
-}
-
-
-
-#if BYTE_ORDER == LITTLE_ENDIAN
-#define le16_to_cpu(val) (val)
-#define le32_to_cpu(val) (val)
-#endif
-#if BYTE_ORDER == BIG_ENDIAN
-#define le16_to_cpu(val) bswap_16(val)
-#define le32_to_cpu(val) bswap_32(val)
-#endif
-
-static uint16_t elf16_to_cpu(uint16_t val)
-{
- return le16_to_cpu(val);
-}
-
-static uint32_t elf32_to_cpu(uint32_t val)
-{
- return le32_to_cpu(val);
-}
-
-static void read_ehdr(FILE *fp)
-{
- if (fread(&ehdr, sizeof(ehdr), 1, fp) != 1) {
- die("Cannot read ELF header: %s\n",
- strerror(errno));
- }
- if (memcmp(ehdr.e_ident, ELFMAG, SELFMAG) != 0) {
- die("No ELF magic\n");
- }
- if (ehdr.e_ident[EI_CLASS] != ELFCLASS32) {
- die("Not a 32 bit executable\n");
- }
- if (ehdr.e_ident[EI_DATA] != ELFDATA2LSB) {
- die("Not a LSB ELF executable\n");
- }
- if (ehdr.e_ident[EI_VERSION] != EV_CURRENT) {
- die("Unknown ELF version\n");
- }
- /* Convert the fields to native endian */
- ehdr.e_type = elf16_to_cpu(ehdr.e_type);
- ehdr.e_machine = elf16_to_cpu(ehdr.e_machine);
- ehdr.e_version = elf32_to_cpu(ehdr.e_version);
- ehdr.e_entry = elf32_to_cpu(ehdr.e_entry);
- ehdr.e_phoff = elf32_to_cpu(ehdr.e_phoff);
- ehdr.e_shoff = elf32_to_cpu(ehdr.e_shoff);
- ehdr.e_flags = elf32_to_cpu(ehdr.e_flags);
- ehdr.e_ehsize = elf16_to_cpu(ehdr.e_ehsize);
- ehdr.e_phentsize = elf16_to_cpu(ehdr.e_phentsize);
- ehdr.e_phnum = elf16_to_cpu(ehdr.e_phnum);
- ehdr.e_shentsize = elf16_to_cpu(ehdr.e_shentsize);
- ehdr.e_shnum = elf16_to_cpu(ehdr.e_shnum);
- ehdr.e_shstrndx = elf16_to_cpu(ehdr.e_shstrndx);
-
- if ((ehdr.e_type != ET_EXEC) && (ehdr.e_type != ET_DYN)) {
- die("Unsupported ELF header type\n");
- }
- if (ehdr.e_machine != EM_386) {
- die("Not for x86\n");
- }
- if (ehdr.e_version != EV_CURRENT) {
- die("Unknown ELF version\n");
- }
- if (ehdr.e_ehsize != sizeof(Elf32_Ehdr)) {
- die("Bad Elf header size\n");
- }
- if (ehdr.e_phentsize != sizeof(Elf32_Phdr)) {
- die("Bad program header entry\n");
- }
- if (ehdr.e_shentsize != sizeof(Elf32_Shdr)) {
- die("Bad section header entry\n");
- }
- if (ehdr.e_shstrndx >= ehdr.e_shnum) {
- die("String table index out of bounds\n");
- }
-}
-
-static void read_shdrs(FILE *fp)
-{
- int i;
- Elf32_Shdr shdr;
-
- secs = calloc(ehdr.e_shnum, sizeof(struct section));
- if (!secs) {
- die("Unable to allocate %d section headers\n",
- ehdr.e_shnum);
- }
- if (fseek(fp, ehdr.e_shoff, SEEK_SET) < 0) {
- die("Seek to %d failed: %s\n",
- ehdr.e_shoff, strerror(errno));
- }
- for (i = 0; i < ehdr.e_shnum; i++) {
- struct section *sec = &secs[i];
- if (fread(&shdr, sizeof shdr, 1, fp) != 1)
- die("Cannot read ELF section headers %d/%d: %s\n",
- i, ehdr.e_shnum, strerror(errno));
- sec->shdr.sh_name = elf32_to_cpu(shdr.sh_name);
- sec->shdr.sh_type = elf32_to_cpu(shdr.sh_type);
- sec->shdr.sh_flags = elf32_to_cpu(shdr.sh_flags);
- sec->shdr.sh_addr = elf32_to_cpu(shdr.sh_addr);
- sec->shdr.sh_offset = elf32_to_cpu(shdr.sh_offset);
- sec->shdr.sh_size = elf32_to_cpu(shdr.sh_size);
- sec->shdr.sh_link = elf32_to_cpu(shdr.sh_link);
- sec->shdr.sh_info = elf32_to_cpu(shdr.sh_info);
- sec->shdr.sh_addralign = elf32_to_cpu(shdr.sh_addralign);
- sec->shdr.sh_entsize = elf32_to_cpu(shdr.sh_entsize);
- if (sec->shdr.sh_link < ehdr.e_shnum)
- sec->link = &secs[sec->shdr.sh_link];
- }
-
-}
-
-static void read_strtabs(FILE *fp)
-{
- int i;
- for (i = 0; i < ehdr.e_shnum; i++) {
- struct section *sec = &secs[i];
- if (sec->shdr.sh_type != SHT_STRTAB) {
- continue;
- }
- sec->strtab = malloc(sec->shdr.sh_size);
- if (!sec->strtab) {
- die("malloc of %d bytes for strtab failed\n",
- sec->shdr.sh_size);
- }
- if (fseek(fp, sec->shdr.sh_offset, SEEK_SET) < 0) {
- die("Seek to %d failed: %s\n",
- sec->shdr.sh_offset, strerror(errno));
- }
- if (fread(sec->strtab, 1, sec->shdr.sh_size, fp)
- != sec->shdr.sh_size) {
- die("Cannot read symbol table: %s\n",
- strerror(errno));
- }
- }
-}
-
-static void read_symtabs(FILE *fp)
-{
- int i,j;
- for (i = 0; i < ehdr.e_shnum; i++) {
- struct section *sec = &secs[i];
- if (sec->shdr.sh_type != SHT_SYMTAB) {
- continue;
- }
- sec->symtab = malloc(sec->shdr.sh_size);
- if (!sec->symtab) {
- die("malloc of %d bytes for symtab failed\n",
- sec->shdr.sh_size);
- }
- if (fseek(fp, sec->shdr.sh_offset, SEEK_SET) < 0) {
- die("Seek to %d failed: %s\n",
- sec->shdr.sh_offset, strerror(errno));
- }
- if (fread(sec->symtab, 1, sec->shdr.sh_size, fp)
- != sec->shdr.sh_size) {
- die("Cannot read symbol table: %s\n",
- strerror(errno));
- }
- for (j = 0; j < sec->shdr.sh_size/sizeof(Elf32_Sym); j++) {
- Elf32_Sym *sym = &sec->symtab[j];
- sym->st_name = elf32_to_cpu(sym->st_name);
- sym->st_value = elf32_to_cpu(sym->st_value);
- sym->st_size = elf32_to_cpu(sym->st_size);
- sym->st_shndx = elf16_to_cpu(sym->st_shndx);
- }
- }
-}
-
-
-static void read_relocs(FILE *fp)
-{
- int i,j;
- for (i = 0; i < ehdr.e_shnum; i++) {
- struct section *sec = &secs[i];
- if (sec->shdr.sh_type != SHT_REL) {
- continue;
- }
- sec->reltab = malloc(sec->shdr.sh_size);
- if (!sec->reltab) {
- die("malloc of %d bytes for relocs failed\n",
- sec->shdr.sh_size);
- }
- if (fseek(fp, sec->shdr.sh_offset, SEEK_SET) < 0) {
- die("Seek to %d failed: %s\n",
- sec->shdr.sh_offset, strerror(errno));
- }
- if (fread(sec->reltab, 1, sec->shdr.sh_size, fp)
- != sec->shdr.sh_size) {
- die("Cannot read symbol table: %s\n",
- strerror(errno));
- }
- for (j = 0; j < sec->shdr.sh_size/sizeof(Elf32_Rel); j++) {
- Elf32_Rel *rel = &sec->reltab[j];
- rel->r_offset = elf32_to_cpu(rel->r_offset);
- rel->r_info = elf32_to_cpu(rel->r_info);
- }
- }
-}
-
-
-static void print_absolute_symbols(void)
-{
- int i;
- printf("Absolute symbols\n");
- printf(" Num: Value Size Type Bind Visibility Name\n");
- for (i = 0; i < ehdr.e_shnum; i++) {
- struct section *sec = &secs[i];
- char *sym_strtab;
- Elf32_Sym *sh_symtab;
- int j;
-
- if (sec->shdr.sh_type != SHT_SYMTAB) {
- continue;
- }
- sh_symtab = sec->symtab;
- sym_strtab = sec->link->strtab;
- for (j = 0; j < sec->shdr.sh_size/sizeof(Elf32_Sym); j++) {
- Elf32_Sym *sym;
- const char *name;
- sym = &sec->symtab[j];
- name = sym_name(sym_strtab, sym);
- if (sym->st_shndx != SHN_ABS) {
- continue;
- }
- printf("%5d %08x %5d %10s %10s %12s %s\n",
- j, sym->st_value, sym->st_size,
- sym_type(ELF32_ST_TYPE(sym->st_info)),
- sym_bind(ELF32_ST_BIND(sym->st_info)),
- sym_visibility(ELF32_ST_VISIBILITY(sym->st_other)),
- name);
- }
- }
- printf("\n");
-}
-
-static void print_absolute_relocs(void)
-{
- int i, printed = 0;
-
- for (i = 0; i < ehdr.e_shnum; i++) {
- struct section *sec = &secs[i];
- struct section *sec_applies, *sec_symtab;
- char *sym_strtab;
- Elf32_Sym *sh_symtab;
- int j;
- if (sec->shdr.sh_type != SHT_REL) {
- continue;
- }
- sec_symtab = sec->link;
- sec_applies = &secs[sec->shdr.sh_info];
- if (!(sec_applies->shdr.sh_flags & SHF_ALLOC)) {
- continue;
- }
- sh_symtab = sec_symtab->symtab;
- sym_strtab = sec_symtab->link->strtab;
- for (j = 0; j < sec->shdr.sh_size/sizeof(Elf32_Rel); j++) {
- Elf32_Rel *rel;
- Elf32_Sym *sym;
- const char *name;
- rel = &sec->reltab[j];
- sym = &sh_symtab[ELF32_R_SYM(rel->r_info)];
- name = sym_name(sym_strtab, sym);
- if (sym->st_shndx != SHN_ABS) {
- continue;
- }
-
- /* Absolute symbols are not relocated if bzImage is
- * loaded at a non-compiled address. Display a warning
- * to user at compile time about the absolute
- * relocations present.
- *
- * User need to audit the code to make sure
- * some symbols which should have been section
- * relative have not become absolute because of some
- * linker optimization or wrong programming usage.
- *
- * Before warning check if this absolute symbol
- * relocation is harmless.
- */
- if (is_abs_reloc(name) || is_rel_reloc(name))
- continue;
-
- if (!printed) {
- printf("WARNING: Absolute relocations"
- " present\n");
- printf("Offset Info Type Sym.Value "
- "Sym.Name\n");
- printed = 1;
- }
-
- printf("%08x %08x %10s %08x %s\n",
- rel->r_offset,
- rel->r_info,
- rel_type(ELF32_R_TYPE(rel->r_info)),
- sym->st_value,
- name);
- }
- }
-
- if (printed)
- printf("\n");
-}
-
-static void walk_relocs(void (*visit)(Elf32_Rel *rel, Elf32_Sym *sym))
-{
- int i;
- /* Walk through the relocations */
- for (i = 0; i < ehdr.e_shnum; i++) {
- char *sym_strtab;
- Elf32_Sym *sh_symtab;
- struct section *sec_applies, *sec_symtab;
- int j;
- struct section *sec = &secs[i];
-
- if (sec->shdr.sh_type != SHT_REL) {
- continue;
- }
- sec_symtab = sec->link;
- sec_applies = &secs[sec->shdr.sh_info];
- if (!(sec_applies->shdr.sh_flags & SHF_ALLOC)) {
- continue;
- }
- sh_symtab = sec_symtab->symtab;
- sym_strtab = sec_symtab->link->strtab;
- for (j = 0; j < sec->shdr.sh_size/sizeof(Elf32_Rel); j++) {
- Elf32_Rel *rel;
- Elf32_Sym *sym;
- unsigned r_type;
- rel = &sec->reltab[j];
- sym = &sh_symtab[ELF32_R_SYM(rel->r_info)];
- r_type = ELF32_R_TYPE(rel->r_info);
- /* Don't visit relocations to absolute symbols */
- if (sym->st_shndx == SHN_ABS &&
- !is_rel_reloc(sym_name(sym_strtab, sym))) {
- continue;
- }
- switch (r_type) {
- case R_386_NONE:
- case R_386_PC32:
- /*
- * NONE can be ignored and and PC relative
- * relocations don't need to be adjusted.
- */
- break;
- case R_386_32:
- /* Visit relocations that need to be adjusted */
- visit(rel, sym);
- break;
- default:
- die("Unsupported relocation type: %s (%d)\n",
- rel_type(r_type), r_type);
- break;
- }
- }
- }
-}
-
-static void count_reloc(Elf32_Rel *rel, Elf32_Sym *sym)
-{
- reloc_count += 1;
-}
-
-static void collect_reloc(Elf32_Rel *rel, Elf32_Sym *sym)
-{
- /* Remember the address that needs to be adjusted. */
- relocs[reloc_idx++] = rel->r_offset;
-}
-
-static int cmp_relocs(const void *va, const void *vb)
-{
- const unsigned long *a, *b;
- a = va; b = vb;
- return (*a == *b)? 0 : (*a > *b)? 1 : -1;
-}
-
-static void emit_relocs(int as_text)
-{
- int i;
- /* Count how many relocations I have and allocate space for them. */
- reloc_count = 0;
- walk_relocs(count_reloc);
- relocs = malloc(reloc_count * sizeof(relocs[0]));
- if (!relocs) {
- die("malloc of %d entries for relocs failed\n",
- reloc_count);
- }
- /* Collect up the relocations */
- reloc_idx = 0;
- walk_relocs(collect_reloc);
-
- /* Order the relocations for more efficient processing */
- qsort(relocs, reloc_count, sizeof(relocs[0]), cmp_relocs);
-
- /* Print the relocations */
- if (as_text) {
- /* Print the relocations in a form suitable that
- * gas will like.
- */
- printf(".section \".data.reloc\",\"a\"\n");
- printf(".balign 4\n");
- for (i = 0; i < reloc_count; i++) {
- printf("\t .long 0x%08lx\n", relocs[i]);
- }
- printf("\n");
- }
- else {
- unsigned char buf[4];
- /* Print a stop */
- fwrite("\0\0\0\0", 4, 1, stdout);
- /* Now print each relocation */
- for (i = 0; i < reloc_count; i++) {
- buf[0] = (relocs[i] >> 0) & 0xff;
- buf[1] = (relocs[i] >> 8) & 0xff;
- buf[2] = (relocs[i] >> 16) & 0xff;
- buf[3] = (relocs[i] >> 24) & 0xff;
- fwrite(buf, 4, 1, stdout);
- }
- }
-}
-
-static void usage(void)
-{
- die("relocs [--abs-syms |--abs-relocs | --text] vmlinux\n");
-}
-
-int main(int argc, char **argv)
-{
- int show_absolute_syms, show_absolute_relocs;
- int as_text;
- const char *fname;
- FILE *fp;
- int i;
-
- regex_init();
-
- show_absolute_syms = 0;
- show_absolute_relocs = 0;
- as_text = 0;
- fname = NULL;
- for (i = 1; i < argc; i++) {
- char *arg = argv[i];
- if (*arg == '-') {
- if (strcmp(argv[1], "--abs-syms") == 0) {
- show_absolute_syms = 1;
- continue;
- }
-
- if (strcmp(argv[1], "--abs-relocs") == 0) {
- show_absolute_relocs = 1;
- continue;
- }
- else if (strcmp(argv[1], "--text") == 0) {
- as_text = 1;
- continue;
- }
- }
- else if (!fname) {
- fname = arg;
- continue;
- }
- usage();
- }
- if (!fname) {
- usage();
- }
- fp = fopen(fname, "r");
- if (!fp) {
- die("Cannot open %s: %s\n",
- fname, strerror(errno));
- }
- read_ehdr(fp);
- read_shdrs(fp);
- read_strtabs(fp);
- read_symtabs(fp);
- read_relocs(fp);
- if (show_absolute_syms) {
- print_absolute_symbols();
- return 0;
- }
- if (show_absolute_relocs) {
- print_absolute_relocs();
- return 0;
- }
- emit_relocs(as_text);
- return 0;
-}
generated by cgit v1.2.3-70-g09d2 (git 2.46.0) at 2025-11-04 08:15:36 +0000