From: "H. Peter Anvin" <[email protected]>
A new option is added to the relocs tool called '--realmode'.
This option causes the generation of 16-bit segment relocations
and 32-bit linear relocations for the real-mode code. When
the real-mode code is moved to the low-memory during kernel
initialization, these relocation entries can be used to
relocate the code properly.
In the assembly code 16-bit segment relocations must be relative
to the 'real_mode_seg' absolute symbol. Linear relocations must be
relative to a symbol prefixed with 'pa_'.
16-bit segment relocation is used to load cs:ip in 16-bit code.
Linear relocations are used in the 32-bit code for relocatable
data references. They are declared in the linker script of the
real-mode code.
The relocs tool is moved to arch/x86/tools/relocs.c, and added new
target archscripts that can be used to build scripts needed building
an architecture. be compiled before building the arch/x86 tree.
[ hpa: accelerating this because it detects invalid absolute
relocations, a serious bug in binutils 2.22.52.0.x which currently
produces bad kernels. ]
[ jsakkine: applied against 3.3.7 ]
Signed-off-by: H. Peter Anvin <[email protected]>
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Jarkko Sakkinen <[email protected]>
Signed-off-by: H. Peter Anvin <[email protected]>
Cc: <[email protected]>
Signed-off-by: Jarkko Sakkinen <[email protected]>
---
Makefile | 9 +-
arch/x86/Makefile | 3 +
arch/x86/boot/compressed/Makefile | 9 +-
arch/x86/boot/compressed/relocs.c | 680 -------------------------------
arch/x86/tools/.gitignore | 1 +
arch/x86/tools/Makefile | 4 +
arch/x86/tools/relocs.c | 797 +++++++++++++++++++++++++++++++++++++
scripts/Makefile | 2 +
8 files changed, 817 insertions(+), 688 deletions(-)
delete mode 100644 arch/x86/boot/compressed/relocs.c
create mode 100644 arch/x86/tools/.gitignore
create mode 100644 arch/x86/tools/relocs.c
diff --git a/Makefile b/Makefile
index 073f74f..98a6b07 100644
--- a/Makefile
+++ b/Makefile
@@ -442,7 +442,7 @@ asm-generic:
no-dot-config-targets := clean mrproper distclean \
cscope gtags TAGS tags help %docs check% coccicheck \
- include/linux/version.h headers_% archheaders \
+ include/linux/version.h headers_% archheaders archscripts \
kernelversion %src-pkg
config-targets := 0
@@ -979,7 +979,7 @@ prepare1: prepare2 include/linux/version.h include/generated/utsrelease.h \
include/config/auto.conf
$(cmd_crmodverdir)
-archprepare: archheaders prepare1 scripts_basic
+archprepare: archheaders archscripts prepare1 scripts_basic
prepare0: archprepare FORCE
$(Q)$(MAKE) $(build)=.
@@ -1049,8 +1049,11 @@ hdr-dst = $(if $(KBUILD_HEADERS), dst=include/asm-$(hdr-arch), dst=include/asm)
PHONY += archheaders
archheaders:
+PHONY += archscripts
+archscripts:
+
PHONY += __headers
-__headers: include/linux/version.h scripts_basic asm-generic archheaders FORCE
+__headers: include/linux/version.h scripts_basic asm-generic archheaders archscripts FORCE
$(Q)$(MAKE) $(build)=scripts build_unifdef
PHONY += headers_install_all
diff --git a/arch/x86/Makefile b/arch/x86/Makefile
index 209ba12..dbd597f 100644
--- a/arch/x86/Makefile
+++ b/arch/x86/Makefile
@@ -117,6 +117,9 @@ KBUILD_CFLAGS += $(call cc-option,-mno-sse -mno-mmx -mno-sse2 -mno-3dnow,)
KBUILD_CFLAGS += $(mflags-y)
KBUILD_AFLAGS += $(mflags-y)
+archscripts:
+ $(Q)$(MAKE) $(build)=arch/x86/tools relocs
+
###
# Syscall table generation
diff --git a/arch/x86/boot/compressed/Makefile b/arch/x86/boot/compressed/Makefile
index fd55a2f..e398bb5 100644
--- a/arch/x86/boot/compressed/Makefile
+++ b/arch/x86/boot/compressed/Makefile
@@ -40,13 +40,12 @@ OBJCOPYFLAGS_vmlinux.bin := -R .comment -S
$(obj)/vmlinux.bin: vmlinux FORCE
$(call if_changed,objcopy)
+targets += vmlinux.bin.all vmlinux.relocs
-targets += vmlinux.bin.all vmlinux.relocs relocs
-hostprogs-$(CONFIG_X86_NEED_RELOCS) += relocs
-
+CMD_RELOCS = arch/x86/tools/relocs
quiet_cmd_relocs = RELOCS $@
- cmd_relocs = $(obj)/relocs $< > $@;$(obj)/relocs --abs-relocs $<
-$(obj)/vmlinux.relocs: vmlinux $(obj)/relocs FORCE
+ cmd_relocs = $(CMD_RELOCS) $< > $@;$(CMD_RELOCS) --abs-relocs $<
+$(obj)/vmlinux.relocs: vmlinux FORCE
$(call if_changed,relocs)
vmlinux.bin.all-y := $(obj)/vmlinux.bin
diff --git a/arch/x86/boot/compressed/relocs.c b/arch/x86/boot/compressed/relocs.c
deleted file mode 100644
index e77f4e4..0000000
--- a/arch/x86/boot/compressed/relocs.c
+++ /dev/null
@@ -1,680 +0,0 @@
-#include <stdio.h>
-#include <stdarg.h>
-#include <stdlib.h>
-#include <stdint.h>
-#include <string.h>
-#include <errno.h>
-#include <unistd.h>
-#include <elf.h>
-#include <byteswap.h>
-#define USE_BSD
-#include <endian.h>
-#include <regex.h>
-
-static void die(char *fmt, ...);
-
-#define ARRAY_SIZE(x) (sizeof(x) / sizeof((x)[0]))
-static Elf32_Ehdr ehdr;
-static unsigned long reloc_count, reloc_idx;
-static unsigned long *relocs;
-
-struct section {
- Elf32_Shdr shdr;
- struct section *link;
- Elf32_Sym *symtab;
- Elf32_Rel *reltab;
- char *strtab;
-};
-static struct section *secs;
-
-/*
- * Following symbols have been audited. There values are constant and do
- * not change if bzImage is loaded at a different physical address than
- * the address for which it has been compiled. Don't warn user about
- * absolute relocations present w.r.t these symbols.
- */
-static const char abs_sym_regex[] =
- "^(xen_irq_disable_direct_reloc$|"
- "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;
- int j;
-
- if (sec->shdr.sh_type != SHT_SYMTAB) {
- continue;
- }
- 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;
-}
diff --git a/arch/x86/tools/.gitignore b/arch/x86/tools/.gitignore
new file mode 100644
index 0000000..be0ed06
--- /dev/null
+++ b/arch/x86/tools/.gitignore
@@ -0,0 +1 @@
+relocs
diff --git a/arch/x86/tools/Makefile b/arch/x86/tools/Makefile
index d511aa9..733057b 100644
--- a/arch/x86/tools/Makefile
+++ b/arch/x86/tools/Makefile
@@ -36,3 +36,7 @@ HOSTCFLAGS_insn_sanity.o := -Wall -I$(objtree)/arch/x86/lib/ -I$(srctree)/arch/x
$(obj)/test_get_len.o: $(srctree)/arch/x86/lib/insn.c $(srctree)/arch/x86/lib/inat.c $(srctree)/arch/x86/include/asm/inat_types.h $(srctree)/arch/x86/include/asm/inat.h $(srctree)/arch/x86/include/asm/insn.h $(objtree)/arch/x86/lib/inat-tables.c
$(obj)/insn_sanity.o: $(srctree)/arch/x86/lib/insn.c $(srctree)/arch/x86/lib/inat.c $(srctree)/arch/x86/include/asm/inat_types.h $(srctree)/arch/x86/include/asm/inat.h $(srctree)/arch/x86/include/asm/insn.h $(objtree)/arch/x86/lib/inat-tables.c
+
+HOST_EXTRACFLAGS += -I$(srctree)/tools/include
+hostprogs-y += relocs
+relocs: $(obj)/relocs
diff --git a/arch/x86/tools/relocs.c b/arch/x86/tools/relocs.c
new file mode 100644
index 0000000..0291470
--- /dev/null
+++ b/arch/x86/tools/relocs.c
@@ -0,0 +1,797 @@
+#include <stdio.h>
+#include <stdarg.h>
+#include <stdlib.h>
+#include <stdint.h>
+#include <string.h>
+#include <errno.h>
+#include <unistd.h>
+#include <elf.h>
+#include <byteswap.h>
+#define USE_BSD
+#include <endian.h>
+#include <regex.h>
+#include <tools/le_byteshift.h>
+
+static void die(char *fmt, ...);
+
+#define ARRAY_SIZE(x) (sizeof(x) / sizeof((x)[0]))
+static Elf32_Ehdr ehdr;
+static unsigned long reloc_count, reloc_idx;
+static unsigned long *relocs;
+static unsigned long reloc16_count, reloc16_idx;
+static unsigned long *relocs16;
+
+struct section {
+ Elf32_Shdr shdr;
+ struct section *link;
+ Elf32_Sym *symtab;
+ Elf32_Rel *reltab;
+ char *strtab;
+};
+static struct section *secs;
+
+enum symtype {
+ S_ABS,
+ S_REL,
+ S_SEG,
+ S_LIN,
+ S_NSYMTYPES
+};
+
+static const char * const sym_regex_kernel[S_NSYMTYPES] = {
+/*
+ * Following symbols have been audited. There values are constant and do
+ * not change if bzImage is loaded at a different physical address than
+ * the address for which it has been compiled. Don't warn user about
+ * absolute relocations present w.r.t these symbols.
+ */
+ [S_ABS] =
+ "^(xen_irq_disable_direct_reloc$|"
+ "xen_save_fl_direct_reloc$|"
+ "VDSO|"
+ "__crc_)",
+
+/*
+ * These symbols are known to be relative, even if the linker marks them
+ * as absolute (typically defined outside any section in the linker script.)
+ */
+ [S_REL] =
+ "^_end$",
+};
+
+
+static const char * const sym_regex_realmode[S_NSYMTYPES] = {
+/*
+ * These are 16-bit segment symbols when compiling 16-bit code.
+ */
+ [S_SEG] =
+ "^real_mode_seg$",
+
+/*
+ * These are offsets belonging to segments, as opposed to linear addresses,
+ * when compiling 16-bit code.
+ */
+ [S_LIN] =
+ "^pa_",
+};
+
+static const char * const *sym_regex;
+
+static regex_t sym_regex_c[S_NSYMTYPES];
+static int is_reloc(enum symtype type, const char *sym_name)
+{
+ return sym_regex[type] &&
+ !regexec(&sym_regex_c[type], sym_name, 0, NULL, 0);
+}
+
+static void regex_init(int use_real_mode)
+{
+ char errbuf[128];
+ int err;
+ int i;
+
+ if (use_real_mode)
+ sym_regex = sym_regex_realmode;
+ else
+ sym_regex = sym_regex_kernel;
+
+ for (i = 0; i < S_NSYMTYPES; i++) {
+ if (!sym_regex[i])
+ continue;
+
+ err = regcomp(&sym_regex_c[i], sym_regex[i],
+ REG_EXTENDED|REG_NOSUB);
+
+ if (err) {
+ regerror(err, &sym_regex_c[i], 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),
+ REL_TYPE(R_386_8),
+ REL_TYPE(R_386_PC8),
+ REL_TYPE(R_386_16),
+ REL_TYPE(R_386_PC16),
+#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(sym->st_shndx);
+ }
+ 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;
+ int j;
+
+ if (sec->shdr.sh_type != SHT_SYMTAB) {
+ continue;
+ }
+ 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_reloc(S_ABS, name) || is_reloc(S_REL, 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 use_real_mode)
+{
+ 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;
+ const char *symname;
+ rel = &sec->reltab[j];
+ sym = &sh_symtab[ELF32_R_SYM(rel->r_info)];
+ r_type = ELF32_R_TYPE(rel->r_info);
+
+ switch (r_type) {
+ case R_386_NONE:
+ case R_386_PC32:
+ case R_386_PC16:
+ case R_386_PC8:
+ /*
+ * NONE can be ignored and and PC relative
+ * relocations don't need to be adjusted.
+ */
+ break;
+
+ case R_386_16:
+ symname = sym_name(sym_strtab, sym);
+ if (!use_real_mode)
+ goto bad;
+ if (sym->st_shndx == SHN_ABS) {
+ if (is_reloc(S_ABS, symname))
+ break;
+ else if (!is_reloc(S_SEG, symname))
+ goto bad;
+ } else {
+ if (is_reloc(S_LIN, symname))
+ goto bad;
+ else
+ break;
+ }
+ visit(rel, sym);
+ break;
+
+ case R_386_32:
+ symname = sym_name(sym_strtab, sym);
+ if (sym->st_shndx == SHN_ABS) {
+ if (is_reloc(S_ABS, symname))
+ break;
+ else if (!is_reloc(S_REL, symname))
+ goto bad;
+ } else {
+ if (use_real_mode &&
+ !is_reloc(S_LIN, symname))
+ break;
+ }
+ visit(rel, sym);
+ break;
+ default:
+ die("Unsupported relocation type: %s (%d)\n",
+ rel_type(r_type), r_type);
+ break;
+ bad:
+ symname = sym_name(sym_strtab, sym);
+ die("Invalid %s relocation: %s\n",
+ rel_type(r_type), symname);
+ }
+ }
+ }
+}
+
+static void count_reloc(Elf32_Rel *rel, Elf32_Sym *sym)
+{
+ if (ELF32_R_TYPE(rel->r_info) == R_386_16)
+ reloc16_count++;
+ else
+ reloc_count++;
+}
+
+static void collect_reloc(Elf32_Rel *rel, Elf32_Sym *sym)
+{
+ /* Remember the address that needs to be adjusted. */
+ if (ELF32_R_TYPE(rel->r_info) == R_386_16)
+ relocs16[reloc16_idx++] = rel->r_offset;
+ else
+ 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 int write32(unsigned int v, FILE *f)
+{
+ unsigned char buf[4];
+
+ put_unaligned_le32(v, buf);
+ return fwrite(buf, 1, 4, f) == 4 ? 0 : -1;
+}
+
+static void emit_relocs(int as_text, int use_real_mode)
+{
+ int i;
+ /* Count how many relocations I have and allocate space for them. */
+ reloc_count = 0;
+ walk_relocs(count_reloc, use_real_mode);
+ relocs = malloc(reloc_count * sizeof(relocs[0]));
+ if (!relocs) {
+ die("malloc of %d entries for relocs failed\n",
+ reloc_count);
+ }
+
+ relocs16 = malloc(reloc16_count * sizeof(relocs[0]));
+ if (!relocs16) {
+ die("malloc of %d entries for relocs16 failed\n",
+ reloc16_count);
+ }
+ /* Collect up the relocations */
+ reloc_idx = 0;
+ walk_relocs(collect_reloc, use_real_mode);
+
+ if (reloc16_count && !use_real_mode)
+ die("Segment relocations found but --realmode not specified\n");
+
+ /* Order the relocations for more efficient processing */
+ qsort(relocs, reloc_count, sizeof(relocs[0]), cmp_relocs);
+ qsort(relocs16, reloc16_count, sizeof(relocs16[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");
+ if (use_real_mode) {
+ printf("\t.long %lu\n", reloc16_count);
+ for (i = 0; i < reloc16_count; i++)
+ printf("\t.long 0x%08lx\n", relocs16[i]);
+ printf("\t.long %lu\n", reloc_count);
+ for (i = 0; i < reloc_count; i++) {
+ printf("\t.long 0x%08lx\n", relocs[i]);
+ }
+ } else {
+ /* Print a stop */
+ printf("\t.long 0x%08lx\n", (unsigned long)0);
+ for (i = 0; i < reloc_count; i++) {
+ printf("\t.long 0x%08lx\n", relocs[i]);
+ }
+ }
+
+ printf("\n");
+ }
+ else {
+ if (use_real_mode) {
+ write32(reloc16_count, stdout);
+ for (i = 0; i < reloc16_count; i++)
+ write32(relocs16[i], stdout);
+ write32(reloc_count, stdout);
+
+ /* Now print each relocation */
+ for (i = 0; i < reloc_count; i++)
+ write32(relocs[i], stdout);
+ } else {
+ /* Print a stop */
+ write32(0, stdout);
+
+ /* Now print each relocation */
+ for (i = 0; i < reloc_count; i++) {
+ write32(relocs[i], stdout);
+ }
+ }
+ }
+}
+
+static void usage(void)
+{
+ die("relocs [--abs-syms|--abs-relocs|--text|--realmode] vmlinux\n");
+}
+
+int main(int argc, char **argv)
+{
+ int show_absolute_syms, show_absolute_relocs;
+ int as_text, use_real_mode;
+ const char *fname;
+ FILE *fp;
+ int i;
+
+ show_absolute_syms = 0;
+ show_absolute_relocs = 0;
+ as_text = 0;
+ use_real_mode = 0;
+ fname = NULL;
+ for (i = 1; i < argc; i++) {
+ char *arg = argv[i];
+ if (*arg == '-') {
+ if (strcmp(arg, "--abs-syms") == 0) {
+ show_absolute_syms = 1;
+ continue;
+ }
+ if (strcmp(arg, "--abs-relocs") == 0) {
+ show_absolute_relocs = 1;
+ continue;
+ }
+ if (strcmp(arg, "--text") == 0) {
+ as_text = 1;
+ continue;
+ }
+ if (strcmp(arg, "--realmode") == 0) {
+ use_real_mode = 1;
+ continue;
+ }
+ }
+ else if (!fname) {
+ fname = arg;
+ continue;
+ }
+ usage();
+ }
+ if (!fname) {
+ usage();
+ }
+ regex_init(use_real_mode);
+ 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, use_real_mode);
+ return 0;
+}
diff --git a/scripts/Makefile b/scripts/Makefile
index df7678f..3626666 100644
--- a/scripts/Makefile
+++ b/scripts/Makefile
@@ -8,6 +8,8 @@
# conmakehash: Create arrays for initializing the kernel console tables
# docproc: Used in Documentation/DocBook
+HOST_EXTRACFLAGS += -I$(srctree)/tools/include
+
hostprogs-$(CONFIG_KALLSYMS) += kallsyms
hostprogs-$(CONFIG_LOGO) += pnmtologo
hostprogs-$(CONFIG_VT) += conmakehash
--
1.7.9.5
On Fri, May 25, 2012 at 02:18:33PM +0300, Jarkko Sakkinen wrote:
> From: "H. Peter Anvin" <[email protected]>
>
> A new option is added to the relocs tool called '--realmode'.
> This option causes the generation of 16-bit segment relocations
> and 32-bit linear relocations for the real-mode code. When
> the real-mode code is moved to the low-memory during kernel
> initialization, these relocation entries can be used to
> relocate the code properly.
>
> In the assembly code 16-bit segment relocations must be relative
> to the 'real_mode_seg' absolute symbol. Linear relocations must be
> relative to a symbol prefixed with 'pa_'.
>
> 16-bit segment relocation is used to load cs:ip in 16-bit code.
> Linear relocations are used in the 32-bit code for relocatable
> data references. They are declared in the linker script of the
> real-mode code.
>
> The relocs tool is moved to arch/x86/tools/relocs.c, and added new
> target archscripts that can be used to build scripts needed building
> an architecture. be compiled before building the arch/x86 tree.
>
> [ hpa: accelerating this because it detects invalid absolute
> relocations, a serious bug in binutils 2.22.52.0.x which currently
> produces bad kernels. ]
>
> [ jsakkine: applied against 3.3.7 ]
Much better, thanks for this, now queued up.
greg k-h