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    Subject[PATCH] x86, realmode: 16-bit real-mode code support for relocs tool
    Date
    From: "H. Peter Anvin" <hpa@linux.intel.com>

    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: pulled tools/include/tools/le_byteshift.h in order
    to make this patch compile in 3.3 ]

    Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
    Link: http://lkml.kernel.org/r/1336501366-28617-2-git-send-email-jarkko.sakkinen@intel.com
    Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@intel.com>
    Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
    Cc: <stable@vger.kernel.org>
    Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@iki.fi>
    ---
    Makefile | 9 +-
    arch/x86/Makefile | 3 +
    arch/x86/boot/compressed/Makefile | 9 +-
    arch/x86/boot/compressed/relocs.c | 682 ------------------------------
    arch/x86/tools/.gitignore | 1 +
    arch/x86/tools/Makefile | 4 +
    arch/x86/tools/relocs.c | 797 ++++++++++++++++++++++++++++++++++++
    scripts/Makefile | 2 +
    tools/include/tools/le_byteshift.h | 70 ++++
    9 files changed, 887 insertions(+), 690 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
    create mode 100644 tools/include/tools/le_byteshift.h

    diff --git a/Makefile b/Makefile
    index 1932984..97a48d3 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 b123b9a..f7a5a7b 100644
    --- a/arch/x86/boot/compressed/Makefile
    +++ b/arch/x86/boot/compressed/Makefile
    @@ -39,13 +39,12 @@ 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 := $(obj)/vmlinux.bin
    diff --git a/arch/x86/boot/compressed/relocs.c b/arch/x86/boot/compressed/relocs.c
    deleted file mode 100644
    index 89bbf4e..0000000
    --- a/arch/x86/boot/compressed/relocs.c
    +++ /dev/null
    @@ -1,682 +0,0 @@
    -#include <stdio.h>
    -#include <stdarg.h>
    -#include <stdlib.h>
    -#include <stdint.h>
    -#include <string.h>
    -#include <errno.h>
    -#include <unistd.h>
    -#include <elf.h>
    -#include <byteswap.h>
    -#define USE_BSD
    -#include <endian.h>
    -#include <regex.h>
    -
    -static void die(char *fmt, ...);
    -
    -#define ARRAY_SIZE(x) (sizeof(x) / sizeof((x)[0]))
    -static Elf32_Ehdr ehdr;
    -static unsigned long reloc_count, reloc_idx;
    -static unsigned long *relocs;
    -
    -struct section {
    - Elf32_Shdr shdr;
    - struct section *link;
    - Elf32_Sym *symtab;
    - Elf32_Rel *reltab;
    - char *strtab;
    -};
    -static struct section *secs;
    -
    -/*
    - * Following symbols have been audited. There values are constant and do
    - * not change if bzImage is loaded at a different physical address than
    - * the address for which it has been compiled. Don't warn user about
    - * absolute relocations present w.r.t these symbols.
    - */
    -static const char abs_sym_regex[] =
    - "^(xen_irq_disable_direct_reloc$|"
    - "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;
    -}
    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
    diff --git a/tools/include/tools/le_byteshift.h b/tools/include/tools/le_byteshift.h
    new file mode 100644
    index 0000000..c99d45a
    --- /dev/null
    +++ b/tools/include/tools/le_byteshift.h
    @@ -0,0 +1,70 @@
    +#ifndef _TOOLS_LE_BYTESHIFT_H
    +#define _TOOLS_LE_BYTESHIFT_H
    +
    +#include <linux/types.h>
    +
    +static inline __u16 __get_unaligned_le16(const __u8 *p)
    +{
    + return p[0] | p[1] << 8;
    +}
    +
    +static inline __u32 __get_unaligned_le32(const __u8 *p)
    +{
    + return p[0] | p[1] << 8 | p[2] << 16 | p[3] << 24;
    +}
    +
    +static inline __u64 __get_unaligned_le64(const __u8 *p)
    +{
    + return (__u64)__get_unaligned_le32(p + 4) << 32 |
    + __get_unaligned_le32(p);
    +}
    +
    +static inline void __put_unaligned_le16(__u16 val, __u8 *p)
    +{
    + *p++ = val;
    + *p++ = val >> 8;
    +}
    +
    +static inline void __put_unaligned_le32(__u32 val, __u8 *p)
    +{
    + __put_unaligned_le16(val >> 16, p + 2);
    + __put_unaligned_le16(val, p);
    +}
    +
    +static inline void __put_unaligned_le64(__u64 val, __u8 *p)
    +{
    + __put_unaligned_le32(val >> 32, p + 4);
    + __put_unaligned_le32(val, p);
    +}
    +
    +static inline __u16 get_unaligned_le16(const void *p)
    +{
    + return __get_unaligned_le16((const __u8 *)p);
    +}
    +
    +static inline __u32 get_unaligned_le32(const void *p)
    +{
    + return __get_unaligned_le32((const __u8 *)p);
    +}
    +
    +static inline __u64 get_unaligned_le64(const void *p)
    +{
    + return __get_unaligned_le64((const __u8 *)p);
    +}
    +
    +static inline void put_unaligned_le16(__u16 val, void *p)
    +{
    + __put_unaligned_le16(val, p);
    +}
    +
    +static inline void put_unaligned_le32(__u32 val, void *p)
    +{
    + __put_unaligned_le32(val, p);
    +}
    +
    +static inline void put_unaligned_le64(__u64 val, void *p)
    +{
    + __put_unaligned_le64(val, p);
    +}
    +
    +#endif /* _TOOLS_LE_BYTESHIFT_H */
    --
    1.7.9.5


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