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Message-Id: <20120528031218.321933087@decadent.org.uk>
Date: Mon, 28 May 2012 04:13:54 +0100
From: Ben Hutchings <ben@...adent.org.uk>
To: linux-kernel@...r.kernel.org, stable@...r.kernel.org
Cc: torvalds@...ux-foundation.org, akpm@...ux-foundation.org,
alan@...rguk.ukuu.org.uk, "H. Peter Anvin" <hpa@...ux.intel.com>,
Jarkko Sakkinen <jarkko.sakkinen@...el.com>
Subject: [ 112/117] x86, realmode: 16-bit real-mode code support for relocs tool
3.2-stable review patch. If anyone has any objections, please let me know.
This is much longer than usually allowed for stable, but there
doesn't seem to be any good alternative. The diff is also much
smaller with rename detection on:
Makefile | 8 +-
arch/x86/Makefile | 3 +
arch/x86/boot/compressed/Makefile | 9 +-
arch/x86/tools/.gitignore | 1 +
arch/x86/tools/Makefile | 3 +
arch/x86/{boot/compressed => tools}/relocs.c | 239 +++++++++++++++++++-------
scripts/Makefile | 2 +
7 files changed, 198 insertions(+), 67 deletions(-)
------------------
From: "H. Peter Anvin" <hpa@...ux.intel.com>
commit 6520fe5564acf07ade7b18a1272db1184835c487 upstream.
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. ]
Signed-off-by: H. Peter Anvin <hpa@...ux.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@...el.com>
Signed-off-by: H. Peter Anvin <hpa@...ux.intel.com>
Cc: <stable@...r.kernel.org>
[bwh: Backported to 3.2:
- Adjust context (no archheaders; no insn_sanity)
- Expand put_unaligned_le32()]
Signed-off-by: Ben Hutchings <ben@...adent.org.uk>
---
Makefile | 8 +-
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 | 3 +
arch/x86/tools/relocs.c | 799 +++++++++++++++++++++++++++++++++++++
scripts/Makefile | 2 +
8 files changed, 818 insertions(+), 687 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 add68f1..680a70d 100644
--- a/Makefile
+++ b/Makefile
@@ -443,6 +443,7 @@ asm-generic:
no-dot-config-targets := clean mrproper distclean \
cscope gtags TAGS tags help %docs check% coccicheck \
include/linux/version.h headers_% \
+ include/linux/version.h headers_% archscripts \
kernelversion %src-pkg
config-targets := 0
@@ -979,7 +980,7 @@ prepare1: prepare2 include/linux/version.h include/generated/utsrelease.h \
include/config/auto.conf
$(cmd_crmodverdir)
-archprepare: prepare1 scripts_basic
+archprepare: archscripts prepare1 scripts_basic
prepare0: archprepare FORCE
$(Q)$(MAKE) $(build)=.
@@ -1046,8 +1047,11 @@ hdr-inst := -rR -f $(srctree)/scripts/Makefile.headersinst obj
# If we do an all arch process set dst to asm-$(hdr-arch)
hdr-dst = $(if $(KBUILD_HEADERS), dst=include/asm-$(hdr-arch), dst=include/asm)
+PHONY += archscripts
+archscripts:
+
PHONY += __headers
-__headers: include/linux/version.h scripts_basic asm-generic FORCE
+__headers: include/linux/version.h scripts_basic asm-generic archscripts FORCE
$(Q)$(MAKE) $(build)=scripts build_unifdef
PHONY += headers_install_all
diff --git a/arch/x86/Makefile b/arch/x86/Makefile
index b02e509..774fd16 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
+
###
# Kernel objects
diff --git a/arch/x86/boot/compressed/Makefile b/arch/x86/boot/compressed/Makefile
index 09664ef..77453c6 100644
--- a/arch/x86/boot/compressed/Makefile
+++ b/arch/x86/boot/compressed/Makefile
@@ -31,13 +31,12 @@ 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 f820826..162a34a 100644
--- a/arch/x86/tools/Makefile
+++ b/arch/x86/tools/Makefile
@@ -29,3 +29,6 @@ HOSTCFLAGS_test_get_len.o := -Wall -I$(objtree)/arch/x86/lib/ -I$(srctree)/arch/
# Dependencies are also needed.
$(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 $(objtree)/arch/x86/lib/inat-tables.c
+HOST_EXTRACFLAGS += -I$(srctree)/tools/include
+hostprogs-y += relocs
+relocs: $(obj)/relocs
diff --git a/arch/x86/tools/relocs.c b/arch/x86/tools/relocs.c
new file mode 100644
index 0000000..2071bad
--- /dev/null
+++ b/arch/x86/tools/relocs.c
@@ -0,0 +1,799 @@
+#include <stdio.h>
+#include <stdarg.h>
+#include <stdlib.h>
+#include <stdint.h>
+#include <string.h>
+#include <errno.h>
+#include <unistd.h>
+#include <elf.h>
+#include <byteswap.h>
+#define USE_BSD
+#include <endian.h>
+#include <regex.h>
+
+static void die(char *fmt, ...);
+
+#define ARRAY_SIZE(x) (sizeof(x) / sizeof((x)[0]))
+static Elf32_Ehdr ehdr;
+static unsigned long reloc_count, reloc_idx;
+static unsigned long *relocs;
+static unsigned long reloc16_count, reloc16_idx;
+static unsigned long *relocs16;
+
+struct section {
+ Elf32_Shdr shdr;
+ struct section *link;
+ Elf32_Sym *symtab;
+ Elf32_Rel *reltab;
+ char *strtab;
+};
+static struct section *secs;
+
+enum symtype {
+ S_ABS,
+ S_REL,
+ S_SEG,
+ S_LIN,
+ S_NSYMTYPES
+};
+
+static const char * const sym_regex_kernel[S_NSYMTYPES] = {
+/*
+ * Following symbols have been audited. There values are constant and do
+ * not change if bzImage is loaded at a different physical address than
+ * the address for which it has been compiled. Don't warn user about
+ * absolute relocations present w.r.t these symbols.
+ */
+ [S_ABS] =
+ "^(xen_irq_disable_direct_reloc$|"
+ "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];
+
+ buf[0] = (v >> 0) & 0xff;
+ buf[1] = (v >> 8) & 0xff;
+ buf[2] = (v >> 16) & 0xff;
+ buf[3] = (v >> 24) & 0xff;
+ 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
--
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