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Date: Thu, 4 Apr 2013 13:07:34 -0700
From: Kees Cook <keescook@...omium.org>
To: linux-kernel@...r.kernel.org
Cc: kernel-hardening@...ts.openwall.com, "H. Peter Anvin" <hpa@...or.com>,
Thomas Gleixner <tglx@...utronix.de>, Ingo Molnar <mingo@...hat.com>,
x86@...nel.org, Jarkko Sakkinen <jarkko.sakkinen@...el.com>,
Matthew Garrett <mjg@...hat.com>,
Matt Fleming <matt.fleming@...el.com>,
Eric Northup <digitaleric@...gle.com>,
Dan Rosenberg <drosenberg@...curity.com>,
Julien Tinnes <jln@...gle.com>, Will Drewry <wad@...omium.org>,
Kees Cook <keescook@...omium.org>
Subject: [PATCH 2/3] x86: build reloc tool for both 64 and 32 bit
Add logic for 64-bit kernel relocations. Since there is no need to
handle 32 and 64 bit at the same time, refactor away most of the 32/64
bit ELF differences and split the build into producing two separate
binaries. Additionally switches to using realloc instead of a two-pass
approach.
Heavily based on work by Neill Clift and Michael Davidson.
Signed-off-by: Kees Cook <keescook@...omium.org>
Cc: Eric Northup <digitaleric@...gle.com>
---
arch/x86/boot/compressed/Makefile | 2 +-
arch/x86/realmode/rm/Makefile | 2 +-
arch/x86/tools/.gitignore | 3 +-
arch/x86/tools/Makefile | 14 +-
arch/x86/tools/relocs.c | 717 ++++++++++++++++++++++++++-----------
arch/x86/tools/relocs_32.c | 1 +
arch/x86/tools/relocs_64.c | 2 +
7 files changed, 533 insertions(+), 208 deletions(-)
create mode 100644 arch/x86/tools/relocs_32.c
create mode 100644 arch/x86/tools/relocs_64.c
diff --git a/arch/x86/boot/compressed/Makefile b/arch/x86/boot/compressed/Makefile
index 376ef47..deaed7d 100644
--- a/arch/x86/boot/compressed/Makefile
+++ b/arch/x86/boot/compressed/Makefile
@@ -48,7 +48,7 @@ $(obj)/vmlinux.bin: vmlinux FORCE
targets += vmlinux.bin.all vmlinux.relocs
-CMD_RELOCS = arch/x86/tools/relocs
+CMD_RELOCS = arch/x86/tools/relocs_$(BITS)
quiet_cmd_relocs = RELOCS $@
cmd_relocs = $(CMD_RELOCS) $< > $@;$(CMD_RELOCS) --abs-relocs $<
$(obj)/vmlinux.relocs: vmlinux FORCE
diff --git a/arch/x86/realmode/rm/Makefile b/arch/x86/realmode/rm/Makefile
index 8869287..2b1e429 100644
--- a/arch/x86/realmode/rm/Makefile
+++ b/arch/x86/realmode/rm/Makefile
@@ -56,7 +56,7 @@ $(obj)/realmode.bin: $(obj)/realmode.elf $(obj)/realmode.relocs
$(call if_changed,objcopy)
quiet_cmd_relocs = RELOCS $@
- cmd_relocs = arch/x86/tools/relocs --realmode $< > $@
+ cmd_relocs = arch/x86/tools/relocs_32 --realmode $< > $@
targets += realmode.relocs
$(obj)/realmode.relocs: $(obj)/realmode.elf FORCE
diff --git a/arch/x86/tools/.gitignore b/arch/x86/tools/.gitignore
index be0ed06..51374a2 100644
--- a/arch/x86/tools/.gitignore
+++ b/arch/x86/tools/.gitignore
@@ -1 +1,2 @@
-relocs
+relocs_32
+relocs_64
diff --git a/arch/x86/tools/Makefile b/arch/x86/tools/Makefile
index bae601f..8c3b17a 100644
--- a/arch/x86/tools/Makefile
+++ b/arch/x86/tools/Makefile
@@ -37,6 +37,16 @@ $(obj)/test_get_len.o: $(srctree)/arch/x86/lib/insn.c $(srctree)/arch/x86/lib/in
$(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 $(objtree)/arch/x86/lib/inat-tables.c
+$(obj)/relocs_64.o: $(srctree)/arch/x86/tools/relocs.c $(srctree)/arch/x86/tools/relocs_64.c
+$(obj)/relocs_32.o: $(srctree)/arch/x86/tools/relocs.c $(srctree)/arch/x86/tools/relocs_32.c
+
HOST_EXTRACFLAGS += -I$(srctree)/tools/include
-hostprogs-y += relocs
-relocs: $(obj)/relocs
+hostprogs-y += relocs_$(BITS)
+relocs_binaries = relocs_$(BITS)
+ifeq ($(CONFIG_64BIT),y)
+ hostprogs-y += relocs_32
+ relocs_binaries += relocs_32
+endif
+relocs: $(relocs_binaries)
+relocs_64: $(obj)/relocs_64
+relocs_32: $(obj)/relocs_32
diff --git a/arch/x86/tools/relocs.c b/arch/x86/tools/relocs.c
index 79d67bd..63c5090 100644
--- a/arch/x86/tools/relocs.c
+++ b/arch/x86/tools/relocs.c
@@ -2,6 +2,7 @@
#include <stdarg.h>
#include <stdlib.h>
#include <stdint.h>
+#include <inttypes.h>
#include <string.h>
#include <errno.h>
#include <unistd.h>
@@ -12,21 +13,78 @@
#include <regex.h>
#include <tools/le_byteshift.h>
+#ifdef CONFIG_X86_64
+#define ELF_BITS 64
+#define ELF_MACHINE EM_X86_64
+#define ELF_MACHINE_NAME "x86_64"
+#define SHT_REL_TYPE SHT_RELA
+#define Elf_Rel Elf64_Rela
+#else
+#define ELF_BITS 32
+#define ELF_MACHINE EM_386
+#define ELF_MACHINE_NAME "i386"
+#define SHT_REL_TYPE SHT_REL
+#define Elf_Rel Elf32_Rel
+#endif
+
+#if (ELF_BITS == 64)
+#define ELF_CLASS ELFCLASS64
+#define ELF_R_SYM(val) ELF64_R_SYM(val)
+#define ELF_R_TYPE(val) ELF64_R_TYPE(val)
+#define ELF_ST_TYPE(o) ELF64_ST_TYPE(o)
+#define ELF_ST_BIND(o) ELF64_ST_BIND(o)
+#define ELF_ST_VISIBILITY(o) ELF64_ST_VISIBILITY(o)
+#else
+#define ELF_CLASS ELFCLASS32
+#define ELF_R_SYM(val) ELF32_R_SYM(val)
+#define ELF_R_TYPE(val) ELF32_R_TYPE(val)
+#define ELF_ST_TYPE(o) ELF32_ST_TYPE(o)
+#define ELF_ST_BIND(o) ELF32_ST_BIND(o)
+#define ELF_ST_VISIBILITY(o) ELF32_ST_VISIBILITY(o)
+#endif
+
+#define ElfW(type) _ElfW(ELF_BITS, type)
+#define _ElfW(bits, type) __ElfW(bits, type)
+#define __ElfW(bits, type) Elf##bits##_##type
+
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;
+static ElfW(Ehdr) ehdr;
+
+struct relocs {
+ uint32_t *offset;
+ unsigned long count;
+ unsigned long size;
+};
+
+struct relocs relocs16;
+struct relocs relocs32;
+#ifdef CONFIG_X86_64
+struct relocs relocs64;
+#endif
+
+static void add_reloc(struct relocs *r, uint32_t offset)
+{
+ if (r->count == r->size) {
+ unsigned long newsize = r->size + 50000;
+ void *mem = realloc(r->offset, newsize * sizeof(r->offset[0]));
+
+ if (!mem)
+ die("realloc of %ld entries for relocs failed\n",
+ newsize);
+ r->offset = mem;
+ r->size = newsize;
+ }
+ r->offset[r->count++] = offset;
+}
struct section {
- Elf32_Shdr shdr;
- struct section *link;
- Elf32_Sym *symtab;
- Elf32_Rel *reltab;
- char *strtab;
+ ElfW(Shdr) shdr;
+ struct section *link;
+ ElfW(Sym) *symtab;
+ Elf_Rel *reltab;
+ char *strtab;
};
static struct section *secs;
@@ -49,6 +107,9 @@ static const char * const sym_regex_kernel[S_NSYMTYPES] = {
"^(xen_irq_disable_direct_reloc$|"
"xen_save_fl_direct_reloc$|"
"VDSO|"
+#ifdef CONFIG_X86_64
+ "__vvar_page|"
+#endif
"__crc_)",
/*
@@ -72,6 +133,11 @@ static const char * const sym_regex_kernel[S_NSYMTYPES] = {
"__end_rodata|"
"__initramfs_start|"
"(jiffies|jiffies_64)|"
+#ifdef CONFIG_X86_64
+ "__per_cpu_load|"
+ "init_per_cpu__.*|"
+ "__end_rodata_hpage_align|"
+#endif
"_end)$"
};
@@ -198,6 +264,24 @@ static const char *rel_type(unsigned type)
{
static const char *type_name[] = {
#define REL_TYPE(X) [X] = #X
+#ifdef CONFIG_X86_64
+ REL_TYPE(R_X86_64_NONE),
+ REL_TYPE(R_X86_64_64),
+ REL_TYPE(R_X86_64_PC32),
+ REL_TYPE(R_X86_64_GOT32),
+ REL_TYPE(R_X86_64_PLT32),
+ REL_TYPE(R_X86_64_COPY),
+ REL_TYPE(R_X86_64_GLOB_DAT),
+ REL_TYPE(R_X86_64_JUMP_SLOT),
+ REL_TYPE(R_X86_64_RELATIVE),
+ REL_TYPE(R_X86_64_GOTPCREL),
+ REL_TYPE(R_X86_64_32),
+ REL_TYPE(R_X86_64_32S),
+ REL_TYPE(R_X86_64_16),
+ REL_TYPE(R_X86_64_PC16),
+ REL_TYPE(R_X86_64_8),
+ REL_TYPE(R_X86_64_PC8),
+#else
REL_TYPE(R_386_NONE),
REL_TYPE(R_386_32),
REL_TYPE(R_386_PC32),
@@ -213,6 +297,7 @@ static const char *rel_type(unsigned type)
REL_TYPE(R_386_PC8),
REL_TYPE(R_386_16),
REL_TYPE(R_386_PC16),
+#endif
#undef REL_TYPE
};
const char *name = "unknown type rel type name";
@@ -240,7 +325,7 @@ static const char *sec_name(unsigned shndx)
return name;
}
-static const char *sym_name(const char *sym_strtab, Elf32_Sym *sym)
+static const char *sym_name(const char *sym_strtab, ElfW(Sym) *sym)
{
const char *name;
name = "<noname>";
@@ -253,15 +338,45 @@ static const char *sym_name(const char *sym_strtab, Elf32_Sym *sym)
return name;
}
+#ifdef CONFIG_X86_64
+static ElfW(Sym) *sym_lookup(const char *symname)
+{
+ int i;
+ for (i = 0; i < ehdr.e_shnum; i++) {
+ struct section *sec = &secs[i];
+ long nsyms;
+ char *strtab;
+ ElfW(Sym) *symtab;
+ ElfW(Sym) *sym;
+
+ if (sec->shdr.sh_type != SHT_SYMTAB)
+ continue;
+
+ nsyms = sec->shdr.sh_size/sizeof(ElfW(Sym));
+ symtab = sec->symtab;
+ strtab = sec->link->strtab;
+
+ for (sym = symtab; --nsyms >= 0; sym++) {
+ if (!sym->st_name)
+ continue;
+ if (strcmp(symname, strtab + sym->st_name) == 0)
+ return sym;
+ }
+ }
+ return 0;
+}
+#endif
#if BYTE_ORDER == LITTLE_ENDIAN
#define le16_to_cpu(val) (val)
#define le32_to_cpu(val) (val)
+#define le64_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)
+#define le64_to_cpu(val) bswap_64(val)
#endif
static uint16_t elf16_to_cpu(uint16_t val)
@@ -274,6 +389,25 @@ static uint32_t elf32_to_cpu(uint32_t val)
return le32_to_cpu(val);
}
+#if (ELF_BITS == 64)
+static uint64_t elf64_to_cpu(uint64_t val)
+{
+ return le64_to_cpu(val);
+}
+#endif
+
+#define elf_half_to_cpu(x) elf16_to_cpu(x)
+#define elf_word_to_cpu(x) elf32_to_cpu(x)
+#if (ELF_BITS == 64)
+#define elf_addr_to_cpu(x) elf64_to_cpu(x)
+#define elf_off_to_cpu(x) elf64_to_cpu(x)
+#define elf_xword_to_cpu(x) elf64_to_cpu(x)
+#else
+#define elf_addr_to_cpu(x) elf32_to_cpu(x)
+#define elf_off_to_cpu(x) elf32_to_cpu(x)
+#define elf_xword_to_cpu(x) elf32_to_cpu(x)
+#endif
+
static void read_ehdr(FILE *fp)
{
if (fread(&ehdr, sizeof(ehdr), 1, fp) != 1) {
@@ -283,8 +417,8 @@ static void read_ehdr(FILE *fp)
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_CLASS] != ELF_CLASS) {
+ die("Not a %d bit executable\n", ELF_BITS);
}
if (ehdr.e_ident[EI_DATA] != ELFDATA2LSB) {
die("Not a LSB ELF executable\n");
@@ -293,36 +427,36 @@ static void read_ehdr(FILE *fp)
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);
+ ehdr.e_type = elf_half_to_cpu(ehdr.e_type);
+ ehdr.e_machine = elf_half_to_cpu(ehdr.e_machine);
+ ehdr.e_version = elf_word_to_cpu(ehdr.e_version);
+ ehdr.e_entry = elf_addr_to_cpu(ehdr.e_entry);
+ ehdr.e_phoff = elf_off_to_cpu(ehdr.e_phoff);
+ ehdr.e_shoff = elf_off_to_cpu(ehdr.e_shoff);
+ ehdr.e_flags = elf_word_to_cpu(ehdr.e_flags);
+ ehdr.e_ehsize = elf_half_to_cpu(ehdr.e_ehsize);
+ ehdr.e_phentsize = elf_half_to_cpu(ehdr.e_phentsize);
+ ehdr.e_phnum = elf_half_to_cpu(ehdr.e_phnum);
+ ehdr.e_shentsize = elf_half_to_cpu(ehdr.e_shentsize);
+ ehdr.e_shnum = elf_half_to_cpu(ehdr.e_shnum);
+ ehdr.e_shstrndx = elf_half_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_machine != ELF_MACHINE) {
+ die("Not for %s\n", ELF_MACHINE_NAME);
}
if (ehdr.e_version != EV_CURRENT) {
die("Unknown ELF version\n");
}
- if (ehdr.e_ehsize != sizeof(Elf32_Ehdr)) {
+ if (ehdr.e_ehsize != sizeof(ElfW(Ehdr))) {
die("Bad Elf header size\n");
}
- if (ehdr.e_phentsize != sizeof(Elf32_Phdr)) {
+ if (ehdr.e_phentsize != sizeof(ElfW(Phdr))) {
die("Bad program header entry\n");
}
- if (ehdr.e_shentsize != sizeof(Elf32_Shdr)) {
+ if (ehdr.e_shentsize != sizeof(ElfW(Shdr))) {
die("Bad section header entry\n");
}
if (ehdr.e_shstrndx >= ehdr.e_shnum) {
@@ -333,7 +467,7 @@ static void read_ehdr(FILE *fp)
static void read_shdrs(FILE *fp)
{
int i;
- Elf32_Shdr shdr;
+ ElfW(Shdr) shdr;
secs = calloc(ehdr.e_shnum, sizeof(struct section));
if (!secs) {
@@ -349,16 +483,16 @@ static void read_shdrs(FILE *fp)
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);
+ sec->shdr.sh_name = elf_word_to_cpu(shdr.sh_name);
+ sec->shdr.sh_type = elf_word_to_cpu(shdr.sh_type);
+ sec->shdr.sh_flags = elf_xword_to_cpu(shdr.sh_flags);
+ sec->shdr.sh_addr = elf_addr_to_cpu(shdr.sh_addr);
+ sec->shdr.sh_offset = elf_off_to_cpu(shdr.sh_offset);
+ sec->shdr.sh_size = elf_xword_to_cpu(shdr.sh_size);
+ sec->shdr.sh_link = elf_word_to_cpu(shdr.sh_link);
+ sec->shdr.sh_info = elf_word_to_cpu(shdr.sh_info);
+ sec->shdr.sh_addralign = elf_xword_to_cpu(shdr.sh_addralign);
+ sec->shdr.sh_entsize = elf_xword_to_cpu(shdr.sh_entsize);
if (sec->shdr.sh_link < ehdr.e_shnum)
sec->link = &secs[sec->shdr.sh_link];
}
@@ -412,12 +546,12 @@ static void read_symtabs(FILE *fp)
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);
+ for (j = 0; j < sec->shdr.sh_size/sizeof(ElfW(Sym)); j++) {
+ ElfW(Sym) *sym = &sec->symtab[j];
+ sym->st_name = elf_word_to_cpu(sym->st_name);
+ sym->st_value = elf_addr_to_cpu(sym->st_value);
+ sym->st_size = elf_xword_to_cpu(sym->st_size);
+ sym->st_shndx = elf_half_to_cpu(sym->st_shndx);
}
}
}
@@ -428,7 +562,7 @@ 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) {
+ if (sec->shdr.sh_type != SHT_REL_TYPE) {
continue;
}
sec->reltab = malloc(sec->shdr.sh_size);
@@ -445,10 +579,13 @@ static void read_relocs(FILE *fp)
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);
+ for (j = 0; j < sec->shdr.sh_size/sizeof(Elf_Rel); j++) {
+ Elf_Rel *rel = &sec->reltab[j];
+ rel->r_offset = elf_addr_to_cpu(rel->r_offset);
+ rel->r_info = elf_xword_to_cpu(rel->r_info);
+#if (SHT_REL_TYPE == SHT_RELA)
+ rel->r_addend = elf_xword_to_cpu(rel->r_addend);
+#endif
}
}
}
@@ -468,19 +605,25 @@ static void print_absolute_symbols(void)
continue;
}
sym_strtab = sec->link->strtab;
- for (j = 0; j < sec->shdr.sh_size/sizeof(Elf32_Sym); j++) {
- Elf32_Sym *sym;
+ for (j = 0; j < sec->shdr.sh_size/sizeof(ElfW(Sym)); j++) {
+ ElfW(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",
+#if (ELF_BITS == 64)
+ printf("%5d %016"PRIx64" %5"PRId64
+ " %10s %10s %12s %s\n",
+#else
+ printf("%5d %08"PRIx32" %5"PRId32
+ " %10s %10s %12s %s\n",
+#endif
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)),
+ sym_type(ELF_ST_TYPE(sym->st_info)),
+ sym_bind(ELF_ST_BIND(sym->st_info)),
+ sym_visibility(ELF_ST_VISIBILITY(sym->st_other)),
name);
}
}
@@ -495,9 +638,9 @@ static void print_absolute_relocs(void)
struct section *sec = &secs[i];
struct section *sec_applies, *sec_symtab;
char *sym_strtab;
- Elf32_Sym *sh_symtab;
+ ElfW(Sym) *sh_symtab;
int j;
- if (sec->shdr.sh_type != SHT_REL) {
+ if (sec->shdr.sh_type != SHT_REL_TYPE) {
continue;
}
sec_symtab = sec->link;
@@ -507,12 +650,12 @@ static void print_absolute_relocs(void)
}
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;
+ for (j = 0; j < sec->shdr.sh_size/sizeof(Elf_Rel); j++) {
+ Elf_Rel *rel;
+ ElfW(Sym) *sym;
const char *name;
rel = &sec->reltab[j];
- sym = &sh_symtab[ELF32_R_SYM(rel->r_info)];
+ sym = &sh_symtab[ELF_R_SYM(rel->r_info)];
name = sym_name(sym_strtab, sym);
if (sym->st_shndx != SHN_ABS) {
continue;
@@ -542,10 +685,16 @@ static void print_absolute_relocs(void)
printed = 1;
}
- printf("%08x %08x %10s %08x %s\n",
+#if (ELF_BITS == 64)
+ printf("%016"PRIx64" %016"PRIx64
+ " %10s %016"PRIx64" %s\n",
+#else
+ printf("%08"PRIx32" %08"PRIx32
+ " %10s %08"PRIx32" %s\n",
+#endif
rel->r_offset,
rel->r_info,
- rel_type(ELF32_R_TYPE(rel->r_info)),
+ rel_type(ELF_R_TYPE(rel->r_info)),
sym->st_value,
name);
}
@@ -555,19 +704,20 @@ static void print_absolute_relocs(void)
printf("\n");
}
-static void walk_relocs(void (*visit)(Elf32_Rel *rel, Elf32_Sym *sym),
- int use_real_mode)
+
+static void walk_relocs(int (*process)(struct section *sec, Elf_Rel *,
+ ElfW(Sym) *, const char *))
{
int i;
/* Walk through the relocations */
for (i = 0; i < ehdr.e_shnum; i++) {
char *sym_strtab;
- Elf32_Sym *sh_symtab;
+ ElfW(Sym) *sh_symtab;
struct section *sec_applies, *sec_symtab;
int j;
struct section *sec = &secs[i];
- if (sec->shdr.sh_type != SHT_REL) {
+ if (sec->shdr.sh_type != SHT_REL_TYPE) {
continue;
}
sec_symtab = sec->link;
@@ -577,101 +727,276 @@ static void walk_relocs(void (*visit)(Elf32_Rel *rel, Elf32_Sym *sym),
}
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;
- int shn_abs;
- rel = &sec->reltab[j];
- sym = &sh_symtab[ELF32_R_SYM(rel->r_info)];
- r_type = ELF32_R_TYPE(rel->r_info);
-
- shn_abs = sym->st_shndx == SHN_ABS;
-
- 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;
+ for (j = 0; j < sec->shdr.sh_size/sizeof(Elf_Rel); j++) {
+ Elf_Rel *rel = &sec->reltab[j];
+ ElfW(Sym) *sym = &sh_symtab[ELF_R_SYM(rel->r_info)];
+ const char *symname = sym_name(sym_strtab, sym);
- case R_386_16:
- symname = sym_name(sym_strtab, sym);
- if (!use_real_mode)
- goto bad;
- if (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;
+ process(sec, rel, sym, symname);
+ }
+ }
+}
- case R_386_32:
- symname = sym_name(sym_strtab, sym);
- if (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);
+#ifdef CONFIG_X86_64
+
+#define PER_CPU_SECTION ".data..percpu"
+static int per_cpu_shndx = -1;
+ElfW(Addr) per_cpu_load_addr;
+
+/*
+ * The .data..percpu section is a special case for x86_64 SMP kernels.
+ * It is used to initialize the actual per_cpu areas and to provide
+ * definitions for the per_cpu variables that correspond to their offsets
+ * within the percpu area. Since the values of all of the symbols need
+ * to be offsets from the start of the per_cpu area the virtual address
+ * (sh_addr) of .data..percpu is 0 in SMP kernels.
+ *
+ * This means that:
+ *
+ * Relocations that reference symbols in the per_cpu area do not
+ * need further relocation (since the value is an offset relative
+ * to the start of the per_cpu area that does not change).
+ *
+ * Relocations that apply to the per_cpu area need to have their
+ * offset adjusted by by the value of __per_cpu_load to make them
+ * point to the correct place in the loaded image (because the
+ * virtual address of .data..percpu is 0).
+ *
+ * For non SMP kernels .data..percpu is linked as part of the normal
+ * kernel data and does not require special treatment.
+ *
+ */
+static void percpu_init(void)
+{
+ int i;
+ for (i = 0; i < ehdr.e_shnum; i++) {
+ ElfW(Sym) *sym;
+ if (strcmp(sec_name(i), PER_CPU_SECTION))
+ continue;
+
+ if (secs[i].shdr.sh_addr != 0) /* non SMP kernel */
+ return;
+
+ sym = sym_lookup("__per_cpu_load");
+ if (!sym)
+ die("can't find __per_cpu_load\n");
+
+ per_cpu_shndx = i;
+ per_cpu_load_addr = sym->st_value;
+ return;
+ }
+}
+
+/*
+ * Check to see if a symbol lies in the .data..percpu section.
+ * For some as yet not understood reason the "__init_begin"
+ * symbol which immediately preceeds the .data..percpu section
+ * also shows up as it it were part of it so we do an explict
+ * check for that symbol name and ignore it.
+ */
+static int is_percpu_sym(ElfW(Sym) *sym, const char *symname)
+{
+ return (sym->st_shndx == per_cpu_shndx) &&
+ strcmp(symname, "__init_begin");
+}
+
+
+static int do_reloc(struct section *sec, Elf64_Rela *rel, ElfW(Sym) *sym,
+ const char *symname)
+{
+ unsigned r_type = ELF64_R_TYPE(rel->r_info);
+ ElfW(Addr) offset = rel->r_offset;
+ int shn_abs = (sym->st_shndx == SHN_ABS) && !is_reloc(S_REL, symname);
+
+ if (sym->st_shndx == SHN_UNDEF)
+ return 0;
+
+ /*
+ * adjust the offset if this reloc applies to the percpu section
+ */
+ if (sec->shdr.sh_info == per_cpu_shndx)
+ offset += per_cpu_load_addr;
+
+ switch (r_type) {
+ case R_X86_64_NONE:
+ case R_X86_64_PC32:
+ /*
+ * NONE can be ignored and PC relative
+ * relocations don't need to be adjusted.
+ */
+ break;
+
+ case R_X86_64_32:
+ case R_X86_64_32S:
+ case R_X86_64_64:
+ /*
+ * References to the percpu area don't need to be adjusted.
+ */
+ if (is_percpu_sym(sym, symname))
+ break;
+
+ if (shn_abs) {
+ /*
+ * whitelisted absolute symbols
+ * do not require relocation
+ */
+ if (is_reloc(S_ABS, symname))
break;
- bad:
- symname = sym_name(sym_strtab, sym);
- die("Invalid %s %s relocation: %s\n",
- shn_abs ? "absolute" : "relative",
- rel_type(r_type), symname);
- }
+
+ die("Invalid absolute %s relocation: %s\n",
+ rel_type(r_type), symname);
+ break;
}
+
+ /*
+ * Relocation offsets for 64 bit kernels are output
+ * as 32 bits and sign extended back to 64 bits when
+ * the relocations are processed.
+ * Make sure that the offset will fit.
+ */
+ if ((int32_t)offset != (int64_t)offset)
+ die("Relocation offset doesn't fit in 32 bits\n");
+
+ if (r_type == R_X86_64_64)
+ add_reloc(&relocs64, offset);
+ else
+ add_reloc(&relocs32, offset);
+ break;
+
+ default:
+ die("Unsupported relocation type: %s (%d)\n",
+ rel_type(r_type), r_type);
+ break;
}
+
+ return 0;
}
-static void count_reloc(Elf32_Rel *rel, Elf32_Sym *sym)
+#else
+
+static int do_reloc(struct section *sec, Elf32_Rel *rel, ElfW(Sym) *sym,
+ const char *symname)
{
- if (ELF32_R_TYPE(rel->r_info) == R_386_16)
- reloc16_count++;
- else
- reloc_count++;
+ unsigned r_type = ELF32_R_TYPE(rel->r_info);
+ int shn_abs = (sym->st_shndx == SHN_ABS) && !is_reloc(S_REL, symname);
+
+ switch (r_type) {
+ case R_386_NONE:
+ case R_386_PC32:
+ case R_386_PC16:
+ case R_386_PC8:
+ /*
+ * NONE can be ignored and PC relative
+ * relocations don't need to be adjusted.
+ */
+ break;
+
+ case R_386_32:
+ if (shn_abs) {
+ /*
+ * whitelisted absolute symbols
+ * do not require relocation
+ */
+ if (is_reloc(S_ABS, symname))
+ break;
+
+ die("Invalid absolute %s relocation: %s\n",
+ rel_type(r_type), symname);
+ break;
+ }
+
+ add_reloc(&relocs32, rel->r_offset);
+ break;
+
+ default:
+ die("Unsupported relocation type: %s (%d)\n",
+ rel_type(r_type), r_type);
+ break;
+ }
+
+ return 0;
}
+#endif
-static void collect_reloc(Elf32_Rel *rel, Elf32_Sym *sym)
+
+static int do_reloc_real(struct section *sec, Elf_Rel *rel, ElfW(Sym) *sym,
+ const char *symname)
{
- /* 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;
+ unsigned r_type = ELF32_R_TYPE(rel->r_info);
+ int shn_abs = (sym->st_shndx == SHN_ABS) && !is_reloc(S_REL, symname);
+
+ switch (r_type) {
+ case R_386_NONE:
+ case R_386_PC32:
+ case R_386_PC16:
+ case R_386_PC8:
+ /*
+ * NONE can be ignored and PC relative
+ * relocations don't need to be adjusted.
+ */
+ break;
+
+ case R_386_16:
+ if (shn_abs) {
+ if (is_reloc(S_ABS, symname))
+ break;
+
+ if (is_reloc(S_SEG, symname)) {
+ add_reloc(&relocs16, rel->r_offset);
+ break;
+ }
+ } else {
+ if (!is_reloc(S_LIN, symname))
+ break;
+ }
+ die("Invalid %s %s relocation: %s\n",
+ shn_abs ? "absolute" : "relative",
+ rel_type(r_type), symname);
+ break;
+
+ case R_386_32:
+ if (shn_abs) {
+ if (is_reloc(S_ABS, symname))
+ break;
+
+ if (is_reloc(S_REL, symname)) {
+ add_reloc(&relocs32, rel->r_offset);
+ break;
+ }
+ } else {
+ if (is_reloc(S_LIN, symname))
+ add_reloc(&relocs32, rel->r_offset);
+ break;
+ }
+ die("Invalid %s %s relocation: %s\n",
+ shn_abs ? "absolute" : "relative",
+ rel_type(r_type), symname);
+ break;
+
+ default:
+ die("Unsupported relocation type: %s (%d)\n",
+ rel_type(r_type), r_type);
+ break;
+ }
+
+ return 0;
}
+
static int cmp_relocs(const void *va, const void *vb)
{
- const unsigned long *a, *b;
+ const uint32_t *a, *b;
a = va; b = vb;
return (*a == *b)? 0 : (*a > *b)? 1 : -1;
}
-static int write32(unsigned int v, FILE *f)
+static void sort_relocs(struct relocs *r)
+{
+ qsort(r->offset, r->count, sizeof(r->offset[0]), cmp_relocs);
+}
+
+static int write32(uint32_t v, FILE *f)
{
unsigned char buf[4];
@@ -679,79 +1004,62 @@ static int write32(unsigned int v, FILE *f)
return fwrite(buf, 1, 4, f) == 4 ? 0 : -1;
}
+static int write32_as_text(uint32_t v, FILE *f)
+{
+ return fprintf(f, "\t.long 0x%08"PRIx32"\n", v) > 0 ? 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);
- }
+ int (*write_reloc)(uint32_t, FILE *) = write32;
- 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);
+ walk_relocs(use_real_mode ? do_reloc_real : do_reloc);
- if (reloc16_count && !use_real_mode)
+ if (relocs16.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);
+ sort_relocs(&relocs16);
+ sort_relocs(&relocs32);
+#ifdef CONFIG_X86_64
+ sort_relocs(&relocs64);
+#endif
+
+ /* output the relocations */
- /* 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");
+ write_reloc = write32_as_text;
}
- 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);
- }
- }
+ if (use_real_mode) {
+ write_reloc(relocs16.count, stdout);
+ for (i = 0; i < relocs16.count; i++)
+ write_reloc(relocs16.offset[i], stdout);
+
+ write_reloc(relocs32.count, stdout);
+ for (i = 0; i < relocs32.count; i++)
+ write_reloc(relocs32.offset[i], stdout);
+ } else {
+#ifdef CONFIG_X86_64
+ /* Print a stop */
+ write_reloc(0, stdout);
+
+ /* Now print each relocation */
+ for (i = 0; i < relocs64.count; i++)
+ write_reloc(relocs64.offset[i], stdout);
+#endif
+ /* Print a stop */
+ write_reloc(0, stdout);
+
+ /* Now print each relocation */
+ for (i = 0; i < relocs32.count; i++)
+ write_reloc(relocs32.offset[i], stdout);
}
+
}
static void usage(void)
@@ -812,6 +1120,9 @@ int main(int argc, char **argv)
read_strtabs(fp);
read_symtabs(fp);
read_relocs(fp);
+#ifdef CONFIG_X86_64
+ percpu_init();
+#endif
if (show_absolute_syms) {
print_absolute_symbols();
goto out;
diff --git a/arch/x86/tools/relocs_32.c b/arch/x86/tools/relocs_32.c
new file mode 100644
index 0000000..8cf7e94
--- /dev/null
+++ b/arch/x86/tools/relocs_32.c
@@ -0,0 +1 @@
+#include "relocs.c"
diff --git a/arch/x86/tools/relocs_64.c b/arch/x86/tools/relocs_64.c
new file mode 100644
index 0000000..419b05a
--- /dev/null
+++ b/arch/x86/tools/relocs_64.c
@@ -0,0 +1,2 @@
+#define CONFIG_X86_64 1
+#include "relocs.c"
--
1.7.9.5
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