Commit bf11655c authored by Kees Cook's avatar Kees Cook Committed by H. Peter Anvin
Browse files

x86, relocs: Generalize ELF structure names 



In preparation for making the reloc tool operate on 64-bit relocations,
generalize the structure names for easy recompilation via #defines.

Based on work by Neill Clift and Michael Davidson.

Signed-off-by: default avatarKees Cook <keescook@chromium.org>
Link: http://lkml.kernel.org/r/1365797627-20874-2-git-send-email-keescook@chromium.org


Signed-off-by: default avatarH. Peter Anvin <hpa@linux.intel.com>
parent 4eefbe79

arch/x86/tools/relocs.c

+99 −71
Original line number Diff line number Diff line
@@ -12,20 +12,42 @@ 
#include <regex.h>

#include <tools/le_byteshift.h>



#define ElfW(type)		_ElfW(ELF_BITS, type)

#define _ElfW(bits, type)	__ElfW(bits, type)

#define __ElfW(bits, type)	Elf##bits##_##type



#define ELF_BITS		32

#define ELF_MACHINE		EM_386

#define ELF_MACHINE_NAME	"i386"

#define SHT_REL_TYPE		SHT_REL



#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)



#define Elf_Rel			ElfW(Rel)

#define Elf_Ehdr		ElfW(Ehdr)

#define Elf_Phdr		ElfW(Phdr)

#define Elf_Shdr		ElfW(Shdr)

#define Elf_Sym			ElfW(Sym)



static void die(char *fmt, ...);



#define ARRAY_SIZE(x) (sizeof(x) / sizeof((x)[0]))

static Elf32_Ehdr ehdr;

static Elf_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;

	Elf_Shdr       shdr;

	struct section *link;

	Elf32_Sym      *symtab;

	Elf32_Rel      *reltab;

	Elf_Sym        *symtab;

	Elf_Rel        *reltab;

	char           *strtab;

};

static struct section *secs;
@@ -240,7 +262,7 @@ 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, Elf_Sym *sym)

{

	const char *name;

	name = "<noname>";
@@ -274,6 +296,12 @@ static uint32_t elf32_to_cpu(uint32_t val) 
	return le32_to_cpu(val);

}



#define elf_half_to_cpu(x)	elf16_to_cpu(x)

#define elf_word_to_cpu(x)	elf32_to_cpu(x)

#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)



static void read_ehdr(FILE *fp)

{

	if (fread(&ehdr, sizeof(ehdr), 1, fp) != 1) {
@@ -283,8 +311,8 @@ 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 +321,36 @@ 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(Elf_Ehdr)) {

		die("Bad Elf header size\n");

	}

	if (ehdr.e_phentsize != sizeof(Elf32_Phdr)) {

	if (ehdr.e_phentsize != sizeof(Elf_Phdr)) {

		die("Bad program header entry\n");

	}

	if (ehdr.e_shentsize != sizeof(Elf32_Shdr)) {

	if (ehdr.e_shentsize != sizeof(Elf_Shdr)) {

		die("Bad section header entry\n");

	}

	if (ehdr.e_shstrndx >= ehdr.e_shnum) {
@@ -333,7 +361,7 @@ static void read_ehdr(FILE *fp) 
static void read_shdrs(FILE *fp)

{

	int i;

	Elf32_Shdr shdr;

	Elf_Shdr shdr;



	secs = calloc(ehdr.e_shnum, sizeof(struct section));

	if (!secs) {
@@ -349,16 +377,16 @@ 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 +440,12 @@ 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(Elf_Sym); j++) {

			Elf_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 +456,7 @@ 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 +473,10 @@ 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);

		}

	}

}
@@ -468,8 +496,8 @@ 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(Elf_Sym); j++) {

			Elf_Sym *sym;

			const char *name;

			sym = &sec->symtab[j];

			name = sym_name(sym_strtab, sym);
@@ -478,9 +506,9 @@ static void print_absolute_symbols(void) 
			}

			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)),

				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 +523,9 @@ static void print_absolute_relocs(void) 
		struct section *sec = &secs[i];

		struct section *sec_applies, *sec_symtab;

		char *sym_strtab;

		Elf32_Sym *sh_symtab;

		Elf_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 +535,12 @@ 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;

			Elf_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;
@@ -545,7 +573,7 @@ static void print_absolute_relocs(void) 
			printf("%08x %08x %10s %08x  %s\n",

				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 +583,19 @@ static void print_absolute_relocs(void) 
		printf("\n");

}



static void walk_relocs(void (*visit)(Elf32_Rel *rel, Elf32_Sym *sym),

static void walk_relocs(void (*visit)(Elf_Rel *rel, Elf_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;

		Elf_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;
@@ -577,16 +605,16 @@ 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;

		for (j = 0; j < sec->shdr.sh_size/sizeof(Elf_Rel); j++) {

			Elf_Rel *rel;

			Elf_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);

			sym = &sh_symtab[ELF_R_SYM(rel->r_info)];

			r_type = ELF_R_TYPE(rel->r_info);



			shn_abs = sym->st_shndx == SHN_ABS;
@@ -647,18 +675,18 @@ static void walk_relocs(void (*visit)(Elf32_Rel *rel, Elf32_Sym *sym), 
	}

}



static void count_reloc(Elf32_Rel *rel, Elf32_Sym *sym)

static void count_reloc(Elf_Rel *rel, Elf_Sym *sym)

{

	if (ELF32_R_TYPE(rel->r_info) == R_386_16)

	if (ELF_R_TYPE(rel->r_info) == R_386_16)

		reloc16_count++;

	else

		reloc_count++;

}



static void collect_reloc(Elf32_Rel *rel, Elf32_Sym *sym)

static void collect_reloc(Elf_Rel *rel, Elf_Sym *sym)

{

	/* Remember the address that needs to be adjusted. */

	if (ELF32_R_TYPE(rel->r_info) == R_386_16)

	if (ELF_R_TYPE(rel->r_info) == R_386_16)

		relocs16[reloc16_idx++] = rel->r_offset;

	else

		relocs[reloc_idx++] = rel->r_offset;

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