path: root/arch/x86/tools/relocs.c

/* This is included from relocs_32/64.c */

#define ElfW(type)		_ElfW(ELF_BITS, type)
#define _ElfW(bits, type)	__ElfW(bits, type)
#define __ElfW(bits, type)	Elf##bits##_##type

#define Elf_Addr		ElfW(Addr)
#define Elf_Ehdr		ElfW(Ehdr)
#define Elf_Phdr		ElfW(Phdr)
#define Elf_Shdr		ElfW(Shdr)
#define Elf_Sym			ElfW(Sym)

static Elf_Ehdr ehdr;

struct relocs {
	uint32_t	*offset;
	unsigned long	count;
	unsigned long	size;
};

static struct relocs relocs16;
static struct relocs relocs32;
static struct relocs relocs64;

struct section {
	Elf_Shdr       shdr;
	struct section *link;
	Elf_Sym        *symtab;
	Elf_Rel        *reltab;
	char           *strtab;
};
static struct section *secs;

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] =
	"^(__init_(begin|end)|"
	"__x86_cpu_dev_(start|end)|"
	"(__parainstructions|__alt_instructions)(|_end)|"
	"(__iommu_table|__apicdrivers|__smp_locks)(|_end)|"
	"__(start|end)_pci_.*|"
	"__(start|end)_builtin_fw|"
	"__(start|stop)___ksymtab(|_gpl|_unused|_unused_gpl|_gpl_future)|"
	"__(start|stop)___kcrctab(|_gpl|_unused|_unused_gpl|_gpl_future)|"
	"__(start|stop)___param|"
	"__(start|stop)___modver|"
	"__(start|stop)___bug_table|"
	"__tracedata_(start|end)|"
	"__(start|stop)_notes|"
	"__end_rodata|"
	"__initramfs_start|"
	"(jiffies|jiffies_64)|"
#if ELF_BITS == 64
	"__per_cpu_load|"
	"init_per_cpu__.*|"
	"__end_rodata_hpage_align|"
	"__vvar_page|"
#endif
	"_end)$"
};


static const char * const sym_regex_realmode[S_NSYMTYPES] = {
/*
 * 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] =
	"^pa_",

/*
 * 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 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
	};