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Commit ae4ac123 authored by Atsushi Nemoto's avatar Atsushi Nemoto Committed by Sam Ravnborg
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kbuild: make better section mismatch reports on i386 and mips 



On i386 and MIPS, warn_sec_mismatch() sometimes fails to show
usefull symbol name.  This is because empty 'refsym' due to 0 r_addend
value.  This patch is to adjust r_addend value, consulting with
apply_relocate() routine in kernel code.

Signed-off-by: default avatarAtsushi Nemoto <anemo@mba.ocn.ne.jp>
Signed-off-by: default avatarSam Ravnborg <sam@ravnborg.org>
parent b70e325c

scripts/mod/modpost.c

+73 −0
Original line number Diff line number Diff line
@@ -374,6 +374,7 @@ static int parse_elf(struct elf_info *info, const char *filename) 
	hdr->e_shstrndx = TO_NATIVE(hdr->e_shstrndx);

	hdr->e_shnum    = TO_NATIVE(hdr->e_shnum);

	hdr->e_machine  = TO_NATIVE(hdr->e_machine);

	hdr->e_type     = TO_NATIVE(hdr->e_type);

	sechdrs = (void *)hdr + hdr->e_shoff;

	info->sechdrs = sechdrs;
@@ -384,6 +385,8 @@ static int parse_elf(struct elf_info *info, const char *filename) 
		sechdrs[i].sh_size   = TO_NATIVE(sechdrs[i].sh_size);

		sechdrs[i].sh_link   = TO_NATIVE(sechdrs[i].sh_link);

		sechdrs[i].sh_name   = TO_NATIVE(sechdrs[i].sh_name);

		sechdrs[i].sh_info   = TO_NATIVE(sechdrs[i].sh_info);

		sechdrs[i].sh_addr   = TO_NATIVE(sechdrs[i].sh_addr);

	}

	/* Find symbol table. */

	for (i = 1; i < hdr->e_shnum; i++) {
@@ -753,6 +756,8 @@ static Elf_Sym *find_elf_symbol(struct elf_info *elf, Elf_Addr addr, 
	for (sym = elf->symtab_start; sym < elf->symtab_stop; sym++) {

		if (sym->st_shndx != relsym->st_shndx)

			continue;

		if (ELF_ST_TYPE(sym->st_info) == STT_SECTION)

			continue;

		if (sym->st_value == addr)

			return sym;

	}
@@ -895,6 +900,58 @@ static void warn_sec_mismatch(const char *modname, const char *fromsec, 
	}

}



static unsigned int *reloc_location(struct elf_info *elf,

					   int rsection, Elf_Rela *r)

{

	Elf_Shdr *sechdrs = elf->sechdrs;

	int section = sechdrs[rsection].sh_info;



	return (void *)elf->hdr + sechdrs[section].sh_offset +

		(r->r_offset - sechdrs[section].sh_addr);

}



static int addend_386_rel(struct elf_info *elf, int rsection, Elf_Rela *r)

{

	unsigned int r_typ = ELF_R_TYPE(r->r_info);

	unsigned int *location = reloc_location(elf, rsection, r);



	switch (r_typ) {

	case R_386_32:

		r->r_addend = TO_NATIVE(*location);

		break;

	case R_386_PC32:

		r->r_addend = TO_NATIVE(*location) + 4;

		/* For CONFIG_RELOCATABLE=y */

		if (elf->hdr->e_type == ET_EXEC)

			r->r_addend += r->r_offset;

		break;

	}

	return 0;

}



static int addend_mips_rel(struct elf_info *elf, int rsection, Elf_Rela *r)

{

	unsigned int r_typ = ELF_R_TYPE(r->r_info);

	unsigned int *location = reloc_location(elf, rsection, r);

	unsigned int inst;



	if (r_typ == R_MIPS_HI16)

		return 1;	/* skip this */

	inst = TO_NATIVE(*location);

	switch (r_typ) {

	case R_MIPS_LO16:

		r->r_addend = inst & 0xffff;

		break;

	case R_MIPS_26:

		r->r_addend = (inst & 0x03ffffff) << 2;

		break;

	case R_MIPS_32:

		r->r_addend = inst;

		break;

	}

	return 0;

}



/**

 * A module includes a number of sections that are discarded

 * either when loaded or when used as built-in.
@@ -938,8 +995,11 @@ static void check_sec_ref(struct module *mod, const char *modname, 
				r.r_offset = TO_NATIVE(rela->r_offset);

#if KERNEL_ELFCLASS == ELFCLASS64

				if (hdr->e_machine == EM_MIPS) {

					unsigned int r_typ;

					r_sym = ELF64_MIPS_R_SYM(rela->r_info);

					r_sym = TO_NATIVE(r_sym);

					r_typ = ELF64_MIPS_R_TYPE(rela->r_info);

					r.r_info = ELF64_R_INFO(r_sym, r_typ);

				} else {

					r.r_info = TO_NATIVE(rela->r_info);

					r_sym = ELF_R_SYM(r.r_info);
@@ -972,8 +1032,11 @@ static void check_sec_ref(struct module *mod, const char *modname, 
				r.r_offset = TO_NATIVE(rel->r_offset);

#if KERNEL_ELFCLASS == ELFCLASS64

				if (hdr->e_machine == EM_MIPS) {

					unsigned int r_typ;

					r_sym = ELF64_MIPS_R_SYM(rel->r_info);

					r_sym = TO_NATIVE(r_sym);

					r_typ = ELF64_MIPS_R_TYPE(rel->r_info);

					r.r_info = ELF64_R_INFO(r_sym, r_typ);

				} else {

					r.r_info = TO_NATIVE(rel->r_info);

					r_sym = ELF_R_SYM(r.r_info);
@@ -983,6 +1046,16 @@ static void check_sec_ref(struct module *mod, const char *modname, 
				r_sym = ELF_R_SYM(r.r_info);

#endif

				r.r_addend = 0;

				switch (hdr->e_machine) {

				case EM_386:

					if (addend_386_rel(elf, i, &r))

						continue;

					break;

				case EM_MIPS:

					if (addend_mips_rel(elf, i, &r))

						continue;

					break;

				}

				sym = elf->symtab_start + r_sym;

				/* Skip special sections */

				if (sym->st_shndx >= SHN_LORESERVE)

scripts/mod/modpost.h

+3 −0
Original line number Diff line number Diff line
@@ -60,6 +60,9 @@ typedef union 
#define ELF64_MIPS_R_SYM(i) \

  ((__extension__ (_Elf64_Mips_R_Info_union)(i)).r_info_fields.r_sym)



#define ELF64_MIPS_R_TYPE(i) \

  ((__extension__ (_Elf64_Mips_R_Info_union)(i)).r_info_fields.r_type1)



#if KERNEL_ELFDATA != HOST_ELFDATA



static inline void __endian(const void *src, void *dest, unsigned int size)