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Commit ff13f926 authored by Sam Ravnborg's avatar Sam Ravnborg
Browse files

kbuild: introduce a few helpers in modpost 



Introducing helpers to retreive symbol and section
names cleaned up the code a bit.

Signed-off-by: default avatarSam Ravnborg <sam@ravnborg.org>
parent 157c23c8

scripts/mod/modpost.c

+38 −35
Original line number Diff line number Diff line
@@ -605,6 +605,26 @@ static int strrcmp(const char *s, const char *sub) 
	return memcmp(s + slen - sublen, sub, sublen);

}



static const char *sym_name(struct elf_info *elf, Elf_Sym *sym)

{

	return elf->strtab + sym->st_name;

}



static const char *sec_name(struct elf_info *elf, int shndx)

{

	Elf_Shdr *sechdrs = elf->sechdrs;

	return (void *)elf->hdr +

	        elf->sechdrs[elf->hdr->e_shstrndx].sh_offset +

	        sechdrs[shndx].sh_name;

}



static const char *sech_name(struct elf_info *elf, Elf_Shdr *sechdr)

{

	return (void *)elf->hdr +

	        elf->sechdrs[elf->hdr->e_shstrndx].sh_offset +

	        sechdr->sh_name;

}



/* if sym is empty or point to a string

 * like ".[0-9]+" then return 1.

 * This is the optional prefix added by ld to some sections
@@ -943,17 +963,14 @@ static Elf_Sym *find_elf_symbol2(struct elf_info *elf, Elf_Addr addr, 
{

	Elf_Sym *sym;

	Elf_Sym *near = NULL;

	Elf_Ehdr *hdr = elf->hdr;

	Elf_Addr distance = ~0;

	const char *secstrings = (void *)hdr +

				 elf->sechdrs[hdr->e_shstrndx].sh_offset;



	for (sym = elf->symtab_start; sym < elf->symtab_stop; sym++) {

		const char *symsec;



		if (sym->st_shndx >= SHN_LORESERVE)

			continue;

		symsec = secstrings + elf->sechdrs[sym->st_shndx].sh_name;

		symsec = sec_name(elf, sym->st_shndx);

		if (strcmp(symsec, sec) != 0)

			continue;

		if (!is_valid_name(elf, sym))
@@ -978,24 +995,21 @@ static Elf_Sym *find_elf_symbol2(struct elf_info *elf, Elf_Addr addr, 
static void warn_sec_mismatch(const char *modname, const char *fromsec,

			      struct elf_info *elf, Elf_Sym *sym, Elf_Rela r)

{

	const char *refsymname = "";

	Elf_Sym *where;

	Elf_Sym *refsym;

	Elf_Ehdr *hdr = elf->hdr;

	Elf_Shdr *sechdrs = elf->sechdrs;

	const char *secstrings = (void *)hdr +

				 sechdrs[hdr->e_shstrndx].sh_offset;

	const char *secname = secstrings + sechdrs[sym->st_shndx].sh_name;

	const char *refsymname = "";

	const char *secname;



	secname = sec_name(elf, sym->st_shndx);

	where = find_elf_symbol2(elf, r.r_offset, fromsec);



	refsym = find_elf_symbol(elf, r.r_addend, sym);

	if (refsym && strlen(elf->strtab + refsym->st_name))

		refsymname = elf->strtab + refsym->st_name;

	if (refsym && strlen(sym_name(elf, refsym)))

		refsymname = sym_name(elf, refsym);



	/* check whitelist - we may ignore it */

	if (secref_whitelist(modname, secname, fromsec,

			     where ? elf->strtab + where->st_name : "",

			     where ? sym_name(elf, where) : "",

	                     refsymname))

		return;
@@ -1003,7 +1017,7 @@ static void warn_sec_mismatch(const char *modname, const char *fromsec, 
		warn("%s(%s+0x%llx): Section mismatch: reference to %s:%s "

		     "in '%s'\n",

		     modname, fromsec, (unsigned long long)r.r_offset,

		     secname, refsymname, elf->strtab + where->st_name);

		     secname, refsymname, sym_name(elf, where));

	} else {

		warn("%s(%s+0x%llx): Section mismatch: reference to %s:%s\n",

		     modname, fromsec, (unsigned long long)r.r_offset,
@@ -1095,14 +1109,10 @@ static void section_rela(const char *modname, struct elf_info *elf, 
	const char *fromsec;

	const char * tosec;



	Elf_Ehdr *hdr = elf->hdr;

	Elf_Rela *start = (void *)hdr + sechdr->sh_offset;

	Elf_Rela *start = (void *)elf->hdr + sechdr->sh_offset;

	Elf_Rela *stop  = (void *)start + sechdr->sh_size;



	const char *secstrings = (void *)hdr +

				 elf->sechdrs[hdr->e_shstrndx].sh_offset;



	fromsec = secstrings + sechdr->sh_name;

	fromsec = sech_name(elf, sechdr);

	fromsec += strlen(".rela");

	/* if from section (name) is know good then skip it */

	if (match(fromsec, section_white_list))
@@ -1111,7 +1121,7 @@ static void section_rela(const char *modname, struct elf_info *elf, 
	for (rela = start; rela < stop; rela++) {

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

#if KERNEL_ELFCLASS == ELFCLASS64

		if (hdr->e_machine == EM_MIPS) {

		if (elf->hdr->e_machine == EM_MIPS) {

			unsigned int r_typ;

			r_sym = ELF64_MIPS_R_SYM(rela->r_info);

			r_sym = TO_NATIVE(r_sym);
@@ -1131,8 +1141,7 @@ static void section_rela(const char *modname, struct elf_info *elf, 
		if (sym->st_shndx >= SHN_LORESERVE)

			continue;



		tosec = secstrings +

			elf->sechdrs[sym->st_shndx].sh_name;

		tosec = sec_name(elf, sym->st_shndx);

		if (section_mismatch(fromsec, tosec))

			warn_sec_mismatch(modname, fromsec, elf, sym, r);

	}
@@ -1148,14 +1157,10 @@ static void section_rel(const char *modname, struct elf_info *elf, 
	const char *fromsec;

	const char * tosec;



	Elf_Ehdr *hdr = elf->hdr;

	Elf_Rel *start = (void *)hdr + sechdr->sh_offset;

	Elf_Rel *start = (void *)elf->hdr + sechdr->sh_offset;

	Elf_Rel *stop  = (void *)start + sechdr->sh_size;



	const char *secstrings = (void *)hdr +

				 elf->sechdrs[hdr->e_shstrndx].sh_offset;



	fromsec = secstrings + sechdr->sh_name;

	fromsec = sech_name(elf, sechdr);

	fromsec += strlen(".rel");

	/* if from section (name) is know good then skip it */

	if (match(fromsec, section_white_list))
@@ -1164,7 +1169,7 @@ static void section_rel(const char *modname, struct elf_info *elf, 
	for (rel = start; rel < stop; rel++) {

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

#if KERNEL_ELFCLASS == ELFCLASS64

		if (hdr->e_machine == EM_MIPS) {

		if (elf->hdr->e_machine == EM_MIPS) {

			unsigned int r_typ;

			r_sym = ELF64_MIPS_R_SYM(rel->r_info);

			r_sym = TO_NATIVE(r_sym);
@@ -1179,7 +1184,7 @@ static void section_rel(const char *modname, struct elf_info *elf, 
		r_sym = ELF_R_SYM(r.r_info);

#endif

		r.r_addend = 0;

		switch (hdr->e_machine) {

		switch (elf->hdr->e_machine) {

		case EM_386:

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

				continue;
@@ -1198,8 +1203,7 @@ static void section_rel(const char *modname, struct elf_info *elf, 
		if (sym->st_shndx >= SHN_LORESERVE)

			continue;



		tosec = secstrings +

			elf->sechdrs[sym->st_shndx].sh_name;

		tosec = sec_name(elf, sym->st_shndx);

		if (section_mismatch(fromsec, tosec))

			warn_sec_mismatch(modname, fromsec, elf, sym, r);

	}
@@ -1221,11 +1225,10 @@ static void check_sec_ref(struct module *mod, const char *modname, 
                          struct elf_info *elf)

{

	int i;

	Elf_Ehdr *hdr = elf->hdr;

	Elf_Shdr *sechdrs = elf->sechdrs;



	/* Walk through all sections */

	for (i = 0; i < hdr->e_shnum; i++) {

	for (i = 0; i < elf->hdr->e_shnum; i++) {

		/* We want to process only relocation sections and not .init */

		if (sechdrs[i].sh_type == SHT_RELA)

			section_rela(modname, elf, &elf->sechdrs[i]);