Commit 7ce3e410 authored by Masahiro Yamada's avatar Masahiro Yamada
Browse files

modpost: remove useless export_from_sec() 



With commit 1743694e ("modpost: stop symbol preloading for
modversion CRC") applied, now export_from_sec() is useless.

handle_symbol() is called for every symbol in the ELF.

When 'symname' does not start with "__ksymtab", export_from_sec() is
called, and the returned value is stored in 'export'.

It is used in the last part of handle_symbol():

    if (strstarts(symname, "__ksymtab_")) {
            name = symname + strlen("__ksymtab_");
            sym_add_exported(name, mod, export);
    }

'export' is used only when 'symname' starts with "__ksymtab_".

So, the value returned by export_from_sec() is never used.

Remove useless export_from_sec(). This makes further cleanups possible.

I put the temporary code:

    export = export_unknown;

Otherwise, I would get the compiler warning:

    warning: 'export' may be used uninitialized in this function [-Wmaybe-uninitialized]

This is apparently false positive because

    if (strstarts(symname, "__ksymtab_")

... is a stronger condition than:

    if (strstarts(symname, "__ksymtab")

Anyway, this part will be cleaned up by the next commit.

Signed-off-by: default avatarMasahiro Yamada <masahiroy@kernel.org>
Reviewed-by: default avatarNick Desaulniers <ndesaulniers@google.com>
parent dc6dc3e7

scripts/mod/modpost.c

+2 −15
Original line number Diff line number Diff line
@@ -369,16 +369,6 @@ static enum export export_from_secname(struct elf_info *elf, unsigned int sec) 
		return export_unknown;

}



static enum export export_from_sec(struct elf_info *elf, unsigned int sec)

{

	if (sec == elf->export_sec)

		return export_plain;

	else if (sec == elf->export_gpl_sec)

		return export_gpl;

	else

		return export_unknown;

}



static const char *namespace_from_kstrtabns(const struct elf_info *info,

					    const Elf_Sym *sym)

{
@@ -576,10 +566,7 @@ static int parse_elf(struct elf_info *info, const char *filename) 
				fatal("%s has NOBITS .modinfo\n", filename);

			info->modinfo = (void *)hdr + sechdrs[i].sh_offset;

			info->modinfo_len = sechdrs[i].sh_size;

		} else if (strcmp(secname, "__ksymtab") == 0)

			info->export_sec = i;

		else if (strcmp(secname, "__ksymtab_gpl") == 0)

			info->export_gpl_sec = i;

		}



		if (sechdrs[i].sh_type == SHT_SYMTAB) {

			unsigned int sh_link_idx;
@@ -703,7 +690,7 @@ static void handle_symbol(struct module *mod, struct elf_info *info, 
	if (strstarts(symname, "__ksymtab"))

		export = export_from_secname(info, get_secindex(info, sym));

	else

		export = export_from_sec(info, get_secindex(info, sym));

		export = export_unknown;



	switch (sym->st_shndx) {

	case SHN_COMMON:

scripts/mod/modpost.h

+0 −2
Original line number Diff line number Diff line
@@ -138,8 +138,6 @@ struct elf_info { 
	Elf_Shdr     *sechdrs;

	Elf_Sym      *symtab_start;

	Elf_Sym      *symtab_stop;

	Elf_Section  export_sec;

	Elf_Section  export_gpl_sec;

	char         *strtab;

	char	     *modinfo;

	unsigned int modinfo_len;