Re: [PATCH] modpost: simplify sec_name()

From: Kees Cook
Date: Wed Aug 09 2017 - 01:17:45 EST


On Tue, Aug 8, 2017 at 8:18 PM, Masahiro Yamada
<yamada.masahiro@xxxxxxxxxxxxx> wrote:
> There is code duplication between sec_name() and sech_name().
> Simplify sec_name() by re-using sech_name(). Also, move them up
> to remove the forward declaration of sec_name().
>
> Signed-off-by: Masahiro Yamada <yamada.masahiro@xxxxxxxxxxxxx>

Reviewed-by: Kees Cook <keescook@xxxxxxxxxxxx>

-Kees

> ---
>
> scripts/mod/modpost.c | 27 +++++++++++----------------
> 1 file changed, 11 insertions(+), 16 deletions(-)
>
> diff --git a/scripts/mod/modpost.c b/scripts/mod/modpost.c
> index 48397feb08fb..b920d186ad4a 100644
> --- a/scripts/mod/modpost.c
> +++ b/scripts/mod/modpost.c
> @@ -261,7 +261,17 @@ static enum export export_no(const char *s)
> return export_unknown;
> }
>
> -static const char *sec_name(struct elf_info *elf, int secindex);
> +static const char *sech_name(struct elf_info *elf, Elf_Shdr *sechdr)
> +{
> + return (void *)elf->hdr +
> + elf->sechdrs[elf->secindex_strings].sh_offset +
> + sechdr->sh_name;
> +}
> +
> +static const char *sec_name(struct elf_info *elf, int secindex)
> +{
> + return sech_name(elf, &elf->sechdrs[secindex]);
> +}
>
> #define strstarts(str, prefix) (strncmp(str, prefix, strlen(prefix)) == 0)
>
> @@ -775,21 +785,6 @@ static const char *sym_name(struct elf_info *elf, Elf_Sym *sym)
> return "(unknown)";
> }
>
> -static const char *sec_name(struct elf_info *elf, int secindex)
> -{
> - Elf_Shdr *sechdrs = elf->sechdrs;
> - return (void *)elf->hdr +
> - elf->sechdrs[elf->secindex_strings].sh_offset +
> - sechdrs[secindex].sh_name;
> -}
> -
> -static const char *sech_name(struct elf_info *elf, Elf_Shdr *sechdr)
> -{
> - return (void *)elf->hdr +
> - elf->sechdrs[elf->secindex_strings].sh_offset +
> - sechdr->sh_name;
> -}
> -
> /* The pattern is an array of simple patterns.
> * "foo" will match an exact string equal to "foo"
> * "*foo" will match a string that ends with "foo"
> --
> 2.7.4
>



--
Kees Cook
Pixel Security