linux-kernel - Re: [PATCH 2/3] modpost: factor out Elf_Sym pointer calculation to section

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Date:   Thu, 22 Jun 2023 12:01:39 -0700
From:   Nick Desaulniers <ndesaulniers@...gle.com>
To:     Masahiro Yamada <masahiroy@...nel.org>
Cc:     linux-kbuild@...r.kernel.org, linux-kernel@...r.kernel.org,
        Nathan Chancellor <nathan@...nel.org>,
        Nicolas Schier <nicolas@...sle.eu>
Subject: Re: [PATCH 2/3] modpost: factor out Elf_Sym pointer calculation to section_rel()

On Tue, Jun 20, 2023 at 5:05 AM Masahiro Yamada <masahiroy@...nel.org> wrote:
>
> Pass the Elf_Sym pointer to addend_arm_rel() as well as to
> check_section_mismatch().
>
> Signed-off-by: Masahiro Yamada <masahiroy@...nel.org>

Thanks for the patch!
Reviewed-by: Nick Desaulniers <ndesaulniers@...gle.com>

> ---
>
>  scripts/mod/modpost.c | 9 +++++----
>  1 file changed, 5 insertions(+), 4 deletions(-)
>
> diff --git a/scripts/mod/modpost.c b/scripts/mod/modpost.c
> index 2551ac9d5bd3..ffe45c54f024 100644
> --- a/scripts/mod/modpost.c
> +++ b/scripts/mod/modpost.c
> @@ -1295,10 +1295,9 @@ static int32_t sign_extend32(int32_t value, int index)
>         return (int32_t)(value << shift) >> shift;
>  }
>
> -static int addend_arm_rel(void *loc, struct elf_info *elf, Elf_Rela *r)
> +static int addend_arm_rel(void *loc, Elf_Sym *sym, Elf_Rela *r)
>  {
>         unsigned int r_typ = ELF_R_TYPE(r->r_info);
> -       Elf_Sym *sym = elf->symtab_start + ELF_R_SYM(r->r_info);
>         uint32_t inst, upper, lower, sign, j1, j2;
>         int32_t offset;
>
> @@ -1493,6 +1492,7 @@ static void section_rel(struct module *mod, struct elf_info *elf,
>                 return;
>
>         for (rel = start; rel < stop; rel++) {
> +               Elf_Sym *tsym;
>                 void *loc;
>
>                 r.r_offset = TO_NATIVE(rel->r_offset);
> @@ -1514,6 +1514,7 @@ static void section_rel(struct module *mod, struct elf_info *elf,
>                 r.r_addend = 0;
>
>                 loc = sym_get_data_by_offset(elf, fsecndx, r.r_offset);
> +               tsym = elf->symtab_start + ELF_R_SYM(r.r_info);
>
>                 switch (elf->hdr->e_machine) {
>                 case EM_386:
> @@ -1521,7 +1522,7 @@ static void section_rel(struct module *mod, struct elf_info *elf,
>                                 continue;
>                         break;
>                 case EM_ARM:
> -                       if (addend_arm_rel(loc, elf, &r))
> +                       if (addend_arm_rel(loc, tsym, &r))
>                                 continue;
>                         break;
>                 case EM_MIPS:
> @@ -1532,7 +1533,7 @@ static void section_rel(struct module *mod, struct elf_info *elf,
>                         fatal("Please add code to calculate addend for this architecture\n");
>                 }
>
> -               check_section_mismatch(mod, elf, elf->symtab_start + r_sym,
> +               check_section_mismatch(mod, elf, tsym,
>                                        fsecndx, fromsec, r.r_offset, r.r_addend);
>         }
>  }
> --
> 2.39.2
>


-- 
Thanks,
~Nick Desaulniers