[2/6] modpost: refactor namespace_from_kstrtabns() to not hard-code section name
diff mbox series

Message ID 20191114174226.7201-2-yamada.masahiro@socionext.com
State New
Headers show
Series
  • [1/6] modpost: add a helper to get data pointed by a symbol
Related show

Commit Message

Masahiro Yamada Nov. 14, 2019, 5:42 p.m. UTC
Currently, namespace_from_kstrtabns() relies on the fact that
namespace strings are recorded in the __ksymtab_strings section.
Actually, it is coded in include/linux/export.h, but modpost does
not need to hard-code the section name.

Elf_Sym::st_shndx holds the section number of the relevant section.
Using it is a more portable way to find the namespace string.

sym_get_value() takes care of it, so namespace_from_kstrtabns() can
simply wrap it. Delete the unneeded info->ksymtab_strings .

While I was here, I added more 'const' qualifiers to pointers.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
---

 scripts/mod/modpost.c | 10 +++-------
 scripts/mod/modpost.h |  1 -
 2 files changed, 3 insertions(+), 8 deletions(-)

Comments

Masahiro Yamada Nov. 14, 2019, 5:46 p.m. UTC | #1
(+CC: Matthias, who might be interested)


On Fri, Nov 15, 2019 at 2:42 AM Masahiro Yamada
<yamada.masahiro@socionext.com> wrote:
>
> Currently, namespace_from_kstrtabns() relies on the fact that
> namespace strings are recorded in the __ksymtab_strings section.
> Actually, it is coded in include/linux/export.h, but modpost does
> not need to hard-code the section name.
>
> Elf_Sym::st_shndx holds the section number of the relevant section.
> Using it is a more portable way to find the namespace string.
>
> sym_get_value() takes care of it, so namespace_from_kstrtabns() can
> simply wrap it. Delete the unneeded info->ksymtab_strings .
>
> While I was here, I added more 'const' qualifiers to pointers.
>
> Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
> ---
>
>  scripts/mod/modpost.c | 10 +++-------
>  scripts/mod/modpost.h |  1 -
>  2 files changed, 3 insertions(+), 8 deletions(-)
>
> diff --git a/scripts/mod/modpost.c b/scripts/mod/modpost.c
> index cd885573daaf..d9418c58a8c0 100644
> --- a/scripts/mod/modpost.c
> +++ b/scripts/mod/modpost.c
> @@ -356,10 +356,10 @@ static enum export export_from_sec(struct elf_info *elf, unsigned int sec)
>                 return export_unknown;
>  }
>
> -static const char *namespace_from_kstrtabns(struct elf_info *info,
> -                                           Elf_Sym *kstrtabns)
> +static const char *namespace_from_kstrtabns(const struct elf_info *info,
> +                                           const Elf_Sym *sym)
>  {
> -       char *value = info->ksymtab_strings + kstrtabns->st_value;
> +       const char *value = sym_get_data(info, sym);
>         return value[0] ? value : NULL;
>  }
>
> @@ -601,10 +601,6 @@ static int parse_elf(struct elf_info *info, const char *filename)
>                         info->export_unused_gpl_sec = i;
>                 else if (strcmp(secname, "__ksymtab_gpl_future") == 0)
>                         info->export_gpl_future_sec = i;
> -               else if (strcmp(secname, "__ksymtab_strings") == 0)
> -                       info->ksymtab_strings = (void *)hdr +
> -                                               sechdrs[i].sh_offset -
> -                                               sechdrs[i].sh_addr;
>
>                 if (sechdrs[i].sh_type == SHT_SYMTAB) {
>                         unsigned int sh_link_idx;
> diff --git a/scripts/mod/modpost.h b/scripts/mod/modpost.h
> index fe6652535e4b..64a82d2d85f6 100644
> --- a/scripts/mod/modpost.h
> +++ b/scripts/mod/modpost.h
> @@ -143,7 +143,6 @@ struct elf_info {
>         Elf_Section  export_gpl_sec;
>         Elf_Section  export_unused_gpl_sec;
>         Elf_Section  export_gpl_future_sec;
> -       char         *ksymtab_strings;
>         char         *strtab;
>         char         *modinfo;
>         unsigned int modinfo_len;
> --
> 2.17.1
>

Patch
diff mbox series

diff --git a/scripts/mod/modpost.c b/scripts/mod/modpost.c
index cd885573daaf..d9418c58a8c0 100644
--- a/scripts/mod/modpost.c
+++ b/scripts/mod/modpost.c
@@ -356,10 +356,10 @@  static enum export export_from_sec(struct elf_info *elf, unsigned int sec)
 		return export_unknown;
 }
 
-static const char *namespace_from_kstrtabns(struct elf_info *info,
-					    Elf_Sym *kstrtabns)
+static const char *namespace_from_kstrtabns(const struct elf_info *info,
+					    const Elf_Sym *sym)
 {
-	char *value = info->ksymtab_strings + kstrtabns->st_value;
+	const char *value = sym_get_data(info, sym);
 	return value[0] ? value : NULL;
 }
 
@@ -601,10 +601,6 @@  static int parse_elf(struct elf_info *info, const char *filename)
 			info->export_unused_gpl_sec = i;
 		else if (strcmp(secname, "__ksymtab_gpl_future") == 0)
 			info->export_gpl_future_sec = i;
-		else if (strcmp(secname, "__ksymtab_strings") == 0)
-			info->ksymtab_strings = (void *)hdr +
-						sechdrs[i].sh_offset -
-						sechdrs[i].sh_addr;
 
 		if (sechdrs[i].sh_type == SHT_SYMTAB) {
 			unsigned int sh_link_idx;
diff --git a/scripts/mod/modpost.h b/scripts/mod/modpost.h
index fe6652535e4b..64a82d2d85f6 100644
--- a/scripts/mod/modpost.h
+++ b/scripts/mod/modpost.h
@@ -143,7 +143,6 @@  struct elf_info {
 	Elf_Section  export_gpl_sec;
 	Elf_Section  export_unused_gpl_sec;
 	Elf_Section  export_gpl_future_sec;
-	char	     *ksymtab_strings;
 	char         *strtab;
 	char	     *modinfo;
 	unsigned int modinfo_len;