* [PATCH 1/2] modpost: remove useless export_from_sec()
@ 2022-04-02 13:00 Masahiro Yamada
2022-04-02 13:00 ` [PATCH 2/2] modpost: move export_from_secname() call to more relevant place Masahiro Yamada
2022-04-04 17:00 ` [PATCH 1/2] modpost: remove useless export_from_sec() Nick Desaulniers
0 siblings, 2 replies; 4+ messages in thread
From: Masahiro Yamada @ 2022-04-02 13:00 UTC (permalink / raw)
To: linux-kbuild
Cc: linux-kernel, Masahiro Yamada, Michal Marek, Nick Desaulniers
With commit 1743694eb235 ("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 this useless function. This makes further cleanups possible.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
---
scripts/mod/modpost.c | 17 +----------------
scripts/mod/modpost.h | 4 ----
2 files changed, 1 insertion(+), 20 deletions(-)
diff --git a/scripts/mod/modpost.c b/scripts/mod/modpost.c
index ed9d056d2108..194ca9083c7a 100644
--- a/scripts/mod/modpost.c
+++ b/scripts/mod/modpost.c
@@ -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;
@@ -702,8 +689,6 @@ 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));
switch (sym->st_shndx) {
case SHN_COMMON:
diff --git a/scripts/mod/modpost.h b/scripts/mod/modpost.h
index 0c47ff95c0e2..a85dcec3669a 100644
--- a/scripts/mod/modpost.h
+++ b/scripts/mod/modpost.h
@@ -25,7 +25,6 @@
#define Elf_Sym Elf32_Sym
#define Elf_Addr Elf32_Addr
#define Elf_Sword Elf64_Sword
-#define Elf_Section Elf32_Half
#define ELF_ST_BIND ELF32_ST_BIND
#define ELF_ST_TYPE ELF32_ST_TYPE
@@ -40,7 +39,6 @@
#define Elf_Sym Elf64_Sym
#define Elf_Addr Elf64_Addr
#define Elf_Sword Elf64_Sxword
-#define Elf_Section Elf64_Half
#define ELF_ST_BIND ELF64_ST_BIND
#define ELF_ST_TYPE ELF64_ST_TYPE
@@ -138,8 +136,6 @@ 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;
--
2.32.0
^ permalink raw reply related [flat|nested] 4+ messages in thread
* [PATCH 2/2] modpost: move export_from_secname() call to more relevant place
2022-04-02 13:00 [PATCH 1/2] modpost: remove useless export_from_sec() Masahiro Yamada
@ 2022-04-02 13:00 ` Masahiro Yamada
2022-04-04 17:03 ` Nick Desaulniers
2022-04-04 17:00 ` [PATCH 1/2] modpost: remove useless export_from_sec() Nick Desaulniers
1 sibling, 1 reply; 4+ messages in thread
From: Masahiro Yamada @ 2022-04-02 13:00 UTC (permalink / raw)
To: linux-kbuild
Cc: linux-kernel, Masahiro Yamada, Michal Marek, Nick Desaulniers
The value returned by export_from_secname() is only used by
sym_add_exported().
Move export_from_secname() just above sym_add_exported().
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
---
scripts/mod/modpost.c | 8 ++++----
1 file changed, 4 insertions(+), 4 deletions(-)
diff --git a/scripts/mod/modpost.c b/scripts/mod/modpost.c
index 194ca9083c7a..f9e54247ae1d 100644
--- a/scripts/mod/modpost.c
+++ b/scripts/mod/modpost.c
@@ -684,12 +684,8 @@ static void handle_modversion(const struct module *mod,
static void handle_symbol(struct module *mod, struct elf_info *info,
const Elf_Sym *sym, const char *symname)
{
- enum export export;
const char *name;
- if (strstarts(symname, "__ksymtab"))
- export = export_from_secname(info, get_secindex(info, sym));
-
switch (sym->st_shndx) {
case SHN_COMMON:
if (strstarts(symname, "__gnu_lto_")) {
@@ -724,7 +720,11 @@ static void handle_symbol(struct module *mod, struct elf_info *info,
default:
/* All exported symbols */
if (strstarts(symname, "__ksymtab_")) {
+ enum export export;
+
name = symname + strlen("__ksymtab_");
+ export = export_from_secname(info,
+ get_secindex(info, sym));
sym_add_exported(name, mod, export);
}
if (strcmp(symname, "init_module") == 0)
--
2.32.0
^ permalink raw reply related [flat|nested] 4+ messages in thread
* Re: [PATCH 1/2] modpost: remove useless export_from_sec()
2022-04-02 13:00 [PATCH 1/2] modpost: remove useless export_from_sec() Masahiro Yamada
2022-04-02 13:00 ` [PATCH 2/2] modpost: move export_from_secname() call to more relevant place Masahiro Yamada
@ 2022-04-04 17:00 ` Nick Desaulniers
1 sibling, 0 replies; 4+ messages in thread
From: Nick Desaulniers @ 2022-04-04 17:00 UTC (permalink / raw)
To: Masahiro Yamada; +Cc: linux-kbuild, linux-kernel, Michal Marek
On Sat, Apr 2, 2022 at 6:00 AM Masahiro Yamada <masahiroy@kernel.org> wrote:
>
> With commit 1743694eb235 ("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 this useless function. This makes further cleanups possible.
>
> Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Thanks for the patch!
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
> ---
>
> scripts/mod/modpost.c | 17 +----------------
> scripts/mod/modpost.h | 4 ----
> 2 files changed, 1 insertion(+), 20 deletions(-)
>
> diff --git a/scripts/mod/modpost.c b/scripts/mod/modpost.c
> index ed9d056d2108..194ca9083c7a 100644
> --- a/scripts/mod/modpost.c
> +++ b/scripts/mod/modpost.c
> @@ -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;
> @@ -702,8 +689,6 @@ 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));
>
> switch (sym->st_shndx) {
> case SHN_COMMON:
> diff --git a/scripts/mod/modpost.h b/scripts/mod/modpost.h
> index 0c47ff95c0e2..a85dcec3669a 100644
> --- a/scripts/mod/modpost.h
> +++ b/scripts/mod/modpost.h
> @@ -25,7 +25,6 @@
> #define Elf_Sym Elf32_Sym
> #define Elf_Addr Elf32_Addr
> #define Elf_Sword Elf64_Sword
> -#define Elf_Section Elf32_Half
> #define ELF_ST_BIND ELF32_ST_BIND
> #define ELF_ST_TYPE ELF32_ST_TYPE
>
> @@ -40,7 +39,6 @@
> #define Elf_Sym Elf64_Sym
> #define Elf_Addr Elf64_Addr
> #define Elf_Sword Elf64_Sxword
> -#define Elf_Section Elf64_Half
> #define ELF_ST_BIND ELF64_ST_BIND
> #define ELF_ST_TYPE ELF64_ST_TYPE
>
> @@ -138,8 +136,6 @@ 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;
> --
> 2.32.0
>
--
Thanks,
~Nick Desaulniers
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH 2/2] modpost: move export_from_secname() call to more relevant place
2022-04-02 13:00 ` [PATCH 2/2] modpost: move export_from_secname() call to more relevant place Masahiro Yamada
@ 2022-04-04 17:03 ` Nick Desaulniers
0 siblings, 0 replies; 4+ messages in thread
From: Nick Desaulniers @ 2022-04-04 17:03 UTC (permalink / raw)
To: Masahiro Yamada; +Cc: linux-kbuild, linux-kernel, Michal Marek
On Sat, Apr 2, 2022 at 6:00 AM Masahiro Yamada <masahiroy@kernel.org> wrote:
>
> The value returned by export_from_secname() is only used by
> sym_add_exported().
>
> Move export_from_secname() just above sym_add_exported().
>
> Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Thanks for the patch!
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
> ---
>
> scripts/mod/modpost.c | 8 ++++----
> 1 file changed, 4 insertions(+), 4 deletions(-)
>
> diff --git a/scripts/mod/modpost.c b/scripts/mod/modpost.c
> index 194ca9083c7a..f9e54247ae1d 100644
> --- a/scripts/mod/modpost.c
> +++ b/scripts/mod/modpost.c
> @@ -684,12 +684,8 @@ static void handle_modversion(const struct module *mod,
> static void handle_symbol(struct module *mod, struct elf_info *info,
> const Elf_Sym *sym, const char *symname)
> {
> - enum export export;
> const char *name;
>
> - if (strstarts(symname, "__ksymtab"))
> - export = export_from_secname(info, get_secindex(info, sym));
> -
> switch (sym->st_shndx) {
> case SHN_COMMON:
> if (strstarts(symname, "__gnu_lto_")) {
> @@ -724,7 +720,11 @@ static void handle_symbol(struct module *mod, struct elf_info *info,
> default:
> /* All exported symbols */
> if (strstarts(symname, "__ksymtab_")) {
> + enum export export;
> +
> name = symname + strlen("__ksymtab_");
> + export = export_from_secname(info,
> + get_secindex(info, sym));
> sym_add_exported(name, mod, export);
> }
> if (strcmp(symname, "init_module") == 0)
> --
> 2.32.0
>
--
Thanks,
~Nick Desaulniers
^ permalink raw reply [flat|nested] 4+ messages in thread
end of thread, other threads:[~2022-04-04 21:23 UTC | newest]
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2022-04-02 13:00 [PATCH 1/2] modpost: remove useless export_from_sec() Masahiro Yamada
2022-04-02 13:00 ` [PATCH 2/2] modpost: move export_from_secname() call to more relevant place Masahiro Yamada
2022-04-04 17:03 ` Nick Desaulniers
2022-04-04 17:00 ` [PATCH 1/2] modpost: remove useless export_from_sec() Nick Desaulniers
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