Re: [PATCH v6 07/20] modpost: replace r->r_offset, r->r_addend with faddr, taddr
From: Nick Desaulniers
Date: Mon May 22 2023 - 14:31:51 EST
On Sun, May 21, 2023 at 9:05 AM Masahiro Yamada <masahiroy@xxxxxxxxxx> wrote:
>
> r_offset/r_addend holds the offset address from/to which a symbol is
> referenced. It is unclear unless you are familiar with ELF.
>
> Rename them to faddr, taddr, respectively. The prefix 'f' means 'from',
> 't' means 'to'.
>
> Signed-off-by: Masahiro Yamada <masahiroy@xxxxxxxxxx>
Do you care to rewrap the parameter lists?
```
diff --git a/scripts/mod/modpost.c b/scripts/mod/modpost.c
index 4da96746a03b..8a787521963d 100644
--- a/scripts/mod/modpost.c
+++ b/scripts/mod/modpost.c
@@ -1115,8 +1115,8 @@ static bool is_executable_section(struct
elf_info *elf, unsigned int secndx)
static void default_mismatch_handler(const char *modname, struct elf_info *elf,
const struct sectioncheck* const mismatch,
- Elf_Sym *tsym,
- unsigned int fsecndx, const char
*fromsec, Elf_Addr faddr,
+ Elf_Sym *tsym, unsigned int fsecndx,
+ const char *fromsec, Elf_Addr faddr,
const char *tosec, Elf_Addr taddr)
{
Elf_Sym *from;
@@ -1217,9 +1217,9 @@ static void check_export_symbol(struct module
*mod, struct elf_info *elf,
}
static void check_section_mismatch(struct module *mod, struct elf_info *elf,
- Elf_Sym *sym,
- unsigned int fsecndx, const char *fromsec,
- Elf_Addr faddr, Elf_Addr taddr)
+ Elf_Sym *sym, unsigned int fsecndx,
+ const char *fromsec, Elf_Addr faddr,
+ Elf_Addr taddr)
{
const char *tosec = sec_name(elf, get_secindex(elf, sym));
const struct sectioncheck *mismatch;
```
Either way:
Reviewed-by: Nick Desaulniers <ndesaulniers@xxxxxxxxxx>
> ---
>
> scripts/mod/modpost.c | 34 +++++++++++++++++++---------------
> 1 file changed, 19 insertions(+), 15 deletions(-)
>
> diff --git a/scripts/mod/modpost.c b/scripts/mod/modpost.c
> index 7848bacd4b42..f364738a236e 100644
> --- a/scripts/mod/modpost.c
> +++ b/scripts/mod/modpost.c
> @@ -1166,18 +1166,18 @@ static bool is_executable_section(struct elf_info *elf, unsigned int secndx)
>
> static void default_mismatch_handler(const char *modname, struct elf_info *elf,
> const struct sectioncheck* const mismatch,
> - Elf_Rela *r, Elf_Sym *tsym,
> - unsigned int fsecndx, const char *fromsec,
> - const char *tosec)
> + Elf_Sym *tsym,
> + unsigned int fsecndx, const char *fromsec, Elf_Addr faddr,
> + const char *tosec, Elf_Addr taddr)
> {
> Elf_Sym *from;
> const char *tosym;
> const char *fromsym;
>
> - from = find_fromsym(elf, r->r_offset, fsecndx);
> + from = find_fromsym(elf, faddr, fsecndx);
> fromsym = sym_name(elf, from);
>
> - tsym = find_tosym(elf, r->r_addend, tsym);
> + tsym = find_tosym(elf, taddr, tsym);
> tosym = sym_name(elf, tsym);
>
> /* check whitelist - we may ignore it */
> @@ -1204,7 +1204,7 @@ static void default_mismatch_handler(const char *modname, struct elf_info *elf,
> break;
> case EXTABLE_TO_NON_TEXT:
> warn("%s(%s+0x%lx): Section mismatch in reference to the %s:%s\n",
> - modname, fromsec, (long)r->r_offset, tosec, tosym);
> + modname, fromsec, (long)faddr, tosec, tosym);
>
> if (match(tosec, mismatch->bad_tosec))
> fatal("The relocation at %s+0x%lx references\n"
> @@ -1212,7 +1212,7 @@ static void default_mismatch_handler(const char *modname, struct elf_info *elf,
> "Something is seriously wrong and should be fixed.\n"
> "You might get more information about where this is\n"
> "coming from by using scripts/check_extable.sh %s\n",
> - fromsec, (long)r->r_offset, tosec, modname);
> + fromsec, (long)faddr, tosec, modname);
> else if (is_executable_section(elf, get_secindex(elf, tsym)))
> warn("The relocation at %s+0x%lx references\n"
> "section \"%s\" which is not in the list of\n"
> @@ -1221,17 +1221,18 @@ static void default_mismatch_handler(const char *modname, struct elf_info *elf,
> "list of authorized sections to jump to on fault.\n"
> "This can be achieved by adding \"%s\" to\n"
> "OTHER_TEXT_SECTIONS in scripts/mod/modpost.c.\n",
> - fromsec, (long)r->r_offset, tosec, tosec, tosec);
> + fromsec, (long)faddr, tosec, tosec, tosec);
> else
> error("%s+0x%lx references non-executable section '%s'\n",
> - fromsec, (long)r->r_offset, tosec);
> + fromsec, (long)faddr, tosec);
> break;
> }
> }
>
> static void check_section_mismatch(const char *modname, struct elf_info *elf,
> - Elf_Rela *r, Elf_Sym *sym,
> - unsigned int fsecndx, const char *fromsec)
> + Elf_Sym *sym,
> + unsigned int fsecndx, const char *fromsec,
> + Elf_Addr faddr, Elf_Addr taddr)
> {
> const char *tosec = sec_name(elf, get_secindex(elf, sym));
> const struct sectioncheck *mismatch = section_mismatch(fromsec, tosec);
> @@ -1239,8 +1240,9 @@ static void check_section_mismatch(const char *modname, struct elf_info *elf,
> if (!mismatch)
> return;
>
> - default_mismatch_handler(modname, elf, mismatch, r, sym, fsecndx, fromsec,
> - tosec);
> + default_mismatch_handler(modname, elf, mismatch, sym,
> + fsecndx, fromsec, faddr,
> + tosec, taddr);
> }
>
> static unsigned int *reloc_location(struct elf_info *elf,
> @@ -1406,7 +1408,8 @@ static void section_rela(const char *modname, struct elf_info *elf,
> /* Skip special sections */
> if (is_shndx_special(sym->st_shndx))
> continue;
> - check_section_mismatch(modname, elf, &r, sym, fsecndx, fromsec);
> + check_section_mismatch(modname, elf, sym,
> + fsecndx, fromsec, r.r_offset, r.r_addend);
> }
> }
>
> @@ -1464,7 +1467,8 @@ static void section_rel(const char *modname, struct elf_info *elf,
> /* Skip special sections */
> if (is_shndx_special(sym->st_shndx))
> continue;
> - check_section_mismatch(modname, elf, &r, sym, fsecndx, fromsec);
> + check_section_mismatch(modname, elf, sym,
> + fsecndx, fromsec, r.r_offset, r.r_addend);
> }
> }
>
> --
> 2.39.2
>
--
Thanks,
~Nick Desaulniers