[PATCH] kbuild: check SHT_REL sections

I found that modpost can not detect section mismatch on mips and i386.  On
mips64, the modpost (with r_info layout fix) can detect it.  The current
modpst only checks SHT_RELA section but I suppose SHT_REL section should be
checked also.  This patch does not contain r_info layout fix.  I'll post an
updated r_info layout fix on next mail.

Check SHT_REL sections as like as SHT_RELA sections to detect section
mismatch.

Signed-off-by: Atsushi Nemoto <anemo@mba.ocn.ne.jp>
Cc: Sam Ravnborg <sam@ravnborg.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

2 files changed, 48 insertions, 19 deletions

diff --git a/scripts/mod/modpost.c b/scripts/mod/modpost.c
index 6d04504b2fc1..1aa52a86c2cf 100644
--- a/scripts/mod/modpost.c
+++ b/scripts/mod/modpost.c
@@ -697,29 +697,56 @@ static void check_sec_ref(struct module *mod, const char *modname,
 
         /* Walk through all sections */
         for (i = 0; i < hdr->e_shnum; i++) {
-                Elf_Rela *rela;
-                Elf_Rela *start = (void *)hdr + sechdrs[i].sh_offset;
-                Elf_Rela *stop  = (void*)start + sechdrs[i].sh_size;
-                const char *name = secstrings + sechdrs[i].sh_name +
-                                                strlen(".rela");
+                const char *name = secstrings + sechdrs[i].sh_name;
+                const char *secname;
+                Elf_Rela r;
                 /* We want to process only relocation sections and not .init */
-                if (section_ref_ok(name) || (sechdrs[i].sh_type != SHT_RELA))
-                        continue;
+                if (sechdrs[i].sh_type == SHT_RELA) {
+                        Elf_Rela *rela;
+                        Elf_Rela *start = (void *)hdr + sechdrs[i].sh_offset;
+                        Elf_Rela *stop  = (void*)start + sechdrs[i].sh_size;
+                        name += strlen(".rela");
+                        if (section_ref_ok(name))
+                                continue;
 
-                for (rela = start; rela < stop; rela++) {
-                        Elf_Rela r;
-                        const char *secname;
-                        r.r_offset = TO_NATIVE(rela->r_offset);
-                        r.r_info   = TO_NATIVE(rela->r_info);
-                        r.r_addend = TO_NATIVE(rela->r_addend);
-                        sym = elf->symtab_start + ELF_R_SYM(r.r_info);
-                        /* Skip special sections */
-                        if (sym->st_shndx >= SHN_LORESERVE)
+                        for (rela = start; rela < stop; rela++) {
+                                r.r_offset = TO_NATIVE(rela->r_offset);
+                                r.r_info   = TO_NATIVE(rela->r_info);
+                                r.r_addend = TO_NATIVE(rela->r_addend);
+                                sym = elf->symtab_start + ELF_R_SYM(r.r_info);
+                                /* Skip special sections */
+                                if (sym->st_shndx >= SHN_LORESERVE)
+                                        continue;
+
+                                secname = secstrings +
+                                        sechdrs[sym->st_shndx].sh_name;
+                                if (section(secname))
+                                        warn_sec_mismatch(modname, name,
+                                                          elf, sym, r);
+                        }
+                } else if (sechdrs[i].sh_type == SHT_REL) {
+                        Elf_Rel *rel;
+                        Elf_Rel *start = (void *)hdr + sechdrs[i].sh_offset;
+                        Elf_Rel *stop  = (void*)start + sechdrs[i].sh_size;
+                        name += strlen(".rel");
+                        if (section_ref_ok(name))
                                 continue;
 
-                        secname = secstrings + sechdrs[sym->st_shndx].sh_name;
-                        if (section(secname))
-                                warn_sec_mismatch(modname, name, elf, sym, r);
+                        for (rel = start; rel < stop; rel++) {
+                                r.r_offset = TO_NATIVE(rel->r_offset);
+                                r.r_info   = TO_NATIVE(rel->r_info);
+                                r.r_addend = 0;
+                                sym = elf->symtab_start + ELF_R_SYM(r.r_info);
+                                /* Skip special sections */
+                                if (sym->st_shndx >= SHN_LORESERVE)
+                                        continue;
+
+                                secname = secstrings +
+                                        sechdrs[sym->st_shndx].sh_name;
+                                if (section(secname))
+                                        warn_sec_mismatch(modname, name,
+                                                          elf, sym, r);
+                        }
                 }
         }
 }
diff --git a/scripts/mod/modpost.h b/scripts/mod/modpost.h
index b14255c72a37..086fa466504c 100644
--- a/scripts/mod/modpost.h
+++ b/scripts/mod/modpost.h
@@ -21,6 +21,7 @@
 #define ELF_ST_BIND ELF32_ST_BIND
 #define ELF_ST_TYPE ELF32_ST_TYPE
 
+#define Elf_Rel     Elf32_Rel
 #define Elf_Rela    Elf32_Rela
 #define ELF_R_SYM   ELF32_R_SYM
 #define ELF_R_TYPE  ELF32_R_TYPE
@@ -34,6 +35,7 @@
 #define ELF_ST_BIND ELF64_ST_BIND
 #define ELF_ST_TYPE ELF64_ST_TYPE
 
+#define Elf_Rel     Elf64_Rel
 #define Elf_Rela    Elf64_Rela
 #define ELF_R_SYM   ELF64_R_SYM
 #define ELF_R_TYPE  ELF64_R_TYPE