Make most arch asm/module.h files use asm-generic/module.h

Use the mapping of Elf_[SPE]hdr, Elf_Addr, Elf_Sym, Elf_Dyn, Elf_Rel/Rela,
ELF_R_TYPE() and ELF_R_SYM() to either the 32-bit version or the 64-bit version
into asm-generic/module.h for all arches bar MIPS.

Also, use the generic definition mod_arch_specific where possible.

To this end, I've defined three new config bools:

 (*) HAVE_MOD_ARCH_SPECIFIC

     Arches define this if they don't want to use the empty generic
     mod_arch_specific struct.

 (*) MODULES_USE_ELF_RELA

     Arches define this if their modules can contain RELA records.  This causes
     the Elf_Rela mapping to be emitted and allows apply_relocate_add() to be
     defined by the arch rather than have the core emit an error message.

 (*) MODULES_USE_ELF_REL

     Arches define this if their modules can contain REL records.  This causes
     the Elf_Rel mapping to be emitted and allows apply_relocate() to be
     defined by the arch rather than have the core emit an error message.

Note that it is possible to allow both REL and RELA records: m68k and mips are
two arches that do this.

With this, some arch asm/module.h files can be deleted entirely and replaced
with a generic-y marker in the arch Kbuild file.

Additionally, I have removed the bits from m32r and score that handle the
unsupported type of relocation record as that's now handled centrally.

Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

2 files changed, 65 insertions, 11 deletions

diff --git a/include/asm-generic/module.h b/include/asm-generic/module.h
index ed5b44de4c91..14dc41d185a7 100644
--- a/include/asm-generic/module.h
+++ b/include/asm-generic/module.h
@@ -5,18 +5,44 @@
  * Many architectures just need a simple module
  * loader without arch specific data.
  */
+#ifndef CONFIG_HAVE_MOD_ARCH_SPECIFIC
 struct mod_arch_specific
 {
 };
+#endif
 
 #ifdef CONFIG_64BIT
-#define Elf_Shdr Elf64_Shdr
-#define Elf_Sym Elf64_Sym
-#define Elf_Ehdr Elf64_Ehdr
-#else
-#define Elf_Shdr Elf32_Shdr
-#define Elf_Sym Elf32_Sym
-#define Elf_Ehdr Elf32_Ehdr
+#define Elf_Shdr	Elf64_Shdr
+#define Elf_Phdr	Elf64_Phdr
+#define Elf_Sym		Elf64_Sym
+#define Elf_Dyn		Elf64_Dyn
+#define Elf_Ehdr	Elf64_Ehdr
+#define Elf_Addr	Elf64_Addr
+#ifdef CONFIG_MODULES_USE_ELF_REL
+#define Elf_Rel		Elf64_Rel
+#endif
+#ifdef CONFIG_MODULES_USE_ELF_RELA
+#define Elf_Rela	Elf64_Rela
+#endif
+#define ELF_R_TYPE(X)	ELF64_R_TYPE(X)
+#define ELF_R_SYM(X)	ELF64_R_SYM(X)
+
+#else /* CONFIG_64BIT */
+
+#define Elf_Shdr	Elf32_Shdr
+#define Elf_Phdr	Elf32_Phdr
+#define Elf_Sym		Elf32_Sym
+#define Elf_Dyn		Elf32_Dyn
+#define Elf_Ehdr	Elf32_Ehdr
+#define Elf_Addr	Elf32_Addr
+#ifdef CONFIG_MODULES_USE_ELF_REL
+#define Elf_Rel		Elf32_Rel
+#endif
+#ifdef CONFIG_MODULES_USE_ELF_RELA
+#define Elf_Rela	Elf32_Rela
+#endif
+#define ELF_R_TYPE(X)	ELF32_R_TYPE(X)
+#define ELF_R_SYM(X)	ELF32_R_SYM(X)
 #endif
 
 #endif /* __ASM_GENERIC_MODULE_H */
diff --git a/include/linux/moduleloader.h b/include/linux/moduleloader.h
index b2be02ebf453..560ca53a75fa 100644
--- a/include/linux/moduleloader.h
+++ b/include/linux/moduleloader.h
@@ -28,21 +28,49 @@ void *module_alloc(unsigned long size);
 /* Free memory returned from module_alloc. */
 void module_free(struct module *mod, void *module_region);
 
-/* Apply the given relocation to the (simplified) ELF.  Return -error
-   or 0. */
+/*
+ * Apply the given relocation to the (simplified) ELF.  Return -error
+ * or 0.
+ */
+#ifdef CONFIG_MODULES_USE_ELF_REL
 int apply_relocate(Elf_Shdr *sechdrs,
 		   const char *strtab,
 		   unsigned int symindex,
 		   unsigned int relsec,
 		   struct module *mod);
+#else
+static inline int apply_relocate(Elf_Shdr *sechdrs,
+				 const char *strtab,
+				 unsigned int symindex,
+				 unsigned int relsec,
+				 struct module *me)
+{
+	printk(KERN_ERR "module %s: REL relocation unsupported\n", me->name);
+	return -ENOEXEC;
+}
+#endif
 
-/* Apply the given add relocation to the (simplified) ELF.  Return
-   -error or 0 */
+/*
+ * Apply the given add relocation to the (simplified) ELF.  Return
+ * -error or 0
+ */
+#ifdef CONFIG_MODULES_USE_ELF_RELA
 int apply_relocate_add(Elf_Shdr *sechdrs,
 		       const char *strtab,
 		       unsigned int symindex,
 		       unsigned int relsec,
 		       struct module *mod);
+#else
+static inline int apply_relocate_add(Elf_Shdr *sechdrs,
+				     const char *strtab,
+				     unsigned int symindex,
+				     unsigned int relsec,
+				     struct module *me)
+{
+	printk(KERN_ERR "module %s: REL relocation unsupported\n", me->name);
+	return -ENOEXEC;
+}
+#endif
 
 /* Any final processing of module before access.  Return -error or 0. */
 int module_finalize(const Elf_Ehdr *hdr,