module: fix up CONFIG_KALLSYMS=n build.

Starting from commit 4a49622 "reduce
symbol table for loaded modules (v2)", the kernel/module.c build is broken
with CONFIG_KALLSYMS disabled.

  CC      kernel/module.o
kernel/module.c:1995: warning: type defaults to 'int' in declaration of 'Elf_Hdr'
kernel/module.c:1995: error: expected ';', ',' or ')' before '*' token
kernel/module.c: In function 'load_module':
kernel/module.c:2203: error: 'strmap' undeclared (first use in this function)
kernel/module.c:2203: error: (Each undeclared identifier is reported only once
kernel/module.c:2203: error: for each function it appears in.)
kernel/module.c:2239: error: 'symoffs' undeclared (first use in this function)
kernel/module.c:2239: error: implicit declaration of function 'layout_symtab'
kernel/module.c:2240: error: 'stroffs' undeclared (first use in this function)
make[1]: *** [kernel/module.o] Error 1
make: *** [kernel/module.o] Error 2

There are three different issues:

    - layout_symtab() takes a const Elf_Ehdr

    - layout_symtab() needs to return a value

    - symoffs/stroffs/strmap are referenced by the load_module() code
      despite being ifdefed out, which seems unnecessary given the noop
      behaviour of layout_symtab()/add_kallsyms() in the case of
      CONFIG_KALLSYMS=n.

Signed-off-by: Paul Mundt <[email protected]>
Acked-by: Jan Beulich <[email protected]>
Acked-by: Rusty Russell <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

kernel/module.c

@@ -1992,12 +1992,14 @@ static inline unsigned long layout_symtab(struct module *mod,
 					  Elf_Shdr *sechdrs,
 					  unsigned int symindex,
 					  unsigned int strindex,
-					  const Elf_Hdr *hdr,
+					  const Elf_Ehdr *hdr,
 					  const char *secstrings,
 					  unsigned long *pstroffs,
 					  unsigned long *strmap)
 {
+	return 0;
 }
+
 static inline void add_kallsyms(struct module *mod,
 				Elf_Shdr *sechdrs,
 				unsigned int shnum,
@@ -2081,9 +2083,8 @@ static noinline struct module *load_module(void __user *umod,
 	struct module *mod;
 	long err = 0;
 	void *percpu = NULL, *ptr = NULL; /* Stops spurious gcc warning */
-#ifdef CONFIG_KALLSYMS
 	unsigned long symoffs, stroffs, *strmap;
-#endif
+
 	mm_segment_t old_fs;
 
 	DEBUGP("load_module: umod=%p, len=%lu, uargs=%p\n",