Simplify kallsyms_lookup()

Several kallsyms_lookup() pass dummy arguments but only need, say, module's
name.  Make kallsyms_lookup() accept NULLs where possible.

Also, makes picture clearer about what interfaces are needed for all symbol
resolving business.

Signed-off-by: Alexey Dobriyan <adobriyan@sw.ru>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Acked-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 4 insertions, 2 deletions

diff --git a/kernel/kallsyms.c b/kernel/kallsyms.c
index f1ea6f66ac6c..f66da025cb7f 100644
--- a/kernel/kallsyms.c
+++ b/kernel/kallsyms.c
@@ -214,8 +214,10 @@ static unsigned long get_symbol_pos(unsigned long addr,
                         symbol_end = (unsigned long)_etext;
         }
 
-        *symbolsize = symbol_end - symbol_start;
-        *offset = addr - symbol_start;
+        if (symbolsize)
+                *symbolsize = symbol_end - symbol_start;
+        if (offset)
+                *offset = addr - symbol_start;
 
         return low;
 }