[PATCH] Create kallsyms_lookup_size_offset()

Some uses of kallsyms_lookup() do not need to find out the name of a symbol
and its module's name it belongs.  This is specially true in arch specific
code, which needs to unwind the stack to show the back trace during oops
(mips is an example).  In this specific case, we just need to retreive the
function's size and the offset of the active intruction inside it.

Adds a new entry "kallsyms_lookup_size_offset()" This new entry does
exactly the same as kallsyms_lookup() but does not require any buffers to
store any names.

It returns 0 if it fails otherwise 1.

Signed-off-by: Franck Bui-Huu <vagabon.xyz@gmail.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 11 insertions, 0 deletions

diff --git a/include/linux/kallsyms.h b/include/linux/kallsyms.h
index 849043ce4ed6..1cebcbc28b47 100644
--- a/include/linux/kallsyms.h
+++ b/include/linux/kallsyms.h
@@ -12,6 +12,10 @@
 /* Lookup the address for a symbol. Returns 0 if not found. */
 unsigned long kallsyms_lookup_name(const char *name);
 
+extern int kallsyms_lookup_size_offset(unsigned long addr,
+                                  unsigned long *symbolsize,
+                                  unsigned long *offset);
+
 /* Lookup an address.  modname is set to NULL if it's in the kernel. */
 const char *kallsyms_lookup(unsigned long addr,
                             unsigned long *symbolsize,
@@ -28,6 +32,13 @@ static inline unsigned long kallsyms_lookup_name(const char *name)
         return 0;
 }
 
+static inline int kallsyms_lookup_size_offset(unsigned long addr,
+                                              unsigned long *symbolsize,
+                                              unsigned long *offset)
+{
+        return 0;
+}
+
 static inline const char *kallsyms_lookup(unsigned long addr,
                                           unsigned long *symbolsize,
                                           unsigned long *offset,