livepatch: add sympos as disambiguator field to klp_reloc

In cases of duplicate symbols, sympos will be used to disambiguate instead
of val. By default sympos will be 0, and patching will only succeed if
the symbol is unique. Specifying a positive value will ensure that
occurrence of the symbol in kallsyms for the patched object will be used
for patching if it is valid. For external relocations sympos is not
supported.

Remove klp_verify_callback, klp_verify_args and klp_verify_vmlinux_symbol
as they are no longer used.

From the klp_reloc structure remove val, as it can be refactored as a
local variable in klp_write_object_relocations.

Signed-off-by: Chris J Arges <chris.j.arges@canonical.com>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Acked-by: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>

1 files changed, 2 insertions, 3 deletions

diff --git a/include/linux/livepatch.h b/include/linux/livepatch.h
index b60e8abab0ab..a8828652f794 100644
--- a/include/linux/livepatch.h
+++ b/include/linux/livepatch.h
@@ -67,8 +67,7 @@ struct klp_func {
 /**
  * struct klp_reloc - relocation structure for live patching
  * @loc:        address where the relocation will be written
- * @val:        address of the referenced symbol (optional,
- *              vmlinux patches only)
+ * @sympos:     position in kallsyms to disambiguate symbols (optional)
  * @type:       ELF relocation type
  * @name:       name of the referenced symbol (for lookup/verification)
  * @addend:     offset from the referenced symbol
@@ -76,7 +75,7 @@ struct klp_func {
  */
 struct klp_reloc {
         unsigned long loc;
-        unsigned long val;
+        unsigned long sympos;
         unsigned long type;
         const char *name;
         int addend;