livepatch: store function sizes

For the consistency model we'll need to know the sizes of the old and
new functions to determine if they're on the stacks of any tasks.

Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Acked-by: Miroslav Benes <mbenes@suse.cz>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Reviewed-by: Kamalesh Babulal <kamalesh@linux.vnet.ibm.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>

1 files changed, 16 insertions, 0 deletions

diff --git a/kernel/livepatch/core.c b/kernel/livepatch/core.c
index 83c4949862b4..10ba3a1578bd 100644
--- a/kernel/livepatch/core.c
+++ b/kernel/livepatch/core.c
@@ -584,6 +584,22 @@ static int klp_init_object_loaded(struct klp_patch *patch,
                                              &func->old_addr);
                 if (ret)
                         return ret;
+
+                ret = kallsyms_lookup_size_offset(func->old_addr,
+                                                  &func->old_size, NULL);
+                if (!ret) {
+                        pr_err("kallsyms size lookup failed for '%s'\n",
+                               func->old_name);
+                        return -ENOENT;
+                }
+
+                ret = kallsyms_lookup_size_offset((unsigned long)func->new_func,
+                                                  &func->new_size, NULL);
+                if (!ret) {
+                        pr_err("kallsyms size lookup failed for '%s' replacement\n",
+                               func->old_name);
+                        return -ENOENT;
+                }
         }
 
         return 0;