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authorJosh Poimboeuf <jpoimboe@redhat.com>2017-02-13 19:42:39 -0600
committerJiri Kosina <jkosina@suse.cz>2017-03-08 09:24:04 +0100
commitf5e547f4ac785c65a39211f0b8e4ffc4fe09112d (patch)
tree8a4826c72030d35bfed306ac748463c25b536cd0
parent68ae4b2b687c3da59ca1d762646ddece4ea1c438 (diff)
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>
-rw-r--r--include/linux/livepatch.h3
-rw-r--r--kernel/livepatch/core.c16
2 files changed, 19 insertions, 0 deletions
diff --git a/include/linux/livepatch.h b/include/linux/livepatch.h
index 9787a63b57ac..6602b34bed2b 100644
--- a/include/linux/livepatch.h
+++ b/include/linux/livepatch.h
@@ -37,6 +37,8 @@
* @old_addr: the address of the function being patched
* @kobj: kobject for sysfs resources
* @stack_node: list node for klp_ops func_stack list
+ * @old_size: size of the old function
+ * @new_size: size of the new function
* @patched: the func has been added to the klp_ops list
*/
struct klp_func {
@@ -56,6 +58,7 @@ struct klp_func {
unsigned long old_addr;
struct kobject kobj;
struct list_head stack_node;
+ unsigned long old_size, new_size;
bool patched;
};
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;