summaryrefslogtreecommitdiff
path: root/include/linux/livepatch.h
diff options
context:
space:
mode:
authorJoe Lawrence <joe.lawrence@redhat.com>2017-10-13 22:08:41 +0300
committerJiri Kosina <jkosina@suse.cz>2017-10-19 11:08:56 +0300
commit93862e385ded7c60351e09fcd2a541d273650905 (patch)
tree22dc512303e988d00e327fa05c884e542fb5af55 /include/linux/livepatch.h
parent19205da6a0da701787d42ad754edd1ffb514c956 (diff)
downloadlinux-93862e385ded7c60351e09fcd2a541d273650905.tar.xz
livepatch: add (un)patch callbacks
Provide livepatch modules a klp_object (un)patching notification mechanism. Pre and post-(un)patch callbacks allow livepatch modules to setup or synchronize changes that would be difficult to support in only patched-or-unpatched code contexts. Callbacks can be registered for target module or vmlinux klp_objects, but each implementation is klp_object specific. - Pre-(un)patch callbacks run before any (un)patching transition starts. - Post-(un)patch callbacks run once an object has been (un)patched and the klp_patch fully transitioned to its target state. Example use cases include modification of global data and registration of newly available services/handlers. See Documentation/livepatch/callbacks.txt for details and samples/livepatch/ for examples. Signed-off-by: Joe Lawrence <joe.lawrence@redhat.com> Acked-by: Josh Poimboeuf <jpoimboe@redhat.com> Acked-by: Miroslav Benes <mbenes@suse.cz> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
Diffstat (limited to 'include/linux/livepatch.h')
-rw-r--r--include/linux/livepatch.h26
1 files changed, 26 insertions, 0 deletions
diff --git a/include/linux/livepatch.h b/include/linux/livepatch.h
index d08eddc00497..fc5c1be3f6f4 100644
--- a/include/linux/livepatch.h
+++ b/include/linux/livepatch.h
@@ -87,10 +87,35 @@ struct klp_func {
bool transition;
};
+struct klp_object;
+
+/**
+ * struct klp_callbacks - pre/post live-(un)patch callback structure
+ * @pre_patch: executed before code patching
+ * @post_patch: executed after code patching
+ * @pre_unpatch: executed before code unpatching
+ * @post_unpatch: executed after code unpatching
+ * @post_unpatch_enabled: flag indicating if post-unpatch callback
+ * should run
+ *
+ * All callbacks are optional. Only the pre-patch callback, if provided,
+ * will be unconditionally executed. If the parent klp_object fails to
+ * patch for any reason, including a non-zero error status returned from
+ * the pre-patch callback, no further callbacks will be executed.
+ */
+struct klp_callbacks {
+ int (*pre_patch)(struct klp_object *obj);
+ void (*post_patch)(struct klp_object *obj);
+ void (*pre_unpatch)(struct klp_object *obj);
+ void (*post_unpatch)(struct klp_object *obj);
+ bool post_unpatch_enabled;
+};
+
/**
* struct klp_object - kernel object structure for live patching
* @name: module name (or NULL for vmlinux)
* @funcs: function entries for functions to be patched in the object
+ * @callbacks: functions to be executed pre/post (un)patching
* @kobj: kobject for sysfs resources
* @mod: kernel module associated with the patched object
* (NULL for vmlinux)
@@ -100,6 +125,7 @@ struct klp_object {
/* external */
const char *name;
struct klp_func *funcs;
+ struct klp_callbacks callbacks;
/* internal */
struct kobject kobj;