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author | Joe Lawrence <joe.lawrence@redhat.com> | 2017-10-13 15:08:41 -0400 |
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committer | Jiri Kosina <jkosina@suse.cz> | 2017-10-19 10:08:56 +0200 |
commit | 93862e385ded7c60351e09fcd2a541d273650905 (patch) | |
tree | 22dc512303e988d00e327fa05c884e542fb5af55 /include | |
parent | 19205da6a0da701787d42ad754edd1ffb514c956 (diff) | |
download | linux-93862e385ded7c60351e09fcd2a541d273650905.tar.gz linux-93862e385ded7c60351e09fcd2a541d273650905.tar.bz2 linux-93862e385ded7c60351e09fcd2a541d273650905.zip |
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')
-rw-r--r-- | include/linux/livepatch.h | 26 |
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; |