Update livepatch shadow variable documentation with respect to new atomic replace / cumulative patch functionality. Signed-off-by: Joe Lawrence <joe.lawrence@xxxxxxxxxx> --- Documentation/livepatch/shadow-vars.txt | 24 ++++++++++++++++++++++++ 1 file changed, 24 insertions(+) diff --git a/Documentation/livepatch/shadow-vars.txt b/Documentation/livepatch/shadow-vars.txt index 89c66634d600..9a2754cf551c 100644 --- a/Documentation/livepatch/shadow-vars.txt +++ b/Documentation/livepatch/shadow-vars.txt @@ -179,6 +179,30 @@ doesn't matter what data value the shadow variable holds, its existence suggests how to handle the parent object. +Use in cumulative patches +------------------------- + +Cumulative livepatches provide a "one-stop" module containing all active +livepatch code. A cumulative patch disables and replaces any previously +loaded livepatch. Shadow variable lifetimes should be carefully +considered when loading cumulative livepatches: + +- If shadow variables lifetimes are specific to livepatch module + versions, it may make sense to free them when the corresponding + livepatch module is unloaded. + +- If shadow variable instances may be safely handled across cumulative + livepatch module versions, then it may make sense to free them from + unpatch callbacks. When a cumulative patch replaces an existing + livepatch, only the cumulative patch's callbacks will be executed. + This means that new cumulative livepatches may be loaded while + deprecated / disabled livepatches may be unloaded without clearing + existing shadow variables. + +See Documentation/livepatch/callbacks.txt and cumulative.txt for more +information on these subjects. + + 3. References ============= -- 1.8.3.1 -- To unsubscribe from this list: send the line "unsubscribe live-patching" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
