perf/uprobe: Convert single-step and uretprobe to SRCU
Both single-step and uretprobes take a refcount on struct uprobe in
handle_swbp() in order to ensure struct uprobe stays extant until a
next trap.
Since uprobe_unregister() only cares about the uprobe_consumer
life-time, and these intra-trap sections can be arbitrarily large,
create a second SRCU domain to cover these.
Notably, a uretprobe with a registered return_instance that never
triggers -- because userspace -- will currently pin the
return_instance and related uprobe until the task dies. With this
convertion to SRCU this behaviour will inhibit freeing of all uprobes.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
2 files changed
