On Mon Jul 6, 2026 at 7:19 AM BST, Byungchul Park wrote:
wait_for_completion() can be used at various points in the code and it's very hard to distinguish wait_for_completion()s between different usages. Using a single dept_key for all the wait_for_completion()s could trigger false positive reports.
Assign unique dept_key to each distinct wait_for_completion() caller to avoid false positive reports.
While at it, add a rust helper for wait_for_completion() to avoid build errors.
This will cause Rust code to share the same dept_key, so it will have all the false positives that the change is trying to avoid.
In general it is easy to create Rust bindings for static inline C functions because it'll be just some computation, while creating bindings for C function-like macros that define additional statics can be challenging.
Is dept_key similar to lock_class_key, where only the address matters? If so, the approach that I use in https://lore.kernel.org/rust-for-linux/DJP0CDOR98N5.29BK8PUFRWRUK@garyguo.ne... could be used for dept_key as well, then we can keep Rust `wait_for_completion` still a function; otherwise we have to turn it into a macro too on the Rust side to create such statics, which isn't ideal.
Best, Gary
Signed-off-by: Byungchul Park byungchul@sk.com
include/linux/completion.h | 100 +++++++++++++++++++++++++++++++------ kernel/sched/completion.c | 60 +++++++++++----------- rust/helpers/completion.c | 5 ++ 3 files changed, 120 insertions(+), 45 deletions(-)