sched_ext: Forbid cpu-form kfuncs from cid-form schedulers

Browse source

cid and cpu are both small s32s, trivially confused when a cid-form
scheduler calls a cpu-keyed kfunc. Reject cid-form programs that
reference any kfunc in the new scx_kfunc_ids_cpu_only at verifier load
time.

The reverse direction is intentionally permissive: cpu-form schedulers
can freely call cid-form kfuncs to ease a gradual cpumask -> cid
migration.

The check sits in scx_kfunc_context_filter() right after the SCX
struct_ops gate and before the any/idle allow and per-op allow-list
checks, so it catches cpu-only kfuncs regardless of which set they
belong to (any, idle, or select_cpu).

v2: Sync per-entry kfunc flags with their primary declarations (Zhao).
    pahole intersects flags across BTF_ID_FLAGS() occurrences, so
    omitting them drops the flags globally.

Signed-off-by: Tejun Heo <tj@kernel.org>
Reviewed-by: Cheng-Yang Chou <yphbchou0911@gmail.com>
Reviewed-by: Zhao Mengmeng <zhaomengmeng@kylinos.cn>
Reviewed-by: Changwoo Min <changwoo@igalia.com>
Reviewed-by: Andrea Righi <arighi@nvidia.com>

...

This commit is contained in:

Tejun Heo 2026-04-29 08:09:11 -10:00

parent 7e655ed7b9

commit 67edfa9eef

1 changed files with 51 additions and 0 deletions

Show all changes Ignore whitespace when comparing lines Ignore changes in amount of whitespace Ignore changes in whitespace at EOL

Download patch file Download diff file Expand all files Collapse all files

51

kernel/sched/ext.c

View file