sched_ext: Convert sub-cap kfuncs to __arena cmask arguments

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The sub-cap kfuncs take their cmask arguments as __ign pointers. The values
cross the kfunc boundary as unchecked scalars and scx_cmask_ref_init()
rebases them into the arena by hand.

BPF now translates between BPF and kernel arena addresses for __arena
arguments. Tag the cmask arguments __arena so the kfuncs receive kernel
addresses and scx_cmask_ref_init() loses the hand-rolled conversion. The
optional denied_out keeps its NULL not-provided signal via
__arena__nullable. The mandatory masks use plain __arena.

scx_qmap's call sites drop the (void *)(long) casts since the BPF-side
declarations type the cmask arguments __arena and take arena pointers
directly.

The arena argument address translation is currently implemented only on
x86-64. Schedulers calling these kfuncs load only there for now.

Signed-off-by: Tejun Heo <tj@kernel.org>

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This commit is contained in:

Tejun Heo 2026-08-12 09:55:33 -10:00

parent 67f1f4a48c

commit a8dc810968

6 changed files with 51 additions and 54 deletions

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11

kernel/sched/ext/cid.c

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8

kernel/sched/ext/ext.c

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49

kernel/sched/ext/sub.c

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6

kernel/sched/ext/types.h

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11

tools/sched_ext/include/scx/common.bpf.h

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20

tools/sched_ext/scx_qmap.bpf.c

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