sched_ext: Use offsetofend on both sides of the ops_cid layout assert

sizeof() includes trailing struct pad, offsetofend() doesn't. On 32-bit PPC, sched_ext_ops_cid tail-pads 4 bytes past @priv and the assert trips. Use offsetofend() on both sides.

Tejun Heo committed 6 months ago

Commit ca1d48a1 parent e18002d1 file · +4 −2Browse files

Showing the changes to kernel (1 of 1 file). Show all

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kernel/sched/ext.c+4−2

@@ -10380,9 +10380,11 @@ static int __init scx_init(void) · 10379 unmodified lines
10380	10380	/*
10381	10381	* cid-form must end exactly at @priv - validate_ops() skips
10382	10382	* cpu_acquire/cpu_release for cid-form because reading those fields
10383		− * past the BPF allocation would be UB.
	10383	+ * past the BPF allocation would be UB. offsetofend() on both sides
	10384	+ * instead of sizeof() on sched_ext_ops_cid to sidestep trailing
	10385	+ * struct padding (e.g. 32-bit PPC tail-pads ops_cid past @priv).
10384	10386	*/
10385		− BUILD_BUG_ON(sizeof(struct sched_ext_ops_cid) !=
	10387	+ BUILD_BUG_ON(offsetofend(struct sched_ext_ops_cid, priv) !=
10386	10388	offsetofend(struct sched_ext_ops, priv));
10387	10389	#undef CID_OFFSET_MATCH
10388	10390