mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
synced 2026-07-23 16:47:49 -04:00
abdc2516f1
ops_cid.set_cmask() expects a cmask. The kernel couldn't write into the arena, so it translated cpumask -> cmask in kernel memory and passed the result as a trusted pointer. The BPF cmask helpers all operate on arena cmasks though, so the BPF side had to word-by-word probe-read the kernel cmask into an arena cmask via cmask_copy_from_kernel() before any helper could touch it. It works, but is clumsy. With direct kernel-side arena access now in place, build the cmask in the arena. The kernel writes to it through the kern_va side of the dual mapping. BPF directly dereferences it via an __arena pointer like any other arena struct. Signed-off-by: Tejun Heo <tj@kernel.org> Reviewed-by: Emil Tsalapatis <emil@etsalapatis.com>