Add a helper kfunc that sets the bitmap of a bpf_cpumask from BPF
memory.
Signed-off-by: Emil Tsalapatis (Meta) <emil@xxxxxxxxxxxxxxx>
---
kernel/bpf/cpumask.c | 21 +++++++++++++++++++++
1 file changed, 21 insertions(+)
diff --git a/kernel/bpf/cpumask.c b/kernel/bpf/cpumask.c
index cfa1c18e3a48..a13839b3595f 100644
--- a/kernel/bpf/cpumask.c
+++ b/kernel/bpf/cpumask.c
@@ -420,6 +420,26 @@ __bpf_kfunc u32 bpf_cpumask_weight(const struct cpumask *cpumask)
return cpumask_weight(cpumask);
}
+/**
+ * bpf_cpumask_fill() - Populate the CPU mask from the contents of
+ * a BPF memory region.
+ *
+ * @cpumask: The cpumask being populated.
+ * @src: The BPF memory holding the bit pattern.
+ * @src__sz: Length of the BPF memory region in bytes.
+ *
+ */
+__bpf_kfunc int bpf_cpumask_fill(struct cpumask *cpumask, void *src, size_t src__sz)
+{
+ /* The memory region must be large enough to populate the entire CPU mask. */
+ if (src__sz < BITS_TO_BYTES(nr_cpu_ids))
+ return -EACCES;
+
+ bitmap_copy(cpumask_bits(cpumask), src, nr_cpu_ids);
+
+ return 0;
+}
+
__bpf_kfunc_end_defs();
BTF_KFUNCS_START(cpumask_kfunc_btf_ids)
@@ -448,6 +468,7 @@ BTF_ID_FLAGS(func, bpf_cpumask_copy, KF_RCU)
BTF_ID_FLAGS(func, bpf_cpumask_any_distribute, KF_RCU)
BTF_ID_FLAGS(func, bpf_cpumask_any_and_distribute, KF_RCU)
BTF_ID_FLAGS(func, bpf_cpumask_weight, KF_RCU)
+BTF_ID_FLAGS(func, bpf_cpumask_fill, KF_RCU)
BTF_KFUNCS_END(cpumask_kfunc_btf_ids)
static const struct btf_kfunc_id_set cpumask_kfunc_set = {
--
2.47.1
