From: Hou Tao houtao1@huawei.com
[ Upstream commit 5d5de3a431d87ac51d43da8d796891d014975ab7 ]
The size of bpf_cpumask is fixed, so there is no need to allocate many bpf_mem_caches for bpf_cpumask_ma, just one bpf_mem_cache is enough. Also add comments for bpf_mem_alloc_init() in bpf_mem_alloc.h to prevent future miuse.
Signed-off-by: Hou Tao houtao1@huawei.com Acked-by: Jiri Olsa jolsa@kernel.org Link: https://lore.kernel.org/r/20230216024821.2202916-1-houtao@huaweicloud.com Signed-off-by: Alexei Starovoitov ast@kernel.org Stable-dep-of: 77473d1a962f ("bpf: Free struct bpf_cpumask in call_rcu handler") Signed-off-by: Sasha Levin sashal@kernel.org --- include/linux/bpf_mem_alloc.h | 7 +++++++ kernel/bpf/cpumask.c | 6 +++--- 2 files changed, 10 insertions(+), 3 deletions(-)
diff --git a/include/linux/bpf_mem_alloc.h b/include/linux/bpf_mem_alloc.h index 3e164b8efaa92..a7104af61ab4d 100644 --- a/include/linux/bpf_mem_alloc.h +++ b/include/linux/bpf_mem_alloc.h @@ -14,6 +14,13 @@ struct bpf_mem_alloc { struct work_struct work; };
+/* 'size != 0' is for bpf_mem_alloc which manages fixed-size objects. + * Alloc and free are done with bpf_mem_cache_{alloc,free}(). + * + * 'size = 0' is for bpf_mem_alloc which manages many fixed-size objects. + * Alloc and free are done with bpf_mem_{alloc,free}() and the size of + * the returned object is given by the size argument of bpf_mem_alloc(). + */ int bpf_mem_alloc_init(struct bpf_mem_alloc *ma, int size, bool percpu); void bpf_mem_alloc_destroy(struct bpf_mem_alloc *ma);
diff --git a/kernel/bpf/cpumask.c b/kernel/bpf/cpumask.c index 52b981512a351..2b3fbbfebdc5f 100644 --- a/kernel/bpf/cpumask.c +++ b/kernel/bpf/cpumask.c @@ -55,7 +55,7 @@ __bpf_kfunc struct bpf_cpumask *bpf_cpumask_create(void) /* cpumask must be the first element so struct bpf_cpumask be cast to struct cpumask. */ BUILD_BUG_ON(offsetof(struct bpf_cpumask, cpumask) != 0);
- cpumask = bpf_mem_alloc(&bpf_cpumask_ma, sizeof(*cpumask)); + cpumask = bpf_mem_cache_alloc(&bpf_cpumask_ma); if (!cpumask) return NULL;
@@ -123,7 +123,7 @@ __bpf_kfunc void bpf_cpumask_release(struct bpf_cpumask *cpumask)
if (refcount_dec_and_test(&cpumask->usage)) { migrate_disable(); - bpf_mem_free(&bpf_cpumask_ma, cpumask); + bpf_mem_cache_free(&bpf_cpumask_ma, cpumask); migrate_enable(); } } @@ -468,7 +468,7 @@ static int __init cpumask_kfunc_init(void) }, };
- ret = bpf_mem_alloc_init(&bpf_cpumask_ma, 0, false); + ret = bpf_mem_alloc_init(&bpf_cpumask_ma, sizeof(struct bpf_cpumask), false); ret = ret ?: register_btf_kfunc_id_set(BPF_PROG_TYPE_TRACING, &cpumask_kfunc_set); ret = ret ?: register_btf_kfunc_id_set(BPF_PROG_TYPE_STRUCT_OPS, &cpumask_kfunc_set); return ret ?: register_btf_id_dtor_kfuncs(cpumask_dtors,