bpf: pass a pointer to a cgroup storage using pcpu variable
This commit introduces the bpf_cgroup_storage_set() helper,
which will be used to pass a pointer to a cgroup storage
to the bpf helper.
Signed-off-by: Roman Gushchin <guro@fb.com>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
diff --git a/include/linux/bpf-cgroup.h b/include/linux/bpf-cgroup.h
index 7d00d58..9a144dd 100644
--- a/include/linux/bpf-cgroup.h
+++ b/include/linux/bpf-cgroup.h
@@ -4,6 +4,7 @@
#include <linux/errno.h>
#include <linux/jump_label.h>
+#include <linux/percpu.h>
#include <linux/rbtree.h>
#include <uapi/linux/bpf.h>
@@ -21,6 +22,8 @@
extern struct static_key_false cgroup_bpf_enabled_key;
#define cgroup_bpf_enabled static_branch_unlikely(&cgroup_bpf_enabled_key)
+DECLARE_PER_CPU(void*, bpf_cgroup_storage);
+
struct bpf_cgroup_storage_map;
struct bpf_storage_buffer {
@@ -97,6 +100,17 @@
int __cgroup_bpf_check_dev_permission(short dev_type, u32 major, u32 minor,
short access, enum bpf_attach_type type);
+static inline void bpf_cgroup_storage_set(struct bpf_cgroup_storage *storage)
+{
+ struct bpf_storage_buffer *buf;
+
+ if (!storage)
+ return;
+
+ buf = READ_ONCE(storage->buf);
+ this_cpu_write(bpf_cgroup_storage, &buf->data[0]);
+}
+
struct bpf_cgroup_storage *bpf_cgroup_storage_alloc(struct bpf_prog *prog);
void bpf_cgroup_storage_free(struct bpf_cgroup_storage *storage);
void bpf_cgroup_storage_link(struct bpf_cgroup_storage *storage,
@@ -250,6 +264,7 @@
return -EINVAL;
}
+static inline void bpf_cgroup_storage_set(struct bpf_cgroup_storage *storage) {}
static inline int bpf_cgroup_storage_assign(struct bpf_prog *prog,
struct bpf_map *map) { return 0; }
static inline void bpf_cgroup_storage_release(struct bpf_prog *prog,