On 1/6/22 1:50 PM, Hao Luo wrote:
Introduce a new program type called "bpf_view", which can be used to
print out a kernel object's state to a seq file. So the signature of
this program consists of two parameters: a seq file and a kernel object.
Currently only 'struct cgroup' is supported.
The following patches will introduce a call site for this program type
and allow users to customize the format of printing out the state of
kernel objects to userspace.
Signed-off-by: Hao Luo <haoluo@xxxxxxxxxx>
---
include/linux/bpf.h | 4 +
include/uapi/linux/bpf.h | 2 +
kernel/bpf/Makefile | 2 +-
kernel/bpf/bpf_view.c | 179 +++++++++++++++++++++++++++++++++
kernel/bpf/bpf_view.h | 24 +++++
kernel/bpf/syscall.c | 3 +
kernel/bpf/verifier.c | 6 ++
kernel/trace/bpf_trace.c | 12 ++-
tools/include/uapi/linux/bpf.h | 2 +
9 files changed, 230 insertions(+), 4 deletions(-)
create mode 100644 kernel/bpf/bpf_view.c
create mode 100644 kernel/bpf/bpf_view.h
diff --git a/include/linux/bpf.h b/include/linux/bpf.h
index 2ec693c3d6f6..16f582dfff7e 100644
--- a/include/linux/bpf.h
+++ b/include/linux/bpf.h
@@ -1622,6 +1622,10 @@ void bpf_iter_map_show_fdinfo(const struct bpf_iter_aux_info *aux,
int bpf_iter_map_fill_link_info(const struct bpf_iter_aux_info *aux,
struct bpf_link_info *info);
+bool bpf_view_prog_supported(struct bpf_prog *prog);
+int bpf_view_link_attach(const union bpf_attr *attr, bpfptr_t uattr,
+ struct bpf_prog *prog);
+
int map_set_for_each_callback_args(struct bpf_verifier_env *env,
struct bpf_func_state *caller,
struct bpf_func_state *callee);
diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h
index b0383d371b9a..efa0f21d13ba 100644
--- a/include/uapi/linux/bpf.h
+++ b/include/uapi/linux/bpf.h
@@ -982,6 +982,7 @@ enum bpf_attach_type {
BPF_MODIFY_RETURN,
BPF_LSM_MAC,
BPF_TRACE_ITER,
+ BPF_TRACE_VIEW,
Please add the new entry to the end of enum list. Otherwise,
this will break backward compatibility.
BPF_CGROUP_INET4_GETPEERNAME,
BPF_CGROUP_INET6_GETPEERNAME,
BPF_CGROUP_INET4_GETSOCKNAME,
@@ -1009,6 +1010,7 @@ enum bpf_link_type {
BPF_LINK_TYPE_NETNS = 5,
BPF_LINK_TYPE_XDP = 6,
BPF_LINK_TYPE_PERF_EVENT = 7,
+ BPF_LINK_TYPE_VIEW = 8,
MAX_BPF_LINK_TYPE,
};
[...]
