[PATCH bpf-next v2 3/7] tools/bpf: sync kernel header bpf.h and add bpf_trace_event_query in libbpf
From: Yonghong Song <hidden>
Date: 2018-05-18 05:03:13
Subsystem:
bpf [general] (safe dynamic programs and tools), bpf [library] (libbpf), the rest · Maintainers:
Alexei Starovoitov, Daniel Borkmann, Andrii Nakryiko, Eduard Zingerman, Kumar Kartikeya Dwivedi, Linus Torvalds
Sync kernel header bpf.h to tools/include/uapi/linux/bpf.h and implement bpf_trace_event_query() in libbpf. The test programs in samples/bpf and tools/testing/selftests/bpf, and later bpftool will use this libbpf function to query kernel. Signed-off-by: Yonghong Song <redacted> --- tools/include/uapi/linux/bpf.h | 27 +++++++++++++++++++++++++++ tools/lib/bpf/bpf.c | 24 ++++++++++++++++++++++++ tools/lib/bpf/bpf.h | 3 +++ 3 files changed, 54 insertions(+)
diff --git a/tools/include/uapi/linux/bpf.h b/tools/include/uapi/linux/bpf.h
index d94d333..6a22ad4 100644
--- a/tools/include/uapi/linux/bpf.h
+++ b/tools/include/uapi/linux/bpf.h@@ -97,6 +97,7 @@ enum bpf_cmd { BPF_RAW_TRACEPOINT_OPEN, BPF_BTF_LOAD, BPF_BTF_GET_FD_BY_ID, + BPF_TASK_FD_QUERY, }; enum bpf_map_type {
@@ -379,6 +380,22 @@ union bpf_attr { __u32 btf_log_size; __u32 btf_log_level; }; + + struct { + int pid; /* input: pid */ + int fd; /* input: fd */ + __u32 flags; /* input: flags */ + __u32 buf_len; /* input: buf len */ + __aligned_u64 buf; /* input/output: + * tp_name for tracepoint + * symbol for kprobe + * filename for uprobe + */ + __u32 prog_id; /* output: prod_id */ + __u32 attach_info; /* output: BPF_ATTACH_* */ + __u64 probe_offset; /* output: probe_offset */ + __u64 probe_addr; /* output: probe_addr */ + } task_fd_query; } __attribute__((aligned(8))); /* The description below is an attempt at providing documentation to eBPF
@@ -2450,4 +2467,14 @@ struct bpf_fib_lookup { __u8 dmac[6]; /* ETH_ALEN */ }; +/* used by <task, fd> based query */ +enum { + BPF_ATTACH_RAW_TRACEPOINT, /* tp name */ + BPF_ATTACH_TRACEPOINT, /* tp name */ + BPF_ATTACH_KPROBE, /* (symbol + offset) or addr */ + BPF_ATTACH_KRETPROBE, /* (symbol + offset) or addr */ + BPF_ATTACH_UPROBE, /* filename + offset */ + BPF_ATTACH_URETPROBE, /* filename + offset */ +}; + #endif /* _UAPI__LINUX_BPF_H__ */
diff --git a/tools/lib/bpf/bpf.c b/tools/lib/bpf/bpf.c
index 6a8a000..da3f336 100644
--- a/tools/lib/bpf/bpf.c
+++ b/tools/lib/bpf/bpf.c@@ -643,3 +643,27 @@ int bpf_load_btf(void *btf, __u32 btf_size, char *log_buf, __u32 log_buf_size, return fd; } + +int bpf_task_fd_query(int pid, int fd, __u32 flags, char *buf, __u32 buf_len, + __u32 *prog_id, __u32 *attach_info, + __u64 *probe_offset, __u64 *probe_addr) +{ + union bpf_attr attr = {}; + int err; + + attr.task_fd_query.pid = pid; + attr.task_fd_query.fd = fd; + attr.task_fd_query.flags = flags; + attr.task_fd_query.buf = ptr_to_u64(buf); + attr.task_fd_query.buf_len = buf_len; + + err = sys_bpf(BPF_TASK_FD_QUERY, &attr, sizeof(attr)); + if (!err) { + *prog_id = attr.task_fd_query.prog_id; + *attach_info = attr.task_fd_query.attach_info; + *probe_offset = attr.task_fd_query.probe_offset; + *probe_addr = attr.task_fd_query.probe_addr; + } + + return err; +}
diff --git a/tools/lib/bpf/bpf.h b/tools/lib/bpf/bpf.h
index 15bff77..9adfde6 100644
--- a/tools/lib/bpf/bpf.h
+++ b/tools/lib/bpf/bpf.h@@ -107,4 +107,7 @@ int bpf_prog_query(int target_fd, enum bpf_attach_type type, __u32 query_flags, int bpf_raw_tracepoint_open(const char *name, int prog_fd); int bpf_load_btf(void *btf, __u32 btf_size, char *log_buf, __u32 log_buf_size, bool do_log); +int bpf_task_fd_query(int pid, int fd, __u32 flags, char *buf, __u32 buf_len, + __u32 *prog_id, __u32 *prog_info, + __u64 *probe_offset, __u64 *probe_addr); #endif
--
2.9.5