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authorAndrii Nakryiko <andriin@fb.com>2020-06-19 16:17:03 -0700
committerAlexei Starovoitov <ast@kernel.org>2020-06-22 17:01:49 -0700
commit075c776658190681d2bf9997306f871d6c8a9b36 (patch)
tree4f2cf6abf36ea9c8a85be8b1164976ca5320ae0e /tools/bpf
parentd53dee3fe0138610fcce5721bae9414377c41ec3 (diff)
tools/bpftool: Add documentation and sample output for process info
Add statements about bpftool being able to discover process info, holding reference to BPF map, prog, link, or BTF. Show example output as well. Signed-off-by: Andrii Nakryiko <andriin@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Reviewed-by: Quentin Monnet <quentin@isovalent.com> Link: https://lore.kernel.org/bpf/20200619231703.738941-10-andriin@fb.com
Diffstat (limited to 'tools/bpf')
-rw-r--r--tools/bpf/bpftool/Documentation/bpftool-btf.rst5
-rw-r--r--tools/bpf/bpftool/Documentation/bpftool-link.rst13
-rw-r--r--tools/bpf/bpftool/Documentation/bpftool-map.rst8
-rw-r--r--tools/bpf/bpftool/Documentation/bpftool-prog.rst11
4 files changed, 35 insertions, 2 deletions
diff --git a/tools/bpf/bpftool/Documentation/bpftool-btf.rst b/tools/bpf/bpftool/Documentation/bpftool-btf.rst
index ce3a724f50c1..896f4c6c2870 100644
--- a/tools/bpf/bpftool/Documentation/bpftool-btf.rst
+++ b/tools/bpf/bpftool/Documentation/bpftool-btf.rst
@@ -36,6 +36,11 @@ DESCRIPTION
otherwise list all BTF objects currently loaded on the
system.
+ Since Linux 5.8 bpftool is able to discover information about
+ processes that hold open file descriptors (FDs) against BTF
+ objects. On such kernels bpftool will automatically emit this
+ information as well.
+
**bpftool btf dump** *BTF_SRC*
Dump BTF entries from a given *BTF_SRC*.
diff --git a/tools/bpf/bpftool/Documentation/bpftool-link.rst b/tools/bpf/bpftool/Documentation/bpftool-link.rst
index 0e43d7b06c11..38b0949a185b 100644
--- a/tools/bpf/bpftool/Documentation/bpftool-link.rst
+++ b/tools/bpf/bpftool/Documentation/bpftool-link.rst
@@ -37,6 +37,11 @@ DESCRIPTION
zero or more named attributes, some of which depend on type
of link.
+ Since Linux 5.8 bpftool is able to discover information about
+ processes that hold open file descriptors (FDs) against BPF
+ links. On such kernels bpftool will automatically emit this
+ information as well.
+
**bpftool link pin** *LINK* *FILE*
Pin link *LINK* as *FILE*.
@@ -82,6 +87,7 @@ EXAMPLES
10: cgroup prog 25
cgroup_id 614 attach_type egress
+ pids test_progs(223)
**# bpftool --json --pretty link show**
@@ -91,7 +97,12 @@ EXAMPLES
"type": "cgroup",
"prog_id": 25,
"cgroup_id": 614,
- "attach_type": "egress"
+ "attach_type": "egress",
+ "pids": [{
+ "pid": 223,
+ "comm": "test_progs"
+ }
+ ]
}
]
diff --git a/tools/bpf/bpftool/Documentation/bpftool-map.rst b/tools/bpf/bpftool/Documentation/bpftool-map.rst
index 31101643e57c..5bc2123e9944 100644
--- a/tools/bpf/bpftool/Documentation/bpftool-map.rst
+++ b/tools/bpf/bpftool/Documentation/bpftool-map.rst
@@ -62,6 +62,11 @@ DESCRIPTION
Output will start with map ID followed by map type and
zero or more named attributes (depending on kernel version).
+ Since Linux 5.8 bpftool is able to discover information about
+ processes that hold open file descriptors (FDs) against BPF
+ maps. On such kernels bpftool will automatically emit this
+ information as well.
+
**bpftool map create** *FILE* **type** *TYPE* **key** *KEY_SIZE* **value** *VALUE_SIZE* **entries** *MAX_ENTRIES* **name** *NAME* [**flags** *FLAGS*] [**dev** *NAME*]
Create a new map with given parameters and pin it to *bpffs*
as *FILE*.
@@ -180,7 +185,8 @@ EXAMPLES
::
10: hash name some_map flags 0x0
- key 4B value 8B max_entries 2048 memlock 167936B
+ key 4B value 8B max_entries 2048 memlock 167936B
+ pids systemd(1)
The following three commands are equivalent:
diff --git a/tools/bpf/bpftool/Documentation/bpftool-prog.rst b/tools/bpf/bpftool/Documentation/bpftool-prog.rst
index 2b254959d488..412ea3d9bf7f 100644
--- a/tools/bpf/bpftool/Documentation/bpftool-prog.rst
+++ b/tools/bpf/bpftool/Documentation/bpftool-prog.rst
@@ -75,6 +75,11 @@ DESCRIPTION
program run. Activation or deactivation of the feature is
performed via the **kernel.bpf_stats_enabled** sysctl knob.
+ Since Linux 5.8 bpftool is able to discover information about
+ processes that hold open file descriptors (FDs) against BPF
+ programs. On such kernels bpftool will automatically emit this
+ information as well.
+
**bpftool prog dump xlated** *PROG* [{ **file** *FILE* | **opcodes** | **visual** | **linum** }]
Dump eBPF instructions of the programs from the kernel. By
default, eBPF will be disassembled and printed to standard
@@ -243,6 +248,7 @@ EXAMPLES
10: xdp name some_prog tag 005a3d2123620c8b gpl run_time_ns 81632 run_cnt 10
loaded_at 2017-09-29T20:11:00+0000 uid 0
xlated 528B jited 370B memlock 4096B map_ids 10
+ pids systemd(1)
**# bpftool --json --pretty prog show**
@@ -262,6 +268,11 @@ EXAMPLES
"bytes_jited": 370,
"bytes_memlock": 4096,
"map_ids": [10
+ ],
+ "pids": [{
+ "pid": 1,
+ "comm": "systemd"
+ }
]
}
]