diff options
Diffstat (limited to 'tools/bpf/bpftool/Documentation/bpftool-map.rst')
| -rw-r--r-- | tools/bpf/bpftool/Documentation/bpftool-map.rst | 99 |
1 files changed, 93 insertions, 6 deletions
diff --git a/tools/bpf/bpftool/Documentation/bpftool-map.rst b/tools/bpf/bpftool/Documentation/bpftool-map.rst index f55a2daed59b..5c984ffc9f01 100644 --- a/tools/bpf/bpftool/Documentation/bpftool-map.rst +++ b/tools/bpf/bpftool/Documentation/bpftool-map.rst @@ -25,12 +25,17 @@ MAP COMMANDS | **bpftool** **map create** *FILE* **type** *TYPE* **key** *KEY_SIZE* **value** *VALUE_SIZE* \ | **entries** *MAX_ENTRIES* **name** *NAME* [**flags** *FLAGS*] [**dev** *NAME*] | **bpftool** **map dump** *MAP* -| **bpftool** **map update** *MAP* **key** *DATA* **value** *VALUE* [*UPDATE_FLAGS*] -| **bpftool** **map lookup** *MAP* **key** *DATA* +| **bpftool** **map update** *MAP* [**key** *DATA*] [**value** *VALUE*] [*UPDATE_FLAGS*] +| **bpftool** **map lookup** *MAP* [**key** *DATA*] | **bpftool** **map getnext** *MAP* [**key** *DATA*] | **bpftool** **map delete** *MAP* **key** *DATA* | **bpftool** **map pin** *MAP* *FILE* | **bpftool** **map event_pipe** *MAP* [**cpu** *N* **index** *M*] +| **bpftool** **map peek** *MAP* +| **bpftool** **map push** *MAP* **value** *VALUE* +| **bpftool** **map pop** *MAP* +| **bpftool** **map enqueue** *MAP* **value** *VALUE* +| **bpftool** **map dequeue** *MAP* | **bpftool** **map help** | | *MAP* := { **id** *MAP_ID* | **pinned** *FILE* } @@ -42,7 +47,8 @@ MAP COMMANDS | | **percpu_array** | **stack_trace** | **cgroup_array** | **lru_hash** | | **lru_percpu_hash** | **lpm_trie** | **array_of_maps** | **hash_of_maps** | | **devmap** | **sockmap** | **cpumap** | **xskmap** | **sockhash** -| | **cgroup_storage** | **reuseport_sockarray** | **percpu_cgroup_storage** } +| | **cgroup_storage** | **reuseport_sockarray** | **percpu_cgroup_storage** +| | **queue** | **stack** } DESCRIPTION =========== @@ -61,7 +67,7 @@ DESCRIPTION **bpftool map dump** *MAP* Dump all entries in a given *MAP*. - **bpftool map update** *MAP* **key** *DATA* **value** *VALUE* [*UPDATE_FLAGS*] + **bpftool map update** *MAP* [**key** *DATA*] [**value** *VALUE*] [*UPDATE_FLAGS*] Update map entry for a given *KEY*. *UPDATE_FLAGS* can be one of: **any** update existing entry @@ -74,7 +80,7 @@ DESCRIPTION the bytes are parsed as decimal values, unless a "0x" prefix (for hexadecimal) or a "0" prefix (for octal) is provided. - **bpftool map lookup** *MAP* **key** *DATA* + **bpftool map lookup** *MAP* [**key** *DATA*] Lookup **key** in the map. **bpftool map getnext** *MAP* [**key** *DATA*] @@ -106,6 +112,21 @@ DESCRIPTION replace any existing ring. Any other application will stop receiving events if it installed its rings earlier. + **bpftool map peek** *MAP* + Peek next **value** in the queue or stack. + + **bpftool map push** *MAP* **value** *VALUE* + Push **value** onto the stack. + + **bpftool map pop** *MAP* + Pop and print **value** from the stack. + + **bpftool map enqueue** *MAP* **value** *VALUE* + Enqueue **value** into the queue. + + **bpftool map dequeue** *MAP* + Dequeue and print **value** from the queue. + **bpftool map help** Print short help message. @@ -127,6 +148,10 @@ OPTIONS -f, --bpffs Show file names of pinned maps. + -n, --nomount + Do not automatically attempt to mount any virtual file system + (such as tracefs or BPF virtual file system) when necessary. + EXAMPLES ======== **# bpftool map show** @@ -169,6 +194,68 @@ The following three commands are equivalent: | **# bpftool map pin id 10 /sys/fs/bpf/map** | **# bpftool map del pinned /sys/fs/bpf/map key 13 00 07 00** +Note that map update can also be used in order to change the program references +hold by a program array map. This can be used, for example, to change the +programs used for tail-call jumps at runtime, without having to reload the +entry-point program. Below is an example for this use case: we load a program +defining a prog array map, and with a main function that contains a tail call +to other programs that can be used either to "process" packets or to "debug" +processing. Note that the prog array map MUST be pinned into the BPF virtual +file system for the map update to work successfully, as kernel flushes prog +array maps when they have no more references from user space (and the update +would be lost as soon as bpftool exits). + +| +| **# bpftool prog loadall tail_calls.o /sys/fs/bpf/foo type xdp** +| **# bpftool prog --bpffs** + +:: + + 545: xdp name main_func tag 674b4b5597193dc3 gpl + loaded_at 2018-12-12T15:02:58+0000 uid 0 + xlated 240B jited 257B memlock 4096B map_ids 294 + pinned /sys/fs/bpf/foo/xdp + 546: xdp name bpf_func_process tag e369a529024751fc gpl + loaded_at 2018-12-12T15:02:58+0000 uid 0 + xlated 200B jited 164B memlock 4096B + pinned /sys/fs/bpf/foo/process + 547: xdp name bpf_func_debug tag 0b597868bc7f0976 gpl + loaded_at 2018-12-12T15:02:58+0000 uid 0 + xlated 200B jited 164B memlock 4096B + pinned /sys/fs/bpf/foo/debug + +**# bpftool map** + +:: + + 294: prog_array name jmp_table flags 0x0 + key 4B value 4B max_entries 1 memlock 4096B + owner_prog_type xdp owner jited + +| +| **# bpftool map pin id 294 /sys/fs/bpf/bar** +| **# bpftool map dump pinned /sys/fs/bpf/bar** + +:: + + Found 0 elements + +| +| **# bpftool map update pinned /sys/fs/bpf/bar key 0 0 0 0 value pinned /sys/fs/bpf/foo/debug** +| **# bpftool map dump pinned /sys/fs/bpf/bar** + +:: + + key: 00 00 00 00 value: 22 02 00 00 + Found 1 element + SEE ALSO ======== - **bpftool**\ (8), **bpftool-prog**\ (8), **bpftool-cgroup**\ (8) + **bpf**\ (2), + **bpf-helpers**\ (7), + **bpftool**\ (8), + **bpftool-prog**\ (8), + **bpftool-cgroup**\ (8), + **bpftool-feature**\ (8), + **bpftool-net**\ (8), + **bpftool-perf**\ (8) |
