From d2ccde1c8e90d38cee87a1b0309ad2827f3fd30d Mon Sep 17 00:00:00 2001
From: hc <hc@nodka.com>
Date: Mon, 11 Dec 2023 02:45:28 +0000
Subject: [PATCH] add boot partition size
---
kernel/tools/bpf/bpftool/Documentation/bpftool-map.rst | 177 ++++++++++++++++++++++++++++++++++++++++++++++++-----------
1 files changed, 144 insertions(+), 33 deletions(-)
diff --git a/kernel/tools/bpf/bpftool/Documentation/bpftool-map.rst b/kernel/tools/bpf/bpftool/Documentation/bpftool-map.rst
index a6258bc..dade10c 100644
--- a/kernel/tools/bpf/bpftool/Documentation/bpftool-map.rst
+++ b/kernel/tools/bpf/bpftool/Documentation/bpftool-map.rst
@@ -15,42 +15,80 @@
*OPTIONS* := { { **-j** | **--json** } [{ **-p** | **--pretty** }] | { **-f** | **--bpffs** } }
*COMMANDS* :=
- { **show** | **list** | **dump** | **update** | **lookup** | **getnext** | **delete**
- | **pin** | **help** }
+ { **show** | **list** | **create** | **dump** | **update** | **lookup** | **getnext**
+ | **delete** | **pin** | **help** }
MAP COMMANDS
=============
-| **bpftool** **map { show | list }** [*MAP*]
+| **bpftool** **map** { **show** | **list** } [*MAP*]
+| **bpftool** **map create** *FILE* **type** *TYPE* **key** *KEY_SIZE* **value** *VALUE_SIZE* \
+| **entries** *MAX_ENTRIES* **name** *NAME* [**flags** *FLAGS*] [**inner_map** *MAP*] \
+| [**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 freeze** *MAP*
| **bpftool** **map help**
|
-| *MAP* := { **id** *MAP_ID* | **pinned** *FILE* }
+| *MAP* := { **id** *MAP_ID* | **pinned** *FILE* | **name** *MAP_NAME* }
| *DATA* := { [**hex**] *BYTES* }
-| *PROG* := { **id** *PROG_ID* | **pinned** *FILE* | **tag** *PROG_TAG* }
+| *PROG* := { **id** *PROG_ID* | **pinned** *FILE* | **tag** *PROG_TAG* | **name** *PROG_NAME* }
| *VALUE* := { *DATA* | *MAP* | *PROG* }
| *UPDATE_FLAGS* := { **any** | **exist** | **noexist** }
+| *TYPE* := { **hash** | **array** | **prog_array** | **perf_event_array** | **percpu_hash**
+| | **percpu_array** | **stack_trace** | **cgroup_array** | **lru_hash**
+| | **lru_percpu_hash** | **lpm_trie** | **array_of_maps** | **hash_of_maps**
+| | **devmap** | **devmap_hash** | **sockmap** | **cpumap** | **xskmap** | **sockhash**
+| | **cgroup_storage** | **reuseport_sockarray** | **percpu_cgroup_storage**
+| | **queue** | **stack** | **sk_storage** | **struct_ops** | **ringbuf** | **inode_storage** }
DESCRIPTION
===========
**bpftool map { show | list }** [*MAP*]
Show information about loaded maps. If *MAP* is specified
- show information only about given map, otherwise list all
- maps currently loaded on the system.
+ show information only about given maps, otherwise list all
+ maps currently loaded on the system. In case of **name**,
+ *MAP* may match several maps which will all be shown.
Output will start with map ID followed by map type and
zero or more named attributes (depending on kernel version).
- **bpftool map dump** *MAP*
- Dump all entries in a given *MAP*.
+ 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 update** *MAP* **key** *DATA* **value** *VALUE* [*UPDATE_FLAGS*]
+ **bpftool map create** *FILE* **type** *TYPE* **key** *KEY_SIZE* **value** *VALUE_SIZE* **entries** *MAX_ENTRIES* **name** *NAME* [**flags** *FLAGS*] [**inner_map** *MAP*] [**dev** *NAME*]
+ Create a new map with given parameters and pin it to *bpffs*
+ as *FILE*.
+
+ *FLAGS* should be an integer which is the combination of
+ desired flags, e.g. 1024 for **BPF_F_MMAPABLE** (see bpf.h
+ UAPI header for existing flags).
+
+ To create maps of type array-of-maps or hash-of-maps, the
+ **inner_map** keyword must be used to pass an inner map. The
+ kernel needs it to collect metadata related to the inner maps
+ that the new map will work with.
+
+ Keyword **dev** expects a network interface name, and is used
+ to request hardware offload for the map.
+
+ **bpftool map dump** *MAP*
+ Dump all entries in a given *MAP*. In case of **name**,
+ *MAP* may match several maps which will all be dumped.
+
+ **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
@@ -58,12 +96,12 @@
exists; **noexist** update only if entry doesn't exist.
If the **hex** keyword is provided in front of the bytes
- sequence, the bytes are parsed as hexadeximal values, even if
+ sequence, the bytes are parsed as hexadecimal values, even if
no "0x" prefix is added. If the keyword is not provided, then
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*]
@@ -75,13 +113,15 @@
**bpftool map pin** *MAP* *FILE*
Pin map *MAP* as *FILE*.
- Note: *FILE* must be located in *bpffs* mount.
+ Note: *FILE* must be located in *bpffs* mount. It must not
+ contain a dot character ('.'), which is reserved for future
+ extensions of *bpffs*.
**bpftool** **map event_pipe** *MAP* [**cpu** *N* **index** *M*]
- Read events from a BPF_MAP_TYPE_PERF_EVENT_ARRAY map.
+ Read events from a **BPF_MAP_TYPE_PERF_EVENT_ARRAY** map.
Install perf rings into a perf event array map and dump
- output of any bpf_perf_event_output() call in the kernel.
+ output of any **bpf_perf_event_output**\ () call in the kernel.
By default read the number of CPUs on the system and
install perf ring for each CPU in the corresponding index
in the array.
@@ -93,34 +133,52 @@
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 freeze** *MAP*
+ Freeze the map as read-only from user space. Entries from a
+ frozen map can not longer be updated or deleted with the
+ **bpf**\ () system call. This operation is not reversible,
+ and the map remains immutable from user space until its
+ destruction. However, read and write permissions for BPF
+ programs to the map remain unchanged.
+
**bpftool map help**
Print short help message.
OPTIONS
=======
- -h, --help
- Print short generic help message (similar to **bpftool help**).
-
- -v, --version
- Print version number (similar to **bpftool version**).
-
- -j, --json
- Generate JSON output. For commands that cannot produce JSON, this
- option has no effect.
-
- -p, --pretty
- Generate human-readable JSON output. Implies **-j**.
+ .. include:: common_options.rst
-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**
+
::
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:
@@ -137,6 +195,7 @@
**# bpftool map dump id 10**
+
::
key: 00 01 02 03 value: 00 01 02 03 04 05 06 07
@@ -144,6 +203,7 @@
Found 2 elements
**# bpftool map getnext id 10 key 0 1 2 3**
+
::
key:
@@ -156,6 +216,57 @@
| **# bpftool map pin id 10 /sys/fs/bpf/map**
| **# bpftool map del pinned /sys/fs/bpf/map key 13 00 07 00**
-SEE ALSO
-========
- **bpftool**\ (8), **bpftool-prog**\ (8), **bpftool-cgroup**\ (8)
+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
--
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