mirror_ubuntu-kernels/kernel/bpf
Kui-Feng Lee 68b04864ca bpf: Create links for BPF struct_ops maps.
Make bpf_link support struct_ops.  Previously, struct_ops were always
used alone without any associated links. Upon updating its value, a
struct_ops would be activated automatically. Yet other BPF program
types required to make a bpf_link with their instances before they
could become active. Now, however, you can create an inactive
struct_ops, and create a link to activate it later.

With bpf_links, struct_ops has a behavior similar to other BPF program
types. You can pin/unpin them from their links and the struct_ops will
be deactivated when its link is removed while previously need someone
to delete the value for it to be deactivated.

bpf_links are responsible for registering their associated
struct_ops. You can only use a struct_ops that has the BPF_F_LINK flag
set to create a bpf_link, while a structs without this flag behaves in
the same manner as before and is registered upon updating its value.

The BPF_LINK_TYPE_STRUCT_OPS serves a dual purpose. Not only is it
used to craft the links for BPF struct_ops programs, but also to
create links for BPF struct_ops them-self.  Since the links of BPF
struct_ops programs are only used to create trampolines internally,
they are never seen in other contexts. Thus, they can be reused for
struct_ops themself.

To maintain a reference to the map supporting this link, we add
bpf_struct_ops_link as an additional type. The pointer of the map is
RCU and won't be necessary until later in the patchset.

Signed-off-by: Kui-Feng Lee <kuifeng@meta.com>
Link: https://lore.kernel.org/r/20230323032405.3735486-4-kuifeng@meta.com
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
2023-03-22 22:53:02 -07:00
..
preload bpf: iterators: Split iterators.lskel.h into little- and big- endian versions 2023-01-28 12:45:15 -08:00
arraymap.c bpf: return long from bpf_map_ops funcs 2023-03-22 15:11:30 -07:00
bloom_filter.c bpf: return long from bpf_map_ops funcs 2023-03-22 15:11:30 -07:00
bpf_cgrp_storage.c bpf: return long from bpf_map_ops funcs 2023-03-22 15:11:30 -07:00
bpf_inode_storage.c bpf: return long from bpf_map_ops funcs 2023-03-22 15:11:30 -07:00
bpf_iter.c bpf: implement numbers iterator 2023-03-08 16:19:51 -08:00
bpf_local_storage.c bpf: Add bpf_local_storage_free() 2023-03-10 11:05:29 -08:00
bpf_lru_list.c bpf_lru_list: Read double-checked variable once without lock 2021-02-10 15:54:26 -08:00
bpf_lru_list.h printk: stop including cache.h from printk.h 2022-05-13 07:20:07 -07:00
bpf_lsm.c bpf: Fix the kernel crash caused by bpf_setsockopt(). 2023-01-26 23:26:40 -08:00
bpf_struct_ops_types.h bpf: Add dummy BPF STRUCT_OPS for test purpose 2021-11-01 14:10:00 -07:00
bpf_struct_ops.c bpf: Create links for BPF struct_ops maps. 2023-03-22 22:53:02 -07:00
bpf_task_storage.c bpf: return long from bpf_map_ops funcs 2023-03-22 15:11:30 -07:00
btf.c bpf: Disable migration when freeing stashed local kptr using obj drop 2023-03-13 16:55:04 -07:00
cgroup_iter.c bpf: Pin the start cgroup in cgroup_iter_seq_init() 2022-11-21 17:40:42 +01:00
cgroup.c bpf: allow ctx writes using BPF_ST_MEM instruction 2023-03-03 21:41:46 -08:00
core.c bpf: add missing header file include 2023-02-22 09:52:32 -08:00
cpumap.c bpf: return long from bpf_map_ops funcs 2023-03-22 15:11:30 -07:00
cpumask.c bpf: Remove bpf_cpumask_kptr_get() kfunc 2023-03-16 12:28:30 -07:00
devmap.c bpf: return long from bpf_map_ops funcs 2023-03-22 15:11:30 -07:00
disasm.c bpf: Relicense disassembler as GPL-2.0-only OR BSD-2-Clause 2021-09-02 14:49:23 +02:00
disasm.h bpf: Relicense disassembler as GPL-2.0-only OR BSD-2-Clause 2021-09-02 14:49:23 +02:00
dispatcher.c bpf: Synchronize dispatcher update with bpf_dispatcher_xdp_func 2022-12-14 12:02:14 -08:00
hashtab.c bpf: return long from bpf_map_ops funcs 2023-03-22 15:11:30 -07:00
helpers.c bpf: Fix bpf_strncmp proto. 2023-03-13 23:08:21 -07:00
inode.c fs: port inode_init_owner() to mnt_idmap 2023-01-19 09:24:28 +01:00
Kconfig rcu: Make the TASKS_RCU Kconfig option be selected 2022-04-20 16:52:58 -07:00
link_iter.c bpf: Add bpf_link iterator 2022-05-10 11:20:45 -07:00
local_storage.c bpf: return long from bpf_map_ops funcs 2023-03-22 15:11:30 -07:00
lpm_trie.c bpf: return long from bpf_map_ops funcs 2023-03-22 15:11:30 -07:00
Makefile bpf: Enable cpumasks to be queried and used as kptrs 2023-01-25 07:57:49 -08:00
map_in_map.c bpf: Add comments for map BTF matching requirement for bpf_list_head 2022-11-17 19:22:14 -08:00
map_in_map.h bpf: Add map_meta_equal map ops 2020-08-28 15:41:30 +02:00
map_iter.c bpf: Introduce MEM_RDONLY flag 2021-12-18 13:27:41 -08:00
memalloc.c bpf: Zeroing allocated object from slab in bpf memory allocator 2023-02-15 15:40:06 -08:00
mmap_unlock_work.h bpf: Introduce helper bpf_find_vma 2021-11-07 11:54:51 -08:00
net_namespace.c net: Add includes masked by netdevice.h including uapi/bpf.h 2021-12-29 20:03:05 -08:00
offload.c bpf: offload map memory usage 2023-03-07 09:33:43 -08:00
percpu_freelist.c bpf: Initialize same number of free nodes for each pcpu_freelist 2022-11-11 12:05:14 -08:00
percpu_freelist.h bpf: Use raw_spin_trylock() for pcpu_freelist_push/pop in NMI 2020-10-06 00:04:11 +02:00
prog_iter.c bpf: Refactor bpf_iter_reg to have separate seq_info member 2020-07-25 20:16:32 -07:00
queue_stack_maps.c bpf: return long from bpf_map_ops funcs 2023-03-22 15:11:30 -07:00
reuseport_array.c bpf: return long from bpf_map_ops funcs 2023-03-22 15:11:30 -07:00
ringbuf.c bpf: return long from bpf_map_ops funcs 2023-03-22 15:11:30 -07:00
stackmap.c bpf: return long from bpf_map_ops funcs 2023-03-22 15:11:30 -07:00
syscall.c bpf: Create links for BPF struct_ops maps. 2023-03-22 22:53:02 -07:00
sysfs_btf.c bpf: Load and verify kernel module BTFs 2020-11-10 15:25:53 -08:00
task_iter.c bpf: keep a reference to the mm, in case the task is dead. 2022-12-28 14:11:48 -08:00
tnum.c bpf, tnums: Provably sound, faster, and more precise algorithm for tnum_mul 2021-06-01 13:34:15 +02:00
trampoline.c bpf: Fix attaching fentry/fexit/fmod_ret/lsm to modules 2023-03-15 18:38:21 -07:00
verifier.c bpf: remember meta->iter info only for initialized iters 2023-03-22 17:04:47 -07:00