linux-stable.git/include/linux/bpf-cgroup.h, branch v5.1.2

bpf: fix warning about using plain integer as NULL

2019-03-08T20:17:07+00:00

Sparse warning below:

sudo make C=2 CF=-D__CHECK_ENDIAN__ M=net/bpf/
CHECK   net/bpf//test_run.c
net/bpf//test_run.c:19:77: warning: Using plain integer as NULL pointer
./include/linux/bpf-cgroup.h:295:77: warning: Using plain integer as NULL pointer

Fixes: 8bad74f9840f ("bpf: extend cgroup bpf core to allow multiple cgroup storage types")
Acked-by: Yonghong Song 
Signed-off-by: Bo YU 
Signed-off-by: Daniel Borkmann

bpf, cgroups: clean up kerneldoc warnings

2019-01-31T09:32:01+00:00

Building with W=1 reveals some bitrot:

  CC      kernel/bpf/cgroup.o
kernel/bpf/cgroup.c:238: warning: Function parameter or member 'flags' not described in '__cgroup_bpf_attach'
kernel/bpf/cgroup.c:367: warning: Function parameter or member 'unused_flags' not described in '__cgroup_bpf_detach'

Add a kerneldoc line for 'flags'.

Fixing the warning for 'unused_flags' is best approached by
removing the unused parameter on the function call.

Signed-off-by: Valdis Kletnieks 
Acked-by: Song Liu 
Signed-off-by: Daniel Borkmann

bpf: introduce per-cpu cgroup local storage

2018-10-01T14:18:32+00:00

This commit introduced per-cpu cgroup local storage.

Per-cpu cgroup local storage is very similar to simple cgroup storage
(let's call it shared), except all the data is per-cpu.

The main goal of per-cpu variant is to implement super fast
counters (e.g. packet counters), which don't require neither
lookups, neither atomic operations.

>From userspace's point of view, accessing a per-cpu cgroup storage
is similar to other per-cpu map types (e.g. per-cpu hashmaps and
arrays).

Writing to a per-cpu cgroup storage is not atomic, but is performed
by copying longs, so some minimal atomicity is here, exactly
as with other per-cpu maps.

Signed-off-by: Roman Gushchin 
Cc: Daniel Borkmann 
Cc: Alexei Starovoitov 
Acked-by: Song Liu 
Signed-off-by: Daniel Borkmann

bpf: rework cgroup storage pointer passing

2018-10-01T14:18:32+00:00

To simplify the following introduction of per-cpu cgroup storage,
let's rework a bit a mechanism of passing a pointer to a cgroup
storage into the bpf_get_local_storage(). Let's save a pointer
to the corresponding bpf_cgroup_storage structure, instead of
a pointer to the actual buffer.

It will help us to handle per-cpu storage later, which has
a different way of accessing to the actual data.

Signed-off-by: Roman Gushchin 
Acked-by: Song Liu 
Cc: Daniel Borkmann 
Cc: Alexei Starovoitov 
Signed-off-by: Daniel Borkmann

bpf: extend cgroup bpf core to allow multiple cgroup storage types

2018-10-01T14:18:32+00:00

In order to introduce per-cpu cgroup storage, let's generalize
bpf cgroup core to support multiple cgroup storage types.
Potentially, per-node cgroup storage can be added later.

This commit is mostly a formal change that replaces
cgroup_storage pointer with a array of cgroup_storage pointers.
It doesn't actually introduce a new storage type,
it will be done later.

Each bpf program is now able to have one cgroup storage of each type.

Signed-off-by: Roman Gushchin 
Acked-by: Song Liu 
Cc: Daniel Borkmann 
Cc: Alexei Starovoitov 
Signed-off-by: Daniel Borkmann

bpf: allocate cgroup storage entries on attaching bpf programs

2018-08-02T22:47:32+00:00

If a bpf program is using cgroup local storage, allocate
a bpf_cgroup_storage structure automatically on attaching the program
to a cgroup and save the pointer into the corresponding bpf_prog_list
entry.
Analogically, release the cgroup local storage on detaching
of the bpf program.

Signed-off-by: Roman Gushchin 
Cc: Alexei Starovoitov 
Cc: Daniel Borkmann 
Acked-by: Martin KaFai Lau 
Signed-off-by: Daniel Borkmann

bpf: pass a pointer to a cgroup storage using pcpu variable

2018-08-02T22:47:32+00:00

This commit introduces the bpf_cgroup_storage_set() helper,
which will be used to pass a pointer to a cgroup storage
to the bpf helper.

Signed-off-by: Roman Gushchin 
Cc: Alexei Starovoitov 
Cc: Daniel Borkmann 
Acked-by: Martin KaFai Lau 
Signed-off-by: Daniel Borkmann

bpf: introduce cgroup storage maps

2018-08-02T22:47:32+00:00

This commit introduces BPF_MAP_TYPE_CGROUP_STORAGE maps:
a special type of maps which are implementing the cgroup storage.

>From the userspace point of view it's almost a generic
hash map with the (cgroup inode id, attachment type) pair
used as a key.

The only difference is that some operations are restricted:
  1) a user can't create new entries,
  2) a user can't remove existing entries.

The lookup from userspace is o(log(n)).

Signed-off-by: Roman Gushchin 
Cc: Alexei Starovoitov 
Cc: Daniel Borkmann 
Acked-by: Martin KaFai Lau 
Signed-off-by: Daniel Borkmann

bpf: include errno.h from bpf-cgroup.h

2018-07-09T08:33:49+00:00

Commit fdb5c4531c1e ("bpf: fix attach type BPF_LIRC_MODE2 dependency
wrt CONFIG_CGROUP_BPF") caused some build issues, detected by 0-DAY
kernel test infrastructure.

The problem is that cgroup_bpf_prog_attach/detach/query() functions
can return -EINVAL error code, which is not defined. Fix this adding
errno.h to includes.

Fixes: fdb5c4531c1e ("bpf: fix attach type BPF_LIRC_MODE2 dependency wrt CONFIG_CGROUP_BPF")
Signed-off-by: Roman Gushchin 
Cc: Sean Young 
Cc: Daniel Borkmann 
Cc: Alexei Starovoitov 
Signed-off-by: Daniel Borkmann

bpf: fix attach type BPF_LIRC_MODE2 dependency wrt CONFIG_CGROUP_BPF

2018-06-26T09:28:38+00:00

If the kernel is compiled with CONFIG_CGROUP_BPF not enabled, it is not
possible to attach, detach or query IR BPF programs to /dev/lircN devices,
making them impossible to use. For embedded devices, it should be possible
to use IR decoding without cgroups or CONFIG_CGROUP_BPF enabled.

This change requires some refactoring, since bpf_prog_{attach,detach,query}
functions are now always compiled, but their code paths for cgroups need
moving out. Rather than a #ifdef CONFIG_CGROUP_BPF in kernel/bpf/syscall.c,
moving them to kernel/bpf/cgroup.c and kernel/bpf/sockmap.c does not
require #ifdefs since that is already conditionally compiled.

Fixes: f4364dcfc86d ("media: rc: introduce BPF_PROG_LIRC_MODE2")
Signed-off-by: Sean Young 
Signed-off-by: Daniel Borkmann