linux-stable.git/kernel/bpf/local_storage.c, branch v5.0

bpf: enable cgroup local storage map pretty print with kind_flag

2018-12-18T00:11:59+00:00

Commit 970289fc0a83 ("bpf: add bpffs pretty print for cgroup
local storage maps") added bpffs pretty print for cgroup
local storage maps. The commit worked for struct without kind_flag
set.

This patch refactored and made pretty print also work
with kind_flag set for the struct.

Acked-by: Martin KaFai Lau 
Signed-off-by: Yonghong Song 
Signed-off-by: Daniel Borkmann

bpf: add bpffs pretty print for cgroup local storage maps

2018-12-12T23:33:38+00:00

Implement bpffs pretty printing for cgroup local storage maps
(both shared and per-cpu).
Output example (captured for tools/testing/selftests/bpf/netcnt_prog.c):

Shared:
  $ cat /sys/fs/bpf/map_2
  # WARNING!! The output is for debug purpose only
  # WARNING!! The output format will change
  {4294968594,1}: {9999,1039896}

Per-cpu:
  $ cat /sys/fs/bpf/map_1
  # WARNING!! The output is for debug purpose only
  # WARNING!! The output format will change
  {4294968594,1}: {
  	cpu0: {0,0,0,0,0}
  	cpu1: {0,0,0,0,0}
  	cpu2: {1,104,0,0,0}
  	cpu3: {0,0,0,0,0}
  }

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

Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net

2018-11-29T06:10:54+00:00

Trivial conflict in net/core/filter.c, a locally computed
'sdif' is now an argument to the function.

Signed-off-by: David S. Miller

bpf, tags: Fix DEFINE_PER_CPU expansion

2018-11-26T00:21:39+00:00

Building tags produces warning:

  ctags: Warning: kernel/bpf/local_storage.c:10: null expansion of name pattern "\1"

Let's use the same fix as in commit 25528213fe9f ("tags: Fix DEFINE_PER_CPU
expansions"), even though it violates the usual code style.

Signed-off-by: Rustam Kovhaev 
Signed-off-by: Daniel Borkmann

bpf: allocate local storage buffers using GFP_ATOMIC

2018-11-17T05:17:49+00:00

Naresh reported an issue with the non-atomic memory allocation of
cgroup local storage buffers:

[   73.047526] BUG: sleeping function called from invalid context at
/srv/oe/build/tmp-rpb-glibc/work-shared/intel-corei7-64/kernel-source/mm/slab.h:421
[   73.060915] in_atomic(): 1, irqs_disabled(): 0, pid: 3157, name: test_cgroup_sto
[   73.068342] INFO: lockdep is turned off.
[   73.072293] CPU: 2 PID: 3157 Comm: test_cgroup_sto Not tainted
4.20.0-rc2-next-20181113 #1
[   73.080548] Hardware name: Supermicro SYS-5019S-ML/X11SSH-F, BIOS
2.0b 07/27/2017
[   73.088018] Call Trace:
[   73.090463]  dump_stack+0x70/0xa5
[   73.093783]  ___might_sleep+0x152/0x240
[   73.097619]  __might_sleep+0x4a/0x80
[   73.101191]  __kmalloc_node+0x1cf/0x2f0
[   73.105031]  ? cgroup_storage_update_elem+0x46/0x90
[   73.109909]  cgroup_storage_update_elem+0x46/0x90

cgroup_storage_update_elem() (as well as other update map update
callbacks) is called with disabled preemption, so GFP_ATOMIC
allocation should be used: e.g. alloc_htab_elem() in hashtab.c.

Reported-by: Naresh Kamboju 
Tested-by: Naresh Kamboju 
Signed-off-by: Roman Gushchin 
Cc: Alexei Starovoitov 
Cc: Daniel Borkmann 
Signed-off-by: Alexei Starovoitov

Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next

2018-10-09T06:42:44+00:00

Alexei Starovoitov says:

====================
pull-request: bpf-next 2018-10-08

The following pull-request contains BPF updates for your *net-next* tree.

The main changes are:

1) sk_lookup_[tcp|udp] and sk_release helpers from Joe Stringer which allow
BPF programs to perform lookups for sockets in a network namespace. This would
allow programs to determine early on in processing whether the stack is
expecting to receive the packet, and perform some action (eg drop,
forward somewhere) based on this information.

2) per-cpu cgroup local storage from Roman Gushchin.
Per-cpu cgroup local storage is very similar to simple cgroup storage
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 in a fast path.
The example of these hybrid counters is in selftests/bpf/netcnt_prog.c

3) allow HW offload of programs with BPF-to-BPF function calls from Quentin Monnet

4) support more than 64-byte key/value in HW offloaded BPF maps from Jakub Kicinski

5) rename of libbpf interfaces from Andrey Ignatov.
libbpf is maturing as a library and should follow good practices in
library design and implementation to play well with other libraries.
This patch set brings consistent naming convention to global symbols.

6) relicense libbpf as LGPL-2.1 OR BSD-2-Clause from Alexei Starovoitov
to let Apache2 projects use libbpf

7) various AF_XDP fixes from Björn and Magnus
====================

Signed-off-by: David S. Miller

bpf: don't accept cgroup local storage with zero value size

2018-10-02T12:42:23+00:00

Explicitly forbid creating cgroup local storage maps with zero value
size, as it makes no sense and might even cause a panic.

Reported-by: syzbot+18628320d3b14a5c459c@syzkaller.appspotmail.com
Signed-off-by: Roman Gushchin 
Cc: Alexei Starovoitov 
Cc: Daniel Borkmann 
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