mbox series

[bpf,v5,0/3] Fix wrong cgroup attach flags being assigned to effective progs

Message ID 20220921104604.2340580-1-pulehui@huaweicloud.com (mailing list archive)
Headers show
Series Fix wrong cgroup attach flags being assigned to effective progs | expand

Message

Pu Lehui Sept. 21, 2022, 10:46 a.m. UTC
From: Pu Lehui <pulehui@huawei.com>

When root-cgroup attach multi progs and sub-cgroup attach a
override prog, bpftool will display incorrectly for the attach
flags of the sub-cgroup’s effective progs:

$ bpftool cgroup tree /sys/fs/cgroup effective
CgroupPath
ID       AttachType      AttachFlags     Name
/sys/fs/cgroup
6        cgroup_sysctl   multi           sysctl_tcp_mem
13       cgroup_sysctl   multi           sysctl_tcp_mem
/sys/fs/cgroup/cg1
20       cgroup_sysctl   override        sysctl_tcp_mem
6        cgroup_sysctl   override        sysctl_tcp_mem <- wrong
13       cgroup_sysctl   override        sysctl_tcp_mem <- wrong
/sys/fs/cgroup/cg1/cg2
20       cgroup_sysctl                   sysctl_tcp_mem
6        cgroup_sysctl                   sysctl_tcp_mem
13       cgroup_sysctl                   sysctl_tcp_mem

For cg1, obviously, the attach flags of prog6 and prog13 can not be
OVERRIDE. And for query with EFFECTIVE flags, exporting attach flags
does not make sense. So let's remove the AttachFlags field and the
associated logic. After these patches, the above effective cgroup
tree will show as bellow:

# bpftool cgroup tree /sys/fs/cgroup effective
CgroupPath
ID       AttachType      Name
/sys/fs/cgroup
6        cgroup_sysctl   sysctl_tcp_mem
13       cgroup_sysctl   sysctl_tcp_mem
/sys/fs/cgroup/cg1
20       cgroup_sysctl   sysctl_tcp_mem
6        cgroup_sysctl   sysctl_tcp_mem
13       cgroup_sysctl   sysctl_tcp_mem
/sys/fs/cgroup/cg1/cg2
20       cgroup_sysctl   sysctl_tcp_mem
6        cgroup_sysctl   sysctl_tcp_mem
13       cgroup_sysctl   sysctl_tcp_mem

v5:
- Adapt selftests for effective query uapi change.

v4:
https://lore.kernel.org/bpf/20220920154233.1494352-1-pulehui@huaweicloud.com
- Reject prog_attach_flags array when effective query. (Martin)
- Target to bpf tree. (Martin)

v3:
https://lore.kernel.org/bpf/20220914161742.3180731-1-pulehui@huaweicloud.com
- Don't show attach flags when effective query. (John, sdf, Martin)

v2:
https://lore.kernel.org/bpf/20220908145304.3436139-1-pulehui@huaweicloud.com
- Limit prog_cnt to avoid overflow. (John)
- Add more detail message.

v1:
https://lore.kernel.org/bpf/20220820120234.2121044-1-pulehui@huawei.com

Pu Lehui (3):
  bpf, cgroup: Reject prog_attach_flags array when effective query
  bpftool: Fix wrong cgroup attach flags being assigned to effective
    progs
  selftests/bpf: Adapt cgroup effective query uapi change

 include/uapi/linux/bpf.h                      |  7 ++-
 kernel/bpf/cgroup.c                           | 28 ++++++----
 tools/bpf/bpftool/cgroup.c                    | 54 +++++++++++++++++--
 tools/include/uapi/linux/bpf.h                |  7 ++-
 .../selftests/bpf/prog_tests/cgroup_link.c    | 11 ++--
 5 files changed, 81 insertions(+), 26 deletions(-)

Comments

patchwork-bot+netdevbpf@kernel.org Sept. 21, 2022, 6:30 p.m. UTC | #1
Hello:

This series was applied to bpf/bpf.git (master)
by Martin KaFai Lau <martin.lau@kernel.org>:

On Wed, 21 Sep 2022 10:46:01 +0000 you wrote:
> From: Pu Lehui <pulehui@huawei.com>
> 
> When root-cgroup attach multi progs and sub-cgroup attach a
> override prog, bpftool will display incorrectly for the attach
> flags of the sub-cgroup’s effective progs:
> 
> $ bpftool cgroup tree /sys/fs/cgroup effective
> CgroupPath
> ID       AttachType      AttachFlags     Name
> /sys/fs/cgroup
> 6        cgroup_sysctl   multi           sysctl_tcp_mem
> 13       cgroup_sysctl   multi           sysctl_tcp_mem
> /sys/fs/cgroup/cg1
> 20       cgroup_sysctl   override        sysctl_tcp_mem
> 6        cgroup_sysctl   override        sysctl_tcp_mem <- wrong
> 13       cgroup_sysctl   override        sysctl_tcp_mem <- wrong
> /sys/fs/cgroup/cg1/cg2
> 20       cgroup_sysctl                   sysctl_tcp_mem
> 6        cgroup_sysctl                   sysctl_tcp_mem
> 13       cgroup_sysctl                   sysctl_tcp_mem
> 
> [...]

Here is the summary with links:
  - [bpf,v5,1/3] bpf, cgroup: Reject prog_attach_flags array when effective query
    https://git.kernel.org/bpf/bpf/c/0e426a3ae030
  - [bpf,v5,2/3] bpftool: Fix wrong cgroup attach flags being assigned to effective progs
    https://git.kernel.org/bpf/bpf/c/bdcee1b0b083
  - [bpf,v5,3/3] selftests/bpf: Adapt cgroup effective query uapi change
    https://git.kernel.org/bpf/bpf/c/d2aa993b7d9d

You are awesome, thank you!