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| author | Alexei Starovoitov <ast@kernel.org> | 2020-03-12 17:33:12 -0700 |
|---|---|---|
| committer | Alexei Starovoitov <ast@kernel.org> | 2020-03-12 17:41:02 -0700 |
| commit | 4823b7210b90a10b88b0c56198f894b27a767509 (patch) | |
| tree | 9b5177a264a126a0e5d9178d7b1585b596528145 /tools/include | |
| parent | 132c1af0a23d049e2ec93eb6a180d9de71d3a32f (diff) | |
| parent | 1c1052e0140af8f211c283c0a333ecff2a6edfc9 (diff) | |
Merge branch 'bpf_get_ns_current_pid_tgid'
Carlos Neira says:
====================
Currently bpf_get_current_pid_tgid(), is used to do pid filtering in bcc's
scripts but this helper returns the pid as seen by the root namespace which is
fine when a bcc script is not executed inside a container.
When the process of interest is inside a container, pid filtering will not work
if bpf_get_current_pid_tgid() is used.
This helper addresses this limitation returning the pid as it's seen by the current
namespace where the script is executing.
In the future different pid_ns files may belong to different devices, according to the
discussion between Eric Biederman and Yonghong in 2017 Linux plumbers conference.
To address that situation the helper requires inum and dev_t from /proc/self/ns/pid.
This helper has the same use cases as bpf_get_current_pid_tgid() as it can be
used to do pid filtering even inside a container.
====================
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Diffstat (limited to 'tools/include')
| -rw-r--r-- | tools/include/uapi/linux/bpf.h | 20 |
1 files changed, 19 insertions, 1 deletions
diff --git a/tools/include/uapi/linux/bpf.h b/tools/include/uapi/linux/bpf.h index 40b2d9476268..15b239da775b 100644 --- a/tools/include/uapi/linux/bpf.h +++ b/tools/include/uapi/linux/bpf.h @@ -2914,6 +2914,19 @@ union bpf_attr { * of sizeof(struct perf_branch_entry). * * **-ENOENT** if architecture does not support branch records. + * + * int bpf_get_ns_current_pid_tgid(u64 dev, u64 ino, struct bpf_pidns_info *nsdata, u32 size) + * Description + * Returns 0 on success, values for *pid* and *tgid* as seen from the current + * *namespace* will be returned in *nsdata*. + * + * On failure, the returned value is one of the following: + * + * **-EINVAL** if dev and inum supplied don't match dev_t and inode number + * with nsfs of current task, or if dev conversion to dev_t lost high bits. + * + * **-ENOENT** if pidns does not exists for the current task. + * */ #define __BPF_FUNC_MAPPER(FN) \ FN(unspec), \ @@ -3035,7 +3048,8 @@ union bpf_attr { FN(tcp_send_ack), \ FN(send_signal_thread), \ FN(jiffies64), \ - FN(read_branch_records), + FN(read_branch_records), \ + FN(get_ns_current_pid_tgid), /* integer value in 'imm' field of BPF_CALL instruction selects which helper * function eBPF program intends to call @@ -3829,4 +3843,8 @@ struct bpf_sockopt { __s32 retval; }; +struct bpf_pidns_info { + __u32 pid; + __u32 tgid; +}; #endif /* _UAPI__LINUX_BPF_H__ */ |