> On Oct 13, 2020, at 2:56 PM, Andrii Nakryiko <andrii.nakry...@gmail.com>
> wrote:
[...]
>
> I'd go with Kconfig + bpf_core_enum_value(), as it's shorter and
> nicer. This compiles and works with my Kconfig, but I haven't checked
> with CONFIG_CGROUP_PIDS defined.
Tested with CONFIG_CGROUP_PIDS, it looks good.
Tested-by: Song Liu <songliubrav...@fb.com>
>
>
> diff --git a/tools/testing/selftests/bpf/progs/profiler.inc.h
> b/tools/testing/selftests/bpf/progs/profiler.inc.h
> index 00578311a423..79b8d2860a5c 100644
> --- a/tools/testing/selftests/bpf/progs/profiler.inc.h
> +++ b/tools/testing/selftests/bpf/progs/profiler.inc.h
> @@ -243,7 +243,11 @@ static ino_t get_inode_from_kernfs(struct
> kernfs_node* node)
> }
> }
>
> -int pids_cgrp_id = 1;
> +extern bool CONFIG_CGROUP_PIDS __kconfig __weak;
> +
> +enum cgroup_subsys_id___local {
> + pids_cgrp_id___local = 1, /* anything but zero */
> +};
>
> static INLINE void* populate_cgroup_info(struct cgroup_data_t* cgroup_data,
> struct task_struct* task,
> @@ -253,7 +257,9 @@ static INLINE void* populate_cgroup_info(struct
> cgroup_data_t* cgroup_data,
> BPF_CORE_READ(task, nsproxy, cgroup_ns, root_cset,
> dfl_cgrp, kn);
> struct kernfs_node* proc_kernfs = BPF_CORE_READ(task, cgroups,
> dfl_cgrp, kn);
>
> - if (ENABLE_CGROUP_V1_RESOLVER) {
> + if (ENABLE_CGROUP_V1_RESOLVER && CONFIG_CGROUP_PIDS) {
> + int cgrp_id = bpf_core_enum_value(enum
> cgroup_subsys_id___local, pids_cgrp_id___local);
> +
> #ifdef UNROLL
> #pragma unroll
> #endif
> @@ -262,7 +268,7 @@ static INLINE void* populate_cgroup_info(struct
> cgroup_data_t* cgroup_data,
> BPF_CORE_READ(task, cgroups, subsys[i]);
> if (subsys != NULL) {
> int subsys_id = BPF_CORE_READ(subsys, ss, id);
> - if (subsys_id == pids_cgrp_id) {
> + if (subsys_id == cgrp_id) {
> proc_kernfs =
> BPF_CORE_READ(subsys, cgroup, kn);
> root_kernfs =
> BPF_CORE_READ(subsys, ss, root, kf_root, kn);
> break;
