Commit 47254777 authored by Andrii Nakryiko's avatar Andrii Nakryiko Committed by Daniel Borkmann
Browse files

selftest/bpf: Fix profiler test using CO-RE relocation for enums 



Instead of hard-coding invalid pids_cgrp_id, use Kconfig to detect the
presence of that enum value and CO-RE to capture its actual value in the
hosts's kernel.

Fixes: 03d4d13f ("selftests/bpf: Add profiler test")
Signed-off-by: default avatarAndrii Nakryiko <andrii@kernel.org>
Signed-off-by: default avatarDaniel Borkmann <daniel@iogearbox.net>
Tested-by: default avatarSong Liu <songliubraving@fb.com>
Link: https://lore.kernel.org/bpf/20201022202739.3667367-1-andrii@kernel.org
parent 435ccfa8

tools/testing/selftests/bpf/progs/profiler.inc.h

+8 −3
Original line number Diff line number Diff line
@@ -243,7 +243,10 @@ 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 = 123, /* value doesn't matter */

};



static INLINE void* populate_cgroup_info(struct cgroup_data_t* cgroup_data,

					 struct task_struct* task,
@@ -253,7 +256,9 @@ 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 +267,7 @@ 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;

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