github-mirror/linux
1
0
Fork 0
mirror of https://github.com/torvalds/linux.git synced 2026-05-30 01:53:29 +02:00
Code Issues Actions Packages Projects Releases Wiki Activity Graph

selftests/sched_ext: Add non_scx_kfunc_deny test

Browse Source 
Verify that the BPF verifier rejects a non-SCX struct_ops program
(tcp_congestion_ops) that attempts to call an SCX kfunc (scx_bpf_kick_cpu).
The test expects the load to fail with -EACCES from scx_kfunc_context_filter.

Signed-off-by: Cheng-Yang Chou <yphbchou0911@gmail.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
This commit is contained in:
Cheng-Yang Chou 2026-04-20 17:28:48 +08:00 committed by Tejun Heo
parent 2d2b026c3e
commit 5897ca15d2
3 changed files with 92 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

1
tools/testing/selftests/sched_ext/Makefile
View File

@ -175,6 +175,7 @@ auto-test-targets := \
maximal \
maybe_null \
minimal \
non_scx_kfunc_deny \
numa \
allowed_cpus \
peek_dsq \

44
tools/testing/selftests/sched_ext/non_scx_kfunc_deny.bpf.c Normal file
View File

@ -0,0 +1,44 @@
/* SPDX-License-Identifier: GPL-2.0 */
/*
* Verify that context-sensitive SCX kfuncs (even "unlocked" ones) are
* restricted to only SCX struct_ops programs. Non-SCX struct_ops programs,
* such as TCP congestion control programs, should be rejected by the BPF
* verifier when attempting to call these kfuncs.
*
* Copyright (C) 2026 Ching-Chun (Jim) Huang <jserv@ccns.ncku.edu.tw>
* Copyright (C) 2026 Cheng-Yang Chou <yphbchou0911@gmail.com>
*/
#include <vmlinux.h>
#include <bpf/bpf_helpers.h>
#include <bpf/bpf_tracing.h>
/* SCX kfunc from scx_kfunc_ids_any set */
void scx_bpf_kick_cpu(s32 cpu, u64 flags) __ksym;
SEC("struct_ops/ssthresh")
__u32 BPF_PROG(tcp_ca_ssthresh, struct sock *sk)
{
/*
* This call should be rejected by the verifier because this is a
* TCP congestion control program (non-SCX struct_ops).
*/
scx_bpf_kick_cpu(0, 0);
return 2;
}
SEC("struct_ops/cong_avoid")
void BPF_PROG(tcp_ca_cong_avoid, struct sock *sk, __u32 ack, __u32 acked) {}
SEC("struct_ops/undo_cwnd")
__u32 BPF_PROG(tcp_ca_undo_cwnd, struct sock *sk) { return 2; }
SEC(".struct_ops")
struct tcp_congestion_ops tcp_non_scx_ca = {
.ssthresh = (void *)tcp_ca_ssthresh,
.cong_avoid = (void *)tcp_ca_cong_avoid,
.undo_cwnd = (void *)tcp_ca_undo_cwnd,
.name = "tcp_kfunc_deny",
};
char _license[] SEC("license") = "GPL";

47
tools/testing/selftests/sched_ext/non_scx_kfunc_deny.c Normal file
View File

@ -0,0 +1,47 @@
/* SPDX-License-Identifier: GPL-2.0 */
/*
* Verify that context-sensitive SCX kfuncs (even "unlocked" ones) are
* restricted to only SCX struct_ops programs. Non-SCX struct_ops programs,
* such as TCP congestion control programs, should be rejected by the BPF
* verifier when attempting to call these kfuncs.
*
* Copyright (C) 2026 Ching-Chun (Jim) Huang <jserv@ccns.ncku.edu.tw>
* Copyright (C) 2026 Cheng-Yang Chou <yphbchou0911@gmail.com>
*/
#include <bpf/bpf.h>
#include <scx/common.h>
#include <unistd.h>
#include <errno.h>
#include <stdio.h>
#include "non_scx_kfunc_deny.bpf.skel.h"
#include "scx_test.h"
static enum scx_test_status run(void *ctx)
{
struct non_scx_kfunc_deny *skel;
int err;
skel = non_scx_kfunc_deny__open();
if (!skel) {
SCX_ERR("Failed to open skel");
return SCX_TEST_FAIL;
}
err = non_scx_kfunc_deny__load(skel);
non_scx_kfunc_deny__destroy(skel);
if (err == 0) {
SCX_ERR("non-SCX BPF program loaded when it should have been rejected");
return SCX_TEST_FAIL;
}
return SCX_TEST_PASS;
}
struct scx_test non_scx_kfunc_deny = {
.name = "non_scx_kfunc_deny",
.description = "Verify that non-SCX struct_ops programs cannot call SCX kfuncs",
.run = run,
};
REGISTER_SCX_TEST(&non_scx_kfunc_deny)