From e7333034387d7cbc80de91d52b3427384902ada7 Mon Sep 17 00:00:00 2001 From: Maxim Khmelevskii Date: Fri, 3 Jul 2026 14:51:36 +0200 Subject: [PATCH] selftests/bpf: Add test for bpf_get_smp_processor_id Add a test which checks on each CPU that the bpf_get_smp_processor_id BPF helper is returning the correct CPU number. Signed-off-by: Maxim Khmelevskii Signed-off-by: Daniel Borkmann Reviewed-by: Ilya Leoshkevich Link: https://lore.kernel.org/bpf/20260703125648.919196-6-max@linux.ibm.com Signed-off-by: Kumar Kartikeya Dwivedi --- .../bpf/prog_tests/get_smp_processor_id.c | 45 +++++++++++++++++++ .../bpf/progs/get_smp_processor_id.c | 20 +++++++++ 2 files changed, 65 insertions(+) create mode 100644 tools/testing/selftests/bpf/prog_tests/get_smp_processor_id.c create mode 100644 tools/testing/selftests/bpf/progs/get_smp_processor_id.c diff --git a/tools/testing/selftests/bpf/prog_tests/get_smp_processor_id.c b/tools/testing/selftests/bpf/prog_tests/get_smp_processor_id.c new file mode 100644 index 000000000000..1b5c738ab81f --- /dev/null +++ b/tools/testing/selftests/bpf/prog_tests/get_smp_processor_id.c @@ -0,0 +1,45 @@ +// SPDX-License-Identifier: GPL-2.0 + +#include +#include "bpf/libbpf_internal.h" +#include "get_smp_processor_id.skel.h" + +void test_get_smp_processor_id(void) +{ + LIBBPF_OPTS(bpf_test_run_opts, opts, + .flags = BPF_F_TEST_RUN_ON_CPU, + .cpu = 0, + ); + struct get_smp_processor_id *skel; + int prog_fd, err, online_cpu_nr, i; + bool *online = NULL; + + err = parse_cpu_mask_file("/sys/devices/system/cpu/online", + &online, &online_cpu_nr); + if (!ASSERT_OK(err, "parse_cpu_mask_file")) + return; + + skel = get_smp_processor_id__open_and_load(); + if (!ASSERT_OK_PTR(skel, "get_smp_processor_id__open_and_load")) + goto cleanup; + + prog_fd = bpf_program__fd(skel->progs.call_bpf_get_smp_processor_id); + + for (i = 0; i < online_cpu_nr; i++) { + if (!online[i]) + continue; + + opts.cpu = i; + skel->bss->cpu_nr_result = -1; + + err = bpf_prog_test_run_opts(prog_fd, &opts); + if (!ASSERT_OK(err, "bpf_prog_test_run_opts")) + goto cleanup; + + ASSERT_EQ(skel->bss->cpu_nr_result, opts.cpu, "cpu_nr_result"); + } + +cleanup: + free(online); + get_smp_processor_id__destroy(skel); +} diff --git a/tools/testing/selftests/bpf/progs/get_smp_processor_id.c b/tools/testing/selftests/bpf/progs/get_smp_processor_id.c new file mode 100644 index 000000000000..cf4791a5cf07 --- /dev/null +++ b/tools/testing/selftests/bpf/progs/get_smp_processor_id.c @@ -0,0 +1,20 @@ +// SPDX-License-Identifier: GPL-2.0 + +#include +#include +#include "bpf_misc.h" + +__u64 cpu_nr_result; + +SEC("raw_tp") +void call_bpf_get_smp_processor_id(void) +{ + register __u64 r0 asm("r0") = -1; + asm volatile ("call %[bpf_get_smp_processor_id];" + : "+r"(r0) + : __imm(bpf_get_smp_processor_id) + : "r1", "r2", "r3", "r4", "r5", "memory"); + cpu_nr_result = r0; +} + +char _license[] SEC("license") = "GPL";