Selftests for typed ksyms. Tests two types of ksyms: one is a struct, the other is a plain int. This tests two paths in the kernel. Struct ksyms will be converted into PTR_TO_BTF_ID by the verifier while int typed ksyms will be converted into PTR_TO_MEM.
Signed-off-by: Hao Luo haoluo@google.com --- .../selftests/bpf/prog_tests/ksyms_btf.c | 77 +++++++++++++++++++ .../selftests/bpf/progs/test_ksyms_btf.c | 23 ++++++ 2 files changed, 100 insertions(+) create mode 100644 tools/testing/selftests/bpf/prog_tests/ksyms_btf.c create mode 100644 tools/testing/selftests/bpf/progs/test_ksyms_btf.c
diff --git a/tools/testing/selftests/bpf/prog_tests/ksyms_btf.c b/tools/testing/selftests/bpf/prog_tests/ksyms_btf.c new file mode 100644 index 000000000000..1dad61ba7e99 --- /dev/null +++ b/tools/testing/selftests/bpf/prog_tests/ksyms_btf.c @@ -0,0 +1,77 @@ +// SPDX-License-Identifier: GPL-2.0 +/* Copyright (c) 2020 Google */ + +#include <test_progs.h> +#include <bpf/libbpf.h> +#include <bpf/btf.h> +#include "test_ksyms_btf.skel.h" + +static int duration; + +static __u64 kallsyms_find(const char *sym) +{ + char type, name[500]; + __u64 addr, res = 0; + FILE *f; + + f = fopen("/proc/kallsyms", "r"); + if (CHECK(!f, "kallsyms_fopen", "failed to open: %d\n", errno)) + return 0; + + while (fscanf(f, "%llx %c %499s%*[^\n]\n", &addr, &type, name) > 0) { + if (strcmp(name, sym) == 0) { + res = addr; + goto out; + } + } + + CHECK(false, "not_found", "symbol %s not found\n", sym); +out: + fclose(f); + return res; +} + +void test_ksyms_btf(void) +{ + __u64 runqueues_addr = kallsyms_find("runqueues"); + __u64 bpf_prog_active_addr = kallsyms_find("bpf_prog_active"); + struct test_ksyms_btf *skel; + struct test_ksyms_btf__data *data; + struct btf *btf; + int percpu_datasec; + int err; + + btf = libbpf_find_kernel_btf(); + if (CHECK(IS_ERR(btf), "btf_exists", "failed to load kernel BTF: %ld\n", + PTR_ERR(btf))) + return; + + percpu_datasec = btf__find_by_name_kind(btf, ".data..percpu", + BTF_KIND_DATASEC); + if (percpu_datasec < 0) { + printf("%s:SKIP:no PERCPU DATASEC in kernel btf\n", + __func__); + test__skip(); + return; + } + + skel = test_ksyms_btf__open_and_load(); + if (CHECK(!skel, "skel_open", "failed to open and load skeleton\n")) + return; + + err = test_ksyms_btf__attach(skel); + if (CHECK(err, "skel_attach", "skeleton attach failed: %d\n", err)) + goto cleanup; + + /* trigger tracepoint */ + usleep(1); + + data = skel->data; + CHECK(data->out__runqueues != runqueues_addr, "runqueues", + "got %llu, exp %llu\n", data->out__runqueues, runqueues_addr); + CHECK(data->out__bpf_prog_active != bpf_prog_active_addr, "bpf_prog_active", + "got %llu, exp %llu\n", data->out__bpf_prog_active, bpf_prog_active_addr); + +cleanup: + test_ksyms_btf__destroy(skel); +} diff --git a/tools/testing/selftests/bpf/progs/test_ksyms_btf.c b/tools/testing/selftests/bpf/progs/test_ksyms_btf.c new file mode 100644 index 000000000000..e04e31117f84 --- /dev/null +++ b/tools/testing/selftests/bpf/progs/test_ksyms_btf.c @@ -0,0 +1,23 @@ +// SPDX-License-Identifier: GPL-2.0 +/* Copyright (c) 2020 Google */ + +#include "vmlinux.h" + +#include <bpf/bpf_helpers.h> + +__u64 out__runqueues = -1; +__u64 out__bpf_prog_active = -1; + +extern const struct rq runqueues __ksym; /* struct type global var. */ +extern const int bpf_prog_active __ksym; /* int type global var. */ + +SEC("raw_tp/sys_enter") +int handler(const void *ctx) +{ + out__runqueues = (__u64)&runqueues; + out__bpf_prog_active = (__u64)&bpf_prog_active; + + return 0; +} + +char _license[] SEC("license") = "GPL";