We need to also export the kfunc set to the syscall program type, and then add a couple of eBPF programs that are testing those calls.
The first one checks for valid access, and the second one is OK from a static analysis point of view but fails at run time because we are trying to access outside of the allocated memory.
Signed-off-by: Benjamin Tissoires benjamin.tissoires@redhat.com
---
changes in v7: - add 1 more case to ensure we can read the entire sizeof(ctx) - add a test case for when the context is NULL
new in v6 --- net/bpf/test_run.c | 1 + .../selftests/bpf/prog_tests/kfunc_call.c | 28 +++++++++++++++ .../selftests/bpf/progs/kfunc_call_test.c | 36 +++++++++++++++++++ 3 files changed, 65 insertions(+)
diff --git a/net/bpf/test_run.c b/net/bpf/test_run.c index dc9dc0bedca0..8ada09ab1b15 100644 --- a/net/bpf/test_run.c +++ b/net/bpf/test_run.c @@ -1649,6 +1649,7 @@ static int __init bpf_prog_test_run_init(void) int ret;
ret = register_btf_kfunc_id_set(BPF_PROG_TYPE_SCHED_CLS, &bpf_prog_test_kfunc_set); + ret = ret ?: register_btf_kfunc_id_set(BPF_PROG_TYPE_SYSCALL, &bpf_prog_test_kfunc_set); return ret ?: register_btf_id_dtor_kfuncs(bpf_prog_test_dtor_kfunc, ARRAY_SIZE(bpf_prog_test_dtor_kfunc), THIS_MODULE); diff --git a/tools/testing/selftests/bpf/prog_tests/kfunc_call.c b/tools/testing/selftests/bpf/prog_tests/kfunc_call.c index c00eb974eb85..7e4804cce6b9 100644 --- a/tools/testing/selftests/bpf/prog_tests/kfunc_call.c +++ b/tools/testing/selftests/bpf/prog_tests/kfunc_call.c @@ -6,10 +6,22 @@ #include "kfunc_call_test_subprog.skel.h" #include "kfunc_call_test_subprog.lskel.h"
+struct syscall_test_args { + __u8 data[16]; + size_t size; +}; + static void test_main(void) { struct kfunc_call_test_lskel *skel; int prog_fd, err; + struct syscall_test_args args = { + .size = 10, + }; + DECLARE_LIBBPF_OPTS(bpf_test_run_opts, syscall_topts, + .ctx_in = &args, + .ctx_size_in = sizeof(args), + ); LIBBPF_OPTS(bpf_test_run_opts, topts, .data_in = &pkt_v4, .data_size_in = sizeof(pkt_v4), @@ -35,6 +47,22 @@ static void test_main(void) ASSERT_OK(err, "bpf_prog_test_run(test_ref_btf_id)"); ASSERT_EQ(topts.retval, 0, "test_ref_btf_id-retval");
+ prog_fd = skel->progs.kfunc_syscall_test.prog_fd; + err = bpf_prog_test_run_opts(prog_fd, &syscall_topts); + ASSERT_OK(err, "bpf_prog_test_run(syscall_test)"); + + prog_fd = skel->progs.kfunc_syscall_test_fail.prog_fd; + err = bpf_prog_test_run_opts(prog_fd, &syscall_topts); + ASSERT_ERR(err, "bpf_prog_test_run(syscall_test_fail)"); + + syscall_topts.ctx_in = NULL; + syscall_topts.ctx_size_in = 0; + + prog_fd = skel->progs.kfunc_syscall_test_null.prog_fd; + err = bpf_prog_test_run_opts(prog_fd, &syscall_topts); + ASSERT_OK(err, "bpf_prog_test_run(syscall_test_null)"); + ASSERT_EQ(syscall_topts.retval, 0, "syscall_test_null-retval"); + kfunc_call_test_lskel__destroy(skel); }
diff --git a/tools/testing/selftests/bpf/progs/kfunc_call_test.c b/tools/testing/selftests/bpf/progs/kfunc_call_test.c index 5aecbb9fdc68..da7ae0ef9100 100644 --- a/tools/testing/selftests/bpf/progs/kfunc_call_test.c +++ b/tools/testing/selftests/bpf/progs/kfunc_call_test.c @@ -92,4 +92,40 @@ int kfunc_call_test_pass(struct __sk_buff *skb) return 0; }
+struct syscall_test_args { + __u8 data[16]; + size_t size; +}; + +SEC("syscall") +int kfunc_syscall_test(struct syscall_test_args *args) +{ + const int size = args->size; + + if (size > sizeof(args->data)) + return -7; /* -E2BIG */ + + bpf_kfunc_call_test_mem_len_pass1(&args->data, sizeof(args->data)); + bpf_kfunc_call_test_mem_len_pass1(&args->data, sizeof(*args)); + bpf_kfunc_call_test_mem_len_pass1(&args->data, size); + + return 0; +} + +SEC("syscall") +int kfunc_syscall_test_null(struct syscall_test_args *args) +{ + bpf_kfunc_call_test_mem_len_pass1(args, 0); + + return 0; +} + +SEC("syscall") +int kfunc_syscall_test_fail(struct syscall_test_args *args) +{ + bpf_kfunc_call_test_mem_len_pass1(&args->data, sizeof(*args) + 1); + + return 0; +} + char _license[] SEC("license") = "GPL";