On Wed, Dec 13, 2023 at 3:24 AM Hou Tao <houtao@xxxxxxxxxxxxxxx> wrote: > > From: Hou Tao <houtao1@xxxxxxxxxx> > > If an abnormally huge cnt is used for multi-kprobes attachment, the > following warning will be reported: > > ------------[ cut here ]------------ > WARNING: CPU: 1 PID: 392 at mm/util.c:632 kvmalloc_node+0xd9/0xe0 > Modules linked in: bpf_testmod(O) > CPU: 1 PID: 392 Comm: test_progs Tainted: G ...... 6.7.0-rc3+ #32 > Hardware name: QEMU Standard PC (i440FX + PIIX, 1996) > ...... > RIP: 0010:kvmalloc_node+0xd9/0xe0 > ? __warn+0x89/0x150 > ? kvmalloc_node+0xd9/0xe0 > bpf_kprobe_multi_link_attach+0x87/0x670 > __sys_bpf+0x2a28/0x2bc0 > __x64_sys_bpf+0x1a/0x30 > do_syscall_64+0x36/0xb0 > entry_SYSCALL_64_after_hwframe+0x6e/0x76 > RIP: 0033:0x7fbe067f0e0d > ...... > </TASK> > ---[ end trace 0000000000000000 ]--- > > So add a test to ensure the warning is fixed. > > Signed-off-by: Hou Tao <houtao1@xxxxxxxxxx> > --- > .../selftests/bpf/prog_tests/kprobe_multi_test.c | 14 ++++++++++++++ > 1 file changed, 14 insertions(+) > > diff --git a/tools/testing/selftests/bpf/prog_tests/kprobe_multi_test.c b/tools/testing/selftests/bpf/prog_tests/kprobe_multi_test.c > index 4041cfa670eb..802554d4ee24 100644 > --- a/tools/testing/selftests/bpf/prog_tests/kprobe_multi_test.c > +++ b/tools/testing/selftests/bpf/prog_tests/kprobe_multi_test.c > @@ -300,6 +300,20 @@ static void test_attach_api_fails(void) > if (!ASSERT_EQ(libbpf_get_error(link), -EINVAL, "fail_5_error")) > goto cleanup; > > + /* fail_6 - abnormal cnt */ > + opts.addrs = (const unsigned long *) addrs; > + opts.syms = NULL; > + opts.cnt = INT_MAX; > + opts.cookies = NULL; > + > + link = bpf_program__attach_kprobe_multi_opts(skel->progs.test_kprobe_manual, > + NULL, &opts); > + if (!ASSERT_ERR_PTR(link, "fail_6")) > + goto cleanup; > + > + if (!ASSERT_EQ(libbpf_get_error(link), -EINVAL, "fail_6_error")) this is unreliable, store errno right after the operation before ASSERT_xxx() macros > + goto cleanup; > + > cleanup: > bpf_link__destroy(link); > kprobe_multi__destroy(skel); > -- > 2.29.2 >
